Download Management of Valvular Heart Disease during Pregnancy

Indian Heart J 2005; 57: 101–108
Anandaraja et al. Management of VHD during Pregnancy
101
Editorial
Management of Valvular Heart Disease during Pregnancy
S Anandaraja, SS Kothari, VK Bahl
Department of Cardiology, All India Institute of Medical Sciences, New Delhi
H
eart disease complicates approximately 0.4-4% of
all pregnancies.1-5 Presence of significant heart
diease during pregnancy is a high risk situation; it
increases the risks of adverse maternal and fetal outcome.
Despite advances in the management of maternal
cardiovascular diseases, heart disease during pregnancy
accounts for as much as one-third of the maternal
6
mortality. Furthermore, about 20% of the pregnancies in
the presence of valvular heart disease are associated with
7,8
poor neonatal outcomes. With the declining incidence of
rheumatic fever and the significant advances in the
management of congenital heart disease, the ratio of
rheumatic heart disease to congenital heart disease in
pregnancy has decreased to approximately 1:3 in other
parts of the world. Rheumatic heart disease is still the most
common heart disease complicating pregnancy in our
5,9
country. In this article, we reiterate the salient aspects of
management of valve disease during pregnancy.
Cardiovascular Physiology during Pregnancy
Pregnancy is associated with obligatory physiological
changes that have an important bearing on the
hemodynamics of the underlying heart disease.10,11 A 50%
increase in intravascular volume occurs during normal
pregnancy by mid third trimester. There is 50% increase in
cardiac output, mainly in the first and second trimesters;
the level peaks by about 24 weeks of pregnancy. The cardiac
output increases by as much as 22% by 8 weeks. In the
first trimester, most of the increase is accounted for by an
increase in the stroke volume. The nearly 30% increase in
stroke volume may be due to ventricular remodeling and a
decrease in afterload due to fall in systemic vascular
resistance. Later on, the increase in cardiac output is
sustained by an increase in heart rate. There is an average
increase in heart rate of about 10-20 beats per minute
(bpm). The increase in heart rate and cardiac output has a
deleterious effect on stenotic lesions.
There is a decrease of 3-5 mmHg in systolic and
5-10 mmHg in diastolic blood pressure during pregnancy,
secondary to an even greater fall in peripheral resistance.
Correspondence: Dr VK Bahl, Professor of Cardiology, All India
Institute of Medical Sciences, New Delhi 110029
e-mail: [email protected]
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The decreased peripheral vascular tone is mediated by
hormonal influences, primarily estrogen, prolactin and
prostacyclins. Additionally the highly vascular placenta
acts as a partial arteriovenous shunt. This decreased
vascular resistance has a favorable effect on the
hemodynamics of regurgitant lesions. Other significant
structural changes in the heart during the third trimester
include myocardial hypertrophy, chamber enlargement,
and mild multivalvular regurgitation. The aorta is larger
12
and more compliant during normal human pregnancy.
These changes in the aorta reduce ventricular afterload but
at the price of increased wall stress and the risk of
dissection. The gravid uterus has been reported to cause
significant compression of the aorta and iliac arteries,
especially in the supine position. This possibly increases the
outflow resistance of the lower arterial tree. The concurrent
increase in ejection of blood into the upper aorta may
predispose to intimal tear, causing aortic dissection.
During labor, cardiac output increases by a further 45%
above the pre-labor level, with up to 500 ml of blood being
pumped into the circulation with each uterine contraction.
After delivery of the baby, caval compression is relieved and
after the placenta is delivered, another auto transfusion
occurs from the placental sinusoids into the maternal
circulation; both increase the cardiac output and stroke
volume by about 80% above baseline.13 Thus the periods of
greatest risk for cardiac events during pregnancy are early
third trimester, delivery and immediate postpartum
period.14 Blood volume is restored to baseline levels after
delivery with spontaneous diuresis occurring over a period
of approximately six weeks.
Diagnosis of Heart Disease during Pregnancy
Clinical diagnosis of heart disease can be difficult during
15
pregnancy. Many normal women experience dyspnea,
fatigue, decreased exercise capacity, palpitations, lightheadedness and pedal edema during uncomplicated
pregnancy—symptoms suggestive of cardiac disease. The
physical examination during normal pregnancy reveals a
slightly fast resting heart rate, bounding pulses, and a
widened pulse pressure with a low normal peak systolic
pressure. Venous pressure is usually elevated above the
normal range for non-pregnant woman but rarely in a
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Indian Heart J 2005; 57: 101–108
clearly abnormal range. The precordial impulse is
hyperkinetic, and the first heart sound may be louder than
normal, with prominent splitting. The second heart is
usually physiologically split but may also widen and appear
fixed during later stages of pregnancy. The third heart
sound is heard in about 80% of pregnant women, whereas
the fourth heart sound is rarely heard. The universal early
ejection systolic flow murmur of less than grade 3/6 along
the left sternal border is heard in 90% of pregnant women
and may be enhanced by anemia. Cervical venous hum and
a continuous murmur due to increased mammary blood
flow may also be heard. Symptoms and signs that should
raise the suspicion of heart failure include paroxysmal
nocturnal dyspnea, chest pain, nocturnal cough, new
regurgitant murmurs, pulmonary crackles, elevated
jugular venous pressure and hepatomegaly. In the
presence of diastolic murmurs, continuous murmurs, or
loud systolic murmurs (> grade 2/6) or when murmurs
are associated with symptoms or an abnormal
electrocardiogram, evaluation by echocardiography is
16
warranted. The increased blood flow and enhanced
cardiac output associated with normal pregnancy can
accentuate the murmurs associated with stenotic heart
valve lesions and the murmurs associated with regurgitant
lesions may actually attenuate due to decreased systemic
vascular resistance. The average weight gain during
pregnancy is about 1.5 kg in the first three months. In each
subsequent month the average gain is 1.5 kg, being a little
more in the last two months. At full term the total gain is
about 10 - 12 kg. Sudden changes in weight, either gains
or loss may be harmful and is a warning sign.
rheumatic heart disease, 113 (22.6%) patients were in
NYHA class III-IV. There were 10 (2.1%) maternal deaths
of which eight patients were in NYHA III and IV.20 In
another Canadian study 7 of heterogenous group of
pregnant women with congenital (75%) or acquired heart
disease (25%), the most significant predictor for morbidity
and mortality was the presence of left ventricular
dysfunction [an ejection fraction (EF)< 40%). Other
predictors of adverse outcomes included a prior cardiac
event (heart failure, transient ischemic attack, stroke) or
arrhythmia, an advanced NYHA functional status (class II
or higher) and the presence of left heart obstructive
diseases. (mitral stenosis with valve area < 2 cm2, aortic
stenosis with valve area < 1.5 cm2). In this study adverse
outcome occurred in 13% of the completed pregnancies;
4% in women with no risk factor, 27% with one risk factor
and 62% with two or more risk factors. It seems appropriate
to dichotomise pregnant patients into asymptomatic (class
I) and symptomatic (class II and above) for prognostic
purposes as done in this study. Abnormal functional
capacity (NYHA class II or higher) and left heart
obstruction were also predictors of neonatal complications.
8
In another cohort of 64 pregnant women with valvular
heart disease, the predictors of adverse maternal events
were moderate and severe aortic and mitral stenosis (valve
2
area < 1.5 cm ). Congenital heart disease with severe
pulmonary arterial hypertension is associated with 30-50%
mortality during pregnancy. Although pulmonary artery
hypertension in valve disease has not been addressed in
these studies, increased pulmonary pressure (> 50 mmHg)
should be a cause for concern.
Risk Assessment and Stratification
during Pregnancy
Assessment of Degree of Valve
Stenosis during Pregnancy
Regardless of the cardiac lesion, maternal outcome
generally depends on the functional class of the patient.
Patients in NYHA class I and II have less than 1% maternal
mortality with pregnancy, whereas those in class III and
17,18
A worsening by one NYHA
IV have 5-15% mortality.
class may be anticipated during pregnancy, although this
is variable. In a study of 64 patients with valvular heart
disease, 62% showed worsening of at least one functional
class during pregnancy which occurred mostly during the
8
second trimester. In another study, patients with mild to
moderate mitral stenosis had only minor deterioration of
clinical status as compared to patients with severe
19
stenosis. All patients with severe mitral stenosis
deteriorated by one to two functional class. In the recent
retrospective study involving 486 pregnant patients with
Doppler assessment is commonly used to evaluate the
severity of valve lesions during pregnancy. But it is unclear
how pressure gradients change during pregnancy with
19
either normal or abnormal heart valves. Also calculation
of valve area is not without fallacies. In a study by Rokey et
21
al. comparing mitral valve area by pressure half time and
continuity equation methods, the valve area obtained using
the pressure half time method underestimated the degree
of obstruction, whereas the continuity equation was more
reliable and in accord with clinical impressions. Also, the
area determined via the pressure half time technique
tended to be greater ante partum than post-partum but the
continuity equation method gave concordant values. The
pressure half time method recognizes that for a given valve
area, pressure half time is inversely related to driving
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Anandaraja et al. Management of VHD during Pregnancy 103
pressure and directly proportional to the transported
volume. In conditions with higher driving pressures or
volumes, valve areas will be over- or underestimated.
Similarly in aortic stenosis, evaluation of severity based on
gradient has to be used with caution.22 The increased force
of contraction from an increased ventricular volume
increases the pressure on the proximal side of the valve and
thus increases the pressure gradient. The decreased
systemic vascular resistance on the distal side of the aortic
valve during pregnancy further increases the pressure
gradient. These effects may be mitigated by increased aortic
diameter and compliance during pregnancy. The net
influence of these events and their time course has not been
fully documented. In the study by Lesniak-Sobelga et al.19
the aortic valve gradient was greater by 20–35 mmHg
during the ante-partum period as compared to during postpartum period. Thus in the absence of appropriate studies,
the clinical significance of increased systolic gradient across
the aortic valve cannot be assumed to be the same in
pregnant and non-pregnant patients. Assessment of the
valve area will be a more appropriate indicator of severity
23
rather than the gradients.
Medical Management
Most patients with pregnancy and valvular heart disease
can be managed medically. Recommendations for patients
with volume overload lesions include restricted physical
activity, salt restriction and diuretics. Diuretics are given to
relieve pulmonary and systemic venous congestion, but
care must be taken to avoid rigorous volume depletion and
uteroplacental hypoperfusion. Diuretics prescribed after the
first trimester of pregnancy may interfere with normal
plasma volume expansion and may cause volume
depletion.24 It is possible that electrolyte imbalance or
volume depletion after prolonged diuretic therapy may have
delayed neurodevelopmental effects on the fetus. Although
diuretics have not been reported to have teratogenic effects,
their use in pregnancy is controversial. Nevertheless,
diuretics are routinely used during pregnancy for
decongestive therapy. Daily weights are the best means of
clinically following the degree of fluid retention since the
presence or absence of visible edema is unreliable. The
extracellular fluid volume can increase by 10% before
edema becomes visible. Apprehension and anxiety adds to
the already strained cardiac reserve. Reassurance and the
use of tranquilizers and sedatives are appropriate. Inspite
of oral iron medication given routinely, iron deficiency
anemia is encountered frequently. In more severe anemia,
intramuscular iron may be given or if the hemoglobin level
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falls below 9 gm, multiple small transfusion with packed
cell are indicated. Infections, especially those accompanied
by high fever, are very detrimental to the cardiac patient.
When intercurrent infections are found they should be
treated vigorously with antibiotics. Digoxin, beta blockers,
adenosine, sotalol, lidocaine and procanamide can be safely
used for the treatment of supraventricular arrhythmias
during pregnancy. Amiodarone is best avoided because of
the risk of fetal hypothyroidism.25 However, in high risk
situations it can be used to suppress atrial and ventricular
arrhythmias.26 Angiotensin converting enzyme inhibitors
and angiotensin receptor blockers are contraindicated
during pregnancy because of the risks of urogenital defects,
intrauterine growth retardation and fetal death.
Open Heart Surgery
Valvular heart disease is the most common indication for
cardiovascular surgery during pregnancy. Cardiac surgery
can be performed during pregnancy with relative safety for
the mother, with maternal mortality of 3-6%,27-30 but fetal
mortality of 20%-30 % still occurs. Maternal deaths were
reported in 9% of valvular surgical procedures and in 22%
of aortic dissection repairs and pulmonary embolectomies.
However the maternal mortality associated with antenatal
aortic valve replacement can be as high as 11% and the
risk is higher for surgery done in the immediate post partum
period.28 The current recommendation for open heart
surgery during pregnancy include (i) avoidance of open
heart surgery, if at all possible, during the first trimester.
The risk of teratogenesis due to drug administration and
possibly cardiopulmonary bypass during the first trimester
of pregnancy is always present, and any surgical procedure
should be avoided during this time; (ii) use of high-flow,
high-pressure, normothermic bypass during the procedure;
(iii) fetal heart and uterine monitoring to allow adjustments
to the blood flow and pharmacological manipulations to
ensure adequate placental perfusion; and (iv) if the fetus is
> 28 weeks of gestational age, to opt for cesarean section
concurrently just prior to the cardiac operation.
Mode of Delivery
Delivery must be planned carefully. Patients in NYHA
classes III and IV as well as many in class II should be
admitted to the hospital a few days earlier in order to
achieve optimum condition for labor and delivery. In the
majority, spontaneous vaginal delivery is the preferred
31,32
However, prolonged and difficult labor should
method.
be avoided and cesarian section should be considered in
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some patients electively. In patients with stable aortic
dissection, Marfan’s syndrome with dilated aortic root, and
in whom warfarin could not be switched over to heparin 2
weeks before delivery, elective cesarian section is
mandatory. Also, cesarean section may be indicated for
obstetrical reasons. Cesarian section has the advantage of
avoiding the physical stress of labor, but it is not free from
the hemodynamic consequences related to general
anesthesia and assisted ventilation. Hemodynamic
fluctuations are also influenced by the volume of blood loss,
which is greater with cesarian section (1400 ml) than with
uncomplicated vaginal delivery (500 ml). The increase in
demand on the heart imposed by the labor requires close
and continuous monitoring of the mother and the fetus.
Careful attention to volume status is essential. Adequate
volume loading is required to avoid hypotension. Left lateral
decubitus position is preferred to attenuate the
hemodynamic effects of the supine position. However,
intravenous fluids are risky in patients with mitral stenosis
and pulmonary hypertension. Epidural anesthesia is
recommended during vaginal delivery to provide adequate
analgesia and thus avoiding increase in cardiac output due
33
to pain and anxiety. It is beneficial to shorten the second
stage of labor by forceps or vacuum application. Unless
blood loss becomes excessive, oxytoxic drugs are withheld
in cardiac patients. In patients on heparin, the drug should
be withdrawn 4 hours before cesarian section or at the
onset of labor and resumed 6-12 hours after either surgical
or vaginal delivery. Post- partum monitoring is generally
recommended up to seven days for high-risk patients.34
Choice of Prosthetic Valve
Many factors determine the choice of prosthetic heart valve
in a patient. 35 The crux of the matter is the risk of
reoperation in case of bioprosthetic valve versus the risk of
bleeding, thromboembolism, and valve thrombosis with
mechanical prosthetic valve, besides complications to the
fetus. Fetal loss of about 30% is associated with pregnancy
in women on anticoagulant therapy. 36 Warfarin
embryopathy occurs in about 6% of pregnancies, and the
risk are highest during 6-12 weeks of gestation.37 The risk
of thromboembolism during pregnancy in women with
mechanical mitral valve has been reported to be 10-15%,38
which is much higher than 1.2%-5.4% annual risk in nonpregnant state39 and bleeding is reported in 2-4% patients
per year.40,41 The maternal mortality rate for pregnancies
37,42,43
following valve replacement surgery was 2.9%-6.1%.
Bioprostheses have a risk of early structural valve
deterioration during or shortly after the end of pregnancy.
Morever, at 10 years there is a high rate of structural valve
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Indian Heart J 2005; 57: 101–108
deterioration (55-77%) and of valve-related reoperation
(60-80%). Also the advantage of avoiding anticoagulants
is lost in the long run. In the Edinburgh heart valves study,44
21% of the patients required reoperation during the followup period of 20 years, but around four times more
reoperations were performed in the bioprosthetic group
compared to the mechanical group. The mortality rate was
15% at 30 days and 22% at one year following reoperations.
While the risks to the mother during pregnancy are higher
with mechanical valves, the reoperation rates are higher
for bioprosthetic valves. Patients already requiring
anticoagulation for atrial fibrillation or other indications
lose advantage of bioprostheses. Yet the risks of death with
mechanical valve thrombosis during pregnancy are
substantial. Various aspects of anticoagulation in pregnant
patients with prosthetic valves have been discussed in a
45
recently published editorial. Individualized approach
taking into account financial status of the patient, risks of
reoperation, structural valve deterioration etc. is needed.
There are no clear guidelines. in this respect. Pregnancy is
best avoided in symptomatic valvular heart disease patients.
Specific Cardiac Lesions/Problems
Mitral stenosis: Mitral stenosis is the most common
rheumatic valvular lesion seen in pregnancy due to its
26
prevalence in young women. Approximately 25% of
patients with mitral stenosis become symptomatic for the
first time during pregnancy.46 Mortality among pregnant
women with minimal symptoms is < 1%.47 With severe
mitral stenosis, pregnancy-related mortality is about 5%.
Predictors of adverse maternal outcomes include a reduced
mitral-valve area (< 1.5 cm2) and an abnormal functional
class before pregnancy.48 Fetal mortality increases with
deteriorating maternal functional capacity; it is 30% when
mother has NYHA class IV symptoms.30
For women with mild or moderate symptoms during
pregnancy, medical therapy is directed at the treatment of
volume overload and includes diuretic therapy, the
avoidance of excessive salt, and the reduction of physical
activity. Beta-blockers attenuate the increases in heart rate
and prolong the diastolic filling period,49,50 which provides
symptomatic benefit.51 Ashcom et al.49 in their study of beta
blockade in seven patients with severe mitral stenosis
concluded that chronic beta blockade afforded some
protection by blunting changes in pulmonary capillary
wedge pressure and right heart pressures during exercise;
however, exercise performance was not enhanced.
Nevertheless, beta-blockers are recommended during
pregnancy, especially if the peak pulmonary artery pressure
31
is > 50 mmHg by echocardiogram. Atrial fibrillation
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Anandaraja et al. Management of VHD during Pregnancy 105
requires prompt treatment, including cardioversion.
Beta-blockers and digoxin are used for rate control. Because
of the increased risk of systemic embolism in patients
with mitral stenosis and atrial fibrillation, anticoagulant
therapy is indicated.52,53 In untreated patients who undergo
an uncomplicated delivery, strict vigilance is required
during the post-partum period as patients can suddenly
worsen.
In patients with significant mitral stenosis and NYHA
class III symptoms intervention is required. Both open and
closed mitral commissurotomy and valve replacement
carry a significant maternal and fetal risk. Closed
commissurotomy has a mean maternal mortality rate of
1.7% and fetal mortality between 5 and 15%,54 though
recent reports depict a more favorable outcome. 55,56
Percutaneous balloon mitral valvuloplasty has given good
results specially in young patients with non-calcific valves
without subvalvular thickening or significant mitral
57-60
In the
regurgitation and is the procedure of choice.
asymptomatic or minimally symptomatic patients with
severe mitral stenosis, balloon mitral valvotomy should be
considered if the NYHA class worsens by one grade. Balloon
mitral valvotomy in pregnant women is a technically
complex procedure that needs to be done quickly avoiding
prolonged radiation exposure due to fluoroscopy, and
should be attempted in centers that have extensive
experience with this procedure.
Mitral regurgitation: Mitral regurgitation is usually well
tolerated during pregnancy if the left ventricular function
is good.61 The increase in blood volume and cardiac output
increases the volume overload but the decrease in systemic
vascular resistance reduces the regurgitant fraction.
Because of the decrease in left ventricular afterload
associated with mitral regurgitation, systolic wall stress is
also lowered. In patients with mitral regurgitation
secondary to mitral valve prolapse, the increase in blood
volume associated with pregnancy decreases the severity
of mitral regurgitation. Pregnancy in patients with mitral
valve prolapse follows a benign and uneventful course. The
physical findings and even symptoms appear less evident
62
and the patients usually feel better during pregnancy.
However, more serious complications of mitral valve
prolapse, such as arrhythmia, infective endocarditis, and
63
cerebral ischemic events may complicate pregnancy.
Patients with pre-existing ventricular dysfunction may
develop progressive congestive heart failure particularly
during the third trimester. They need diuretics and
vasodilators to reduce the systemic vascular resistance.
Angiotensin-converting enzyme inhibitors and angiotensin
receptor blockers are contraindicated. In symptomatic
EDITORIAL.p65
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pregnant patients with mitral regurgitation,
dihydropyridine group of calcium channel blockers,
hydralazine hydrochloride, diuretics, and digoxin can be
used when systolic function is impaired. In severe
symptomatic mitral regurgitation, surgical mitral valve
repair is a good option because it avoids the need for
anticoagulant therapy. Mitral valve replacement can be
done as a last resort.
Aortic stenosis: Pregnancy in patients with aortic stenosis
is uncommon. The major problem in pregnant patients
with severe aortic stenosis is to maintain an adequate
cardiac output across a fixed aortic valve. With severe
stenosis, there is a narrow window of appropriate fluid
loading. Small decreases in preload due to hemorrhage or
regional anesthesia may result in decreased cardiac output
and dangerous clinical hypotension. Also, small increases
in vascular volume may produce dramatic increase in filling
pressure, resulting in pulmonary edema. The clinical
consequences of the increased aortic gradient depend on
the degree of pre-existing left ventricular hypertrophy and
left ventricular systolic function. Women with aortic valve
area > 1.0 cm2 tolerate pregnancy well and have a good
outcome. However, women with more severe aortic stenosis
may have symptoms of left-sided heart failure. The
maternal mortality in pregnant patients with severe aortic
stenosis is as high as 17%.64 Most asymptomatic patients
and those who have mild to moderate stenosis can be
managed with medical therapy and close monitoring. It is
important to maximize cardiac output and fetal blood flow
by avoiding intense exercise, potent vasodilators, and
diuretics. Termination of pregnancy should be strongly
considered if the patient is symptomatic before the end of
the first trimester. Women with severe aortic stenosis are
more likely to experience cardiac complications during
pregnancy and require interventions during the course of
65
pregnancy. Aortic-valve replacement has mortality as
high as 11% during pregnancy with associated fetal
27,28,66,67
and only case series of successful balloon
risk.
68,69
The
valvotomy during pregnancy is available.
association between congenital bicuspid aortic valve and
70
aortic dissection has long been recognized. Pregnant
patients with bicuspid aortic valve and enlarged aortic root
71
should be counseled like Marfans syndrome patients.
Aortic root of >5.0 cm is considered an indication for
elective repair before conception. If aortic root enlargement
(>4.0 cm) is first detected during pregnancy, termination
with prompt aortic repair is recommended, especially if
serial echocardiographic studies demonstrate progressive
dilation over time. Dissection and rupture are most likely
to occur during the third trimester or near the time of
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106 Anandaraja et al. Management of VHD during Pregnancy
Indian Heart J 2005; 57: 101–108
delivery. The use of prophylactic ß-blockade throughout
the pregnancy is strongly recommended. Special care must
be taken to provide adequate analgesia to prevent wide
surges in blood pressure and its rate of rise (dp/dt) during
labor and delivery. Obstetrical techniques to shorten the
second stage of labor are recommended. General anesthesia
and cesarean section may allow more optimal
hemodynamic control.
outcome was good though there was an increased risk of
prematurity and dysmaturity in the babies born to mother
with cyanosis. There were no congenital anomalies in the
babies. In addition, a significantly lower birth weight babies
were delivered by the cyanotic mothers. Thus pregnancy is
well tolerated in these patients.
Aortic regurgitation: In pregnant women aortic
regurgitation, most commonly secondary to rheumatic
fever is often seen with co-existing mitral valve disease. The
decreased systemic vascular resistance during pregnancy
reduces afterload and hence the amount of regurgitant flow
across the valve. This adaptation appears to maintain the
forward flow unless systolic dysfunction sets in. Therefore,
as with mitral insufficiency, chronic aortic insufficiency is
well tolerated during pregnancy. 72 In asymptomatic
patients, close monitoring is all that is needed. Symptomatic
patients can be treated with vasodilators, as for mitral
regurgitation. In the women who develop signs of
congestive heart failure, physical activity should be
restricted and inotropic and diuretic therapy should be
initiated. Women with aortic regurgitation tolerate
bradycardia poorly, as this increases the duration of diastole
and the amount of regurgitation across the valve; hence
maternal heart rate should be maintained between 80 and
100 bpm.73
Rheumatic fever and heart disease occur in younger age in
our country and it is rare, but possible to have acute
rheumatic fever during pregnancy. Secondary prophylaxis
with injection penicillin is required and sulfonamides are
contraindicated in these patients. Rheumatic fever may
recur during pregnancy and carditis can be a serious
complication during pregnancy.78 Chorea gravidarum is
rarely seen now but can result in fetal death and
occasionally, maternal death.79 More frequently chorea is
seen in the primigravida, with about half of the cases
occurring in the early pregnancy. Approximately one-third
of these cases resolve before delivery and the remainder
resolve shortly thereafter. When chorea is severe
interruption of pregnancy is indicated.
Pulmonary stenosis: Pulmonary stenosis is well tolerated
during pregnancy despite the gestational volume overload
imposed on the already pressure overloaded right ventricle.
In three series comprising 106 pregnancies, no maternal
17,74,75
However, if the stenosis is
mortality was reported.
severe, pregnancy can precipitate right heart failure, atrial
arrhythmias or tricuspid regurgitation. In case of right
ventricular failure during pregnancy, balloon valvotomy
31
may be done for severe stenosis.
Tricuspid valve/Ebstein’s anomaly: Isolated tricuspid
regurgitation can be managed conservatively, although
greater care is required to protect against diuretic-induced
hypoperfusion. In patients with Ebstein’s anomaly, the
physiological changes associated with pregnancy may have
appreciable adverse hemodynamic consequences. In the
presence of impaired right ventricular function, the
increased stroke volume may be poorly tolerated and result
in worsening symptoms. Complications of pregnancy and
delivery such as hemorrhage may not be well tolerated by
76,77
these patients. In two series comprising 153 pregnancies
in 56 women, pregnancy was well tolerated in the absence
of significant maternal cyanosis or arrhythmias. Neonatal
EDITORIAL.p65
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Rheumatic Fever Complicating Pregnancy
Infective endocarditis: Infective endocarditis is
uncommon during pregnancy80-83 and is typically limited
to patients with pre-existing valve disease or a history of
intravenous drug abuse. The majority of cases (74%) are
caused by viridans streptococci, while enterococci and group
B streptococci were uncommon except after abortion. In a
recent review the maternal and fetal mortality following
maternal endocarditis was found to be 22.1% and 14.7 %
respectively.82 Aortic valve endocarditis had the highest
mortality rate (42%) while the tricuspid valve endocarditis
had only 9% mortality rate. Infective endocarditis is a
serious disease that can be missed in the early stages
because of the paucity of physical signs. The low grade fever
may pass unnoticed by the patient and the frequency of
micturation associated with the gravid state often leads to
false diagnosis of urinary tract infection and the use of
antibiotic further masks the disease. Murmurs may also be
interpreted as benign and of hemic origin specially in the
absence of history of heart disease. However, pregnancy
itself does not affect the natural history of the disease.
Medical management of endocarditis is broadly similar
to the non-pregnant patient but special attention has to be
given to certain aspects. The increased glomerular filtration
rate and expanded blood volume that occurs in pregnancy
results in shortened half life and reduced serum levels of
those antibiotics that are excreted by the kidney (penicillins,
cephalosporins and aminoglycosides). The serum level of
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Anandaraja et al. Management of VHD during Pregnancy 107
antibiotics may be reduced to <50% and hence monitoring
of serum levels is appropriate to ensure adequate tissue
levels and therapeutic efficacy. Penicillins and
cephalosporins cross the placenta and are well tolerated
by the fetus. Aminiglycosides carry small risk of fetal
ototoxicity.
Currently there are no uniform guidelines for infective
endocarditis prophylaxis in pregnant patients. Routine
antibiotic prophylaxis is not recommended in patients with
valvular heart disease undergoing uncomplicated vaginal
delivery or cesarean section unless infection is suspected.
Though infective endocarditis prophylaxis is indicated only
for high risk patients, the effects of endocarditis can be so
devastating that the need for prophylaxis should be
individualized.84
Conclusions
Management of valvular heart disease during pregnancy
is challenging. A thorough knowledge of the expected
natural history of the disease during pregnancy and of the
possible treatment options is required for clinical decision
making. A meticulous individualized patient care by a team
of physician, obstetrician, and anesthetist is required for
optimal outcome of the pregnancy for the mother and the
baby.
References
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Sungnoon et al. Anti-arrhythmic Effects
of Herbs
109
Review
Article
Anti-Arrhythmic Effects of Herbal Medicine
Rattapong Sungnoon, Nipon Chattipakorn
Cardiac Electrophysiology Unit, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
H
erbs have been used for medical treatment since the
beginning of human civilization.1 Herbal medicine
has made many contributions to commercial drug
preparations manufactured today including ephedrine
from Ephedra sinica (ma-huang), digitoxin from Digitalis
purpurea (foxglove), salicin (the source of aspirin) from Salix
alba (willow bark), and reserpine from Rauwolfia serpentine
(snake root).1 With wide use of herbs in Eastern traditional
medicine as well as in Western medicinal drugs, continuing
research is necessary to elucidate the pharmacological
activities of many herbal remedies now being used to treat
cardiovascular diseases, such as congestive heart failure,
hypertension, angina pectoris, atherosclerosis, and
arrhythmias.1
Arrhythmias have accounted for significant cardiac
morbidities and mortalities over the past few decades.2
Although some arrhythmias may appear benign or
potentially dangerous, the majority of sudden cardiac
arrests are a direct result of ventricular tachycardia (VT)
and/or ventricular fibrillation (VF). 3,4 Although
conventional anti-arrhythmic drugs have been shown to
be effective in preventing arrhythmias, they themselves can
also cause lethal arrhythmias in some conditions.4 It is
known that electrical defibrillation is the only effective
clinical means to treat VF.5 Currently, the shock strength
required to successfully defibrillate is still high. A number
of studies have been done to lower the defibrillation
threshold (DFT). One of the means to decrease the DFT is
to combine the defibrillation with the drugs. 6 Both
pharmacological and non-pharmacological interventions
to prevent these lethal arrhythmias have been widely
investigated. Recently, many herbal products have been
shown to be anti-arrhythmic and would be useful to treat
and prevent arrhythmias.
This review focuses on some herbal medicines, both
crude extracts and pure compounds, that have been widely
studied for their anti-arrhythmic effects in recent years.
These consist of trilinolein, garlic, and certain other
common herbal products. Continuing research is necessary
Correspondence: Dr Nipon Chattipakorn, Cardiac Electrophysiology Unit
Department of Physiology, Faculty of Medicine, Chiang Mai University
Chiang Mai 50200, Thailand. e-mail: [email protected]
IHJ-772-04 (RA).p65
109
to provide more information regarding the safety and
efficacy of herbal medications now being used to treat
arrhythmias.
Trilinolein and its Anti-Arrhythmic Effects
Trilinolein, isolated from the traditional Chinese herb
Sanchi (Panax notoginseng),7 has been used for treating
circulatory disorders in China for hundreds of years.
Chemical structure of trilinolein consists of a triacylglycerol
with the fatty acid and linoleic acid, which carries two
unsaturated bonds, at all three esterified positions of
glycerol. Trilinolein has been shown to have various
beneficial effects, including reduction in thrombogenicity,
erythrocyte deformability and having antioxidant, antiischemic, and anti-arrhythmic effects in various
experimental models.8-10
In a rat model study, trilinolein was reported to reduce
ischemia-induced arrhythmias.9 In this study, trilinolein
(0.01-100 ng/kg) was administered intravenously 15 min
before ligation of the coronary artery. At dose of 100 ng/
kg, trilinolein has been shown to completely suppress all
ventricular arrhythmias. Trilinolein also reduced the
incidence, rate and duration of VT and the number of
ectopic beats during the first 30 min of coronary ligation.9
Additionally, similar doses of trilinolein also reduced
ventricular arrhythmias during 10 min reperfusion of the
myocardium, following the 30 min of coronary artery
ligation.9 Furthermore, the effect of trilinolein on infarct
size was evaluated by occluding the coronary artery for 4
hours before the infarct zone was stained and weighed. In
rats subjected to 4-hour coronary ligation, pre-treatment
with 10-7 g/kg trilinolein infused intravenously at 15 min
prior to the coronary ligation significantly reduced infarct
size. 9
The anti-arrhythmic effects of trilinolein have been
investigated in ventricular arrhythmia caused by digitalis
intoxication.10 Ventricular arrhythmia is a frequent side
effect with the use of digitalis, the mechanism underlying
the arrhythmias induced by cardiac glycosides being
complex. It has been shown that delayed afterdepolarization (DAD) is responsible for such arrhythmia.11
DAD is believed to be generated by the overloading of
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110 Sungnoon et al. Anti-arrhythmic Effects of Herbs
intracellular Ca2+ stores, caused by the inhibitory effect of
digitalis on the Na+/K+ pump which subsequently activates
the reverse mode of the Na+/Ca2+ exchanger.12 Treatment
of guinea pigs with trilinolein (0.1-100 µg/kg) prior to
intravenous administration of strophanthidine
significantly reduced ventricular extrasystoles which were
related to DADs induced by cardiac glycoside.10 It is known
that low concentrations of trilinolein effectively reduced
Ca 2+ influx in isolated rat cardiomyocytes. 13 Similar
mechanisms may be involved in reducing strophanthidineinduced ventricular extrasystoles. Excess of Ca 2+ and
overloading of Ca2+ not only favors abnormal automaticity
as well as triggered activity created by DADs, but also
induces cell-to-cell uncoupling and block of conduction by
inhibition of gap junction channels with down-regulation
of intermyocyte communication which can initiate
reentry.14 Trilinolein also dose-dependently narrowed the
width of the QRS complex during VT, possibly due to the
improvement of the conduction velocity between muscle
fibers through the action of trilinolein on Ca2+ metabolism
that contributed to prevention of further arrhythmias.10
Since VF induction and failed defibrillation have been
demonstrated to be related to intracellular calcium
overload,15,16 it is likely that trilinolein could be beneficial
in this case. Further studies are needed to verify this
hypothesis.
Garlic and its Anti-Arrhythmic Effects
Garlic (Allium sativum) is a perennial plant that is cultivated
worldwide. Its bulb has been used as a spice or medicinal
herb for many centuries. 17 It contains a higher
concentration of sulfur compounds than any other Allium
species. The sulfur compounds are responsible both for
garlic’s pungent odor and many of its medicinal effects.
Dried, powdered garlic contains approximately 1% alliin
(S-allylcysteine sulfoxide).18 One of the most biologically
active compounds, allicin (diallylthiosulfinate or diallyl
disulfide) does not exist in garlic until it is crushed or cut
since injury to the garlic bulb activates the enzyme allinase,
which metabolizes alliin to allicin. 19 Allicin is further
metabolized to vinyldithiines. This breakdown occurs
within hours at room temperature and within minutes
during cooking.20 Garlic oil, aged garlic and steam-distilled
garlic do not contain significant amounts of aliin or allicin,
but instead contain various products of allicin
transformation; none appears to have as much physiologic
activity as fresh garlic or garlic powder. 19,21,22 In rats, aliin
is well absorbed orally, reaching maximum serum
concentrations within 10 min, and is completely excreted
IHJ-772-04 (RA).p65
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Indian Heart J 2005; 57: 109–113
within 6 hours. Allicin and vinyldithiines are absorbed
more slowly, reaching peak levels between 30 and 120 min
and persisting in the body for up to four days.23 There is a
significant first pass effect in which allicin is metabolized
to allylmercaptan, ajoene and vinyldithiines.24 Excretion
occurs renally and through hepatic breakdown, fecal
excretion and exhalation.
In modern medicine, garlic and its preparations have
been widely recognized as agents for prevention and
treatment of cardiovascular and other metabolic diseases,
atherosclerosis, hyperlipidemia, thrombosis, hypertension
and diabetes.25 These biological responses have been largely
attributed to the ability of garlic to reduce risk factors for
cardiovascular diseases and cancer, stimulate immune
function, and enhance detoxification of foreign
compounds. It also has hepatoprotective, antimicrobial and
antioxidant effect.25
Previous studies have demonstrated that garlic has a
significant anti-arrhythmic effect in both ventricular and
supraventricular arrhythmias,25,26 especially its free radical
scavenging activity which reduces the incidence of VT and
VF induced by myocardial ischemic-reperfusion injury.27
However, the definite mechanism by which garlic
suppresses arrhythmia is still unclear. Martin et al. 26
demonstrated that garlic dialysate prolonged sinus node
recovery time (SNRT) and effective refractory period (ERP)
of isolated rat atria in a dose-dependent manner.26 They also
reported that garlic depresses a Ca2+ influx which is related
to prevention of DAD.26,28 It is known that the mechanism
underlying the generation of DAD involves an overload of
intracellular Ca2+ with oscillation of the transmembrane
potential, giving rise to new activations.29,30 Thereafter,
arrhythmia can be induced from these activations
(triggered activity) if they reach a critical threshold. In a
study by Kojima et al.31 normalization of intracellular Ca2+
has been suggested to contribute to termination of VF by
suppressing DAD and/or slowing ventricular conduction
in the isolated rat heart model. The ability of garlic to
prevent intracellular Ca2+ oscillation could help prevent
DAD. In human studies, many clinical trials studying
cardiovascular effects of garlic used dried garlic powder that
contains approximately 1.3% alliin (precursor of allicin)
at a dosage of 300 to 900 mg/day (5-15 mg/kg),
corresponding to 0.9 to 2.7 g of fresh garlic daily.32 For
example, in a prospective, 4-year clinical trial of patients
treated with 900 mg daily of standardized garlic powder,
there was a 9-18% reduction in plaque volume, a 4%
decrease in low-density lipoprotein (LDL) levels, an 8%
increase in high-density lipoprotein (HDL) concentrations,
and a 7% decrease in blood pressure. 33 However, in
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Indian Heart J 2005; 57: 109–113
randomized, controlled trials, side effects in those taking
garlic included heartburn, nausea, vomiting, diarrhea,
flatulence, bloating, mild orthostatic hypotension, flushing,
tachycardia, headache, insomnia, sweating and dizziness
as well as offensive body odor.34 Although the exact toxicity
of garlic has yet to be definitively determined, side effects
are rare at the dosage mentioned above.32,35 Nevertheless,
further human studies are required to evaluate the antiarrhythmic properties of garlic, especially its definite
mechanisms.
Anti-Arrhythmic Effects of Other Herbal Products
Many herbal products show their effects on inhibition of
VT, VF and/or extrasystole during the period of ischemiareperfusion injury or acute myocardial infarction in
animals. Pre-treatment with magolol and honokiol, the
active components of Magnolia officinalis significantly
reduced the incidence and duration of ventricular
arrhythmia including VT and VF in rats subjected to
coronary ligation.36,37 These could in part be relevant to
the vasorelaxant effects due to an increased nitric oxide
(NO) synthesis. Dauricine, an active compound found in
Menispermum dauricum, ameliorates acute myocardial
ischemia-induced VT and VF in anesthetized dogs.38 The
mechanism of its antagonistic effect lies in its blocking effect
on inward K+ current in ventricular myocytes.39 Neferine,
isolated from the seeds of Nelumbo nucofera, prevented
the onset of re-entrant VT and sudden cardiac death
after myocardial ischemic damage studied in open-chest
dogs. 40 It lengthened the ERP as well as decreased
the dispersion of the ERP, and increased the diastolic
excitability threshold of normal and infarct myocardium
in both ventricles.40 All of these effects stabilize membrane
potential of cardiac myocytes, and thus, could prevent
arrhythmias.
Oxymatrine, an alkaloid isolated from Sophora japonica,
increased the diastolic excitability threshold and
lengthened ERP in dogs after myocardial infarction. 41
However, it had no effects on the dispersion of ERP, QTc
interval and VT or VF induced by programmed electric
stimulation. On the other side, studies using hawthorn
berry (Crataegus oxyacantha) demonstrated beneficial antiarrhythmic effects.42,43 Using Langendorff-perfused rat
heart, reperfusion arrhythmias of a 3-month oral pretreatment with a dried Crataegus extract were reduced
significantly.42 Crataegus, however, aggravated rather than
prevented arrhythmias with its long-term application in a
recent study.43
Tetrandrine, an extract from Stephania tetrandra, has
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Sungnoon et al. Anti-arrhythmic Effects of Herbs 111
been shown to inhibit VT and VF during regional ischemiareperfusion injury without further reducing ischemiareduced heart rate and coronary artery flow.44 It may be a
better choice for the treatment of arrhythmia and infarction
induced by myocardial ischemia and reperfusion than a
classical Ca 2+ channel blocker, i.e. verapamil, which
can reduce heart rate during ischemia.44 Pre-treatment
with sinomenine, a compound found in Sinomenium
acutum, could also reduce the incidence of VT and VF
in isolated perfused rat heart subject to ischemiareperfusion injury by lowering intracellular Ca 2+
accumulation.45
Other herbal products having anti-arrhythmic effects
are hirsutine, EGB761 and dehydroevodiamine. Hirsutine,
an indole alkaloid found in Uncaria rhynchphylla, showed
anti-arrhythmic action on membrane potentials of rabbit
sinoatrial node and guinea-pig right ventricle and left
atrium by decreasing the slope of the pacemaker (phase 4)
depolarization and prolongation of the action potential
duration.46 EGB761, a Ginkgo biloba (maidenhair tree)
extract, in combination with superoxide dismutase
significantly attenuated both the formation of oxygen-free
radicals and the incidence of reperfusion-induced VF and
VT in isolated rat hearts.47 Dehydroevodiamine, an alkaloid
from Evodiac rutaecarpa, has been shown to depress
arrhythmias in calcium-overloaded guinea-pig cardiac
myocytes through its inhibitory actions on the Na +dependent inward current, the transient inward current
and, to a smaller extent, the L-type Ca2+ current.48 In
addition, dehydroevodiamine has been shown to possess
anti-arrhythmic effect similar to class III anti-arrhythmic
drugs through a reduction of outward K+ currents across
the sarcolemma.48
Conclusions
Herbal medicines have been used for centuries and their
potential benefits have been corroborated by high
prevalence of their use worldwide. For cardiovascular
disorders, many herbal treatments are available with
limited scientific assessment of both benign and malignant
arrhythmias. Some herbal medicines (crude extracts and
pure compounds) that have been studied extensively for
their anti-arrhythmic effects such as trilinolein, garlic and
other herbal products may be beneficial as effective
pharmacological therapies as well as for prevention of lethal
arrhythmias such as VT and VF. Further basic and clinical
studies are needed to elucidate the pharmacological effects
of these herbal products and their potential impact on the
prevention and treatment of arrhythmias.
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112 Sungnoon et al. Anti-arrhythmic Effects of Herbs
Acknowledgements
This work is supported in part by the Thai Research Fund
(TRF) grant.
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114 Unverdorben
et al.
Original
Article
Indian Heart J 2005; 57: 114–120
Reused Balloon Catheters
Clinical and Angiographic Procedural and Mid-term
Outcome with New versus Reused Balloon Catheters in
Percutaneous Coronary Interventions
Martin Unverdorben, Ralf Degenhardt, Dominique Erny, Manfred Scholz, Eberhard Wagner,
Henning Köhler, Heiner K Berthold, Christian Vallbracht
Institute for Clinical Research, Center for Cardiovascular Diseases, Rotenburg an der Fulda, Germany
Background: To reduce procedural cost, cardiac centers increasingly use resterilized balloon catheters for
percutaneous coronary interventions. Data addressing the procedural and mid-term outcome in a prospective
randomized trial comparing new and resterilized balloons are not available.
Methods and Results: Percutaneous coronary interventions were performed at random in 238 consecutive
patients with either new or 1–3 times reused balloon catheters. Crossing of the stenosis decreased from 96%
with new balloon catheters to 93.2% (p=0.46), with 1 time reused balloon catheters to 81.8% (p=0.0056)
with 2 times reused balloon catheters and to 80.8% (p=0.01)with 3 times reused balloon catheters. In all
primary failures using resterilized balloon catheters, new ones of the same nominal diameter were successful.
The 4.1±1.9 month angiographic follow-up rates were 96/124 (77.4 %) for new balloon catheter, 35/44 (79.5%)
for 1 time reused balloon catheters, 33/44 (75.0 %) for 2 times reused balloon catheters, and 21/26 (80.8%)
for 3 times reused balloon catheters (p for all >0.05). The late losses for new versus reused balloon catheters
were 0.48±0.75 mm versus 0.73±0.79 mm (p=0.03). The percent stenosis was higher in reused versus new
balloon catheters (51.9±23.2% v. 42.3±22.3%; p=0.0042) as was the restenosis rate [39/89 (43.8%] v.
31/96 (32.3%), p=0.13]. There was one death in reused balloon catheter category but no event of myocardial
infarction. Rates of target lesion revascularizations were similar in stent recipients and more frequent after
stand-alone balloon angioplasty with reused versus new balloon catheters [15/55 (27.3%) versus [5/59 (8.5%),
p=0.01].
Conclusions: The use of two or three times resterilized balloon catheters of the type tested does not seem to be
justified in stand-alone balloon angioplasty of de novo coronary stenoses and should be limited to stent procedures
until data is available for other indications. (Indian Heart J 2005; 57: 114-120)
Key Words: Coronary artery disease, Angioplasty, Re-used catheters
W
orldwide more than 1,000,000 percutaneous
coronary interventions (PCIs) are performed
annually imposing a tremendous financial and ecologic
burden on the health care systems. Although
manufacturers’ warranties recommend single use for the
majority of their products, many cardiac centers resterilize
angioplasty catheters for multiple use.1-6
Investigators have not been able to document additional
risks, neither of transmitting infectious diseases, nor of
adverse reactions to the disinfectants when catheters are
reused after, careful cleansing7,8 and resterilization by either
ethylene oxide9-13 or hydrogen peroxide.14 To date, however,
Correspondence: Professor Heiner K Berthold, Executive Secretary,
Drug Commission of the German Medical Association, Herbert-Lewin-Platz 1
10623 Berlin, Germany. e-mail: [email protected]
IHJ-819-05(OA).p65
114
only limited data is available on the clinical performance
of reused angioplasty balloon catheters with conflicting
results in small cohorts of patients2,6,15 and no angiographic
follow-up data. We therefore investigated acute and midterm results of new versus resterilized balloon catheters.
Methods
Study design: The study is a prospective, randomized
clinical trial comparing the acute and mid-term outcome
of new and 1–3 times reused balloon catheters in patients
with significant de novo coronary artery stenosis.
Ethical considerations: The trial was conducted in
accordance with the Declaration of Helsinki and
International Commission for Harmonization - Good
6/21/2005, 2:32 PM
Indian Heart J 2005; 57: 114–120
Clinical Practice Guidelines. An independent ethics
committee had approved the protocol. Each patient’s
written informed consent was obtained prior to enrolment.
Characterization of catheter: The catheter used was a
standard monorail system featuring a proximal stainless
steel hypotube shaft with LEAP, a nylon derivative,
serving as balloon material. In vitro data on its mechanical
properties after several cycles of resterilization were
published elsewhere.16
Resterilization of balloon catheters: The balloon
catheters were cleansed by a disinfectant containing
laurylpropylenediamine and dodecylbispropylenetriamine
(Korsolex, Bode Chemie, Hamburg, Germany),
desalinated, and dried by air (Medikat, Hungen, Germany).
After packaging, the devices were gas-sterilized for 7 hours
15 min by ethylene oxide, which well penetrates a narrow
lumen.8 As assessed by an independent institute (Servis,
Gilching, Germany), post-conditioning (26-34ºC/81-93ºF)
for 3 days resulted in complete degasification of the
catheters to escape the toxic effects of the agent,10 thus,
meeting FDA requirements.17
Study population: Three hundred and ten male and
female patients scheduled for angioplasty of a de novo
coronary stenosis were eligible for participation (Fig. 1). In
18/310 (5.8%) patients informed consent could not be
obtained, in 49/310 (15.8%) the required balloons were
not available according to the random list, and in
5/310 (1.6%), crossing of the stenosis with the wire was
unsuccessful. Therefore, 238 patients were randomized
(Table 1).
Inclusion criteria comprised coronary artery stenosis of
≥ 70% and < 100% of a visually estimated maximum lesion
length of < 20 mm in association with angina pectoris.
Exclusion criteria included angina at rest, recent
myocardial infarction (< 24 hours), congestive heart
failure, severe valvular heart disease, ejection fraction (EF)
Unverdorben et al. Reused Balloon Catheters 115
Table 1. Patients’ characteristics
Variable
New balloons
Reused balloons
p-value
124
65.9 ± 9.8
96 (77.4)
114
66.3 ± 8.1
87 (76.3)
0.74
0.88
1- Vessel disease
32 (25.8)
34 (29.8)
0.56
2- Vessel disease
37 (29.8)
39 (34.2)
0.58
3- Vessel disease
55 (44.4)
41 (36.0)
0.23
56.6 ± 21.5
60.1 ± 16.3
0.56
0.07
Number of patients
Age (years)
Male
Severity of coronary
artery disease
EF (%)
Angina pectoris
CCS I
60 (48.4)
41 (36)
CCS II
30 (24.2)
27 (23.7)
1.0
CCS III
16 (12.9)
26 (22.8)
0.06
CCS IV
Unstable angina
Hypercholesterolemia
2 (1.6)
2 (1.8)
1.0
16 (12.9)
18 (15.8)
0.58
100 (80.6)
92 (80.7)
1.0
Total cholesterol
206 ± 44
198 ± 48
0.18
LDL-cholesterol
118 ± 40
113 ± 41
0.35
HDL-cholesterol
51 ± 13
53 ± 19
0.34
Diabetes mellitus
30 (24.2)
29 (25.4)
0.88
Current smokers
0.49
23 (18.6)
17 (14.9)
Family history of CAD 49 (39.5)
50 (43.9)
0.60
Hypertension
73 (58.9)
69 (60.5)
0.90
Statin use
65 (52.4)
63 (55.3)
0.69
Values in parentheses are percentages
EF: ejection fraction; CCS: Canadian Cardiovascular Society; LDL: lowdensity lipoprotein; HDL: high-density lipoprotein; CAD: coronary artery
disease
< 20%, unprotected left main stenosis, serum creatinine
> 2.5 mg/dl, untreated hyperthyroidism, pregnant or
lactating women, associated diseases precluding follow-up
(e.g., malignancy), and simultaneous participation in other
clinical trials.
Primary end point: Crossing of the lesion with balloon,
and inflation of the balloon within the lesion was defined
as success of device.
Secondary end points: Secondary end points included
procedural success, myocardial infarction, emergent target
lesion revascularization, rupture of the balloon, the
number of balloons used per procedure, and consumption
of contrast, time taken for the procedure, and exposure time
to radiation, all taken after the wire had crossed the lesion.
Fig. 1. Patient flow chart.
IHJ-819-05(OA).p65
115
6/21/2005, 2:32 PM
116 Unverdorben et al. Reused Balloon Catheters
Interventional procedure: The procedures followed
common clinical practice with the exception that only one
defined brand of balloon catheter was allowed.
Angiographic success was defined as a residual stenosis of
< 30 %, achieved either by stand-alone balloon angioplasty,
stenting, or by any other means. A total of three
angiograms were performed: the qualifying and the postprocedural angiograms (2 views each) and the follow-up
angiogram using the same two views as for the qualifying
procedure and additional projections, if required.
Only experienced operators with extensive skills in
using resterilized balloon catheters performed the
procedures.18-22
Medication : Aspirin 100 mg/day was given orally at least
two days preceding the procedure. During the intervention,
heparin 100-200 U/kg body weight was given intraarterially upon insertion of the sheath. In procedures
lasting >1 hour, 75 U/kg body weight of heparin was
supplemented. Intracoronary nitroglycerine 0.2 mg was
administered before the first and prior to the last reference
angiogram. Other medications were allowed when
indicated.
During follow-up, aspirin 100 mg/day orally was given
to all patients. Clopidogrel with a loading dose of 300 mg
followed by 75 mg/day for 4 weeks was added after stent
procedures.
Follow-up angiographies were performed under heparin
100 U/kg body weight upon insertion of the sheath and
intracoronary nitroglycerine 0.2 mg 5 min prior to the first
reference view.
Quantitative coronary analysis (QCA): The angiograms
were reviewed by two blinded observers using qualitative
morphologic and quantitative angiographic methods
(CAAS II, Pie-Medical, Maastricht, The Netherlands) at the
Angiographic Core Lab of the Institute for Clinical Research
at Rotenburg an der Fulda. The contrast-filled catheters
served as the calibration standard, while the reference and
minimal lumen diameters were determined using an
automated edge-detection algorithm. Reference contours
were calculated by using a linear regression algorithm with
assessment of the reference diameter at the site of the
minimal lumen diameter.23 The diameters were taken from
the worst view and its close orthogonal projection preprocedure, after stent deployment, and at follow-up. The
mean of both of the values determined the severity of
stenosis. Obvious false assessment of the vessel by CAAS
allowed for operator adjustment.
In case of the difference between the two operators
exceeding 5%, a third operator made the final decision
IHJ-819-05(OA).p65
116
Indian Heart J 2005; 57: 114–120
based on his evaluation blinded to the previous
assessments.
Definition of complications: A thrombus was defined as
a non-calcified filling defect within the vascular lumen,
which was visible in several views and which could migrate
into the peripheral artery. An acute thrombosis was defined
by a total occlusion (TIMI grade 0) occurring within
24 hours after stent deployment whereas subacute
thrombosis was the one that occured > 24 hours and <
1 month after stenting. Q-wave myocardial infarction was
diagnosed with the occurrence of new Q-waves (> 0.04 s)
and rise of creatine kinase twice the upper limit of normal
with significant increase in CK-MB whereas in non-Q-wave
myocardial infarctions pathologic Q-waves were absent.
Statistical analysis: It was to be tested whether the
procedural successes of new and 1–3 times resterilized
balloon catheters would not be different (Null hypothesis).
Based on an estimated procedural success rate of 95% for
new versus 80% for reused balloon catheters, a level of
significance of α = 0.05, and a beta error of β = 0.10, a
sample size of 2 ×114 patients was calculated.
The Kolmogoroff-Smirnoff-test was used to prove
Gaussian distribution allowing for calculation of the mean
and standard deviation. Non-Gaussian samples were
described by the median and the maximal and minimal
values. Categorical variables were evaluated with the twosided exact Fisher test. Simple or multiple logistic regression
analysis and analysis of variance were used to analyze the
influence of one or more parameters on primary procedural
success rate or other dependent variables. The Bonferroni/
Dunn test was used to analyze differences between groups
post hoc, if analysis of variance was significant. For all tests
the significance level α was 0.05.
Results
Out of 310 patients eligible for the study, 238 were
randomized. The reasons for not randomizing a patient are
given in Fig. 1. In 124/238 (52.1%) patients a new balloon
was used as first choice, whereas in 114/238 (47.9%)
patients’ lesion dilation was attempted initially by means
of a resterilized balloon. Resterilized balloons were either
once [44/114 (38.6 %)], twice [44/114 (38.6%)] or three
times [26/114 (22.5%)] resterilized. The reason for less
frequent use of the latter was non-availability of the specific
balloon size (according to the random list) at the time of
the procedure.
Primary and secondary end point: Crossing of the
stenosis was significantly less successful with reused
6/21/2005, 2:32 PM
Indian Heart J 2005; 57: 114–120
Unverdorben et al. Reused Balloon Catheters 117
compared to new balloons [86% v. 96%; odds ratio (OR)
3.89 (95 % CI 1.37-10.99), p = 0.0056]. The size of the
guiding catheter used (6F or 8F) had no influence (data
not shown). When the number of resterilization cycles was
included in the model, primary success of the balloon
catheter was only significantly decreased with catheters
that had been resterilized more than once (Table 2). In all
failures with the resterilized balloons, use of a new one of
the same nominal diameter completed the procedure
successfully.
Table 2. Success rate of balloon catheter according to the
number of resterilization cycles
No. of
resterilization
cycles
Success of
balloon
catheter %
Odds ratio
(95 % CI)
0 (new catheters) 119/124 (96)
–
p-value*
–
Total no.
of balloons
needed for
successful
procedure
p-value**
–
p=0.81
2 cycles
36/44 (81.8) 5.29 (1.63–17.2) p=0.0056 1.34±0.57
3 cycles
21/26 (80.8) 5.67 (1.51–21.3) p=0.01
1.46±0.76
p=0.04
p=0.0055
*Logistic likelihood ratio test
**Post hoc analysis versus new catheters using Bonferroni/Dunn test (p = 0.015 for
ANOVA)
Primary procedural success (%)
The number of resterilization cycles remained a
significant predictor of success (p = 0.0075, logistic
likelihood ratio tests). However, when severity of stenosis
was included in the model, there was no significant
influence on success of device (p = 0.59) (Fig. 2). The
success of balloon catheter of multiply resterilized catheters
becomes apparent specially in higher grade (> 75 %)
stenosis.
Fig. 2. Primary procedural success (cumulative %) according to severity of
stenosis before angioplasty, separated by number of resterilization cycles.*
*indicates new catheters, 1 indicates 1 resterilization cycle etc.
The number of resterilization cycles had a significant
impact on the total number of balloons needed to
successfully complete the procedure (p = 0.015, ANOVA)
(Table 2). New balloons and once resterilized balloon
IHJ-819-05(OA).p65
117
Parameter
Procedure
time (min)*
Fluoroscopy
Exposure to
Contrast dye
time (min) radiation (cGy cm-2) use (ml)
0 cycle
(new catheters)
9.9±6.8
2.6±2.8
740±1060
1 cycle
9.3±4.9
2.4±1.9
904±1100
40±27
2 cycles
12.5±7.2a
3.2±2.7b
690±643
47±26
3 cycles
11.5±10.6
4.2±5.4c
887±1511
49±29
p=0.076
p=0.052
p=0.82
p=0.29
44±32
*All parameters were log-transformed before statistical testing; only significant p
values of post hoc tests are indicated
1.18±0.45
41/44 (93.2) 1.74 (0.40–7.61) p=0.46
Table 3. Procedure-related parameters according to the
number of resterilization cycles*
p value (ANOVA)
1.16±0.41
1 cycle
catheters in comparison to 2–3 times reused catheters
showed a trend toward reduction in procedure and
fluoroscopy time, while the exposure to radiation and use
of contrast dye was unaffected (Table 3).
Bonferroni/Dunn test v. 0 cycles: ap = 0.012, bp = 0.044, cp = 0.026
Angiographic data: Procedures resulted in a percent
stenosis reduction from 80.8±8.6% to 26.2±12.1% in the
total cohort. The overall acute lumen gain of 1.66±0.56
mm showed no significant differences between new or used
catheters (Table 4). The acute gain was significantly larger
in stent recipients compared to patients with stand-alone
balloon angioplasty (1.79±0.58 mm v. 1.53±0.50 mm, p
= 0.0003). This benefit could only be observed in patients
treated initially with a new or once resterilized balloon (data
not shown).
After 4.1±1.9 months, the angiographic follow-up rate
was 185/238 (77.7%), 96/124 (77.4%) for new and 89/
114 (78.1%) for reused balloons (p = NS). The follow-up
rates did not differ between the groups. In patients receiving
stand-alone balloon angioplasty, late loss differed
significantly between the groups (Table 4). For new balloons
it was 0.42±0.70 mm and statistically higher in balloons
resterilized twice (1.25±0.54 mm), which translated into
late loss indices of 0.21±0.42 in new balloons and
0.93±0.58 in balloons resterilized twice (p < 0.0001). In
patients receiving stents no differences were observed.
Therefore, in stand-alone balloon angioplasty patients, the
percent stenosis at follow-up was significantly more severe
in the once resterilized catheter group compared to the new
catheter group (68±23% v. 41±18%, p = 0.0001).
The overall binary restenosis rate was not significantly
higher in patients dilated with reused compared to new
balloons [39/89 (43.8%) v. 31/96 (32.3 %), p=0.13], being
significantly more pronounced (p = 0.00097) after standalone balloon angioplasty [9/12 (75%)] in patients treated
with twice resterilized catheters and unchanged (p = 0.97)
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Indian Heart J 2005; 57: 114–120
118 Unverdorben et al. Reused Balloon Catheters
Table 4. Angiographic data: procedural and mid-term angiographic outcome
New Catheters
0 cycle (n = 124)
Stand-alone angioplasty
59/124 (47.6%)
Angiographic follow-up
45/59 (76.3%)
Lesion diameter pre-intervention (mm)
0.51±0.25
Stenosis pre-intervention (%)
82±8
Lesion diameter post intervention (mm)
2.1±0.54
Stenosis post-intervention (%)
27±12
Lesion diameter at follow-up (mm)
1.75±0.68
Stenosis at follow-up
41±18
Acute gain (mm)
1.59±0.53
Late loss (mm)
0.42±0.70
Late loss index*
0.21±0.42
Binary restenosis rate
12/45 (26.7 %)
Odds ratio, 95 % CI, p value
N/A
Rate of TLR**
Odds ratio, 95 % CI, p value
5/59 (8.5 %)
N/A
Stent procedures
65/124 (52.4%)
Angiographic follow-up
51/65 (78.5%)
Lesion diameter pre-intervention (mm)
0.62±0.29
Stenosis pre-intervention (%)
80±9
Lesion diameter post-intervention (mm)
2.39±0.58
Stenosis post-intervention (%)
24±12
Lesion diameter at follow-up (mm)
1.81±0.93
Stenosis at follow-up (%)
43±25
Acute gain (mm)
1.77±0.60
Late loss (mm)
0.54±0.80
Late loss index*
0.32±0.55
Binary restenosis rate
19/51 (37.3 %)
Odds ratio, 95% CI, p value
N/A
Rate of TLR**
Odds ratio, 95% CI, p value
11/63 (17.5%)
N/A
1 cycle (n = 44)
Reused catheters
2 cycles (n = 44)
3 cycles (n = 26)
p value
24/44 (54.5%)
17/24 (70.8%)
0.60±0.25
78 ±8
1.94±0.54
30±13
1.31±0.62a
52±21c
1.33±0.55e
0.6±0.61
0.44±0.48g
8/17 (47.1%)
2.44, 0.77–7.8
p=0.13
6/24 (25 %)
3.6, 0.98–13
p=0.054
20/44 (45.5%)
18/20 (90%)
0.66±0.31
79±10
2.63±0.44i
18±8k
1.64±0.93
49±25
1.97±0.59
0.93±0.93
0.51±0.48
7/18 (38.9%)
1.07, 0.36–3.2,
p=0.90
5/20 (25%)
1.58, 0.47–5.2,
p=0.46
20/44 (45.5%)
12/20 (60%)
0.60±0.27
79±9
2.06±0.45
31±12
0.95±0.71b
68±23d
1.46±0.44
1.25±0.54f
0.93±0.58h
9/12 (75%)
8.3, 1.9–36,
p=0.0047
6/19 (31.6%)
5.0, 13.0–18.9,
p=0.018
24/44 (54.5%)
21/24 (87.5%)
0.52±0.27
83 ±9
2.11±0.51j
31±12l
1.64±0.88
49±24
1.6±0.51
0.51±0.81
0.24±0.62
8/21 (38.1%)
1.04, 0.36–2.9,
p=0.95
7/24 (29.2%)
1.9, 0.65–5.8,
p=0.23
11/26 (42.3%)
10/11 (90.9%)
0.51±0.21
82±6
2.24±0.4
25±10
1.87±0.69
46±23
1.73±0.35
0.3±0.72
0.17±0.41
2/10 (20%)
0.67, 0.13–3.7,
p =0.66
3/11 (27.3%)
4.05, 0.81–20.3,
p = 0.089
15/26 (57.7%)
11/15 (73.3%)
0.57±0.29
81±10
2.49±0.52
22±10
1.71±0.87
50±19
1.92±0.53
0.86±0.73
0.46±0.37
5/11 (45.5%)
1.4, 0.38–5.2,
p =0.61
3/14 (21.4%)
1.29, 0.31–5.4
p=0.73
–
–
p=0.28†
p=0.17†
p=0.40†
p=0.44†
p=0.001†
p=0.0008†
p=0.094†
p=0.0018†
p < 0.0001
p=0.0097†
p=0.13†
p=0.053†
p=0.054†
–
–
–
p=0.33†
p=0.53†
p=0.017†
p=0.003†
p=0.87†
p=0.71†
p=0.16†
p=0.22†
p=0.40†
p=0.97‡
p=0.67 ‡
* TLR: target lesion revascularization; ** Late loss index: the ratio between late loss and acute gain; N/A : not applicable;
ANOVA; ‡Logistic likelihood ratio test
Superscript letters: Bonferroni/Dunn test v. new catheters: ap = 0.025, bp = 0.0005, cp = 0.058, dp < 0.0001, ep = 0.038, fp = 0.0003, gp = 0.086,
h
p < 0.0001, ip = 0.088, jp = 0.036, kp = 0.029, lp = 0.018
†
in stented vessels (Table 4). No myocardial infarction
occurred and one death was registered (in those with the
resterilized balloon catheter used first (p=NS).
In a logistic regression model using procedural success
as the dependent parameter and the number of
resterilization cycles, the operator skill, the age of the
patient, low-density lipoprotein (LDL)-cholesterol, diabetes,
smoking status, and stenting as independent parameters,
only the number of resterilization cycles was a significant
predictor for success (decreased after 2 and 3 cycles, p =
0.0028 and 0.069).
Discussion
The primary reason for using resterilized catheters in
percutaneous coronary interventions is the expectation
IHJ-819-05(OA).p65
118
of providing the same quality of medical care at reduced
cost. 4,24,25 This expectation, however, cannot be
unequivocally substantiated by the data available at
present.2,4,6,15,26
For the procedural success of coronary stenosis of
≥ 70 % and < 100 % with reused balloon catheters, similar
rates for new and reused balloon catheters in the present
study are in keeping with data of others, 6,15,26,27 who
reported comparable procedural success rates at the cost
of significantly more stents required in one study.2
The crossing of the lesions with reused catheters was
significantly inferior compared to new balloons (OR 3.89,
95% CI 1.37–10.99, p = 0.0056) and was associated with
an increased number of balloon catheters required per
procedure (p=0.015). These differences reached statistical
significance for 2–3 times reused balloon catheters only
6/21/2005, 2:32 PM
Indian Heart J 2005; 57: 114–120
opposed to once resterilized balloon catheters. The inferior
performance can be attributed to the increased crossing
profile secondary to the blunted rewrap after the first
inflation.16 For both, fluoroscopy and procedure time,
trends toward 'more time needed' were observed whereas
exposure to radiation and use of contrast dye were similar.
These results are in keeping with a dual-center work in
which one hospital used new balloons whereas in the
second center only resterilized balloon catheters had to be
chosen.15 For resterilized balloon catheters, significantly
more balloons were required per lesion (2.4±1.5 v. 1.2±0.5,
p < 0.00001), a higher incidence of initial balloon failure
occurred (10.2 % v. 3.3 %, p < 0.00001), and prolongation
of the procedure time (81 ± 41 v. 68±32 min, p < 0.0001)
and increased volume of contrast medium use (201±86 v.
165±61 ml, p < 0.0001) were observed. These results were
confirmed in lesions of 90% and beyond.26 In yet another
study comparing 53 consecutive patients with multiple use
catheters to a second series of 54 patients with single use
balloons the values for fluoroscopy time, the number of
guiding catheters, and the number of angioplasty balloons
used were similar. 6
The most intriguing finding of the present trial, however,
is the fact that after 4.1±1.9 months of follow-up
parameters such as late loss, late loss index, percent
stenosis, and binary restenosis rate showed significantly
higher values when stand-alone balloon angioplasty was
attempted with reused balloons compared to the new ones.
This holds true despite the fact that the rates of myocardial
infarction and death were the same in both groups. This
finding is not contradictory to the angiographic results
since this trial does not provide any information whether
the process of intimal proliferation was completed after four
months or, more likely, will be continuing. In other series,
higher rates of adverse clinical events of 7.8% v. 3.8% (p <
0.025) after 10-month clinical follow-up15 and of 10.0%
v. 7.9% during the hospital stay were observed. The latter,
however, could not be confirmed in a multivariate reanalysis.5
Possible mechanisms of the enhanced restenosis rate
encompass more mechanical vascular trauma induced by
the higher crossing profile and the less smooth balloon
surface.16 While leaking of the balloons is very unlikely,16
alterations in the balloon material could have induced
more inflammation.
Limitations of the study: There is possibility of bias of
the procedural results by the participating operators. The
use of resterilized balloon catheters used to be the common
approach in this center for the years preceding this study.
Therefore, it is not very likely that the operators would
IHJ-819-05(OA).p65
119
Unverdorben et al. Reused Balloon Catheters 119
jeopardize their current way of performing percutaneous
interventional procedures. Since patients with restenosis
were excluded, it may be assumed that the procedural
results in restenotic lesions and in-stent restenosis lesions
may be different. The overall importance of the present data
is limited by the fact that the number of stent procedures is
increasing worldwide.
With respect to the enhanced late loss and its associated
parameters it must be emphasized that this trial was
randomized for the primary and not for the secondary end
points; therefore, some caution is recommended. Post hoc
analysis, however, disclosed a power of 80% for a level of
significance α=0.05 for the late loss index suggesting that
the enhanced mid-term proliferation following stand-alone
balloon angioplasty is more than an accidental finding.
The results apply for the four months follow-up period
only and may not be translated to a longer period. There
are also uncertainties whether balloons manufactured from
different materials would result in different outcomes.
Conclusions: The findings of this study raise serious
concerns with respect to reusing resterilized balloon
catheters in stand-alone balloon angioplasty of de novo
lesions due to their impaired procedural performance and
apparently enhanced restenosis rate. Evaluation for a longer
time period, i.e. for a nine months follow-up period is
warranted. In non-drug eluting stent procedures of de novo
coronary lesions, however, reused balloon catheters may
still be used provided the altered mechanical properties of
the devices are known and taken into account.16
Acknowledgments
We are indebted to Mrs. Claudia Krapf and Miss Tina Iffland
for their expert assistance in conducting this trial.
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Indian Heart J 2005; 57: 121–127
Sainani et al. Endothelin-1
and CAD
121
Original
Article
Role of Endothelin-1 in Genesis of Coronary Artery Disease
Gurmukh S Sainani, Vibhuti G Maru, Arun P Mehra
Departments of Biochemistry and Cardiothoracic Surgery, Jaslok Hospital and Research Centre, Mumbai
Background: The endothelial cells produce the most potent vasoconstrictor known as endothelin-1. Elevated
plasma levels of endothelin have been associated with coronary artery disease, essential hypertension and heart
failure. The aims of the present study were, to compare the plasma endothelin-1 levels in coronary artery disease
patients and healthy controls, to confirm endothelin-1 as surrogate marker for coronary artery disease and to
compare the presence of endothelin-1 like immunoreactivity in aortic and internal mammary artery specimens
obtained during coronary artery bypass graft surgery.
Methods and Results: The circulating levels of endothelin-1 were determined by enzyme-linked immunoassay
in patients of coronary artery disease (n=145) and compared with healthy controls (n=70). Tissue endothelin-1
immunoreactivity was examined by immunohistochemical method in aortic and internal mammary artery
tissue specimens obtained from 20 patients of coronary artery disease during coronary artery bypass grafting
to understand the role of endothelin in atherosclerosis. Significantly higher levels (p < 0.001) of endothelin-1
were observed in all patients of coronary artery disease as compared to healthy controls. The immunoreactivity
of endothelin-1 was localized to endothelial cell layer in internal mammary artery whereas in aortic specimens,
in addition to endothelial cell layer, immunoreactivity was seen in the cytoplasm of smooth muscle cells of
intima and media.
Conclusions: The significant increase in plasma endothelin-1 in coronary artery disease cases as compared to
healthy subjects and presence of tissue endothelin-1 immunoreactivity in smooth muscle cells of intimal as
well as medial layers of aorta confirms the role of endothelin-1 as a surrogate marker of atherosclerosis. (Indian
Heart J 2005; 57: 121–127)
Key Words: Coronary artery disease, Atherosclerosis, Endothelial dysfunction
C
ardiovascular disease and its sequelae account for
significant morbidity and mortality. Endothelial cell
dysfunction is the early and key factor in the development
of atherosclerosis. Endothelium, due to its strategic location
between the circulating blood and vascular smooth
muscles, is a primary target and mediator of cardiovascular
diseases. In healthy individuals, the predominant effect of
stimulation of the endothelium is vasodilation. But in the
presence of risk factors such as hypertension, diabetes
mellitus, dyslipidemias and smoking, an imbalance
between endothelium-derived constricting and relaxing
factors results in endothelial dysfunction. It may be the
cause or consequence of vascular disease and is a hallmark
of known cardiovascular risk factors.1
In 1988, a 21-amino acid, endothelium-derived
bioactive peptide was cloned and named endothelin (ET).2
Secretion of ET is stimulated by epinephrine, angiotensin
Correspondence: Dr Gurmukh S Sainani, 201, Buena Vista, Gen.
Jagannath Bhosle Road, Mumbai 400 021. e-mail : [email protected]
IHJ-769-04(OA).p65
121
II, vasopressin, transforming growth factor beta (TGF-β),
thrombin, interleukin-1 and hypoxia.3,4 Originally isolated
from porcine aortic endothelial cells, endothelin-1 (ET-1)
is now known to be one of a family of three mammalian
vasoactive peptides that also includes endothelin-2
(ET-2) and endothelin-3 (ET-3). Individual endothelin may
possess separate physiological or pathophysiological roles
in different target tissues. The endothelins are produced by
a variety of tissues in vivo, including lung and kidney, as
well as brain, pituitary, and peripheral endocrine tissues
and placenta.5 In contrast to ET-2 and ET-3, ET-1 is also
produced by endothelial cells; the vascular endothelium
being the most abundant source of ET-1 in vivo.6 ET-1 is
the most potent vasoconstrictor, hence for this study we
measured ET-1.
In this study, our objectives were to compare the
circulating levels of ET-1 in patients of coronary artery
disease (CAD) and healthy controls and to examine the
presence of ET-1 like immunoreactivity in aortic and
internal mammary artery specimens obtained during
6/21/2005, 2:33 PM
Indian Heart J 2005; 57: 121–127
122 Sainani et al. Endothelin-1 and CAD
coronary artery bypass graft (CABG) surgery as a possible
clue to understand the role of ET-1 as a surrogate marker
of atherosclerosis.
Methods
Venous blood samples were collected after 14 hours of
fasting in sterile, vacumed tubes containing ethylene
diamine tetra acetic acid (EDTA) as anticoagulant. Plasma
was separated within half an hour, by centrifugation for
10 min at approximately 1000 × g, aliquotted and stored
at ≤ -20° C. Repeated freeze-thaw cycles were avoided.
Plasma ET-1 was measured by quantitative sandwich
enzyme immunoassay technique using commercial kit (R
& D systems). Cholesterol, triglycerides, high-density
lipoprotein cholesterol (HDL-c) and low-density lipoprotein
cholesterol (LDL-c) were measured as routine parameters
on dry chemistry autoanalyzer (Vitros 750).
Male patients of CAD (n=145) in the age range 35-65
years, (confirmed by coronary angiography), before
commencement of any drugs for CAD, were enrolled in the
study over a period of 3 years for plasma ET-1
measurement. Out of 145 CAD subjects, 52 had single
vessel disease (SVD), 45 had double vessel disease (DVD)
and 48 had triple vessel disease (TVD). Seventy agematched male subjects were enrolled as controls. The
control subjects had no history of hypertension, diabetes
or dyslipidemia and were not on any medication. All control
subjects had negative stress test and in 15 subjects on whom
coronary angiography was done due to atypical chest pain,
angiograms were normal.
For the detection of tissue ET-1 immunoreactivity, tissue
samples from both males (n=17) and females (n=3)
undergoing CABG surgery were obtained. These 20 subjects
were in addition to above 145 cases. Their plasma ET-1
levels were not measured because they were known cases
of CAD and were taking medicines such as nitrates and
beta-blockers which affect plasma ET-1 levels.
Tissue ET-1 immunoreactivity was studied from aortic
and internal mammary artery specimens obtained during
CABG surgery from 20 subjects with TVD (mean age 57.4
± 2.95 years). The study was approved by the institutional
review committee. Informed consent was taken from all the
subjects prior to sample collection.
A three-step method consisting of the sequential
application of primary antibody, link antibody and avidinbiotin complex (ABC) method was used (Dako). The tissues
were fixed in 10% buffered formalin, dehydrated in graded
series of alcohol and embedded in paraffin blocks. Serial
sections of 6 µm thickness were taken for staining. Rabbit
IHJ-769-04(OA).p65
122
polyclonal anti-endothelin anti-serum (Pharmingen) in
1:100 dilution was used as primary antibody. As secondary
antibody, biotinylated link goat anti-rabbit antibody was
used followed by treatment with peroxidase-labeled
streptavidin. The peroxidase activity was viewed by staining
with diamino benzidine (DAB) substrate (brown staining).
The slides were counterstained with hematoxylin. As
controls, sections from human internal mammary artery
with intact endothelial cell layers were used which gave the
expected well-localized pattern within endothelial cells with
negative staining of subintimal and medial layers. The
stained slides were examined by the histopathologist in our
institution.
Statistical analysis: The differences in categorical
variables were analysed by χ 2 test. The comparison of
continuous variables was done using unpaired student’s
t test. Analysis of variance (ANOVA) followed by
Bonferroni’s post hoc analysis was used for multiple
comparison between different groups. Somer’s d statistical
analysis was used to evaluate the correlation of ET-1 level
with the number of diseased vessel. A value of p < 0.05
was considered statistically significant.
Results
The clinical features of the study population are shown in
Table 1. The χ2 analysis revealed no significant difference
between the prevalence of risk factors such as smoking,
alcohol consumption, personality type and significant
family history of cardiovascular diseases (CVD) in CAD
groups (SVD, DVD, TVD) as compared to controls. Hence
there was no bias due to these risk factors in further
analysis.
Table 2 summarizes continuous variables of the study
population. The multiple comparisons using statistical
method of ANOVA followed by Bonferroni’s post hoc method
showed no difference in the mean levels of age between all
Table 1. Comparison of categorical variables
Variables
Control
SVD
DVD
(n=70) (n=52) (n=45)
Smokers*
Alcohol consumers**
Type A personality
Positive family
history
16
26
28
21
13
23
23
18
12
15
16
14
TVD
(n=48)
χ2
p value
10
19
21
15
0.499
1.303
0.953
0.308
0.918
0.728
0.812
0.958
Variables expressed as number of subjects
*Current or past users of any types of tobacco products
** Subjects consuming at least 1-2 pegs of alcohol daily
Always remaining tense, anxious and overambitious
Positive family history of coronary artery disease in at least one of the blood relations (≤ 60 years)
SVD: single vessel disease; DVD: double vessel disease; TVD: triple vessel disease
6/21/2005, 2:33 PM
Indian Heart J 2005; 57: 121–127
Sainani et al. Endothelin-1 and CAD 123
Table 2. Comparison of continuous variables
Age (years)
BMI (kg/m2)
ET-1 (pg/ml)
Control
(n=70)
51.0 ±7.66
25.0 ±2.36
0.57 ±0.19
SVD
(n=52)
DVD
(n=45)
TVD
(n=48)
p value
53.0 ± 6.88 52.5 ±8.69 52.4 ±6.92 0.407
24.5 ±2.74 26.1 ±2.74 25.2 ±2.82 0.031
0.84 ±0.29 0.88 ±0.29 0.89 ±0.29 <0.001
% Subjects
Variables
Variables expressed as mean±SD
SVD: single vessel disease; DVD: double vessel disease; TVD: triple vessel disease;
BMI: body mass index; ET-1: endothelin-1
IHJ-769-04(OA).p65
123
Con
n1
n2
14
56
SVD
DVD
TVD
29
23
34
11
33
15
χ2
p value
51.36
<0.001
Fig. 1. Comparison of number of subjects having ET-1 levels above median
level in different CAD groups (Bartholomew’s test).
n1: number of subjects having values above median level (0.77 pg/ml)
n2: number of subjects having values below or equal to median level
Con: controls; SVD: single vessel disease; DVD: double vessel disease; TVD:
triple vessel disease; ET-1: endothelin-1; CAD: coronary artery disease
to detect a difference of at least 0.23 using the Bonferroni
(with control) multiple comparison test at a 0.05
significance level. The common standard deviation within
a group is assumed to be 0.20. However, there was no
significant difference in ET-1 levels between UAP group,
SAP group and NA group (Fig. 2).
Smoking, hypertension, diabetes mellitus and
1.4
1.2
Concentration (pg/ml)
the four study groups. However, ANOVA showed significant
difference (p = 0.031) in mean levels of body mass index
(BMI) between these groups. Bonferroni’s post hoc method
showed significant increase in BMI level in DVD cases as
compared to SVD subjects (p = 0.02, 95% CI 0.169, 3.064).
However, there was no significant difference in BMI
amongst other study groups. There was significant increase
(p < 0.001) in mean ET-1 level in all the grades of CAD i.e.
SVD [p<0.001, 95% confidence interval (CI) -0.198,
0.143], DVD (p<0.001, 95% CI –0.446, 0.180) and TVD
(p<0.001, 95% CI –0.456, 0.195) as compared to controls.
In this single factor ANOVA study, the total sample of 215
subjects achieved 95% power to detect a difference of at
least 0.23 using the Bonferroni (with control) multiple
comparison test at a 0.05 significance level. The common
standard deviation within a group is assumed to be 0.19.
However, Bonferroni’s post hoc method showed no
significant difference amongst the three groups of CAD
cases (SVD, DVD and TVD). The correlation of the median
level of plasma ET-1 (calculated from the total study
population, 0.77 pg/ml) with number of diseased vessels
i.e. with different grades of CAD with χ2 analysis using the
Somer’s d statistical method showed significant positive
association of plasma ET-1 levels with the number of
diseased vessels. χ2 analysis using Bartholomew’s test for
proportions also showed that the number of subjects having
ET-1 level > 0.77 pg/ml increased significantly (χ2 = 51.3,
p < 0.001) with increase in number of diseased vessels
(Fig. 1). This analysis can detect increasing trend with
power of 100%.
The statistical analysis performed by method of ANOVA
followed by Bonferroni’s adjustment showed significant
increase in ET-1 levels in CAD subjects grouped as per their
clinical presentation i.e. in subjects having unstable angina
pectoris (UAP) (0.89 ± 0.31, n=52, p < 0.001, 95% CI
0.231, 0.408), subjects having stable angina pectoris (SAP)
(0.86 ± 0.26, n=56, p < 0.001, 95% CI 0.206, 0.373) and
subjects with no angina (NA) but with symptoms of angina
equivalent (0.86 ± 0.28, n = 37, p < 0.001, 95% CI 0.201,
0.379) as compared to controls. In this single factor ANOVA
study, the total sample of 215 subjects achieved 95% power
1.0
0.8
0.6
0.4
0.2
0
Fig. 2. Diagram showing comparison of ET-1 levels between different groups
of CAD according to clinical presentation and control group.
Values expressed as mean ± SD
CON : controls, n=70; UAP : unstable angina pectoris, n = 52; SAP : stable
angina pectoris, n=56; ET-1: endothein-1; CAD: coronary artery disease;
NA : no angina, n = 37
dyslipidemia are major risk factor for CVD. The comparison
of mean ET-1 levels between smokers (n = 16) and nonsmokers (n = 54) in control group using unpaired student's
t test showed significant rise (p = 0.045, 95% CI 0.005,
0.215) in plasma ET-1 levels in smokers as compared to
non-smokers. Group sample sizes of 16 and 54 achieved
6/21/2005, 2:33 PM
Indian Heart J 2005; 57: 121–127
124 Sainani et al. Endothelin-1 and CAD
50% power to detect a difference of 0.1. A study with larger
sample size is required to achieve increase in power of
detection. In CAD group, there was no significant difference
(p = 0.364) in ET-1 levels between smokers (n = 35) and
non-smokers (n = 110) (Fig. 3). None of the control subjects
had hypertension, diabetes or dyslipidemia. When CAD
subjects were sub-grouped with respect to all these risk
factors, and compared using student’s t test, no significant
difference in ET-1 levels was seen between diabetics versus
non-diabetic subjects, normotensive versus hypertensive
subjects and normolipidemic versus dyslipidemic subjects
as seen in Table 3. In many subjects there were multiple
risk factors, hence the comparison of ET-1 levels with
respect to one risk factor may be masked by presence of
other risk factors.
Tissue ET-1-immunohistochemical staining in aortic
specimens confirmed that ET-1 like immunoreactivity was
not only localized in endothelial cells but was also seen in
the cytoplasm of the intimal and medial vascular smooth
muscle cells suggesting the involvement of ET-1 in
neovascularization and smooth muscle cell proliferation
associated with atherosclerosis (Fig. 4). In contrast, in
sections taken from internal mammary artery specimens,
where there was no atherosclerosis, mild brown staining
was seen only in endothelial cells, but not in the cytoplasm
of the vascular smooth muscle cells (Fig. 5).
Table 3. Comparison of ET-1 levels between subjects with
and without cardiovascular risk factors in CAD group
Characteristics
Non-diabetic (n = 103)
Diabetics* (n = 42)
Normotensive (n = 92)
Hypertensive** (n = 53)
Normal lipids (n = 26)
Dyslipidemia (n = 119)
Mean ± SD
t
p value
0.87 ± 0.29
0.86 ± 0.30
0.87 ± 0.30
0.86 ± 0.28
0.82 ± 0.28
0.88 ± 0.29
0.199
0.842
0.193
0.847
0.960
0.338
* Documented cases
**Systolic blood pressure ≥ 140 mmHg, Diastolic blood pressure ≥ 90mmHg
Total cholesterol >200 mg/dl, triglycerides >150 mg/dl, LDL >130 mg/dl, HDL
< 40 mg/dl
ET-1: endothelin-1, CAD: coronary artery disease, LDL: low-density lipoprotein;
HDL: high-density lipoprotein
Fig. 4. Photomicrographs of immunostaining of sections of aorta removed from
subject undergoing CABG, stained with DAB substrate, as seen under
magnification of 25×. Black arrows show brown immunostaining of ET-1. Note
the strong staining of endothelial cells and cytoplasmic staining of intimal as
well as medial smooth muscle cells. The staining suggests very high grade of
endothelial cell dysfunction.
CABG: coronary artery bypass graft surgery; DAB: diamino benzidine;
ET-1: endothelin-1
1.4
1.2
1.0
0.8
Non-smokers
Smokers
0.6
0.4
0.2
0
CONTROL
CAD
Fig. 3. Diagram showing comparison of non-smokers versus smokers in control
and CAD group.
Values expressed as mean ± SD
CAD: coronary artery disease
IHJ-769-04(OA).p65
124
Fig. 5. Photomicrographs of immunohistochemical staining of sections of
internal mammary artery with intact endothelial cells, stained with DAB
substrate, as seen under magnification of 25×. Black arrow shows brown
immunostaining of ET-1 which is seen only in endothelial cells, not in cytoplasm
of smooth muscle cells.
DAB: diamino benzidine; ET-1: endothelin-1
6/21/2005, 2:33 PM
Indian Heart J 2005; 57: 121–127
Discussion
Endothelial dysfunction has been implicated as a major
event in the pathogenesis of atherosclerosis. So, there is
considerable scope for research in diagnostic assays for the
assessment of endothelial function. Elevated plasma levels
of ET-1 have been associated with CAD, essential
hypertension and heart failure, 7-13 where endothelial
dysfunction is the key factor.
In the present study, plasma ET-1 levels were determined
in CAD patients and compared with normal subjects. The
number of subjects having high levels (higher than median)
of ET-1 increased with number of diseased vessels showing
significant positive correlation with grade of CAD. Our
results are in agreement with the findings of other
researchers who also found increase in ET-1 in different
stages of CAD.7-9
Lerman et al.7 reported significantly elevated levels of
ET-1 in 40 patients with atherosclerosis of various arteries
(aortic, coronary, renal and peripheral) as compared to 100
normal subjects. There was a significant correlation
between plasma ET-1 and the number of sites of disease
involvement (r = 0.89, p < 0.001). Salomone et al. 8
reported significant rise in ET-1 in cases having chronic
stable angina with angiographically documented CAD and
chronic stable angina cases having normal angiogram as
compared to normal subjects. ET-1 was also found to be
correlated with severity of the disease (r = 0.25, p = 0.04)
and number of stenoses (r = 0.36, p = 0.002). Kaski et al.9
compared plasma ET-1 levels in 54 patients with angina
pectoris who underwent baseline testing of
electrocardiography (ECG), stress test, two-dimensional
echocardiography (2D echo), thallium stress test and
coronary angiography and 21 healthy control subjects. The
plasma ET concentrations were significantly higher in
patients compared with control subjects. Borries et al.10
determined ET-1 in patients with stable angina, unstable
angina and healthy subjects. The concentration of ET-1 of
the patients with SAP and UAP were significantly higher
than that of healthy controls. These results were similar to
our findings.
However, other researchers did not find significant
difference in their studies. Yasuda et al.11 and Stewart et
al.13 in their comparative study of patients with SAP with
controls did not find significant difference in ET-1 levels.
This could be due to their small sample size. Our sample
size was much larger, hence we found significant increase
in plasma ET-1 levels in CAD subjects having stable angina
as compared to controls. Table 4 shows an overview of the
results of studies conducted in different countries. Our
IHJ-769-04(OA).p65
125
Sainani et al. Endothelin-1 and CAD 125
results are in agreement with majority of studies (4 out of
6 studies) which point to the importance of ET-1 as a
surrogate marker of CAD.
Table 4. Overview of results from different studies
Authors
Lerman et al.7
Salomone et al.8
Kaski et al.9
Borries et al.10
Yasuda et al.11
Stewart et al.13
Sainani et al.14
Present study
Country
Number of subjects
USA
UK
40 atherosclerosis / 100 Con
65 SAP with CAD / 49 Con
11 SAP (normal CAG) / 49 Con
UK
54 CAD / 21 Con
Germany
20 SAP / 11 Con
12 UAP / 11 Con
Japan
10 SAP / 25 Con
Canada
7 SAP / 22 Con
India
145 CAD / 70 Con
India
52 UAP / 70 Con
56 SAP / 70 Con
p value
<0.001
<0.001
<0.01
<0.01
<0.01
<0.001
> 0.05
> 0.05
<0.001
<0.001
<0.001
SAP: stable angina pectoris; Con: controls; CAD: coronary artery disease;
CAG: coronay angiogram; UAP: unstable angina pectoris
Cigarette smoking is a well-known risk factor for the
development of CVD. The experiment carried out by Sainani
et al.14 on cigarette smoke extracts indicated that it induces
oxidation of LDL which is the initial stage of endothelial
dysfunction. In our study, smokers and non-smokers were
compared in control group to ascertain the effect of smoke
on endothelial dysfunction. Our results showed that there
was a significant increase (p = 0.045) in ET-1 levels in
smokers (n = 16) as compared to non-smokers (n = 54) in
control group. Our results were in agreement with the work
done by Orem et al.15 who measured plasma ET-1 in 24
males who had no coronary atherosclerotic lesions
established by coronary angiography. They also reported
higher plasma ET-1 concentration in patients who were
smokers than those who were non-smokers. All these
results suggest an increase in ET-1 in a very early stage of
endothelial dysfunction before actual disease manifests.
However, we did not find any significant difference between
smokers and non-smokers in CAD cases possibly because
atherosclerosis in CAD cases in both smokers and nonsmokers was already established. Thus, ET-1 seems to be
an important early marker of endothelial dysfunction,
which is a key factor for atherogenesis.
Autocrine action of ET-1 is well established. Not only
do the vascular endothelium but, under certain conditions,
smooth muscle cells also generate ET-1.16
In our study, we found significant staining in
endothelial cells as well as in cytoplasm of subintimal and
medial smooth muscle cells in aorta specimens from
subjects who had TVD, and had undergone CABG surgery.
In sections taken from internal mammary artery, staining
was localized only in endothelial cells and that was also
not as significant as seen in endothelial cells of aorta.
6/21/2005, 2:33 PM
126 Sainani et al. Endothelin-1 and CAD
Lerman et al.7 studied ET-1 like immunoreactivity in
atheromatous aortic tissues obtained from 5 subjects
undergoing CABG and Zeiher et al. 17 studied it from
atherectomy specimens obtained from subjects undergoing
percutaneous transluminal coronary angioplasty (PTCA)
and found similar results. The results obtained from all these
studies including ours highlight the role of ET-1 in
atherosclerosis. As mentioned earlier, ET-1 is not only
released from the vascular endothelium, but under certain
conditions, is also generated by smooth muscle cells. The
presence of ET-1 like immunoreactivity in endothelial cells
and also in vascular smooth muscle cells shows that this
peptide is involved in neovascularization and smooth
muscle cell proliferation associated with atherosclerosis.
Minamino et al.18 examined the expression and localization
of endothelin-converting enzyme-1 (ECE-1), the final key
enzyme of ET-1 processing, in human atherosclerotic
lesions and found that the patterns of ECE-1 localization
resemble those of ET-1 localization described in previous
study by Lerman et al.6 Ihling et al.19 performed qualitative
and quantitative immuno-histochemistry in normal
internal mammary arteries (n = 10), in coronary arteries
with adaptive intimal fibrosis (n = 10), in aortic fatty streaks
(n = 10) and in distinct regions of advanced carotid plaques
(n = 15). They reported that together with ET-1, ECE-1 was
abundantly present in human arteries and the upregulation of ECE-1/ET-1 system was closely linked with
the presence of chronic inflammation, and was present in
very early stages of plaque evolution. Their findings
suggested that enhanced production of active ET-1 may
substantially contribute to cell growth and the regulation
of vascular tone in advanced atherosclerotic lesion as well
as in the very early stages of plaque evolution, when a
plaque is still imperceptible clinically.
The measurement of circulating ET-1 in our population,
where prevalence of CAD is increasing day by day, would
be helpful in diagnosing endothelial cell dysfunction at a
very early stage, thereby helping in implementing
preventive measures. Early detection of endothelial cell
dysfunction, which is seen in this study, in smokers with
no apparent cardiac problem, may be a useful measure to
guide therapy prior to the development of symptomatic
atherosclerosis.
Conclusions: Measurement of ET-1 in smokers above 35
years can give an early and useful clue about endothelial
cell dysfunction if the ET-1 levels are raised. Such persons
should be advised specifically regarding prevention of CAD
by diet and lifestyle modification. Many challenging issues
still remain unsolved, and therefore, the endothelium at
IHJ-769-04(OA).p65
126
Indian Heart J 2005; 57: 121–127
both the molecular and cellular levels must be further
studied for both research and clinical interests.
Acknowledgements
We are grateful to the Managing Trustee of Jaslok Hospital
and Research Centre, Seth MK Chanrai, members of
scientific advisory committee, Research Director - NH
Wadia and former Research Director - MG Deo for providing
us with necessary facilities, the financial support for the
project and valuable suggestions for undertaking the
research project at this centre.
We express our gratitude to AB Mehta, Director,
Cardiology Department, Jaslok Hospital and Research
Centre, the entire team of Cardiologists and the staff of
Cardiology Department for their help in providing patients
and coronary angiography reports for the study and to SR
Khubchandani, Head, Histopathology and Electron
Microscopy Department, for examining the tissue samples.
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128 Kasliwal
et al.
Original
Article
Indian Heart J 2005; 57: 128–137
Three-Dimensional Echocardiography
Real-Time Three-Dimensional Transthoracic
Echocardiography
Ravi R Kasliwal, Nagendra S Chouhan, Ashish Sinha, Pankaj Gupta, Sharad Tandon, Naresh Trehan
Escorts Heart Institute and Research Centre, New Delhi
Background: Complex anatomy of intra-cardiac structures requires spatial orientation of image in three
dimensions for better understanding and enhanced image interpretation. We evaluated the feasibility and efficacy
of the emerging ‘real-time three-dimensional transthoracic echocardiography’ technique for comprehensive
assessment of cardiac anatomy, physiology, pathomorphology and pathophysiology in patients with structural
heart disease.
Methods and Results: Patients with structural heart disease (n=152) were evaluated by conventional twodimensional transthoracic echocardiography and real-time three-dimensional transthoracic echocardiography
using standard protocol. Fifty-six cases were of rheumatic etiology with multi-valvular involvement (mitral
stenosis: 32; mitral regurgitation: 29; tricuspid regurgitation: 8; aortic valve disease: 11) and 21 cases of nonrheumatic valvular heart disease. A total of 38 congenital heart disease patients were examined including 23
patients with atrial septal defect. Left ventricular function (n=20) and right ventricular function (n=10) were
also assessed using dedicated software.
Conclusions: Results of real-time three-dimensional transthoracic echocardiography mitral valve area assessment
by planimetery are comparable to two-dimensional transthoracic echocardiography with additional information
about surface anatomy of leaflets and the subvalvular apparatus in real time with clear demarcation of commissural
fusion and scallops of leaflets. Enface view of atrial septal defect with direct visualization of shape, size and number
of defects, tricuspid valve area by planimetery, right ventricular shape, objective assessment of ventricular volumes
and regurgitation vena contracta area are the fields where three-dimensional transthoracic echocardiography
was of additive value to conventional two-dimensional transthoracic echcardiography. This study proves clinical
feasibility of real-time three-dimensional transthoracic echocardiography but requires further validation of
quantitative observations. (Indian Heart J 2005; 57: 128–137)
Key Words: Echocardiography, Congenital heart disease, Valvular heart disease
C
onventional two-dimensional (2D) echocardiography
requires mental conceptualization of a series of
multiple orthogonal planar or tomographic images into an
imaginary multidimensional reconstruction for better
understanding of complex intra-cardiac structures and
their spatial relation with surroundings. The emerging
three-dimensional (3D) echocardiographic imaging
technique is a major step ahead toward the final goal of
complete visualization and comprehensive assessment of
cardiac anatomy, physiology, pathomorphology and
pathophysiology in real-time, which could potentially
facilitate image interpretation and reduce inter-observer
Correspondence: Dr Ravi R Kasliwal, Director, Non-Invasive Cardiology
Escorts Heart Institute and Research Centre, Okhla Road
New Delhi 110025
e-mail: [email protected]
IHJ-794-04(OA).p65
128
variability.1 Historically, 3D echocardiography started in the
early 90’s and is based on serial acquisition of 2D images2
but limitations like electrocardiographic (ECG) and
respiratory gating, motion artifacts, time consuming offline reconstruction and analysis restricted its use only as a
research tool. In recent past, various studies have
demonstrated the potential clinical applicability of newer
generation real time 3D echocardiography with advances
in technique for image acquisition and digital data
processing in non-invasive evaluation of heart diseases.3-4
Furthermore, real-time 3D echocardiography is the only
on-line 3D method based on real time volumetric scanning,
as compared with other 3D imaging techniques such as
magnetic resonance imaging (MRI) and computed
tomography (CT), which are based on post-acquisition
reconstruction and not on volumetric scanning.
6/21/2005, 2:35 PM
Indian Heart J 2005; 57: 128–137
We report our experience of first 152 cases done on real
time 3D transthoracic echocardiographic (3DTTE)
imaging system in different cardiac conditions and its
incremental value over conventional 2D transthoracic
echocardiography (2DTTE) in assessment of intra-cardiac
anatomy and clinical decision making.
Kasliwal et al. Three-Dimensional Echocardiography 129
intra-cardiac structures from different sides (Fig. 2A, 2B).5
Methods
Study population: Real-time 3DTTE was performed in
152 patients in our Institute (age range 2-71 years) with
structural heart diseases diagnosed on 2DTTE. 2DTTE was
performed using a Sonos 5500 (Philips Medical Systems,
USA) ultrasound system and 2.5 and 8 MHz transducer
capable of providing real time B mode and color Doppler
image. Clinical impression made from review of real time
3DTTE and 2DTTE obtained at the same visit were
compared for final assessment by two independent, blinded
echocardiographers.
3DTTE data acquisition and analysis: In all patients
3DTTE images were obtained from standard parasternal,
apical and sub-costal windows using a Sonos 7500 Live
3D Echo (Philips Medical Systems, USA) ultrasound system.
Method of data acquisition was based on recommendations
of Adhoc 3D Echo Protocol Working Group endorsed by
the International Society of Cardiovascular Ultrasound.5
Data analysis was performed using integrated tools for
advanced image processing to obtain views with details of
endocardial and valvular surfaces and their relationship
with adjoining structures. Quantitative assessment was
performed on a dedicated personal computer using
dedicated software capable of measuring three-dimensional
data sets.
Qualitative analysis: These 3DTTE images were analyzed
using integrated software system by cropping in three
different color-coded cutting planes perpendicular to each
other (Fig. 1A). Besides these cutting planes, an additional
oblique plane capable of cropping the image in any desired
angulation was also used. This particular plane is
advantageous in assessing the intra-cardiac structures
placed at an angle other than the perpendicular one
(Fig. 1B). One single 3D data set acquired in any possible
view is good enough to get all the conventional 2D views
[short axis (Fig.1B), three-chamber (Fig.1C) and fourchamber (Fig.1D)].The echocardiographic images were
sectioned to obtain the desired cut planes. Brightness,
contrast and color mapping were adjusted to obtain the
optimal image quality. These acquired real-time and full
volume cine images can be rotated in space to visualize
IHJ-794-04(OA).p65
129
Fig. 1. Full volume three-dimensional transthoracic echocardiographic image
has been obtained from apical window by acquiring four ECG triggered sequential
data sets. Full volume 3D data set has been shown with three orthogonal cutting
planes depicted by lines in the cube (A). The same image has been cropped from
apex to base of heart using oblique cutting plane to obtain the modified short
axis view which was not perpendicular to the orthogonal cutting plane (B). The
same image has been cropped using three orthogonal cutting planes to obtain
the conventional four-chamber view with clear visualization of four cardiac
chambers and two atrioventricular valves (arrow) (C). Conventional threechamber view with clear visualization of aortic mitral relationship. Arrowhead
shows closed aortic valve (D).
Quantitative analysis: The acquired 3DTTE data sets
were stored on CD-ROM in DICOM format and transferred
to a separate workstation for off-line data analysis.
Quantitative analysis was done using dedicated software
analysis systems (QLAB Advanced Quantification software,
version 3.0, Philips Ultrasound, USA, and Tomtec 4D
Cardio-view, version 1.2, Tomtec, Gmbh, Germany) for
measurement of distance, area, volumes and angles.6,7
Quantitative assessment of valve area: For planimetery
assessment of valve area, conventional 2DTTE short-axis
view and 3DTTE images were acquired from any available
window. Measurements were done using off-line analysis
software (QLAB Advanced Quantification software, version
3.0) which provides a 3D cine image along with
corresponding 2D images in three modifiable cutting
planes. These planes were aligned to the axis of valve
opening plane to get short axis image in the plane of
shortest valve area enface. Results were compared.
6/21/2005, 2:35 PM
130 Kasliwal et al. Three-Dimensional Echocardiography
Indian Heart J 2005; 57: 128–137
dyssynchrony could also be detected and analyzed by the
segmental time-volume curve.
Right ventricular volume and EF analysis was performed
on optimal 3D images encompassing the complete right
ventricle (RV) volume using Tomtec Cardio-view software.
The images were cropped in three orthogonal cutting planes
to obtain best possible image of RV in long axis. Endocardial
borders were manually traced in eight contiguous
volumetric slices of tagged end-systolic and end-diastolic
frames with formation of volume-rendered holographic
cast. End-systolic volume, end-diastolic volume and EF were
calculated from these images.7
Fig. 2. Real time 3DTTE data set taken from parasternal window showing mitral
valve (zoomed) viewed from left ventricular side (A) and LA side (B) showing
the surface of the thickened anterior and posterior mitral leaflet. The cropped
3D image obtained from apical window to show the thickened mitral valve with
unfused commissures (arrowheads) and three scallops of anterior mitral leaflet
A1, A2 and A3 (black arrows) (C). Full volume 3D data set acquired from
parasternal window. Anterolateral left ventricular wall was cropped to visualize
mitral apparatus with subvalvular structures. Arrowheads point to the thickened
chordae (D).
3DTTE: three-dimensional transthoracic echocardiography
Quantitative assessment of atrial septal defect (ASD):
Consecutive patients diagnosed to have ASD with 2DTTE
were enrolled in the protocol of transcatheter device
closure. ASD shape, number and dimensions (major
diameter D1, minor diameter D2 and area) were determined
by 2DTTE, 2DTEE and 3DTTE. During transcatheter
closure, balloon occlusive diameter (BOD) which was
regarded as the gold standard for selection of the size of
any device,8-10 was measured using standard technique and
was correlated with echo-derived measurements by
different techniques.
Quantitative assessment of ventricular volumes: Left
ventricular volume analysis was done using a semi
automated border detection software (Tomtec 4D LV
Analysis v.1.2, Tomtec, Gmbh, Germany). The original
3DTTE pyramidal volume, acquired encompassing the
complete left ventricle (LV), was used to calculate global as
well as segmental volumes, actual stroke volume and
ejection fraction (EF). EF was calculated off-line from timevolume curve of entire reconstructed cast. This cast can be
subdivided into conventional 17 segment model of LV with
estimation of individual segmental motion and volumes in
time-volume curve.11 Wall motion abnormalities and LV
IHJ-794-04(OA).p65
130
Statistical analysis: In patients of mitral stenosis,
measurements of maximal area obtained by 2DTTE, 2DTEE
and 3DTTE, and in patients of ASD maximal diameter and
area obtained by 2DTTE, 2DTEE, 3DTTE and cardiac
catheterization were compared using linear regression
analysis, paired t test for continuous variables, and
calculation of the mean difference. A p value < 0.05 was
considered statistically significant. Inter-observer and intraobserver variabilities for 3D measurements were
determined in all studies.
Results
A total of 152 patients studied included valvular heart
disease (n=77), congenital heart disease (n=38), ischemic
and non-ischemic cardiomyopathy (n=20) and other
miscellaneous cardiac anomalies (n=17). The average time
required for data acquisition including patient preparation
was 8.2±2.1 min and for analysis 20.3±6.8 min.
Valvular heart disease: 3D echocardiography gives
additional information about surface anatomy of cardiac
valves and their relation with surroundings in real time
which was found to be useful in assessing the functional
and anatomical integrity of the valve by partly overcoming
the limitations of 2D study especially in patients with poor
acoustic windows.
Mitral valve: In our study of 32 patients (12 females, mean
age 36.45±8.88 years) with rheumatic mitral stenosis,
assessment of mitral valve area was done using
conventional 2DTTE short-axis view and 3DTTE image
acquired from any available window. Mitral valve area was
measured with greater confidence by 3DTTE planimetery
with additional information about commissural fusion and
scallops of leaflets (Fig. 2) with clear demarcation of surface
anatomy of leaflets and the subvalvular apparatus
(Fig. 2). 3DTTE-derived planimetry mitral valve area
(MVA) (Fig. 3) had a good correlation with conventional
6/21/2005, 2:35 PM
3D MVA
Fig. 4. Comparison between three-dimensional and two-dimensional transthoracic echocardiography PHT-derived MVA.
MVA: mitral valve area; PHT: pressure half time
2D MVA Planimetery
2DTTE methods (3DTTE planimetry MVA and 2DTTE
planimetry MVA, r=0.985; 3DTTE MVA and 2DTTE
pressure half time MVA, r=0.965) (Figs 4 and 5). It was
also found that 3DTTE valve area correlated better with
smaller MVA value derived from two different 2DTTE
methods (r=0.987) (Table 1). Inter-observer and intraobserver variability was good for 3DTTE (r=0.93 and 0.96
for mitral valve area). In seven patients who underwent
balloon mitral valvotomy (BMV), 3DTTE provided images
with spitted commissures and it was possible to measure
splitting width objectively. Leaflet tears, if any, were also
better visualized.
On evaluating 29 patients with mitral regurgitation
(MR) it was possible to visualize entire regurgitant jet with
its varied asymmetrical shapes with actual calculation of
regurgitant orifice area. It was also observed that vena
contracta was not a circular structure as assumed earlier,
but rather with varied geometric shapes (Fig. 6A, 6B).
Kasliwal et al. Three-Dimensional Echocardiography 131
2D MVA PHT
Indian Heart J 2005; 57: 128–137
3D MVA
Fig. 5. Comparison between three-dimensional and two-dimensional transthoracic echocardiography (planimetery)-derived MVA.
MVA: mitral valve area
Table 1. Correlation between 3DTTE and 2DTTE mitral
valve area measurements
Fig. 3. Full volume three-dimensional data set has been obtained from apical
window shown with three orthogonal cutting planes (D) along with
contemporary two dimensional images in respective planes (A), (B) and (C).
The 'C' cutting plane was aligned to the opening plane of mitral valve in ‘A’ and
‘B’ images to visualize the shortest mitral valve opening area (arrowhead) in
image ‘C’ for measurement.
Prosthetic heart valves: Ten patients with prosthetic heart
valve were also studied. In 2 patients with bioprosthetic
valves at mitral and aortic positions respectively, we were
able to delineate actual site, size and shape of the
paravalvular leak and its relation to the surrounding
structures while evaluating for the feasibility of putting a
IHJ-794-04(OA).p65
131
Measurement
Mean Diff.
(mm)
r
SEE
Equation
p value
2D PHT MVA
v. 3D
planimetry MVA
0.129
0.965
0.051
y=0.874x + 0.041
<0.0001
2D planimetry
MVA v. 3D
planimetry MVA
0.069
0.985
0.035
y= 0.924x+ 0.029
<0.0001
2D minimum
MVA v. 3D
planimetry MVA
0.020
0.987
0.033
y=0.937x + 0.059
<0.0001
3DTTE: three-dimensional transthoracic echocardiography; 2DTTE: twodimensional transthoracic echocardiography; Mean Diff: mean difference; SEE:
standard error of estimation; PHT: pressure half time; MVA: mitral valve area
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Indian Heart J 2005; 57: 128–137
132 Kasliwal et al. Three-Dimensional Echocardiography
percutaneous closure device (Fig. 6C, 6D). In 8 cases of
metallic prosthetic valve, this technique was not very useful
except in 2 cases where we were able to identify left atrial
appendage clots. An innate limitation of all ultrasound
systems is that they cannot pass through metal.
Tricuspid valve: Tricuspid valve area was evaluated in 17
patients (9 cases of rheumatic and 8 cases of nonrheumatic tricuspid valve disease). Real time 3DTTE was
clearly superior to 2DTTE and even two-dimensional
transesophageal echocardiography (2DTEE) by providing
enface view of all leaflets at any point in cardiac cycle by
single acquisition (Fig. 7A, 7B, 7C, 7D). Planimetry of
tricuspid valve area, details of subvalvular structures and
tricuspid regurgitation vena contracta area were calculated
as for mitral valve disease, and were highly reproducible.
Fig. 6. 3D volume data set showing mitral regurgitant jet from native (A) and
bioprosthetic mitral valve. Image ‘A’ has been cropped to level-1 (level of vena
contracta) (arrowhead) to highlight its irregular shape (B). Image ‘C’ shows
bioprosthetic mitral valve viewed from left ventricular side with clear visualization
of three struts (arrowhead) and an echolucent area (arrow) outside the valve
opening area (C). Three-dimensional data set of same valve with regurgitant jet
of paravalvular leak arising from echolucent area with clear delineation of shape
and size (arrow) (D).
Atrial septal defects: 3DTTE evaluation of 24 cases of
ASD provided unique enface views of the defect from the
right atrial (RA) as well as left atrial (LA) sides and its spatial
orientation with information about adequacy of rims for
device closure and its relation to surrounding structures
(Fig. 8A). In our preliminary study of 10 consecutive
patients having 11 ASDs (one patient had 2 ASDs) (9
females, mean age 31.25±4.99 years), compared with
conventional echocardiographic methods, 3DTTE-derived
maximum ASD diameter had best correlated with the
invasively determined BOD (3DTTE r = 0.930, p ≤0.0001,
2DTEE r = 0.927, p ≤0.0001, 2DTTE r = 0.921, p
=0.0002). 3DTTE-derived ASD area also best correlated
with the invasively determined BOD (3DTTE r = 0.926,
2DTEE r = 0.870) (Table 2) (Figs 9 and 10). Inter-observer
and intra-observer variability were good for 3DTTE
(r=0.91and 0.94 for ASD diameter, r=0.90 and 0.95 for
ASD area). Post-procedure assessment of ASD device also
gives details about shape and position of device in situ and
shows its proper placement (Fig. 8B).
Table 2. Correlation between BOD and other ASD size
measurements
Measurement
Fig. 7. The 3DTTE pyramidal section has been cropped using oblique plane to
show enface view of all the three leaflets of the tricuspid valve in different diastolic
phases. A: Closed tricuspid valve, B: Early diastole, C: Mid diastole, D: Late
diastole.
3DTTE: three-dimensional transthoracic echocardiography
IHJ-794-04(OA).p65
132
Mean Diff.
(mm)
r
SEE
Equation
p value
2DTTE dia v. BOD
0.670
0.921
0.126 y=0.844x + 0.946
2DTEE dia v. BOD
0.327
0.927
0.114 y=0.848x + 0.632 <0.0001
3DTTE dia v. BOD
0.027
0.930
0.115 y=0.871x + 0.277 <0.0001
2DTEE area v.
Cath area
3DTTE area v.
Cath area
2.321
0.870
0.242 y=1.281 x + 1.652
1.599
0.926
0.200 y =1.468 x + 0.148 <0.0001
0.0002
0.0005
BOD: balloon occlusive diameter; ASD: atrial septal defect; Mean Diff: mean difference; SEE: standard
error of estimation; 2DTTE: two-dimensional transthoracic echocardiography; 2DTEE: twodimensional transesophageal echocardiography; 3DTTE: three-dimensional transthoracic
echocardiography; Cath area: balloon occlusive area
6/21/2005, 2:35 PM
Kasliwal et al. Three-Dimensional Echocardiography 133
3D ASD area
Indian Heart J 2005; 57: 128–137
Cath ASD area
Fig. 10. Comparison between balloon occlusion diameter (BOD) and threedimensional transthoracic echocardiography-derived atrial septal defeat (ASD)
area.
3D ASD Dia
Fig. 8. Three-dimensional echocardiographic images in congenital heart disease:
atrial septal defect enface view (arrowhead) with 2D reference image visualizing
the actual shape of defect and its relation with surrounding structures (A), same
patient with Amplatzer device in situ (B). Enface view of cleft mitral valve (C)
and ventricular septal defect (arrow) and its relation with surrounding structures
i.e. aortic valve, mitral annulus (arrowhead) (D).
3D MVA
BOD
Fig. 9. Comparison between balloon occlusion diameter (BOD) and threedimensional transthoracic echocardiography-derived maximal atrial septal defect
diameter.
Other congenital heart diseases: Two cases of cleft
mitral valve were done on 3DTTE with clear delineation of
the cleft, its edges and position (Fig. 8C) and was well
correlated with intra-operative visualization. Other
congenital heart disease cases studied included 3
ventricular septal defects (Fig. 8D), 2 patent ductus
arteriosus, 2 sinus of valsalva aneurysms, 2 Ebstein
anomaly, and 4 cases of supra-mitral ring. In these complex
congenital lesions, 3DTTE had given additional information
by providing the spatial orientation of the anatomical
structures.
IHJ-794-04(OA).p65
133
Intra-cardiac masses: We evaluated 2 left atrial myxomas, 1 right atrial myxoma, 1 tricuspid valve tumor and
2 cases each of LV thrombus, left atrial thrombus and a
large LV hydatid cyst. In 2 cases of LV thrombus it was
possible to section the thrombus sequentially. Initially the
thrombus was a solid structure and on follow-up, central
liquefaction with gradual resolution and fibrous septa
formation was observed. One patient had a large cystic mass
in LV cavity, in which on systematically cropping the 3D
pyramidal data set, we were able to see grand daughter cyst
budding from the inner wall of the large cyst which helped
us in arriving at a definite diagnosis of hydatid cyst.
Ventricular functions: In our preliminary assessment
from 20 cases of cardiomyopathy for evaluation of LV
function using 3DTTE, it was feasible to objectively assess
EF in routine clinical practice. Off-line analysis was done
on Tomec software, which required 10.2±2.4 min. LV
volumes during complete cardiac cycle were depicted in a
time-volume curve with sequential change with time. It also
gives information about segmental contribution to the EF
and segmental wall motion in a time-volume curve. By
analyzing these superimposed time-volume curves of 16
conventional ventricular segments, assessment of
ventricular synchrony can also be done along with
identification of individual segments which contract late
(Fig. 11).
Evaluation of RV volume and shape was undertaken in
10 cases of pulmonary hypertension (PHTN) (PA pressure
= 67±30 mmHg). Off-line assessment of global and
segmental RV cavity area along with RV end-systolic, enddiastolic volumes and RVEF was done using dedicated
software (Tomtec 4D Cardio-view, version 1.2, Tomtec,
Gmbh, Germany) (Fig. 12). Patients with PHTN had greater
RV volumes and RV end-diastolic diameters than normal
individuals.
6/21/2005, 2:35 PM
134 Kasliwal et al. Three-Dimensional Echocardiography
Fig. 11. A surface-rendered LV cast obtained using dynamic reconstruction of
the LV after semi-automated border analysis of the long-axis views (A) from
corresponding 4-chamber view (B). The bull’s-eye display (C) is depicted in
different shades for individual regions for wall motion analysis. Segmental timevolume curve from individual segments were used for assessment of global and
regional ejection fractions (D).
LV: left ventricle
Fig. 12. Three-dimensional reconstruction of the surface-rendered RV cast using
manual endocardial border plotting in multiple cutting planes in systole and
diastole. RV volume analysis with accurate depiction of right ventricular shape
and volume in systole and diastole depicted in different shades as shown in lower
right panel (D) along with end-systolic and end-diastolic volumes and calculated
ejection fraction.
RV: right ventricle
Discussion
This study proves immense potentials of emerging real time
echocardiographic systems in all the fields of clinical
cardiology.
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Indian Heart J 2005; 57: 128–137
3D echocardiography and valvular heart disease:
Conventional 2D echocardiography is the most commonly
used modality for assessing valvular heart disease. The
conventional planimetry of mitral valve orifice by 2D
echocardiography, pressure half time, continuity equation
and proximal iso-velocity surface area (PISA) are the
acceptable methods for assessment of mitral valve area
(MVA), however they have their own pitfalls. Doppler-based
methods are of limited value as they are heavily dependent
on hemodynamic variables and coexisting valvular
lesions.12,13 As reported by Martin et al.14 success rate of
planimetry is said to be as low as 75%. A study by Binder et
al.15 reported an overestimation of MVA in the range of
63% for a small deviation of 6º from the optimal plane. 15
This error further increases with a small change of
transducer position, angulations and rotation.15 Difficulty
in defining the correct imaging plane that displays the true
mitral valve orifice is a major limitation. On the contrary,
3D echocardiographic estimation has overcome most of the
limitations as it measures actual anatomical valve area in
an ideal short axis plane and is independent of
hemodynamic variables.16 By using the oblique plane on
the 3D acquired data set, we can correctly ascertain the
plane of the opening of the valve and by cropping the image
in that particular plane at a level, we get the smallest
opening area of the leaflets and the actual mitral valve
orifice area (Fig. 13). We found a high degree of correlation
in measured valve area by this method and calculated valve
area by conventional 2D and Doppler-based methods
(3DTTE planimetery MVA and 2DTTE planimetry MVA,
r=0.985; 3DTTE MVA and 2DTTE pressure half time MVA,
r=0.965). Theoretically all these facts also hold true for
aortic, tricuspid and pulmonary valves. In a previous study,
we reported the comparison of MVA by reconstructed
3DTEE and mitral valve area measured at operating table
with high degree of agreement (r=0.95).17 Applebaum et
al.18 have also demonstrated the value of visualizing the
mitral valve commissural splitting and leaflet tears in
reconstructed 3DTEE which were not visualized on
conventional 2D images in patients who underwent balloon
mitral valvotomy (BMV) for mitral stenosis. Now with real
time imaging, the correlation was found to be even better
with high reproducibility.16 The other practical use of this
new technique has been in the cases of mitral valve
prolapse, which is frequently under-or over-estimated using
M-mode and 2D techniques because of its non-planar
leaflet-annular relations.19 Enface visualization of mitral
valve from ventricular and atrial side along with clear
demarcation of scallops of valvular leaflets incorporated
in prolapse is possible in volume-rendered images acquired
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Indian Heart J 2005; 57: 128–137
using 3DTTE. Quantification of severity of mitral
regurgitation is also a challenging task while deciding for
operative management. Real time 3D echocardiography has
theoretical advantage over conventional methods by
incorporating entire regurgitant jet area in spatial
orientation. It provides unique information about direction
and extent of jet which are useful in eccentric jets. Clinical
feasibility of this technique for assessment of valve
functions has been validated by previous studies, but for
any clinical significance it requires standardization and
further validation.20,21 Planimetry measurement of the area
of vena contracta and mitral regurgitation area was also
possible by this technique and correlates well with
conventional Doppler-based methods.22
Two-dimensional echocardiography was proved to be
reliable in diagnosis of mitral and aortic stenosis. Their role
in the diagnosis of rheumatic tricuspid stenosis is still being
defined as interpretations are based on indirect evidences
and not the actual measurement.23 With advent of 3DTTE
technique, assessment of tricuspid valve had been now
Fig. 13. Two-dimensional echocardiographic images of mitral valve in long axis
(right panel) and its corresponding short axis views (right panel) depicting
importance of cutting plane for measuring accurate mitral valve area. Top row
shows actual valve area in an obliquely cut plane, while middle and lower rows
show the different possible conditions with over-estimation of valve area using
conventional perpendicular short-axis cut plane.
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135
Kasliwal et al. Three-Dimensional Echocardiography 135
possible with clear delineation of all the three leaflets in
enface view (Fig. 7D). With this technology one can actually
measure tricuspid valve area by planimetry along with
greater details about valvular morphology, and can be
considered as gold standard in absence of any other
modality after standardization with autopsy studies. 3DTTE
also provides reproducible images of entire tricuspid
regurgitant jet along with actual measurement of
regurgitant valve area but requires validation studies before
being used for clinical decision making.24
In aortic valve disease also 3DTEE, by overcoming the
limitations of conventional echocardiography and
correctly ascertaining the actual valve area (Fig. 13) and
effective regurgitant valve area, can reduce the need for
transesophageal echocardiography, though the paucity of
validation study makes it still a hypothesis.25
3D echocardiography in patients with prosthetic
heart valves: 3D echocardiography gives ‘enface’ view of
prosthetic valves along with position of struts and opening
and closing motion in a single image, especially in patients
with peri-prosthetic leak in which it was very difficult to
localize the site and shape of leak by conventional echocardiography. In 2 of our cases, accurate localization and
assessment of size and shape by 3DTTE was the key point
in deciding for device closure of these leaks.
3D echocardiography in congenital heart diseases:
Congenital heart disease evaluation requires mental
conceptualization of planar 2DTTE images in 3D construct
of cardiac anatomy by integrating observation from
adjacent views, something that is possible only for an
experienced echocardiographer. The emerging real time
3DTTE has eliminated need for imaginary reconstruction
of cardiac structures and their anatomical relation by
different observers. In patients with complex congenital
lesions, 3DTTE had given additional information by
providing the spatial orientation of the anatomical
structures.26 In our study, 3DTTE was found advantageous
in enface visualization of ASDs, their shape, size and
number. 3DTTE was found to be useful in measurement of
ASD and was correlated well with cardiac catheterizationderived parameters (3DTTE r = 0.930, p ≤0.0001) used
for the selection of transcatheter ASD occluder size. 3DTTE
is also informative in assessment of abnormal ASD device
placement as reported in previous studies.27 Cleft mitral
valve is another condition which is sometimes difficult to
diagnose by 2DTTE but on 3DTTE it has high probability
of being visible.28 These 3D images have been useful for the
surgeons in analyzing the anatomy in situ and deciding the
type of intervention before opening the heart.
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136 Kasliwal et al. Three-Dimensional Echocardiography
3D echocardiography in assessment of ventricular
function: LVEF is the singlemost important marker for
prognostic assessment in patients with LV dysfunction.
Until recently, 2DTTE had widespread acceptance for serial
evaluation of EF which was done by eyeballing which is
subjective with limited test-retest reliability. With advent
of 3D echocardiographic technology, objective assessment
of quantitative measurement of dimensions, areas,
volumes and function is possible more convincingly as
compared to conventional 2D echocardiographic
measurements and is highly reproducible. 29,30 While
quantification of ventricular volumes and mass with 2D
imaging requires geometric assumptions, their
determination by live 3D echocardiography is actual and
is not assuming anything to calculate the EF. In our study
we demonstrated the feasibility of this technique which was
already validated for assessment of LV functions.31,32 By
analysis of regional wall motion, LV contraction patterns,
their cyclic changes and temporal differences in regional
wall motion pattern, this technique with higher frame rates
can be used for assessment of intraventricular
dyssynchrony and feasibility of biventricular pacing
(Fig. 11).33,34
Right ventricular volume measurement using 2D
echocardiography is very difficult because of its complex
asymmetrical shape.35,36 Real-time 3DTTE has led to a
revolution in this field as it gives complete assessment of
RV geometry and RVEF in a holographic 3D volume data
set and provides new insights into its physiology. The
in vitro data indicate that RV volume calculation of excised
hearts with a high speed volumetric ultrasound system is
accurate but requires further validation.37-39 In our study
on patients with long standing pulmonary hypertension,
actual assessment of RVEF and change in shape by
analyzing a volume-rendered cast of RV cavity revealed that
in response to longstanding pulmonary hypertension, the
RV remodels into a more globular shape from its original
shape.
Future prospects: The emerging second-generation real
time 3D echocardiography extends the benefits of more
complete and precise information in real clinical decision
making. However, it has certain limitations like dependence
on available echocardiographic window, lower frame rate
(20 Hz), and motion artifacts in full volume acquisition.
Respiratory and other beat-to-beat variations also damage
image quality. Acquisition angle in real time mode requires
technical advances to increase the size of insonated volume
and frame rate of acquisition. It appears that 3D
echocardiography is the technology of future, and with
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Indian Heart J 2005; 57: 128–137
wider availability and further technological advancement
it has potential to replace 2D echocardiography as a tool
for routine clinical assessment of heart diseases.
Conclusions: The results of this preliminary study
demonstrate that: (i) 3DTTE planimetery is comparable to
2DTTE in assessment of mitral valve area with better
reproducibility; (ii) 3DTTE gives additional information
about surface anatomy of cardiac valves and their relation
with surroundings in real time; (iii) comprehensive
assessment of tricuspid valve including planimetry for valve
area and regurgitant orifice area is possible using real time
3DTTE; (iv) 3DTTE is additive to conventional 2D imaging
in ‘enface’ visualization of atrial septal defects with better
assessment of shape, size, area and number; and
(v) objective assessment of LV and RV volumes is feasible
with 3DTEE and is based on actual measurements and not
on assumptions.
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6/21/2005, 2:35 PM
138 Raghunandan
Original
Articleet al.
Indian Heart J 2005; 57: 138–142
QT Variability in Congestive Cardiac Failure
Increased Beat-to-Beat QT Variability in Patients with
Congestive Cardiac Failure
DS Raghunandan, Nagaraj Desai, Mallika Mallavarapu, Ronald D Berger, Vikram K Yeragani
Department of Cardiology, MS Ramaiah Medical College Hospital and Bangalore University, Bangalore; Johns Hopkins
University School of Medicine, Baltimore, USA; and Department of Psychiatry and Behavioral Neurosciences, Wayne State
University School of Medicine, Michigan, USA
Background: QT interval on the surface electrocardiogram reflects the time for repolarization of myocardium.
Prolongation of rate-corrected QT interval, QTc is strongly associated with sudden cardiac death. Recent studies
using novel techniques on beat-to-beat QT interval variability have shown that an increase in QT interval
variability is associated with increased sympathetic activity and is a predictor of sudden cardiac death. We
studied QT variability in patients with congestive cardiac failure, as it is associated with an increase in cardiac
sympathetic activity and also sudden death.
Methods and Results: We compared beat-to-beat heart rate and QT interval data in 23 patients with congestive
cardiac failure and 19 age-matched normal controls. The electrocardiographic data were acquired in lead II
configuration at a sampling rate of 1000 Hz. Heart rate variability was found to be significantly lower while QT
variability measures were significantly higher in patients compared to controls. QTvi (a common log ratio of
QT variability normalized for mean QT interval squared divided by heart rate variability normalized for mean
heart rate squared) was also significantly higher in patients compared to controls. Clinical improvement in
some of these patients is associated with a decrease in QTvi, due mainly to an increase in cardiac vagal function.
Conclusions: Our results suggest a decrease in cardiac vagal and an increase in cardiac sympathetic functions
in patients with congestive cardiac failure. QTvi may prove to be a useful surrogate end point to evaluate treatment
effect in these patients. (Indian Heart J 2005; 57: 138–142)
Key Words: QT Variability, Heart rate variability, Congestive heart failure
C
ongestive cardiac failure is associated with
abnormalities in autonomic function including a
decrease in vagal function, increase in sympathetic function
and abnormal baroreceptor reflex responsiveness.1-8 There
is strong evidence showing decreased heart rate (HR)
variability in these patients.8 A decrease in HR variability
is shown to be a strong predictor of mortality in patients
with cardiac disease as well as normal controls.9-11 We have
recently shown that there is an impaired response of QT
variabiliy measures to orthostatic challenge.12
QT interval measured on the surface electrocardiogram
(ECG) reflects the time for repolarization of myocardium
and rate-corrected QT interval (QTc) prolongation is
strongly associated with sudden cardiac death. Cardiac
repolarization plays an important role in causing sudden
Correspondence: Dr VK Yeragani, Professor of Psychiatry and Behavioral
Neurosciences, Wayne State University School of Medicine, Flat No 103
Embassy Orchid, 8 Main, Sadashiva Nagar, Bangalore 560080
e-mail: [email protected]
IHJ-735-04(OA).p65
138
death and an increase in sympathetic activity, and a
decrease in cardiac vagal activity makes the myocardium
vulnerable to fatal arrhythmias.13-15 QT variability closely
follows HR variability and a recent measure, beat-to-beat
QT interval variability appears to be an important and
independent measure of cardiac mortality and severity of
illness in patients with heart disease and also in coronary
patients with effort angina.16-18 We have conducted several
studies on the effects of autonomic nervous system on QT
variability and found that it significantly increases during
challenges associated with an increase in sympathetic
activity.19-22 These studies have used QTvi, which is an index
of QT interval variability corrected for mean QT squared
divided by heart rate variability corrected for mean heart
rate squared.
In the present study, we sought to test the hypothesis
that repolarization lability is elevated at baseline in patients
with congestive cardiac failure (CCF), and normalizes with
treatment.
6/21/2005, 2:36 PM
Indian Heart J 2005; 57: 138–142
Raghunandan et al. QT Variability in Congestive Cardiac Failure 139
Methods
Subjects: The patients were known cases of CCF and
already receiving some medications (Table 1) without much
benefit. The subjects were outpatients that were
consecutively recruited from the hospital with a diagnosis
of congestive cardiac failure. Age-matched control subjects
were recruited from the staff working in the hospital and
their relatives. There were 23 patients (19 males, 4 females;
age: 54±15 years) and 19 normal controls (13 males, 6
females; age: 53±13 years).
Data acquisition: Electrocardiogram (ECG) was
continuously acquired for 5 min in supine posture in lead
II configuration in a noise-free environment. All subjects
were asked to breathe normally to auditory cues from a
cassette player at 12 breaths/min. All patients included in
this study were able to breathe at 12 breaths/min. The ECG
signal was digitized at 1000 Hz and the data were saved on
Zip diskettes for later analyses.
QT variability: All analyses were conducted on 256 s
segments of data sampled at 1000 Hz. This QT variability
algorithm has been described in detail by Berger et al.16
and has been used by his group as well as ours in previous
studies.16,19-22 This was performed on a PC using Solaris
Desktop Unix software (Sunsoft, Mountainview, USA)
which uses a graphical interface of digitized ECG where the
time of the ‘R’ wave is obtained using a peak detection
algorithm. Then the operator provides the program with
the beginning and the end of the QT wave template. This
algorithm finds the QT interval for each beat using the timestretch model. If the operator chooses a longer QT template,
all the QT intervals will be biased accordingly. This
algorithm is used to study QT variability and not the mean
QT.
The HR [beats per minute (bpm)] time series were
sampled at 4 Hz using the technique of Berger et al.23 We
used HR time series free of ventricular premature beats and
noise. The data were then detrended by using the best-fit
line prior to the computation of spectral analyses. The mean
HR (HRm), detrended HR variance (HRv), mean QT interval
(QTm), detrended QT variance (QTv), spectral powers [total
power (TP): 0-0.50 Hz, very low frequency (VLF) power: 00.04 Hz, low frequency (LF) power: 0.04-0.15 Hz and high
frequency (HF) power: 0.15-0.50 Hz] of HR and QT after
detrending were calculated from the instantaneous HR and
QT time series of 1024 points (256 s).
Table 1. Descriptive data on patients
Patient
Age
Sex
NYHA
Preclassification LVEF%
Pedal
edema
JVP
Basal
rales
Medications at baseline
PostLVEF%
Clinical
improvement
1
47
M
III
45
+
↑
+
Digoxin, furosemide, thiazide, enalapril, ranitidine
46
Not improved
2
68
M
IV
23
+
↑
+
Digoxin, furosemide, perindopril, L-carnitine, trimetazidine
37
Improved
3
58
F
IV
40
+
↑
+
Digoxin, enalapril, aspirin, clopidogrel, trimetazidine,
L-carnitine, carvedilol, nitrate, pantoprazole
39
Not improved
4
40
M
III
36
+
↑
+
Digoxin, carvedilol, ciprofloxacin
56
Improved
5
58
F
IV
23
+
↑
+
Digoxin, furosemide, spironolactone, losartan, L-carnitine, antioxidant
23
Not improved
6
50
M
III
40
+
N
–
Digoxin, furosemide, thiazide, amiloride, carvedilol
45
Improved
7
38
M
III
20
+
N
+
Digoxin, enalapril, furosemide, spironolactone, penicillin
25
Improved
8
49
M
III
40
+
↑
+
Digoxin, enalapril, furosemide, spironolactone
40
Not improved
9
62
F
IV
44
+
↑
+
Digoxin, lisinopril, aspirin, L-carnitine
44
Improved
10
37
M
III
41
+
N
+
Digoxin, furosemide, enalapril, carvedilol, spironolactone,
amiodarone, nitrate
50
Not improved
11
69
M
III
35
+
↑
+
Digoxin, furosemide, enalapril, spironolactone
38
Improved
12
65
M
III
38
+
↑
+
Spironolactone, enalapril, metoprolol, pioglitazone, glibenclamide, aspirin 40
13
71
M
IV
27
–
N
+
Digoxin, spironolactone, enalapril, L-carnitine, aspirin
36
14
42
M
III
29
+
N
–
Digoxin, furosemide,L-carnitine, spironolactone
43
15
30
M
III
38
+
N
+
Digoxin, furosemide, spironolactone, lisinopril, L-carnitine, antioxidant
No follow-up
No follow-up
Improved
Not improved
Improved
16
28
M
III
48
–
N
+
Digoxin, furosemide, enalapril, salbutamol inhalant
17
65
M
III
35
+
↑
+
Digoxin, furosemide, L-carnitine, aspirin, trimetazidine, nitrate
No follow-up
18
63
M
III
35
–
N
+
Salbutamol inhalant
No follow-up
19
66
M
III
30
+
↑
+
Digoxin, furosemide, L-carnitine
No follow-up
20
40
M
IV
–
+
↑
+
Furosemide, nitrate, L-carnitine
No follow-up
21
68
M
IV
27
+
↑
+
Digoxin, furosemide, enalapril, carvedilol, spironolactone, amiodarone, nitrate
No follow-up
22
60
M
III
32
+
N
+
Digoxin, furosemide, enalapril, spironolactone
No follow-up
23
85
M
III
–
+
N
+
Digoxin, lisinopril, L-carnitine
No follow-up
LVEF: left ventricular ejection fraction; JVP: jugular venous pressure; Pre- and Post-LVEF refer to treatment effect; M: male; F: female
IHJ-735-04(OA).p65
139
6/21/2005, 2:36 PM
Indian Heart J 2005; 57: 138–142
140 Raghunandan et al. QT Variability in Congestive Cardiac Failure
A normalized QT variability index was calculated as
suggested by Berger et al.16
QTvi = Log10
QTv/QTm2
HRv/HRm2
This index represents the log-ratio between the QT
interval and the HR variabilities, each normalized for the
corresponding mean.
Spectral analyses: QT time series (256 s at 4 Hz =1024
points) was subjected to spectral analyses and the power
spectrum was computed with the Blackman Tukey
method.16 The powers were integrated in the bands of VLF,
LF and HF regions. HR and QT interval time series were
subjected to spectral analysis and the cross spectrum
between the two time series was computed from 256 s.16
Clinical improvement: In most of the patients, treatment
was continued with the same medications they were on and
only dosages were adjusted. The eight patients that showed
improvement and the six, that did not improve were retested
after 4-8 weeks of continued treatment. Patients were
judged to have improved clinically if there was a decrease
in the severity of dyspnea, pedal edema, hepatomegaly and
pleural effusion, and a decrease in jugular venous pressure
(JVP). We also used the left ventricular ejection fraction
(LVEF) criteria to assess the improvement (Table 1).
Table 2. Heart rate and QT variability measures of normal
controls and patients with congestive cardiac failure
Supine
Controls (n=19)
HRm
HR-TP (0-0.50 Hz)
HR-VLF (0-0.04 Hz)
HR-LF (0.04-0.15 Hz)
HR-HF (0.15-0.50 Hz)
QTm
QT-TP (0-0.50 Hz)
QT-VLF (0-0.04 Hz)
QT-LF (0.04-0.15 Hz)
QT-HF (0.15-0.5 Hz)
HR-QT coherence
(0-0.5 Hz)
QTvi
Patients (n=23)
79±11
2.4±1.0
1.27±1.17
0.87±1.29
1.38±1.10
372±29
3.29±0.58
1.56±0.68
1.69±0.64
2.69±0.72
87±17
1.3±1.4b
0.23±1.13 b
-0.38±1.7 b
0.04±1.72 b
456±71 d
4.51±1.26 c
2.65±1.11 b
2.72±0.91 c
3.62±0.96 c
0.20±0.07
-0.91±0.53
0.23±0.10
-0.09±0.63 d
HRm (heart rate mean) is in beats per min (bpm); QTm (QT interval mean) is in ms;
Powers are in Ln (natural logarithm) of bpm squared and ms squared; total power
(TP): 0-0.5 Hz; very low frequency (VLF): 0-0.04 Hz; low frequency (LF): 0.04-0.15
Hz; high frequency (HF): 0.15-0.5 Hz
Patients v. controls: a<0.05; b<0.01; c<0.001; d<0.0001.
Statistical analysis: We used student's t test to compare
HR and QT variables after using analysis of variance
(ANOVA) with adjustment for gender. A probability level
of ≤ 0.05 was accepted as significant.
Results
Results remained the same after adjusting for gender as
there was a higher proportion of females in the control
group. Table 2 shows the comparison of patients and
controls in supine posture during controlled breathing at
12 breaths/min. HR spectral powers were significantly
higher and QT spectral powers were significantly lower in
controls compared to patients. QTvi was significantly
higher in patients compared to controls (Fig. 1).
Effect of treatment: Table 3 shows the HR and QT
variability measures of 14 patients after treatment. Eight
of these subjects showed clinical improvement and 6 did
not. In the group that showed improvement, there was a
significant increase in HR-HF power and a decrease in QTvi
(Fig. 2). There was also a significant decrease in HR-QT
coherence in the band of 0-0.5 Hz in the group that did
not improve.
IHJ-735-04(OA).p65
140
Fig. 1. Instantaneous heart rate and QT interval time series with the values of
QTvi in a control subject (A) and a patient (B) with congestive cardiac failure in
supine posture sampled at 4 Hz (256 s=1024 points).
HR (bpm): heart rate, beats per minute
Fig. 2. The values of QTvi before and after treatment in the group of 8 patients
that showed clinical improvement.
6/21/2005, 2:36 PM
Indian Heart J 2005; 57: 138–142
Raghunandan et al. QT Variability in Congestive Cardiac Failure 141
Table 3. Heart rate and QT variability measures of patients with congestive cardiac failure before and after treatment in
supine posture (n=14)
Improved (n=8)
HRm
HR-TP (0-0.50 Hz)
HR-VLF (0-0.04 Hz)
HR-LF (0.04-0.15 Hz)
HR-HF (0.15-0.50 Hz)
QTm
QT-TP (0-0.50 Hz)
QT-VLF (0-0.04 Hz)
QT-LF (0.04-0.15 Hz)
QT-HF (0.15-0.50 Hz)
HR-QT coherence (0-0.50 Hz)
QTvi
Not improved (n=6)
Pre-
Post-
Pre-
Post-
88±18
2.2±2.4
0.71±1.7
0.70±3.0
1.3±2.7
485±101
4.7±1.3
2.5±1.6
3.3±1.4
4.1±1.2
0.23±0.11
-0.39±0.93
80±12
3.0±1.7
1.9±1.1*
1.8±1.9
2.5±2.2*
405±78
4.6±0.5
2.6±0.6
3.1±0.6
4.0±0.6
0.24±0.13
-0.73±0.69*
80±12
2.4±1.9
1.0±1.4
0.90±2.0
1.4±2.1
428±70
4.5±0.8
2.9±0.8
3.0±0.9
3.8±1.0
0.21±0.08
-0.49±0.80
77±13
2.4±1.7
1.4±1.2
1.1±1.8
0.9±2.0
373±87
4.3±0.5
2.3±1.1
3.0±0.6
3.8±0.3
0.15±0.06*
-0.45±0.79
HRm (HR mean) is in beats per minute (bpm); QTm (QT interval mean) is in ms
Powers are in Ln (natural logarithm) of bpm squared and ms squared; TP: 0-0.50 Hz; VLF: 0-0.04 Hz; LF: 0.04-0.15 Hz; HF: 0.15-0.50 Hz
Pre-treatment v. post-treatment: *p<0.05
TP: total power; VLF: very low frequency; LF: low frequency; HF: high frequency
Correlations: There was no significant correlation
between ejection fraction (EF) and QTvi. There were also
no significant correlations between mean QT and QT total
power or QTvi either in patients or controls.
Discussion
The findings of decreased HR variability and increased QT
variability in patients with CCF are consistent with previous
reports.7,16 We have previously shown that an increase in
sympathetic function is associated with an increase in
QTvi. 19,22 This is also consistent with the higher QTvi
reflecting a higher sympathetic activity in patients with
congestive cardiac failure. However, we did not find a
significant difference in coherence between HR and QT time
series in any frequency band between patients and controls.
Previous evidence suggests that an increase in HR-HF
power is an important prognostic factor in these patients.
However, the most important finding in this study is that
after treatment, QTvi decreased only in the subgroup of
patients that showed clinical improvement. Though there
was no significant increase in the total power of HR or
coherence between HR and QT in these patients, there was
a significant increase in VLF and HF powers of HR and a
trend toward a significant increase for total power of HR.
HR time series usually shows three peaks in the following
bands: TP (0-0.50 Hz), VLF (0-0.04 Hz), LF (0.04-0.15 Hz)
24-26
HF power reflects respiratory
and HF (0.15-0.50 Hz).
sinus arrhythmia and thus cardiac vagal function, LF
power, baroreceptor mechanisms, influenced by
sympathetic as well as parasympathetic mechanisms and
VLF power, peripheral vascular, thermoregulatory and
IHJ-735-04(OA).p65
141
renin-angiotensin systems. These results suggest a possible
increase in cardiac vagal function after successful
treatment. This may have been responsible for the decrease
in QTvi, which suggests that QT interval fluctuations
became more appropriate for the level of HR fluctuations.
This did not happen in patients that did not show any
clinical improvement. In their report, Bonnemeier et al.27
have shown that QT interval variability decreased after
successful reperfusion by percutaneous transluminal
coronary angioplasty. This preliminary report adds to the
literature suggesting that QT interval variability may prove
to be another useful surrogate end point in heart failure.28
Limitations: A larger number of patients and controls
would have brought more reliable results although the
differences in QTvi were highly significant. We had data of
only 256 s during controlled breathing; further, the number
of subjects that improved after treatment was only eight
and those that did not improve were six. Hence, the results
should be viewed with caution until studies with larger
samples examine the effect of treatment on QTvi. Thus
these results should be considered preliminary.
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Dhingra et al. Induction ofOriginal
Aortoarteritis
143
Article
Indian Heart J 2005; 57: 143–150
An Experimental Design for Induction of
Non-Specific Aortoarteritis
R Dhingra, KK Talwar, P Chopra, R Kumar
Departments of Anatomy, Cardiology and Pathology, All India Institute of Medical Sciences, New Delhi
Background: An attempt was made to induce aortoarteritis in mice by using various antigens.
Methods and Results: The Swiss mice were immunized with eight different antigens and were grouped A to
G. Group H served as control. The mice were then bled at 1st, 2nd, 4th, 6th and 8th month interval postimmunization for estimating antibody titer. Then the mice were sacrificed and the heart, aorta and kidney were
taken out and processed for hematoxylin-eosin staining. There was gradual increase in the antibody titer from
1st month till 4th month within all the experimental groups (A-G), when compared with control group H. The
titer started falling sharply from 6th month post-immunization. However, the control group H did not show
much variation. When each individual group was compared separately with control group H, the significant
statistical value was obtained. Histopathological examination revealed mild inflammation (+) in kidney by 2nd
month, moderate inflammation (++) by 6th month, extensive inflammation (+++) by 8th month and alteration
in the normal parenchyma of kidney by 8th month.
Conclusions: The histopathological changes brought out through antigens were more pronounced by 8th
month following injection of tunica media, tunica adventitia, tunica intima and aorta collagen as compared to
that of standard collagen and mouse aorta injections. (Indian Heart J 2005; 57: 143–150)
Key Words: Aortoarteritis, Vascular disease, Takayasu's arteritis
T
akayasu’s arteritis (TA) or non-specific aortoarteritis
(NSAA) is an idiopathic inflammatory disease of
aorta and its major branches.1 It usually affects the
young individuals and results in occlusive changes in these
vessels. The etiopathogenesis of the disease is still poorly
understood but an autoimmune basis is suggested.2-4 In
addition, genetic and environmental factors also probably
play an important role. Experimental studies were
conducted on various animals in the past with an attempt
to induce arteritis using various non-specific antigens,5 yet
the exact immunological status of the animal has not been
analyzed so far. The present study was designed to make
an attempt to produce an experimental model of NSAA
subsequent to the administration of specific antigen(s) and
to analyze the sequence of events involved in the disease
process using mouse as a model.
Methods
A total of 160 female Swiss mice were taken for induction
of the disease. They were divided into various groups (A-H)
Correspondence: Dr Renu Dhingra, Assistant Professor, Department of
Anatomy, All India Institute of Medical Sciences, New Delhi 110 029
IHJ-548-03.p65
143
on the basis of injection of different antigens. Each group
had 20 mice (Table 1).
Tabel 1. Antigens given to various groups of Swiss mice
Group (n=20)
Antigen Injected
Group A
Group B
Group C
Group D
Group E
Group F
Group G
Group H
Mouse aorta (MA)
Mouse peripheral artery (MP)
Standard collagen (SC)
Aorta collagen (AC)
Intima (IN)
Media (MD)
Adventitia (AV)
Normal saline (NS)
Preparation of various antigens:
Mouse aorta and mouse peripheral arteries: 20 to 30 mice were
killed. Aorta and peripheral arteries were dissected out from
each mouse. They were cleaned thoroughly with normal
saline, minced and homogenized in the Polytron
homogenizer.The homogenate was centrifuged at 3000
rpm for 30 min separately. Protein estimation of the
supernate was done by Lowry’s method.6
6/21/2005, 2:37 PM
144 Dhingra et al. Induction of Aortoarteritis
Standard collagen: It was procured from Sigma Chemical Co.
The source was calf skin.
Aorta collagen7: Its source was human aorta. Human aorta
obtained from autopsy cases being done at mortuary of our
institution were cleaned. Histopathology was done to
confirm that it was normal. Then it was minced and
homogenized at 4°C in 0.5 M acetic acid. Pepsin was added
at 20 mg per gm weight and the tissue was digested for 3
days at 4°C with continuous stirring. The clarified extract
was neutralized to inactivate peptic activity and the
collagen precipitated overnight at room temperature by
addition of sodium chloride to a fine concentration of 20%.
The precipitate was then collected and resolubilized in
0.1 M phosphate buffer (pH 7.6) clarified by centrifugation
and the collagen reprecipitated by addition of sodium
chloride (15%). This procedure was repeated 3 times. The
final precipitate was collected in 0.5 M acetic acid, dialyzed
against 0.1% acetic acid and lyophilized. Electrophoresis
was performed on standard 10% SDS-polyacrylamide gels
and also 3.75% gels in tubes (tube electrophoresis). The
protein bands of aorta collagens corresponded to that of
standard collagen (procured from Sigma) on 10% SDSPAGE and 3.75% SDS-PAGE which confirmed the extraction
of aorta collagen.
Intima, media, advnetitia: The three layers of human aorta
i.e. intima, media and adventitia were separated and their
extracts were prepared.
The mice were divided into various groups A-H on the
basis of these antigens. Each group comprised of 20
animals. The mice were immunized with these antigens
separately (emulsified with Complete Freund’s adjuvant
and Incomplete Freund’s adjuvant) on day 0, day 14 and
day 21. They were bled on day 30th post-immunization.
The mice were given boosters once a month for 8 months
and then bled after 15 days of giving each booster. The
antibody titers were estimated by enzyme-linked
immunosorbant assay (ELISA) at 1st, 2nd, 4th, 6th and
8th month interval post-immunization (day 0). The
animals were sacrificed at 2nd, 4th, 6th and 8th month
interval after post-immunization (day 0).
The antibody titer: It was estimated at 1st, 2nd, 4th, 6th
and 8th month post-immunization (day 0). Mean
absorbance value at 492 nm was calculated for the animals
of all groups bled at above time intervals separately. The
statistical analysis was done by comparing the antibody
titers among all the groups at the above time periods of the
sacrifice by one-way ANOVA. When the p value obtained
from one-way ANOVA was found to be significant only then
Student’s Newman Kaull’s Multiple Range Test (MRT) was
IHJ-548-03.p65
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Indian Heart J 2005; 57: 143–150
applied to compare the individual groups with one another.
Histopathological studies: The organs such as heart,
aorta and kidney were dissected out and fixed in 10%
formalin. Five to six micron thick sections were processed
for routine histology. Tissue sections were cut and stained
with hematoxylin-eosin. Histopathology of heart, kidney
and aorta was done on 2nd, 4th, 6th and 8th month
interval post-immunization.
Results
Antibody titer in mice bled at various intervals after
injection of different antigens: Fig. 1 represents the
mean values of antibody titer in mice of groups A–H.
1st month: The antibody titer ranged from 0.412±0.04 in
Fig. 1. Antibody titer of mice at different intervals after immunizing them with
various antigens.
group F (MD) to 0.114±0.02 in group H (NS) in the order:
group F (MD) >group G (AV) >group D (AC) >group E (IN)
>group A (MA) >group B (MP)>group C (SC) >group H
(NS). These values were statistically significant (p<0.001)
by one-way ANOVA analysis.
The p values were obtained following comparison
between each group using MRT. The antibody titers of
group F (MD) and group G (AV) were significantly higher
(p<0.05) when compared to the antibody titer of group C
(SC), group B (MP), group A (MA), group E (IN) and group
H (NS), whereas no significant difference was seen when
these two groups were compared with that of group D (AC)
and with one another.
2nd month: The values ranged from 0.616±0.0412 in
group G (AV) to 0.106± 0.025 in group H (NS) in the order:
group G (AV) > group F (MD) >group D (AC) > group E
(IN) > group A (MA) > group B (MP) > group C (SC) >group
H (NS). These values were statistically significant
(p < 0.001) by one-way ANOVA. The p values after MRT
analysis showed that the antibody titer of all the antigenic
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Indian Heart J 2005; 57: 143–150
groups (group A-G) were statistically significant (p <0.05)
when compared with the control group H (NS). Also group
F (MD) and group G (AV) had significantly high antibody
titer as compared to group D (AC) (p<0.05), group A (MA),
group B (MP), group C (SC), group E (IN) (p<0.001) and
group H (NS) (p<0.0001).
4th month: The mean antibody titer ranged from
0.785±0.050 in group F (MD) to 0.108±0.018 in group
H (NS) in the order: group F (MD) > group G (AV) > group
D (AC) > group E (IN) > group C (SC) > group A (MA)
>group H (NS). The antibody titer showed an increase in
all the test groups. These values were statistically significant
(p<0.001) as assessed by one-way ANOVA analysis.
The p values after MRT showed that the antibody titer
of all the antigenic groups i.e. from group A to group G
were significantly different when compared with that of
control group H (NS). Also group F (MD) and group G (AV)
had significantly high antibody titer as compared to group
B (MP) (p<0.0001), group A (MA), group C (SC), group E
(IN) (p<0.001) and group D (AC) (p<0.05). The antibody
titer of group D (AC) was significantly different from only
group B (MP) (p<0.001) and group C (SC) (p<0.05).
6th month: The mean values of antibody titer ranged from
0.696±0.061 in group G (AV) to 0.111±0.024 in group H
(NS) in the order: group G (AV) > group F (MD) > group D
(AC) > group C (SC) > group E (IN) > group B (MP) > group
A (MA) > group H (NS). There was an overall increase in
the antibody titer in all the groups as compared to the antibody titer in sera of mice bled at 4th month.
The p values after MRT were same as that of the 4th
month except that of p values obtained after comparison
between group F (MD) and group E (IN). At 6th month, the
antibody titer of group G (AV) was significantly higher
(p<0.001) as compared to the group E (IN) whereas
antibody titer of group F (MD) was statistically significant
at only p<0.05 when compared to group E (IN).
8th month: The mean values of antibody titer ranged from
0.604±0.001 in group G (AV) to 0.111±0.02 in group H
(NS) in the order: group G (AV) > group F (MD) > group E
(IN) > group D (AC) > group C (SC) > group A (MA) > group
B (MP) > group H (NS). There was a decrease in the level of
antibody titer in all the groups except group H (NS) when
compared to antibody titer in sera of mice killed at 6th
month interval, but it was more than the value at 1st month
sacrifice in all the groups except group H (NS) where the
antibody titer was more or less same at all the sacrifices.
When MRT was applied, the values of group A (MA),
group C (SC), group D (AC), group E (IN), group F (MD)
and group G (AV) were significant at p<0.05 compared to
IHJ-548-03.p65
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Dhingra et al. Induction of Aortoarteritis 145
that of group H (NS) and group B (MP). Highly significant
difference was observed between group F (MD), group G
(AV) and the groups E (IN), D (AC), C (SC), B (MP), A (MA)
and H (NS). The values of group D (AC) were significant at
p<0.05 when compared with group C (SC) and group A
(MA).
Histopathology of heart, kidney and aorta of mice
sacrificed at various intervals after injection of
different antigens:
2nd month: The histology of heart, kidney and aorta was
normal in all the groups from A to H till this stage. Very
few inflammatory cells were seen in the kidney of mouse
of group F (MD).
4th month
Heart: No histological change was observed in the heart in
any one of the animals killed at 4th month in all the groups
from A to H.
Kidney: Few inflammatory cells were present around the
arterioles of kidney of mice in group A (MA), group C (SC)
and group D (AC). Inflammatory foci were seen in the
parenchyma of kidney of mice of group F (MD) and group
G (AV) whereas no changes were observed in mice of group
B (MP), group E (IN) and group H (NS).
Aorta: Normal structure was seen in the mice of all the
groups except group F (MD) and group G (AV) where few
inflammatory cells were seen around the aorta in the
periadventitial region.
6th month
Heart: Pericardial inflammation was observed in group F
(MD) and group G (AV) mice. The structure of myocardium
was normal in all the groups.
Kidney: Extensive inflammatory foci were seen around
arterioles, tubules and glomeruli in all the animals (3/3)
of group A (MA), in 1/3 animals of group C (SC), 4/4
animals of group D (AC) and 4/5 animals of group E (IN).
One animal of group D (AC) showed very large
inflammatory patches in the kidney (Fig. 2) and distortion
of the shape of the tubules in the medulla (Fig. 3). The
structure of kidney parenchyma was altered in groups F
(MD) and G (AV). There was extensive inflammation, cavity
formation, thinning of epithelial cells lining the tubules and
collection of fluid in the lumen of kidney tubules (Fig. 4).
The kidneys of group H (NS) and group B (MP) showed few
inflammatory cells around arterioles.
Aorta: Peri-adventitial inflammation was seen in aorta of
6/21/2005, 2:37 PM
146 Dhingra et al. Induction of Aortoarteritis
Fig 2. Photomicrograph of kidney of mouse injected with aorta collagen group
D (AC) and sacrificed at 6th month post-immunization. It shows extensive inflammatory zone (I) around the arteriole (a) and glomerulus (G) in the cortex.
Fig. 3. Photomicrograph of kidney of mouse injected with aorta collagen group
D (AC) and sacrificed at 6th month post-immunization depicting the altered
shape of the tubules (T) and ducts in medulla of kidney of the same animal
(Stain : H and E).
group C (SC), group D (AC), group F (MD) and group G (AV).
The para-aortic lymph nodes were enlarged in the media
and adventitia groups.
8th month
Heart: Extensive pericardial inflammation was reported in
group F (MD) and group G (AV) mice (Fig. 5). The structure
of heart was normal in all the groups except few
inflammatory cells seen in the pericardial zone of group D
(AC).
Kidney: Kidney was infiltrated with dense patches of
inflammation around arterioles and tubules in all the
groups except group B (MP) where few inflammatory foci
were observed around arterioles. Lumens of some of the
tubules were occluded. The cytoplasm was dense and
opaque. Extensive lymphocytic infiltration was also seen
in the adrenal glands. Hemorrhagic spots were noted.
IHJ-548-03.p65
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Indian Heart J 2005; 57: 143–150
Fig. 4. Photomicrograph of kidney of mouse injected with media group F (MD)
and sacrificed at 6th month post-immunization showing extensive inflammatory zone (I) around the tubule (T) and arteriole (a) in the cortex. Most of the
tubules are filled with fluid (F) (Stain : H and E).
Fig. 5. Photomicrograph of heart of mouse injected with media group F (MD)
and sacrificed at 8th month post-immunization showing extensive pericardial
inflammatory zone (I) (Stain : H and E).
Morphology of tubules and ducts was altered in medulla
and cortex in group F (MD), group G (AV) and group D (AC)
(Fig. 6). The damage was limited to few regions in group E
(IN), group A (MA) and group C (SC). No change was
observed in the heart, kidney and aorta of mice injected
with normal saline.
Aorta: No change was observed except scanty inflammation
in periadventitial region in group B (MP) whereas moderate
peri-adventitial inflammation was seen in group A (MA),
group C (SC) and group E (IN). Extensive inflammation in
peri-adventitial zone, and enlarged paraaortic lymph nodes
were observed in group F (MD), group G (AV) and group D
(AC) (Fig. 7). Spaces in the aortic fibers and straightening
of the elastic fibers was observed in mice of group F (MD)
and group G (AV).
Summary of Results : The results on antibody titer clearly
6/21/2005, 2:37 PM
Indian Heart J 2005; 57: 143–150
Dhingra et al. Induction of Aortoarteritis 147
Discussion
Fig. 6. Photomicrograph of kidney of mouse injected with adventitia group G
(AV) and sacrificed at 8th month post-immunization. Part of the parenchyma
is destroyed and part of it is normal (Stain : H and E).
indicate that there is gradual increase in the titer from 1st
month till 4th month within all the experimental groups
(A-G), when compared with group H (NS). The titer then
starts falling sharply from 8th month post-immunization.
However, the control group H (NS) does not show much
variation (Fig. 1). When each individual group was
compared separately with control group H (NS), the
significant statistical value was obtained.
Histopathological observation revealed mild
inflammation (+) in kidney by 2nd month, moderate
inflammation (++) by 6th month, extensive inflammation
(+++) by 8th month and alteration in the normal
parenchyma of kidney by 8th month was seen in only group
F (MD), group G (AV), group E (IN) and group D (AC),
whereas group C (SC) and group A (MA) showed less severe
changes by this time.
Fig. 7. Photomicrograph of aorta of mouse injected with aorta collagen group
D (AC) sacrificed at 8th month post-immunization showing extensive periaortic inflammation (Stain : H and E).
IHJ-548-03.p65
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The presence of circulating antibodies against aortic
components in NSAA (Takayasu’s) patients have been
described.8-12 The role of such antibodies in the underlying
immunopathological process remains obscure.
Experimenting directly on humans is not ethically possible
and the T cell dependence and subset requirements for
autoantibody production in vivo can only be inferred from
in vitro studies and animal models. Therefore, we made an
attempt to induce the disease in mice by immunizing them
with various antigens separately followed by estimation of
the antibody titer in these animals. The phenotypic
expression of T lymphocytes by immunohistochemical
techniques has also been done. The histopathological
changes in heart, kidney and aorta have been studied in
these animals to see the extent and severity of the disease.
Various animal models have been tried in the past using
homologous/heterologous aortic extracts.5,13-15 In these
models histological changes similar to that of human
vasculitis were studied, but were not correlated with the
immunological status of the host animal. Also only the
crude aortic extracts were used. The antigenicity of the
three layers of aorta or its components was not analyzed.
Till date, the animal models of aortoarteritis were poorly
defined, hence the present experimental design was used
as a prototype to investigate the pathogenesis of the disease
and the mechanism of induction and regulation of
autoantibody production.
Our experiments showed that there was an initial
increase in the antibody titer followed by a peak between
4th and 6th month and then a decline by 8th month in all
the experimental animals (Fig. 1). Ueda et al.5 also detected
the presence of complement fixing antibodies against the
rabbit aorta (isologous) in rabbits injected for 10 months.
The peak value in these animals was observed between 2-7
months after the beginning of immunization and then
gradual decline was reported. However, they did not use
the heterologous aortic extract i.e. human aorta as has been
used in our study and also by Scebat et al.14 However, they
did not isolate the three layers of the heterologous aorta or
any of its components to produce aortitis which was done
in our experiments.
In our experiments, the pattern of rise and fall in the
antibody titer was almost uniform in all the experimental
groups. However, when the titer was compared within all
the groups, it was maximum in the sera of mice immunized
with human media (group F) and adventitia (group G)
extract at all the time periods, followed by the titers in the
mice injected with aorta collagen and standard collagen.
This could be due to higher antigenicity of human media
6/21/2005, 2:37 PM
148 Dhingra et al. Induction of Aortoarteritis
and adventitia or the presence of any one of their basic
components e.g. collagen indicated in our study.
Findings of our experimental studies can be extrapolated
with those of human studies where we observed the higher
titer of antiaorta antibodies against adventitia and media
in sera of NSAA patients. The possible role of collagen was
suggested as the antiaorta titer in human sera decreased
when the antigen (three layers of aorta) was treated with
the enzyme collagenase (ultra pure form). 16 Further
experiments can be designed to evaluate the possible role
of other constitutents of the aorta.
The antibody titer in mice immunized with isologous
aortic extract [group A (MA) and group B (MP)] was much
less as compared to the other experimental groups (C-F)
(Fig. 1). This observation was somewhat similar to that of
Scebat and colleagues14 where they could detect low level
of antibodies by passive hemagglutination in the rabbit sera
injected with the rat aorta (heterologous) and not with
rabbit aorta (isologous)-injected animals.
The antibody titer in mice injected with mouse aorta
extract group A (MA) was higher as compared to the titer
in mice injected with mouse peripheral artery extract group
B (MP). It has been reported that the disease involves mainly
the aorta and its major branches as compared to peripheral
arteries. The difference in the antigenicity of the aorta and
periperal arteries can be attributed to the qualitative or
quantitiative difference in the antigen involved or the
absence of antigen in peripheral arteries. This observation
of group B (MP) in experimental mice is in concurrence
with that of human studies of Ueda et al.10 where they could
not detect the antiaorta antibodies against the extract of
peripheral arteries in the sera of NSAA patients.
Thus our experiments have shown the presence of
antibodies in mice injected with isologous (group A) as well
as heterologous tissue extracts while Ueda and colleagues10
could detect antibodies against isologous aorta and Scebat
and colleagues14 reported these antibodies only against
heterologous tissue extracts.
Histological changes in aortoarteritis cases on autopsy
have been described by a number of workers.17-19 They
suggested that the spectrum of histological changes seen
in aorta and other affected organs in NSAA is closely related
to the stage of the disease. The disease is characterized by
early acute phase followed by late occlusive phase. The early
systemic generalized manifestations last for several weeks/
months or years and as they subside, signs and symptoms
of occlusive phase appear. Histologically the disease starts
with the inflammatory process affecting aorta, heart and
kidney (acute phase) which gradually subsides over the
years and finally gets completely resolved. The adventitia
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Indian Heart J 2005; 57: 143–150
and media get replaced by the fibrous tissue leading to
stenosis and narrowing of aortic lumen causing rat tail
aorta (chronic phase).
The histological examination in our experiments
revealed inflammation in the kidney parenchyma as early
as 4th month in group F (MD) and group G (AV) and by 6
months in mice of group D (SC), and group E (IN) (Figs 3
and 4). The lesions were severe by 8th month in the above
groups. The kidney parenchyma was destroyed and altered
morphology was observed in groups F (MD), G (AV) and D
(AC) (Fig. 6) at 8th month of sacrifice. However, moderate
inflammation in the kidney of mice of group A (MA),
minimal in group B (MP) and no changes in the control
group (NS) were noticed by 8th month.
These histological lesions in the kidney may be due to
the occlusion/stenosis of renal artery (branch of abdominal
aorta) in the affected mice. Initially the NSAA was thought
to be confined only to the aortic arch but more diffuse
involvement of aorta and its major branches is now
commonly seen. The involvement of branches of abdominal
aorta in NSAA patients was first reported by Harbitz.20
Danaraj and Wong 21 focussed the attention to the
involvement of renal arteries leading to nephrogenic
hypertension in these patients. Since then involvement of
renal arteries has been noted by several authors as the most
frequently involved branch of the abdominal aorta,22-25
although some amount of collateral circulation develops
following occlusion of renal arteries and aortorenal bypass
in these patients appeared to result in long-term success
rates comparable to bypass performed for either
atherosclerosis or fibromuscular dysplasia.25
In NSAA patients pericardial and myocardial
involvement has been reported in clinical and autopsy
cases,27-29 which is a feature of acute phase of the disease.
This may precipitate as congestive cardiac failure. However,
the involvement of the endocardium is debated.
The autopsy data indicates myocardial necrosis,
inflammatory cell infilteration, myocytosis with minimal
or absent muscle hypertrophy.29 However, in our studies
extensive inflammation around pericardium was observed
in mice of group F (MD) and G (AV) (Fig. 5), inflammatory
foci in outer myocardium in only one animal of group G (AV)
and no change in the endocardium was seen by 8th month
of sacrifice. Talwar et al. 28 studied the morphology of
myocardium on the biopsies taken from these patients. They
observed myocardial inflammation in 50% of these patients.
Mild to moderate hypertrophy and mild interstitial fibrosis
was revealed in 2 out of 7 patients of congestive heart
failure.
The aortic lesions in the acute stage are usually confined
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Indian Heart J 2005; 57: 143–150
to the peri-adventitial inflammation, occasional infiltration
of lymphocytes/plasma cells in media, whereas fibrosis,
hyalinization and collagenization of the fibrous tissue
replaces the functional elements of the tunica adventitia
and media in the chronic stage.
We observed extensive peri-adventitial inflammation
around the aorta of mice of group C (SC), group D (AC),
group E (IN), group F (MD), and group G (AV).
Patchy deposits in media as well as thickened tunica
adventitia was observed in one of the animals of group G
(AV). One or two animals belonging to group G (AV)
exhibited spaces in the elastic fibers of media and
straightening of these fibers of aorta. We could not observe
the destruction of the elastic fibres in media as described in
Takayasu’s arteritis patients31 whereas Scebat et al.14, Ueda
et al.5 and Sen et al.23 could induce somewhat similar lesions
in the rabbit aorta as those of NSAA patients. Scebat et al.14
observed increased number of collagen and elastic fibers,
accumulation of fibroblasts along with intimal lesions,
disruption of the elastic lamina and necrotic muscle fibers.
Scebat and colleagues14 thus put forward a hypothesis that
the lesions modify the structure of the arterial tissue which
would turn into an autoantigen during the pathologic
period. This hypothesis, however, does not correlate with
our findings where the rise in antiaorta antibody titer
preceded the lesions. Thus it can be speculated that this
rise in antibody titer may not be the result, but probably
the cause of the lesions seen in our experimental animals.
Similarly the experimental lesions produced in Ueda’s
study on rabbits which showed the fragmentation of elastic
fibers, degeneration of muscle fibers and cellular infiltration
in the media were also preceded by the rise in antibody titer.
Sen et al.23 injected various physical agents, chemical
irritants (25% hypertonic saline, 2.5% phenol in glycerine,
2% phenol, 2% glacial acetic acid and 4% glycerine),
antigenic and bacterial products (PPD, BCG, streptococcus
and tuberculin) to produce aortitis in rabbits, but they could
observe gross changes in periaortic tissues as well as all the
layers of aorta only in animals injected with bovine tubercle
bacilli and human tubercle bacilli. They found minimal
changes like mild peri-adventitial inflammation in animals
who received chemical injury, Freund’s adjuvant and BCG.
Rest of the animals showed no changes.
However, they did not perform any immunological
studies in these animals. Experimental work carried out
by them corroborated the hypothesis that adventitia
develops the inflammatory reaction first as has also been
observed in our experimental animals. This was followed
by fibrous proliferation of intima leading to marked
occlusion of the lumen and probably medial changes in the
aorta at a later stage of the disease. Somewhat similar
IHJ-548-03.p65
149
Dhingra et al. Induction of Aortoarteritis 149
findings have also been seen in our study suggesting that
the disease is in acute phase which will be followed by
chronic phase later.
References
1. Kinare S, Gandhi MS, Deshpande JR. Non-specific aortoarteritis pathology and radiology. 1st ed. Quest publications, 1998
2. Lupi-Herrera E, Sanchez-Torres G. Marcushamer J, Mispireta J, H
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produced immunologically in rabbits. Jpn Heart J 1968; 573-582
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7. Trelstad RL. Human aorta collagens: evidence for three distinct
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antibody from patients sera. Jpn Circ J 1966; 30:75
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10. Ueda H, Saito Y, Ito I, Yamaguchi H, Takeda T. Further immunological
studies of aortitis syndrome. Jpn Heart J 1971; 12: 1–21
11. Sam Rose. PhD thesis. Immunological studies on aortoarteritis. 1989
12. Baltazares M, Mendoza F, Dabague J, Reyes PA. Antiaorta antibodies
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immunosorbent essay for detection of antiaorta antibodies in
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aortoarteritis (Takayasu’s disease). An immunological and autopsy
study. Jpn Heart J 1983; 24: 549–556
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and Radiographic Aspects. Published in Raven Press New York,
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21. Danaraj TJ, Wong HO. Primary arteritis of abdominal aorta in
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Bhavani et al. Lipid Profile and Apolipoprotein E Original
Polymorphism
151
Article
Lipid Profile and Apolipoprotein E Polymorphism in
Essential Hypertension
AB Bhavani, KB Sastry, N Krishna Reddy, T Padma
Departments of Genetics and Cardiology, Osmania University and CARE Hospital, Hyderabad
Background: Studies in several populations have indicated that genetic variation at the apolipoprotein E
structural locus influences atherosclerosis leading to cardiovascular diseases. The possible role of apolipoprotein
E polymorphism in the development of essential hypertension has not been sufficiently investigated. In this
case-control study, we aimed to determine the significance of association between essential hypertension and
apolipoprotein E genotypes. In addition, apolipoprotein E genotypes were correlated with serum lipid levels in
order to understand the possible interaction between the specific genotype and the lipid profiles that can
contribute to hypertension.
Methods and Results: The apolipoprotein E genotypes were assayed in 185 patients and 200 controls by
polymerase chain reaction followed by enzymatic digestion with Hha I. Using logistic regression analysis, the
multivariate-adjusted odds of hypertension were calculated. The incidence of ε4allele was found to be significantly
higher in patients (12.16%) than in controls (5.75%, χ2=10.87; p<0.05) and also in patients with positive
family history (16.7%) as compared to negative family history (8.87%, χ2=8.45; p<0.1). Further, it was observed
that carriers of ε4 allele have twice as much risk (p<0.05) for developing hypertension as compared to carriers
of other alleles. Patients with ε4 allele had significantly higher levels of total cholesterol and low-density
lipoprotein- cholesterol as compared to ε4 allele non-carriers (p<0.05). The adjusted odds ratios for ε4 and ε2alleles
versus ε3 allele were 2.2 (95% confidence interval 1.2 to 3.8, p< 0.05) and 1.2 (95 % CI, 0.75 to 1.77, p<
0.514), respectively.
Conclusions: Our study revealed a strong association of apolipoprotein E locus with hypertension and lipid
profile. However, large population-based studies are needed to understand the exact role played by the locus in
causing the condition. (Indian Heart J 2005; 57: 151–157)
Key Words: Essential hypertension, Apolipoprotein E polymorphism, Dyslipidemia
P
revalence of hypertension (HTN) is higher in adult
Indians in urban areas compared with rural areas (2040% v. 12-17%).1-3 Patients with hypertension are usually
asymptomatic and its significance derives from target organ
damage.4,5 The pathologic effects of hypertension are
mediated through changes in blood vessels including
fibromuscular hyperplasia of vessel walls and accelerated
arteriosclerosis6 leading to coronary artery disease (CAD),
congestive heart failure, stroke and renal failure. Blood
pressure acts synergistically with other risk factors such as
diabetes mellitus (DM), hypercholesterolemia, and smoking
and increases the risk for cardiovascular diseases (CVD)
especially in the elderly.1,7,8 Apart from classic vascular risk
factors, genetic factors are also known to play a role in the
etiology of CVD.9,10
Correspondence: Prof T Padma, Department of Genetics, Osmania
University, Hyderabad 500007. e-mail: [email protected]
IHJ-698-04.p65
151
Previously, the role of apolipoprotein E (apo E) polymorphism in causing atherosclerotic events has been
reported.11-13 Apo E is an exchangeable protein which acts
as ligand for low-density lipoprotein (LDL) receptors. It also
has a repair function in response to tissue injury. It plays
an essential role in lipid metabolism, specially in the
removal of atherogenic remnants of triglyceride-rich
lipoproteins14,15 and by reversing cholesterol transport in
plasma and intercellular lipid transport within tissues.
The human apo E gene is 3.7 kb including 4 exons and
3 introns 16,17 and is mapped on the short arm of
chromosome 19.17-19 The mature protein is composed of
299 amino acids, i.e. 34 KDa with several functional
domains.16,20
The presence of apo E polymorphism was first described
by Utermann et al.21 Three common isoforms of apo E
including E2, E3 and E4 22,23 have been identified. The three
6/21/2005, 2:38 PM
152 Bhavani et al. Lipid Profile and Apolipoprotein E Polymorphism
alleles ε2, ε3, and ε4 show differences in amino acid residues
at two sites, 112 and 158.23,24 E3 is the most common of
these isoforms and is distinguished by cysteine at position
112 and arginine at position 158 in the receptor-binding
region of apo E.23,24 Apo ε2 has a lower binding affinity to
LDL receptors (1% of the apo ε3 binding activity), whereas
the binding of ε4 to the LDL receptor is higher.21
The genetic variations at apo E have been shown to affect
lipid and lipoprotein levels in the general population.25-27
The E4 isoform is associated with increased levels of total
cholesterol (TC) and beta lipoprotein 28 and increased
susceptibility to CVD. 27 Most patients with type II
hyperlipoproteinemia are homozygous for the E2 isoform
that binds with reduced affinity to cellular receptors.29,30
Population-based studies reveal that the E2 isoform is
associated with decreased levels of cholesterol and beta
lipoprotein.28 In the present study we aimed to find out the
association of apo E genotypes with HTN by comparing
hypertensives with normotensives, familial hypertensives
with non-familial hypertensives and also apo E
polymorphism in relation to lipid levels.
Methods
Patients: The study group consisted of patients who were
admitted to the cardiology unit of CARE hospital as well as
outpatients who had previously been diagnosed to have
essential hypertension (EH). The diagnosis was based on
the complete physical and clinical examination of patients
by the cardiologist followed by appropriate investigations.
Hypertension was considered to be present if an
individual had a history of HTN or was using antihypertensive agents or if the systolic blood pressure (SBP)
exceeded 140 mmHg or the diastolic blood pressure (DBP)
exceeded 90 mmHg.5
Controls: Random subjects who were free of HTN were
included in the study as controls.
Inclusion and exclusion criteria: For the present study,
only patients with EH were included while patients with
secondary HTN and those associated with renal,
pulmonary and Alzheimer’s disease etc. were excluded.
Potential confounders: In the present study, evaluation
of the contribution of confounding risk factors to the
development of EH was based on the individual’s personal
history, physical examination and laboratory findings.
Control subjects were also similarly evaluated. The
confounding risk factors included smoking and alcohol
consumption, body mass index (BMI), dyslipidemia, and
family history of HTN.
IHJ-698-04.p65
152
Indian Heart J 2005; 57: 151–157
Collection of samples: 5 ml of 12 hours fasting
venous blood samples were collected from 185 hypertensive
patients and 200 controls. Serum from the samples was
used to estimate lipid levels.
Biochemical markers: TC, high-density lipoprotein
(HDL)-cholesterol (HDL-c) and triglyceride concentrations
were determined enzymatically using commercially
available kits and auto analyzer available at the CARE
Hospital. LDL-c was estimated using Friedewald’s formula.31
Apo E genotyping: Leucocyte DNA was extracted
following standard protocols.32 DNA was amplified by PCR
in a DNA thermal cycler (Perkin Elmer Cetus) using
oligonucleotide primers (Hysel India Ltd), forward (5’ACAGAATTCGCCCCGGCCTGGTACAC-3’) and reverse (5’TAAGCTTGGCACGGCTGTCCAAGGA-3’) as described by
Hixson et al.33 Electrophoresis of amplified products (244
bp) was performed on 14% polyacrylamide gel, after
digesting with the Hha I restriction enzyme (10 µl PCR
product + 5 units of enzyme incubated at 37oC overnight).
After electrophoresis, the gel was stained with ethidium
bromide (0.2 mg/L) for 10 min and the digested fragments
were visualized under UV illumination. Sizes of Hha1
fragments (91 bp, 83 bp, 72 bp, 48 bp, 38 bp and 35 bp)
were determined by comparison with known size marker
(50 bp) and the genotypes were determined (Fig. 1).
Statistical analysis: Standard statistical procedures from
the SPSS package were used for the analysis of the data.
For major risk factors and potential confounders,
differences between hypertensive cases and control groups
were tested by using appropriate tests of significance (χ2,
and t test). As the distribution of triglycerides was
skewed, the log-transformed values were used for the
analysis. Allele frequencies were calculated as per gene
frequency formula and following Hardy-Weinberg law and
the frequencies were tested for Hardy-Weinberg
equilibrium. The allelic association was further tested by
Wolf ’s test.34
To evaluate the association of apo E polymorphism with
HTN, multiple logistic regression was used with maximum
likelihood estimation of the regression coefficients and their
standard errors. All the potential confounders were systematically tested in the regression model. Multivariateadjusted odds ratios were calculated for apo ε4 allele (ε4/4
and ε3/4) and ε2 allele (ε2/2, ε2/3 and ε2/4) taking ε3 allele
(ε3/3) as reference. For each odds ratio we calculated twotailed p values and 95% confidence intervals (CI). Significance levels were set at 0.05 in all cases.
6/21/2005, 2:38 PM
Indian Heart J 2005; 57: 151–157
Bhavani et al. Lipid Profile and Apolipoprotein E Polymorphism 153
Table 1. General characteristics observed in hypertensive
patients and controls
General characteristics
Mean age (years)
Male ratio (%)
Family history of EH (%)
DM (%)
CAD (%)
Stroke (%)
Smoking (%)
Alcohol consumption (%)
SBP (mmHg)
DBP (mmHg)
BMI (kg/m2)
Patients (n=185)
Controls (n=200)
51.0 ± 0.64*
87*
42*
50*
27*
5
24
30*
150.4 ±1.58*
92.4 ± 0.57*
26.1 ± 0.28*
45.6 ± 0.53
52
18
8
2
2
18
12
119.9 ± 0.50
80.0 ± 0.24
25.5 ± 0.29
* p<0.05 difference between patients and controls (χ2 or t test)
EH: essential hypertension; DM: diabetes mellitus; CAD: coronary artery disease;
SBP: systolic blood pressure; DBP: diastolic blood pressure, BMI: body mass index
Fig. 1. Electrophoretic separation of Hha I fragmented after gene amplification; the fragment sizes (in bp) of a DNA standard (50 bp, lane-marked as M)
are shown to the left of the gel. With the exception of a shared 38 bp fragment
(common Hha I site at position 38, the other shared fragments were not detected due to their smaller sizes), each genotype possessed unique combinations
of Hha I fragment sizes. The E3/E3 sample contained the 91 bp fragment (112
cys), as well as 48 and 35 bp fragments from cleavage site at 158 arg. The E4/
E4 sample also contained these 48 and 35 fragments (158 arg), as well as a
unique 72 bp fragment from cleavage at 112 arg (the 19 bp fragment was too
small for detection). Each sample from heterozygotic combinations contained
both sets of fragments from each apo E allele.
Results
Characteristics of the study sample: In the present
study 185 patients with EH were compared with 200
normotensive controls for the association with different
epidemiological factors as specified in Table 1. The patients
were in the age group of 35-65 years with a mean age of
51.0±0.64 years, while the controls were in age range from
35-60 years with a mean age of 45.6±0.53 years.
Significant differences were observed between the mean
ages of patients and controls (p<0.05). SBP (150.4±1.58
mmHg, p<0.05) and DBP (92.4±0.57 mmHg, p<0.05)
were found to be significantly higher in patients than in
controls (119.9±0.50 mmHg and 80.0±0.24 mmHg,
respectively).
Statistically significant sex differences were observed
between patients and controls (χ2=5.495, p<0.05) with a
significant preponderance of males in the patient group
(87%) as compared to controls (52%); 42% of the patients
had a positive family history for EH, compared to 18%
positive family history among the controls (χ2=26.91,
p<0.05, Table 1). Cigarette smoking did not show any
statistically significant difference between patients and
controls. However, alcohol consumption in patients was
highly significant (30%, χ2=19.49, p<0.05) as compared
IHJ-698-04.p65
153
to controls (12%). Though the BMI in patients (26.1±0.28
kg/m2) showed slight elevation, the value did not differ
significantly from the BMI of controls (25.5± 0.29 kg/m2).
Frequencies of alleles and genotypes: The distribution
of apo E genotypes in hypertensives differed significantly
from controls ( χ 2=10.87, p<0.05, Table 2). Similar
observation was made when the distribution in males versus
females and familial versus non-familial cases were
considered ( χ 2=8.45, p<0.1, and χ 2=26.93, p<0.05,
respectively.)
The prevalence of genotypes and the allele frequencies
among patients and controls are shown in Table 3. It was
observed that prevalence of E3/4 genotypes was 1.5-fold
high in patients when compared to controls (14.5% v.
10.0%, p<0.05) while prevalence of E2/3 genotypes was
high in controls than in patients (6.5% v. 4.3%). Statistically
significant difference was not found between patients and
controls with respect to ε2 and ε3 allele frequencies, while
ε4 allele frequency was found to be much more prevalent
in patients (12.16%) than in controls (5.75%, χ2=10.87,
p<0.05). Further, the allelic distribution was found to be
deviated significantly from Hardy-Weinberg equilibrium in
patients but not in controls (χ2=14.4, p<0.05, Table 3).
When tested by Wolf ’s method, this allelic association
showed higher relative incidence of ε4 allele (RI= 2.24, χ2=
9.13, p<0.05) as compared to other alleles and also in cases
with family history of hypertension (RI=2.407, χ2=6.79,
p<0.05, Table 4).
We divided individuals according to sex, age groups and
either ε 4 allele carriers (ε 4+) or ε 4 allele non-carriers
(ε4-) in order to find out the relationship between age, sex
and the occurrence of hypertension. We found that, ε4+/ε4+
groups had more male patients in the 45-55 years age
group than in controls (χ2 =6.78, p<0.05).
6/21/2005, 2:38 PM
Indian Heart J 2005; 57: 151–157
154 Bhavani et al. Lipid Profile and Apolipoprotein E Polymorphism
Table 2. Prevalence of apo E genotypes with reference to gender and presence of family history
Variable/Genotype
χ2 (df=4)
3/3
3/4
2/3
4/4
2/4
Total
Hypertensives
Controls
140 (75.68)
165 (82.5)
27 (14.60)
20 (10.00)
8 (4.32)
13 (6.50)
8 (4.32)
1 (0.50)
2 (1.08)
1 (0.50)
185
200
10.87*
Family history:
Positive
Negative
Male
Female
53 (67.95)
87 (81.31)
130 (80.75)
10 (41.67)
14 (17.95)
13 (12.15)
20 (12.42)
7 (29.17)
5 (6.41)
3 (2.80)
3 (1.86)
5 (20.83)
6 (7.69)
2 (1.87)
6 6(3.73)
2 (8.33)
0 (0.00)
2 (1.87)
2 (1.24)
0 (0.00)
78 (42.16%)
107 57.84%)
161 (87.02%)
24 (12.97%)
8.45**
26.93*
The values in parentheses are percentages
* p<0.05, **p<0.10
Table 3: Prevalence of apo E genotypes and allele frequencies in hypertensive patients and controls
Patients
Genotype Observed Percent
3/3
3/4
2/3
4/4
2/4
2/2
140
27
8
8
2
0
Total
78.4
14.6
4.3
4.3
1.1
0
185
χ2
Controls
Observed Percent
0.2593
3.3371*
0.0302
10.1316*
0.5075
0.1349
165
20
13
1
1
0
14.4006**
200
Allele frequencies:
ε3 = 0.8514
ε4 = 0.1216
ε2 = 0.0270
*p<0.05 with 1 degree of freedom
**p<0.05 with 3 degrees of freedom
82.5
10.0
6.5
0.5
0.5
0
χ2
0.0834
0.0366
0.0069
0.5124
0.0472
0.2450
0.9315
ε3 = 0.9075
ε4 = 0.0575
ε2 = 0.0350
2 v. 3
2 v. 4
3 v. 2
3 v. 4
4 v. O
Disease v. control
Familial v. non-familial
RI
χ2
RI
χ2
0.8128
0.3651
1.2303
0.4490
2.2420
0.2423
4.2818*
0.0242
8.9542*
9.1295*
0.6667
0.7308
1.5000
0.4872
2.4070
0.3980
1.0796
1.2716
4.9674*
6.7918*
Apo E: apolipoprotein E; RI: relative incidence; O: others
*p<0.05
Apo E genotypes and lipids: Table 5 shows mean
distribution of lipid levels in patients and controls. In
general, TC, LDL-c and triglyceride levels were found to be
significantly elevated in patients (200.0±2.83 mg/dl,
195.85±3.6 mg/dl and 195.61±8.91 mg/dl respectively,
p<0.05) than in controls (180.78±1.9 mg/dl,
139.22±1.11 mg/dl and 122.4±1.86 mg/dl, respectively).
HDL-c levels were found to be significantly reduced in
patients (43.77±1.49 mg/dl, p<0.05) when compared to
controls (46.47± 0.48 mg/dl).
In general it was observed that TC, LDL-c and TG levels
were significantly elevated in ε4 allele carriers than in ε4
allele non-carriers (p<0.05, Table 6), while HDL-c levels
IHJ-698-04.p65
154
Association between genotype and phenotype:
Multiple stepwise logistic regression analysis indicated that
LDL-c levels (p<0.05), alcohol consumption (p<0.05), TC
levels (p<0.05), family history (p<0.05) and sex (p<0.05)
were significant and independent predictors of
hypertension (Table 7). Multivariate-adjusted odds ratios
for ε4 and ε2 alleles versus ε3 allele were 2.2 (95% CI 1.2 3.8, p< 0.05) and 1.2 (95 % CI, 0.75 - 1.77), respectively.
Discussion
Table 4. Allelic association with disease and family history
Apo E allele
were reduced in ε4 allele non-carriers (p<0.05). These
observations clearly indicate the correlation between the
alleles at apo E locus and the lipid metabolism.
Studies conducted in different parts of the globe reveal
that the gene frequencies at apo E locus are highly
heterogeneous between the populations. The ε3 is the most
common form of the gene in most of the populations
followed by ε4 and ε2 alleles.24,26 In a population-based study
Venkataramana et al.35 reported the allele frequencies in
Indian population as 85-92% for ε3 allele, 3-9% for ε4 allele
and 3-5% for ε2 allele. In the present study, apo E allele
frequencies in the control group are comparable with the
study of Venkataramana et al.35
It is well known that the ε4 allele of Apo E is associated
with the increased prevalence of atherosclerosis and
CAD. 36,37 However, there are controversial results
Table 5. Plasma lipid profiles as observed in hypertensive
patients and controls
Lipids
n
TC (mg/dl)
HDL-c (mg/dl)
LDL-c (mg/dl)
TG (mg/dl)
185
185
185
185
Patients
Mean
SE
200.00* 2.83
43.77* 1.49
195.85* 3.60
195.61* 8.91**
n
200
200
200
200
Controls
Mean
180.78
46.47
139.22
122.4
SE
1.90
0.48
1.11
1.86
TC: total cholesterol; HDL-c: high-density lipoprotein cholesterol; LDL-c: low- density lipoprotein cholesterol; TG: triglyceride; SE: standard error
*p< 0.05 (t test)
**test with log-transformed variable
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Indian Heart J 2005; 57: 151–157
Bhavani et al. Lipid Profile and Apolipoprotein E Polymorphism 155
Table 6. Mean distribution of lipid levels in hypertensive
patients and controls with respect to apo ε alleles
Table 7. Multiple logistic regression analysis showing the
contribution of risk factors to hypertension
Variable
Variable
Patients
a
TC
HDL-c
LDL-c
TG
ε4+ (n=37)
b
ε4- (n=148)
216.2 (5.75)* 206.3 (3.94)
40.2 (1.31)*
39.5 (0.65)
135.2 (4.83)* 130.5 (3.40)
210.6 (16.35)* 182.7 (7.99)
Controls
a
ε4+ (n=22)
205.4 (7.67)
45.1 (0.92)
114.4 (7.02)
165.8 (11.83)
b
ε4- (n=178)
189.1 (2.65)
44.3 (0.54)
106.2 (5.15)
158.8 (4.68)
TC: total cholesterol; HDLc: High-density lipoprotein cholesterol: LDL-c: low- density
lipoprotein cholesterol; TG: triglyceride
a
ε4+ (ε4 allele carriers - E4/4, E3/4, E2/4)
b
ε4– (ε4 allele non-carriers - E3/3, E2/3)
Figures in parentheses represent standard errors
*p<0.05
concerning the association between apo E genotype and
some cardiovascular risk factors. Some studies have
suggested that high blood pressure may be associated with
the presence of the ε4 allele,38-40 while others have found its
association with ε2 allele.41 However, no association was
found in few studies.42 Apo E may interfere with smooth
muscle cell proliferation,14,43 and thus participate in smooth
muscle cell hypertrophy in the arterial wall. These
mechanisms may explain the association found in young
or middle-aged populations that were mainly included in
the previous studies. However, other mechanisms such as
increased rigidity and decreased elasticity of the aorta and
other large vessels43,44 may contribute to the development
of high blood pressure, and thus explain the lack of
association in the elderly subjects.
Recent investigations on the effect of age and sex on the
apo E genotypes suggest that in middle aged men (<51
years), ε 4 allele carriers are at a greater risk for the
development of the disease.45 Context-dependency of apo
E polymorphism and associated effects have been
demonstrated suggesting other genetic components to be
equally important, and lifestyle including dietary habits are
now recognized factors that can either mask or expose an
effect of a specific apo E genotype.46,47
The lower plasma total cholesterol levels observed in
subjects carrying the ε2 allele generally correlate with
reduced coronary and peripheral artery atherosclerosis,
and the higher cholesterol level seen in ε 4 carriers is
associated with a higher prevalence of cardiovascular
disease. However, the effect of apo E variation on clinical
atherosclerosis is not completely explained by its impact on
risk factor levels, as recent studies have demonstrated
association between carotid atherosclerosis 48-50 and
coronary artery calcification51 in asymptomatic adults.
There is convincing evidence that the relationship
between apo E genotype and plasma lipoprotein-lipid levels
is context-dependent, being significantly influenced by age52
and sex. 53-55 Recent evidence 24 also indicates that the
IHJ-698-04.p65
155
β
Apo E4 a
0.771
Apo E2 b
0.142
LDL-c (mg/dl) 1.671
1.467
Alcohol c
TC (mg/dl)
2.215
d
Family history 1.827
e
1.615
Smoking
Sex f
0.723
SE
df
p value
Odds ratio
95% CI for
odds ratio
0.291
0.218
0.314
0.351
0.331
0.341
0.403
0.295
1
1
1
1
1
1
1
1
0.008*
0.514
0.000*
0.000*
0.000*
0.000*
0.000*
0.014*
2.160
1.153
5.317
4.338
9.161
6.217
5.028
2.060
1.22 – 3.83
0.75 – 1.77
2.87 – 9.84
2.18 –8.63
4.49 – 17.52
3.19 – 12.13
2.28 – 11.07
1.16 – 3.67
a E4/4 and E3/4 v. E3/3, E3/3 as reference
b E2/4 and E2/3 v. E3/3, E3/3 as reference
c Non-alcoholic as reference
d Absence of family history as reference
e Non-Smokers as reference
f Female sex as reference
* p<0.05
CR: confidence interval; Apo: apolipoprotein; LDL-c: low-density lipoprotein cholesterol; TC: total cholesterol
responses of plasma lipoprotein-lipid levels to different lipidlowering interventions may be affected by an individual’s
apo E genotype, indicating the significance of geneenvironment interactions.
These changes in lipid parameters indicate a delayed
degradation of the administered fatty load. The most
significant changes were evident in the subgroup of apo ε4
carriers reflecting their higher fasting lipid levels. This
abnormal lipid metabolism is similar in character as
observed in patients with confirmed ischemic heart disease
or carotid atherosclerosis and is another manifestation of
an increased atherogenic risk of hypertension patients.
Conclusions: A significant association of ε 4 allele is
observed with hypertension in addition to the other well
known risk factors and positive family history. Carriers of
ε4 allele together with dyslipidemia form a higher risk group
showing greater susceptibility to CAD. These observations
emphasize the need to monitor HTN and lipid metabolism,
specially in middle-aged males and those with a positive
family history, to reduce the susceptibility to CAD. Further,
this complex interplay between genetic and environmental
factors must be thoroughly considered in order to evaluate
the etiological role of apo E in hypertension.
Acknowledgements
We extend our gratitude to K Vishweshwar Rao (formerly
statistician at National Institute of Nutrition) for his
valuable guidance in the statistical analysis.
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158 Mohan
et al.
Brief
Report
Indian Heart J 2005; 57: 158–160
M-Shaped Doppler Signal across VSD
M-Shaped Doppler Signal Across Ventricular Septal Defect:
Potential Implications for Estimation of Right Ventricuilar
Systolic Pressure
JC Mohan, LR Nath
Department of Interventional Cardiology, Metro Golden Heart Institute, New Delhi
An 8-year-old child suffering from ventricular septal defect and severe valvular pulmonary stenosis was
evaluated by echo-Doppler technique and cardiac catheterization. A peak instantaneous transventricular systolic
gradient of 64 mmHg was recorded across the ventricular septal defect with an interesting M-shaped spectral
pattern. However, cardiac catheterization revealed a peak-to-peak non-simultaneous gradient between the right
and the left ventricle of only 14 mmHg. This discrepancy along with its implications are discussed in this report.
(Indian Heart J 2005; 57: 158–160)
Key Words: Ventricular septal defect, Echocardiography, Congenital heart disease
N
on-invasive estimation of right ventricular (RV)
systolic pressure in patients with ventricular septal
defect (VSD) can be done by two methods. If a complete
signal of tricuspid valve regurgitation can be accurately
obtained, the modified Bernoulli equation will allow for
calculation of the RV systolic pressure by adding the
assumed right atrial pressure to the gradient.1 The second
method that measures the Doppler velocity across the VSD
can evaluate RV systolic pressure if the transventricular
gradient is substracted from the left ventricular (LV)
pressure which equals cuff systolic blood pressure in the
absence of LV obstruction.2,3 Most of transventricular
continuous wave Doppler signals show a plateau allowing
the peak Doppler velocity to accurately estimate peak-topeak gradient between the right and the left ventricles on
cardiac catheterization tracings.4 This helps in treating
patients with VSD properly by providing a non-invasive
estimation of the RV systolic pressure and of the pulmonary
pressure in absence of RV obstruction. Minor differences
between non-invasively Doppler-determined pressure and
the one obtained at cardiac catheterization can be
attributed to the limitations of the simplified Bernoulli
equation. Significant differences between the estimated
pressure by two methods, which could impact the
management of such patients have received scant
attention.5,6 This report describes such a situation in a
patient with VSD and its possible explanations.
Correspondence: Prof. JC Mohan, Metro Golden Heart Institute
Third Floor, Jaipur Golden Hospital, Sector 3, Rohini, New Delhi 110085
e-mail: [email protected]
IHJ-787-04.p65
158
Case Report
An 8-year-old asymptomatic boy underwent Dopplerechocardiography for a systolic murmur detected at routine
examination. He denied history of effort intolerance.
Physical examination revealed a healthy child with heart
rate of 78 beats per min (bpm), supine systolic blood
pressure of 90/60 mmHg and no evidence of heart failure.
Precordial examination showed imperceptible apical
impulse, systolic thrill along left sternal border, normal first
heart sound, widely split second sound with muffled
pulmonary component and a grade IV/VI pansystolic
murmur along the left parasternal border radiating on both
sides. A 12-lead electrocardiogram (ECG) showed sinus
rhythm and complete right bundle branch block (RBBB).
Plain chest skiagram had prominent hilar pulmonary
shadow with normal cardiac size. Two-dimensional (2D)echocardiography showed situs solitus, levocardia, normalsized LV and normal left and right atria, RV hypertrophy,
and a small (4 mm) perimembranous VSD (Fig. 1) with an
aneurysm of the membranous septum and domed
restricted pulmonary valve. Color flow mapping revealed
left-to-right shunt across the VSD, mild tricuspid
regurgitation and turbulent systolic flow in the RV outflow
tract.
Continuous-wave Doppler examination showed a peak
systolic gradient of 71 mmmHg across the RV outflow tract
(Fig.2), an M-shaped Doppler spectrum across the VSD
(Fig.3) and an incomplete Doppler signal of tricuspid
regurgitation. The VSD Doppler signal had an early peak
systolic velocity of 4.0 m/s (gradient : 64 mmHg ), late
6/21/2005, 2:39 PM
Indian Heart J 2005; 57: 158–160
Mohan et al. M-Shaped Doppler Signal across VSD 159
Fig. 1. Two-dimensional echocardiographic parasternal long axis view showing
small subaortic ventricular septal defect.
Fig. 3. Continuous-wave Doppler signal across ventricular septal defect. Note
the typical M-shaped spectrum with higher peak velocities in early and late
systole (zoomed picture on the right side with a peak early systolic velocity of
4 m/s).
Fig. 2. Continuous-wave Doppler signal across right ventricular outflow tract
showing a peak velocity of 4.2 m/s (estimated peak gradient: 71 mmHg).
velocity of 3.5 m/s (gradient : 49 mmHg) and the midsystolic dip at 1.8 m/s (gradient : 13 mmHg). Cardiac
catheterization performed within two hours of the
echocardiographic examination under light sedation
revealed a peak LV systolic pressure of 96 mmHg (aortic
pressure 96/60 mmHg) and the non-simultaneous peak
RV systolic pressure of 82 mmHg with a pullback pressure
gradient of 66 mmHg across the RV outflow tract. Mean
right atrial pressure (4 mmHg) and the pulmonary artery
pressure (17/8 mmHg) were normal. The patient was
recommended for percutaneous balloon pulmonary
valvuloplasty.
Discussion
Echo-Doppler is a robust and validated technique to assess
intracardiac pressures by deploying modified Bernoulli
equation despite minor discrepancies.1 Transventricular
IHJ-787-04.p65
159
pressure gradient across the VSD provides an accurate
assessment of the RV pressures.2,3 Plateau appearance of
the transventricular Doppler signal is necessary for such
an estimation. This is to make sure that both the ventricular
systolic pressures peak almost simultaneously. Delay in
peaking of ventricular pressure curves may introduce
inaccuracy in assessment of RV pressure by use of
transventricular peak gradient. Physiologically, RV systolic
pressure peaks later than the LV but this delay is minor and
can be ignored. However, delayed peaking of the RV has
been described as the cause of sloped VSD signals leading
to erroneous pressure calculations.5 This delayed peaking
of the RV systolic pressure may occur due to right bundle
branch block (RBBB) and /or due to significant RV outflow
tract obstruction.5,6 Sloped Doppler signal peaks in early
systole and tapers off in mid and late systole. It has been
suggested that mid-systolic or late systolic pressure gradient
provides an accurate assessment of RV pressure in such
cases.
M-shaped VSD Doppler signal is rare and only one such
case has been reported so far.6 This occurred in a 4-yearold child who was operated for VSD, pulmonary atresia and
multiple branch pulmonary stenoses. By simultaneous
ventricular pressure recordings with transducer-tipped
catheters, the authors demonstrated larger early systolic
and a smaller late systolic pressure gradients corresponding
with the M-shaped pattern of the Doppler signal although
mean systolic pressure difference between the two
ventricles was negligible. The RV systolic pressure curve
peaked later but reached its peak earlier than the LV. The
authors hypothesized that the RBBB was the cause of initial
delayed increase in RV pressure but did not have satisfactory
6/21/2005, 2:39 PM
160 Mohan et al. M-Shaped Doppler Signal across VSD
Indian Heart J 2005; 57: 158–160
explanation for the prolonged LV pressure curve that
accounted for the terminal peak of the M-shaped signal.
Our patient had a classic M-shaped VSD Doppler signal with
a nadir velocity of 1.8 m/s (peak gradient : 13 mmHg)
which was very close to the peak-to-peak gradient (14
mmHg) obtained at cardiac catheterization. Estimating RV
systolic pressure from early or late systolic velocity gradients
could result in significant underestimation which may
impact the management of such patients.
It is easy to explain early systolic gradient in our patient
(first limb of M) because of the delay in RV pressure rise
due to the RBBB and the RV outflow tract obstruction. We
do not have a cogent explanation for the prolonged LV
pressure curve responsible for the late peak velocity
gradient (second limb of M). However, it is possible that
instead of prolonged LV pressure decay, it is the rapid right
ventricular pressure decay during late systole and
isovolumic relaxation which is responsible for this
phenomenon. Such an explanation needs further
validation in these patients.
RV and the LV. Velocity at the valley of the Doppler signal
provides a true estimate of peak-to-peak transventricular
gradient, and should be used.
Conclusions: This is a rare case report of a patient with
an M-shaped Doppler signal across a VSD that shows the
potential for underestimation of RV pressure. In this case,
maximum instantaneous Doppler gradient erroneously
overestimates peak-to-peak systolic gradient between the
IHJ-787-04.p65
160
References
1. Ensing G, Seward J, Darragh R, Caldwell R. Feasibility of generating
hemodynamic pressure curves from non-invasive Doppler
echocardiographic signals. J Am Coll Cardiol 1994; 23: 434–442
2. Marx GR, Allen HD, Goldberg SJ. Doppler echocardiographic
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with interventricular communications. J Am Coll Cardiol 1985; 6:
1132–1137
3. Pieroni DR, Nishimura RA, Bierman FZ, Colan SD, Kaufman S,
Sanders SP, et al. Second natural history study of congenital heart
defect: ventricular septal defect: echocardiography. Circulation 1993;
87: 180–188
4. Murphy DL Jr, Ludomirsky A, Huhta JC. Continuous-wave Doppler
in children with ventricular septal defect: non-invasive estimation
of interventricular pressure gradient. Am J Cardiol 1986; 57:
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5. Schamberger MS, Farrell AG, Darragh RK, Cordes TM, Ensing GJ.
Use of peak Doppler gradient across ventricular septal defect leads
to underestimation of right-sided pressure in patients with "sloped"
Doppler signals. J Am Soc Echocardiogr 2001; 14: 1197–1202
6. Lindblade CL, Schamberger MS, Darragh RK, Cordes TM. Use of peak
Doppler gradient across ventricular septal defect leads to
underestimation of right-sided pressures in a patient with M-shaped
Doppler signal: a case report. J Am Soc Echocardiogr 2004; 17:
1207–1209
6/21/2005, 2:39 PM
Indian Heart J 2005; 57: 161–163
Rohit et al.
Transcatheter Closure
of APW
161
Brief
Report
Transcatheter Closure of Aortopulmonary Window
Manojkumar Rohit, S Nandakumar, Ajay Bahl, S Kubba, KK Talwar
Department of Cardiology, Post Graduate Institute of Medical Education and Research, Chandigarh
Aortopulmonary window is an uncommon congenital cardiac defect. Most infants presenting with
aortopulmonary window will require conventional surgical repair. Experience with transcatheter closure of
aortopulmonary window is limited. We report the case of a 9-year-old girl with aortopulmonary window, in
whom transcatheter closure was performed successfully using Amplatzer ductal occluder device. (Indian Heart
J 2005; 57: 161–163)
Key Words: Aortopulmonary window, Amplatzer ductal occluder, Congenital heart disease
A
n aorto-pulmonary window (APW) is a
communication between the pulmonary artery and
the ascending aorta in the presence of two separate semilunar valves.1 The window is usually a large oval defect but
in about 10% of cases it is small. 2 APW accounts for
approximately 0.1% of all congenital cardiac anomalies.3
Associated anomalies occur in 50% of cases and include
interrupted aortic arch, right pulmonary artery from aorta,
coarctation of aorta, coronary artery from main
pulmonary artery, tetrology of Fallot, or even pulmonary
atresia or aortic atresia. Mori et al.4 classified APW as Type
I (proximal defect between ascending aorta and main
pulmonary artery), Type II (distal defect between ascending
aorta and right pulmonary artery), and Type III (all the
defectsw inclusive, Type I+II). In most cases, surgical repair
is undertaken during infancy using different techniques like
ligation without cardiopulmonary bypass (CPB), division
and over-sewing between clamps on CPB, or transaortic
patch closure.1 The experience with transcatheter closure
of APW is limited. We report a case of successful closure of
APW using Amplatzer ductal occluder device.
Case Report
A 9-year-old girl presented to us with history of recurrent
episodes of respiratory tract infection and congestive heart
failure during infancy and childhood, which was managed
medically. On examination, she had a high volume
collapsing pulse with a rate of 80 per min. Her blood
pressure was 100/60 mmHg. Apex beat was felt in the left
Correspondence: Dr Manojkumar Rohit, Assistant Professor
Department of Cardiology, Post Graduate Institute of Medical Education and
Research, Chandigarh 160021. e-mail: [email protected]
IHJ-804-05.p65
161
6th intercostal space 1 cm outside the mid-clavicular line.
Grade V/VI continuous murmur was present which was
best heard over the left 2nd and 3rd intercostal space.
Hemoglobin was 12 gm/dl and baseline biochemical
parameters were normal. Echocardiogram showed
turbulent flow across APW and holo-diastolic run off in
descending aorta. However, the size of APW was not clear
on echocardiography. Left atrium and ventricle were
dilated. There was no patent ductus arteriosus or
coarctation of aorta. The pulmonary valve was thick,
doming with a gradient of 40 mmHg. Cardiac
catheterization and selective aortogram were performed.
A 26% step-up in oxygen saturation was noted in the main
pulmonary artery. Pulmonary artery pressure was 22 /12
mmHg (mean 16 mmHg). Pulmonary to systemic flow ratio
(Qp / Qs) was 6.5 (Table 1). Selective ascending aortogram
in lateral view showed the presence of APW measuring 6
mm in diameter (Fig. 1). It was round in shape, and was
located in the left lateral wall of the ascending aorta, 8 mm
away from the origin of the left main coronary artery
(LMCA). It communicated with the main pulmonary artery
on its right wall with adequate margin from the pulmonary
valve and the bifurcation of the pulmonary trunk. The
APW was crossed from the venous side via the right femoral
vein, inferior vena cava, right atrium, right ventricle and
pulmonary trunk with a 5 F Picard catheter and 0.035"
Terumo wire. The Picard catheter was then advanced over
the wire and its tip positioned in the descending aorta. The
Terumo wire was exchanged with an extra stiff Amplatzer
J-tipped 0.035" wire leaving its tip in the descending aorta.
A long 7 F Cook’s sheath and dilator were advanced over
the wire and its tip positioned across the APW into the
descending aorta. A 10×8 mm Amplatzer ductal occluder
device was deployed across the APW. A check aortogram
6/21/2005, 2:41 PM
162 Rohit et al.
Indian Heart J 2005; 57: 161–163
Transcatheter Closure of APW
was done to ensure complete occlusion of the defect
without impinging upon LMCA. The device was delivered
and the sheath was withdrawn to the inferior vena cava.
An aortic root angiogram performed after 10 min showed
the device occluding the APW completely (Fig. 2). There
was no impingement of left coronary artery or aortic or
pulmonary regurgitation. The continuous murmur
disappeared and the follow-up echocardiography done at
3 months showed no residual shunt and valvular
pulmonary stenosis was mild (28 mmHg).
Table 1. Pressure and oximetry data
Pressure data (mmHg)
PA wedge (mean)
MPA
RV (systolic)
RA (mean)
LV (systolic)
Aorta
Oximetry (%)
12
22/12 (16)
SVC
RA
66
70
58
6
108
108/45 (70)
RV
MPA
Aorta
Qp/Qs
68
96
98
6.5
PA: pulmonary artery; MPA: mean pulmonary artery; RV: right ventricle;
RA: right atrium; LV: left ventricle; SVC: superior vena cava
Fig. 1. Angiogram in ascending aorta demonstrating aortopulmonary window
connecting ascending aorta and pulmonary trunk.
Fig. 2. Angiogram after successful deployment of Amplatzer duct occluder in
aortopulmonary window shows complete occlusion of the defect with the device.
Subsequently, Rashkind double umbrella occluder systems
were successfully used in a child with post-operative APW
and an infant with native APW.2,7 A buttoned device was
used to close post-operative APW in an adult. In our patient,
we used an Amplatzer duct occluder device. Literature
review revealed three case reports of closure of APW using
Amplatzer device; one in a child with post-operative APW
using a custom-made Amplatzer device and one in native
APW.8,9 In the third report, a septal occluder device and a
ductal occluder device was used in two patients.6 Our
patient also had an associated mild valvular pulmonary
stenosis which did not require balloon dilation. Most infants
presenting with APW will require conventional surgical
repair. The type of APW most suitable for device closure is
small APW located in the middle of the two great arteries,
away from the origin of the left coronary artery and the
right and left main pulmonary arteries, with no associated
congenital anomalies. 3 Significantly less discomfort,
avoidance of CPB and surgical scar, and shorter duration
of hospital stay make device closure the treatment of choice
in such selected cases of APW.
Discussion
This case report demonstrates the feasibility of non-surgical
closure of APW using Amplatzer duct occluder device in
carefully selected cases. Transcatheter closure of APW
should be considered when anatomy is favorable in terms
of location and size of the defect, in the absence of
associated anomalies. 5 Initial report of transcatheter
closure of APW describing the use of umbrella occluder
system in a child resulted in incomplete closure. 6
IHJ-804-05.p65
162
References
1. Backer CL, Mavroudis C. Surgical management of aortopulmonary
window: a 40-year experience. Eur J Cardiothorac Surg 2002; 21:
773–779
2. Tulloh RM, Rigby ML. Transcatheter umbrella closure of aortopulmonary window. Heart 1997; 77: 479–480
3. Jureidini SB, Spadaro JJ, Rao PS. Successful transcatheter closure
with the buttoned device of aortopulmonary window in an adult.
Am J Cardiol 1998; 81: 371–372
4. Mori K, Ando M, Takao A, Ishikawa S, Imai Y. Distal type of
6/21/2005, 2:41 PM
Indian Heart J 2005; 57: 161–163
aortopulmonary window: report of 4 cases. Br Heart J 1978; 40:
681–689
5. Naik GD, Chandra VS, Shenoy A, Isaac BC, Shetty GG, Padmakumar
P, et al. Transcatheter closure of aortopulmonary window using
Amplatzer device. Catheter Cardiovasc Interv 2003; 59: 402–405
6. Lock JE, Cockerham JT, Keane JF, Finley JP, Wakely PE Jr, Fellows
KE. Transcatheter umbrella closure of congenital heart defects.
Circulation 1987; 75: 593–599
7. Stamato T, Benson LN, Smallhorn JF, Freedom RM. Transcatheter
IHJ-804-05.p65
163
Rohit et al.
Transcatheter Closure of APW 163
closure of an aortopulmonary window with a modified double
umbrella occluder system. Cathet Cardiovasc Diagn 1995; 35: 165–
167
8. Richens T, Wilson N. Amplatzer device closure of a residual
aortopulmonary window. Catheter Cardiovasc Interv 2000; 50: 431–
433
9. Atiq M, Rashid N, Kazmi KA, Qureshi SA. Closure of aortopulmonary window with Amplatzer duct occluder device. Pediatr
Cardiol 2003; 24: 298–299
6/21/2005, 2:41 PM
164 Vaidyanathan
Brief
Report et al.
Residual VSD closure with Amplatzer Duct Occluder
Indian Heart J 2005; 57: 164–166
Device Closure of Residual Ventricular Septal Defect after
Repair of Tetralogy of Fallot Using the Amplatzer Duct
Occluder
B Vaidyanathan, BRJ Kannan, R Krishna Kumar
Department of Pediatric Cardiology, Amrita Institute of Medical Sciences and Research Center, Kochi
Residual ventricular septal defect after surgical repair for tetralogy of Fallot can occasionally be hemodynamically
important requiring re-intervention. Transcatheter closure using ventricular septal defect devices is an attractive
option for such defects. We describe two such cases where the Amplatzer duct occluder was used as an innovative,
less costly alternative for closure of residual membranous ventricular septal defects. Complete occlusion of the
residual ventricular septal defect with significant symptomatic improvement could be accomplished in both
patients. (Indian Heart J 2005; 57: 164–166)
Key Words: Ventricular septal defect, Tetralogy of Fallot, Amplatzer duct occluder
R
esidual ventricular septal defect (VSD) requiring reintervention is rare after primary surgical repair of
tetralogy of Fallot (TOF).1 Closure of these VSDs is indicated
if they are associated with significant left-to-right shunt or
clinical symptoms. Repeat surgery can be associated with
significant morbidity and mortality. Transcatheter closure
has emerged as a safe and effective alternative to surgery
in patients with native or post-operative residual perimembranous VSDs.2 -7 Most of these reports have used the
Amplatzer membranous ventricular septal occluder
(AMVSO) for this purpose. Pediatric cardiologists in
developing countries employ technical innovations and
utilize alternative hardware in order to cut down the cost
involved.8 We describe such an innovation whereby we used
the Amplatzer duct occluder (ADO) to close post-operative
residual membranous VSD in two patients following repair
of tetralogy of Fallot.
Case Reports
Case 1: A 17-year-old girl who had undergone intracardiac
repair for TOF at the age of 3 years presented with gradually
worsening dyspnea and palpitation on effort. Clinical
evaluation suggested a hemodynamically significant VSD
with no evidence of congestive heart failure. Chest X-ray
revealed mild cardiomegaly (cardiothoracic ratio 55%) with
Correspondence: Dr R Krishna Kumar, Chief Pediatric Cardiologist
Amrita Institute of Medical Sciences and Research Centre
PO Elamakkara, Kochi 682026. e-mail: [email protected]
IHJ-818-05(BR).p65
164
increased pulmonary blood flow. Transthoracic
echocardiogram (TTE) revealed a 7.8 mm residual VSD at
the inferior margin of the VSD patch with left-to-right
shunt (Fig. 1A). There was free pulmonary regurgitation
with no pulmonary arterial hypertension. The left
ventricular (LV) function was normal. At cardiac
catheterization, the mean right atrial and pulmonary
arterial pressures were 10 mmHg and 19 mmHg,
respectively. Oximetry revealed a Qp - Qs ratio of 2.1. The
LV end-diastolic pressure was 14 mmHg. The basal indexed
pulmonary vascular resistance was 0.5 Wood units/m2.
The LV angiogram profiled the VSD patch projecting into
the right ventricle as a diverticulum with a 7 mm residual
VSD at its inferior margin (Fig. 2A). The remaining
procedure was carried out under general anesthesia for the
purpose of transesophageal echocardiographic (TEE)
guidance.
The defect was crossed with a no-torque right coronary
catheter (Bard USCI Division; CR Bard Inc). An
arteriovenous railroad was created with an exchange
length (360 cm) 0.038" Terumo glide wire (Terumo Inc.,
Japan) using the standard technique. A 9 F long delivery
sheath was introduced from the venous side over the guidewire and was placed in the ascending aorta. After removing
the guidewire, a 10-8 ADO was taken into the sheath and
deployed. The aortic retention disc of ADO could open only
above the aortic valve and hence full deployment was not
possible. Attempts to pull the sheath below the aortic valve
resulted in slippage of the entire assembly into the right
ventricle. The arteriovenous railroad was formed again; the
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Indian Heart J 2005; 57: 164–166
Vaidyanathan et al. Residual VSD closure with Amplatzer Duct Occluder 165
sheath was placed across the VSD just below the aortic
valve. A 6 F internal mammary catheter was taken parallel
to the guidewire through the sheath through which
a 0.038" Teflon wire was directed toward the LV cavity
(Fig. 3). The guidewire in the aorta was removed and the
delivery sheath was tracked over the catheter into the left
ventricle. The same 10-8 ADO could then be deployed
across the residual VSD successfully. LV angiogram (Fig.
2B) and TEE showed the device to be well away from the
aortic valve with no residual flow across the VSD. Aortic
root angiogram showed no aortic regurgitation. The
fluoroscopy time was 35 min. The patient was extubated
immediately after the procedure and was discharged from
the hospital on the next day on anti-platelet doses of aspirin.
TTE at discharge showed stable device position with no
residual flow and no impingement on aortic valve (Fig. 1B).
She was asymptomatic when reviewed 1 month later.
A
B
Fig. 3. Angiogram showing the use of the left internal mammary artery catheter
(indicated by the white arrow) to direct the 9 F sheath (black arrow) toward the
left ventricular cavity.
Fig. 1A. Transthoracic echocardiogram showing residual defect (indicated by
arrow) in the VSD patch; the upper portion of the VSD patch ends in a
diverticulum (D) which then communicates with RV through the defect. 1B.
Transthoracic echocardiogram after device implantation; device is indicated by
arrow and is well away from aortic valve.
VSD: ventricular septal defect; RV: right ventricle; AO: aorta; LV: left
ventricle
A
Fig. 2A. Left ventricular angiogram in LAO 60° and cranial 20° showing a
defect in the VSD patch (indicated by the arrow). 2B. Left ventricular angiogram
in same view after deployment of the device; there is no residual shunt. A
constriction in the center of the device (indicated by arrow) is seen.
LAO: left anterior oblique; VSD: ventricular septal defect
IHJ-818-05(BR).p65
165
Case 2: An 11-year-old girl with TOF with relatively smallsized branch pulmonary arteries (right pulmonary artery
3.5 mm at origin; 6.5 mm at hilum; left pulmonary artery
6.7 mm at hilum) underwent intracardiac repair with an
8 mm fenestration in the VSD patch. Post-operatively, the
patient developed severe and refractory congestive heart
failure with generalized edema and ascites. Attempts to
stabilize the patient with high doses of diuretics and
inotropes were unsuccessful. Echocardiogram revealed
significant left-to-right shunt across the fenestration in the
VSD patch. The patient was taken up for cardiac
catheterization to quantify the left-to-right shunt and to
determine whether closure of the fenestration would
improve the hemodynamic parameters.
Oximetry showed a 12% step up yielding a Qp-Qs ratio
of 1.8. The right atrial pressures were markedly elevated
(a 34 mmHg, v 27 mmHg, mean 25 mmHg). The right
ventricular pressures were high (systolic 60 mmHg, enddiastolic 24 mmHg). The pulmonary artery pressure was
45/20 mmHg (mean 28 mmHg). The fenestration was
temporarily balloon-occluded with a 7 F Swan-Ganz
catheter that was passed over an arteriovenous railroad
between right femoral artery and vein. This resulted in
reduction of the right atrial mean pressure to 15 mmHg
with normalization of pulmonary arterial pressure (21/16
mmHg; mean 20 mmHg). Hence, we proceeded to close the
VSD using the same technique as described for the first
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166 Vaidyanathan et al. Residual VSD closure with Amplatzer Duct Occluder
patient. A 12-10 ADO was deployed successfully in the first
attempt through a 9 F long delivery sheath that completely
sealed the fenestration. TEE showed no residual shunt
without any impingement onto the aortic valve by the
device. The fluoroscopy time was 28.4 min. Central venous
pressure decreased and peripheral edema started improving
on the same day. She could gradually be weaned off from
inotropes and mechanical ventilation over the next 3 days
and was discharged from the hospital one week after the
procedure. The patient was symptom-free at one-month
and at 3 months follow-up.
Discussion
Hemodynamically significant residual VSD following repair
for TOF imposes significant morbidity, mortality and
economic burden on the family of the patient. This is
specially relevant in developing countries like India.
Though closure of such defects using AMVSO has been
proved to be a safer alternative, it costs more than the repeat
surgery. The two cases described in this report have shown
that ADO is safe and effective to close residual post-operative
VSD in perimembranous area and thus a cheaper
alternative to AMVSO. Both patients had significant
symptomatic improvement and perhaps it was life-saving
in the second patient who had refractory congestive cardiac
failure. To our knowledge, this is the first report of using
ADO for closure of a post-operative residual VSD.
In both the patients, the residual defects were away by a
safe distance from the aortic valve. Hence one could have
chosen Amplatzer muscular VSD device. Even this device
costs 1.5 times the cost of ADO and hence we did not opt
for it. While there are two retention discs at either end in
the muscular VSD device, the ADO has retention disc only
at one end. The concern regarding the use of ADO for
closing VSD arises because the device can potentially
dislodge and embolize into the LV cavity if there is elevation
in the right ventricular pressure. Our patients either had
normal or only mildly elevated pulmonary artery pressure.
Moreover, we chose slightly larger-sized devices that
resulted in the formation of a waist at the level of the
septum, splaying the right ventricular end (Fig. 2B). Hence
no instability of the device was noted.
Because of the close proximity of the VSD to the aortic
valve it becomes important not to impinge on the aortic
IHJ-818-05(BR).p65
166
Indian Heart J 2005; 57: 164–166
valve while deploying the device. Placement of the delivery
sheath well into the body of the left ventricle before the
formation of the retention disc is a key step in the procedure.
Using an additional arterial catheter, Pedra et al.6 have
described a method where they allowed the same wire to
be used for forming arteriovenous railroad to loop into the
left ventricle over which the delivery sheath was
maneuvered into the left ventricle. We adopted a different
technique by passing an internal mammary artery catheter
through the delivery sheath parallel to the guidewire to
direct the delivery sheath toward the LV cavity (Fig. 3). TEE
plays a vital role in safe deployment of the device. Complete
closure could be achieved in both our cases with no
procedure-related morbidity.
Conclusions: The present report illustrates the innovative
use of the ADO for the transcatheter closure of residual
VSD in the perimembranous region after surgical repair of
tetralogy of Fallot. The ADO is an effective alternative for
the more expensive AMVSO and is a particularly attractive
option in a developing country where cost constraint is a
major factor.
References
1. Calder AL, Barratt-Boyes BG, Brandt PW, Neutze JM. Postoperative
evaluation of patients with tetralogy of Fallot repaired in infancy. J
Thorac Cardiovasc Surg 1979; 77: 704–720
2. Lock JE, Block PC, McKay RG, Baim DS, Keane JF. Transcatheter
closure of ventricular septal defects. Circulation 1988; 78: 361–368
3. Rigby ML, Redington AN. Primary transcatheter umbrella closure
of perimembranous ventricular septal defect. Br Heart J 1994; 23:
368–371
4. Hijazi ZM, Hakim F, Haweleh AA, Madani A, Tarawna W, Hiari A, et
al. Catheter closure of perimembranous ventricular septal defects
using the new Amplatzer membranous VSD occluder: initial clinical
experience. Catheter Cardiovasc Interv 2002; 56: 508–515
5. Hijazi ZM. Device closure of ventricular septal defects. Catheter
Cardiovasc Interv 2003; 60: 107–114
6. Pedra CA, Pedra SR, Esteves CA, Pontes SC Jr, Braga SL, Arrieta SR,
et al. Percutaneous closure of perimembranous ventricular septal
defects with the Amplatzer device: technical and morphological
considerations. Catheter Cardiovasc Interv 2004; 61: 403–410
7. Knauth AL, Lock JE, Perry SB, McElhinney DB, Gauvreau K,
Landzberg MJ, et al. Transcatheter device closure of congenital and
postoperative residual ventricular septal defects. Circulation 2004;
110: 501–507
8. Krishna Kumar, Tynan M. Catheter interventions for congenital
heart disease in third world countries. J Interv Cardiol (in press)
6/21/2005, 2:43 PM
Indian Heart J 2005; 57: 167–169
Balasundaram et al.
ASO Endocarditis
167
Brief Report
Infective Endocarditis Following Implantation of
Amplatzer Atrial Septal Occluder
Ram Prakash Balasundaram, S Anandaraja, Rajnish Juneja, Shiv Kumar Choudhary
Departments of Cardiology and Cardiothoracic Surgery, All India Institute of Medical Sciences, New Delhi
Infective endocarditis is a rare but serious complication following device closure of atrial septal defect. Surgical
removal of the device is mandatory in such cases. We report a rare case of polymicrobial endocarditis following
implantation of Amplatzer septal occluder in an eight-year-old child. (Indian Heart J 2005; 57: 167–169)
Key Words: Amplatzer septal occluder, Atrial septal defect, Infective endocarditis
D
evice closure of atrial septal defect is now an accepted
modality of treatment. Of the various devices used for
the closure of atrial septal defect (ASD), the preferred device
is the Amplatzer septal occluder (AGA Medical Corporation,
Minnesota, USA). Complete closure is observed in 95.5%
of patients with this device.1 Reported complications with
the use of Amplatzer device include device embolization,
arrhythmias, device malposition, thromboembolism, access
site complications, cardiac tamponade and infective
endocarditis.2 We present a case of endocarditis on an
Amplatzer atrial septal occluder in an 8-year-old boy.
Case Report
meropenam. A transthoracic echocardiographic (TTE)
examination revealed the device in place and there was no
residual ASD flow. There was no evidence of any vegetations
on the device or any valve. In view of the high suspicion
of infective endocarditis, a transesophageal echocardiographic (TEE) examination was done under short
general anesthesia, which revealed vegetations on the left
atrial side of the device (Fig. 1). A contrast-enhanced
multislice computerized tomographic (CT) angiography of
head did not show any infarct or mycotic aneurysm. After
10 days of appropriate antibiotic therapy with cefaperazone-sulbactam combination along with vancomycin
and rifampicin, he underwent surgery for device removal
and ASD closure.
An 8-year-old male child underwent implantation of 24
mm Amplatzer atrial septal occluder in December 2003 at
a secondary level hospital. Three months after the device
implantation, the patient developed prolonged fever for
which he empirically received linezolid, cefotaxime and
amikacin for 4 weeks. The fever responded initially but
recurred in 2 weeks and the child was referred to our
institution for further management.
At presentation to our institution the patient was febrile,
had a pulse rate of 110 beats per min (bpm) and a blood
pressure (BP) of 100/70 mmHg. His spleen was palpable
2 cm below the left costal margin and examination of
cardiovascular and other systems was unremarkable. The
blood cultures grew Klebiella pneumoniae and Acinetobacter,
both of which were sensitive to cefaperazone-sulbactam
combination, piperacillin-tozabactam combination and
Correspondence: Dr Rajnish Juneja, Associate Professor of Cardiology
Cardiothoracic Sciences Centre, All India Institute of Medical Sciences
New Delhi 110 029. e-mail: [email protected]
IHJ-748-04.p65
167
Fig. 1. Transesophageal echocardiogram showing vegetation (arrow) attached
to the left side of the Amplatzer atrial septal occluder.
LA: left atrium; Ao: aorta
6/21/2005, 2:44 PM
168 Balasundaram et al.
ASO Endocarditis
The patient was operated through a mid sternotomy
approach using mildly hypothermic cardiopulmonary
bypass (CPB) and cold, hyperkalemic cardioplegic arrest.
On opening the right atrium, the device was found to be
completely endothelialized and there were numerous small
(2 mm - 5 mm), rounded, smooth, mushroom-like vegetations at the junction of the device and the septal rim in
the superior part. The septum was incised for about 1 cm
inferiorly and a plane was developed between the device
and septal margin. Gradually the device was separated from
the septal margin. On the left side also, there were similar
vegetations along the rim with a small necrotic pocket
superiorly. All the vegetations and the necrotic material
were removed and cardiac chambers washed thoroughly
with antibiotic-mixed saline. The resultant defect was closed
with a free patch of right atrial wall keeping the endocardial
surface on the left atrial side.
The vegetations removed during the surgery showed
inflammatory infiltrates in the form of pus cells and
necrotic debris. Gram stain and culture of the vegetations
did not yield any organisms. The patient was continued on
the same antibiotics for a further three weeks. He developed
allergic reaction to the combination of antibiotics with fever
and eosinophelia. The antibiotics were changed to
meropenam and teicoplanin that were continued for a
further 2 weeks. He remained afebrile subsequently and
repeat blood cultures after stopping antibiotics were sterile.
However, he developed multiple discharging sinuses from
the sternal suture sites and superficial infection of the
sternal wound needing debridement and regular antibiotic
dressings for over a month, even after the antibiotic
treatment for endocarditis was over.
Discussion
Atrial septal defect occurs in one child per 1500 live births.3
With the early attempts in the seventies by Mills and King,4
device closure of ASDs gained widespread acceptance after
the introduction of the Amplatzer septal occluder. Results
have been comparable to surgical closure and the procedure
is associated with less morbidity and more patient
comfort.5,6
Of the various complications described following ASD
device closure, the least common is the infection of the
device. Only four such cases are available in literature
including two cases involving ASDOS device, one case
involving Amplatzer septal occluder and another involving
CardioSEAL device for patent foramen ovale.2,7,8 The case
involving the Amplatzer septal occluder was in a 10month-old infant with ASD and pulmonary stenosis. The
IHJ-748-04.p65
168
Indian Heart J 2005; 57: 167–169
procedure (ASD device closure with pulmonary valve
balloon dilation) was carried out in this infant who was
suffering from recurrent lower respiratory tract infection
by Staphylococcus aureus. The case involving a CardioSEAL
device for the closure of a patent foramen ovale was in an
adult patient. This patient presented with fever following
device implantation with large vegetation on the left atrial
side of the device. His blood cultures grew Bacillus pumilus.
The vegetation as such was sterile and gram staining did
not yield any microorganism.
In adult patients, TEE is more sensitive and specific for
the diagnosis of endocarditis. TEE is also indispensable in
the diagnosis of vegetations in the presence of prosthetic
material. In our patient, despite good transthoracic
windows, the vegetations could not be picked up by TTE
probably because of acoustic shadowing on the left atrial
side of the device, whereas TEE directly profiles that aspect
of the device. This reinforces the assumption that TEE is
superior to TTE for detection of vegetations in patients with
prosthetic material and high suspicion of infective endocarditis.
Device infection can occur in two ways: one due to
introduction of microbes during the procedure of
implantation, other due to seeding of microorganisms after
the procedure. After device implantation, it takes 6 months
for complete neoendothelialization of the device. Till such
time the device is prone to development of thrombus
formation on the surface, and hence, also predisposed to
non-bacterial thrombotic endocarditis. Any transient
bacteremia during this time can cause seeding of the device
material with the microorganisms.9 The organisms grown
in our patient (Klebsiella and Acinetobacter) are classical of
a nosocomial infection and hence probably indicate that
the seeding occurred during the procedure of device
implantation. This also stresses the importance of prompt
treatment of infection and need for infective endocarditis
prophylaxis in these patients for at least 6 months after
device implantation.
This report emphasizes the significance of aseptic
precautions during cardiac catheterization and the interventional procedures.
References
1. Fischer G, Stieh J, Uebing A, Hoffmann U, Morf G, Kramer HH.
Experience with transcatheter closure of secundum atrial septal
defects using the Amplatzer septal occluder: a single centre study in
236 consecutive patients. Heart 2003; 89: 199–204
2. Sievert H, Babic UU, Hausdorf G, Schneider M, Hopp HW, Pfeiffer D,
et al. Transcatheter closure of atrial septal defect and patent foramen
ovale with the ASDOS device (a multi-institutional European trial).
Am J Cardiol 1998; 82: 1405–1413
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3. Samanek M. Children with congenital heart disease: probability of
natural survival. Pediatr Cardiol 1992;13:152–158
4. Mills NL, King TD. Non-operative closure of left-to-right shunts. J
Thorac Cardiovasc Surg 1976; 72: 371–378
5. Sharafuddin MJ, Gu X, Titus JL, Urness M, Cervera-Ceballos JJ,
Amplatz K. Transvenous closure of secundum atrial septal defects:
preliminary results with a new self expanding nitinol prosthesis in a
swine model. Circulation 1997; 95: 2162–2168
6. Du ZD, Hijazi ZM, Kleinman CS, Silverman NH, Larntz K. Comparison
between transcatheter and surgical closure of secundum atrial septal
defects in children and adults: results of a multicenter non-
IHJ-748-04.p65
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Balasundaram et al.
ASO Endocarditis 169
randomized trial. J Am Coll Cardiol 2002; 39: 1836–1844
7. Bullock AM, Menahem S, Wilkinson JL. Infective endocarditis on
an occluder closing an atrial septal defect. Cardiol Young 1999; 9:
65–67
8. Goldstein JA, Beardslee MA, Xu H, Sundt TM, Losala JM. Infective
endocarditis resulting from cardioSEAL closure of a patent foramen
ovale. Catheter Cardiovasc Interv 2002; 55: 217–220
9. Chessa M, Carminati M, Butera G, Bini RM, Drago M, Rosti L, et al.
Early and late complications associated with transcatheter occlusion
of secundum atrial septal defect. J Am Coll Cardiol 2002; 39: 1061–
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170 Trehan
et al.
Brief
Report
Indian Heart J 2005; 57: 170–171
Successful Closure of Coronary Artery Perforation
Successful Closure of Coronary Artery Perforation Using
Non-Conventional Embolic Material
Vijay Kumar Trehan, Saibal Mukhopadhyay, Jamal Yusuf, Umamahesh C Rangasetty, Ramesh Arora
Department of Cardiology, GB Pant Hospital, New Delhi
Coronary perforation during percutaneous coronary interventions is a rare but dreadful complication. While
coronary perforation involving large vessels are managed successfully by covered stents, small distal vessel
perforation is usually managed by prolonged balloon inflation or embolization of gel foam/thrombogenic metallic
coils. We describe a case, where perforation of a small ventricular branch of the right coronary artery was
successfully occluded by packing it with pieces of thrombogenic floppy tips of used coronary angioplasty
guidewires instead of conventional metallic coils. (Indian Heart J 2005; 57: 170–171)
Key Words: Coronary angioplasty, Coil embolization, Coronary artery disease
C
oronary perforation during percutaneous transluminal
coronary angioplasty (PTCA) is a rare but potentially
serious complication.1 The therapeutic approach to these
perforations is determined by various factors like size of
the vessel, size of the perforation, its location (near a
bifurcation, within a stented segment, distal to a chronic
occlusion), whether patient has received glycoprotein IIb/
IIIa receptor antagonist and hemodynamic stability of the
patient. Small distal vessel perforation in hemodynamically
stable patients is usually managed by prolonged balloon
inflation and reversal of anticoagulation. Recent reports
have also demonstrated successful use of gel foam and
thrombogenic metallic coil embolization.2-4
We describe a case, where rupture of a small ventricular
branch of the right coronary artery (RCA) due to dilation
with an oversized balloon was successfully sealed by placing
cut floppy tips of used PTCA wires instead of conventional
metallic coils in the leaking vessel.
Case Report
A 54-year-old hypertensive male patient on regular medical
therapy for chronic stable angina for last two years,
presented with crescendo angina not being controlled with
maximal antianginal drugs of one month's duration. He
was on a combination of aspirin and clopidogrel prior to
coronary angiography which was undertaken with plan
Correspondence: Dr Saibal Mukhopadhyay, Room No. 126, Academic
Block, Department of Cardiology, GB Pant Hospital, New Delhi 110002
e-mail: [email protected]
IHJ-447-03.p65
170
for angioplasty, if required. Coronary angiogram revealed
99% stenosis in mid left anterior descending artery (LAD)
with TIMI-II flow and total occlusion of proximal RCA with
distal RCA filling through homocoronary collaterals. The
patient was taken up for angioplasty of LAD and RCA after
receiving a bolus of 5000 units of heparin. The LAD was
successfully stented with a 3×28 mm Pura Vario stent
(Devon, Germany) after serial dilations with 1.5×20 mm
and 2.5×20 mm balloons (Maverick, Boston Scientific/
Scimed, France) resulting in TIMI-III flow. Following this,
the RCA was intubated with a 7 F left Amplatz 1 guiding
catheter (Medtronic Vascular, Ireland) after failing to
intubate it with a Judkin’s right coronary catheter. Then
the lesion was crossed with a Crosswire (Terumo Corporation, Japan). As no balloon could be passed over it, so a
0.014" floppy Rotawire was passed across the lesion and
rotational ablation was done using a 1.25 mm burr.
Following rotational ablation, TIMI-II flow was established
with multiple lesions seen in mid and distal RCA. Hence,
dilation was started from distal RCA. However, following
dilation of the distal RCA with a 2.5 mm balloon, it was
realized that the balloon which was passed over the
guidewire, presuming it to be lying in distal RCA, was
actually lying in a small branch of the RCA. Following
dilation with a 2.5 mm balloon, the artery perforated, with
contrast leaking freely into the pericardium (Fig.1).
Activated clotting time (ACT) at this point of time was >
300 s. After reversing anticoagulation by giving protamine
at rate of 1 mg/100 units of heparin, we tried to seal the
perforation by prolonged balloon inflation with a 2×9 mm
balloon (Maverick, Boston Scientific/Scimed, France).
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Indian Heart J 2005; 57: 170–171
Trehan et al.
Successful Closure of Coronary Artery Perforation 171
However, since there was persistent leak, we decided to seal
the perforation by coil embolization. Instead of using
conventional metallic coils, we thought of occluding the
artery with pieces of thrombogenic floppy tips of used PTCA
guidewires sterilized in ethylene oxide. An over-the-wire
Ranger balloon 2.5×10 mm (Boston Scientific, USA) was
passed on the wire lying in the leaking artery. Then the
guidewire was withdrawn and through the central lumen
of the balloon, two pieces of floppy tips of used PTCA wires
(each about 1 cm long) were pushed into the target artery
using the non-floppy end of an exchange length PTCA wire.
After placing two pieces of wire in the artery, check
angiogram after 15 min showed complete occlusion of the
leaking artery (Fig. 2). Following this, successful
angioplasty and stenting of the RCA was done establishing
TIMI-III flow in the artery.
Fig. 2. Arrow showing floppy tips of used angioplasty wires sealing the
perforation.
reversal of anticoagulation, embolization of gel foam or
thrombogenic metallic (stainless steel/platinum) coils into
the leaking vessels. But delivery of metallic coils not only
requires an additional system for delivering the coils, it also
adds to the cost of the procedure. Our method of using cut
floppy tips of used PTCA guidewires can be considered as
an alternative to metallic coils for sealing perforations
arising from small vessels. The advantages of our procedure
are (i) easy availability of the material (used PTCA
guidewires) needed for sealing the perforation in the
catheterization laboratory (ii) no requirement of a special
delivery system (iii) cost effectiveness and (iv) simplicity.
Fig. 1. Arrow showing site of perforation through small ventricular branch of
right coronary artery.
Discussion
Coronary perforation following PTCA is a dreadful complication. The therapeutic approach to these perforations
includes initial stabilization of the patient and addressing
any compromise from cardiac tamponade. This is followed
by determination of the vessel size at the site of the
perforation. The choice of therapy for larger vessels has
traditionally been emergency surgery with suture ligation
of the perforation and usually coronary artery bypass
surgery. Polytetrafluoroethylene-coated stent and autologous vein-covered stents have also been reported to be
efficacious for large proximal vessels provided they can be
delivered.5,6 The different methods described for small distal
vessel perforation include prolonged balloon inflation and
IHJ-447-03.p65
171
References
1. Ellis SG, Ajluni S, Arnold AZ, Popma JJ, Bittl JA, Eigler NL, et al.
Increased coronary perforation in the new device era: incidence,
classification, management and outcome. Circulation 1994; 90:
2725–2730
2. Dixon SR, Webster MW, Ormiston JA, Wattie WJ, Hammett CJ.
Gelfoam embolization of a distal coronary artery guidewire
perforation. Catheter Cardiovasc Interv 2000; 49: 214–217
3. Dorros G, Jain A, Kumar K. Management of coronary artery rupture:
covered stent or microcoil embolization. Cathet Cardiovasc Diagn
1995; 36: 148–154
4. Aslam MS, Messesmith RN, Gilber J, Lakier JB. Successful
management of coronary artery perforation with helical platinum
microcoil embolization. Catheter Cardiovasc Interv 2001; 51: 320–
322
5. Ramsdale DR, Mushahwar SS, Morris JL. Repair of coronary artery
perforation after rotastenting by implantation of the JoStent covered
stent. Cathet Cardiovasc Diagn 1998; 45: 310–313
6. Caputo RP, Amin N, Marvasti M, Wagner S, Levy C, Giambartolomei
A. Successful treatment of a saphenous vein graft perforation with
an autologous vein-covered stent. Catheter Cardiovasc Interv 1999;
48: 382–386
6/21/2005, 2:45 PM
172 Agarwal
Brief
Reportet al.
Indian Heart J 2005; 57: 172–174
Ductal Aneurysm with Aortic Regurgitation
Calcified Ductal Aneurysm with Severe Aortic
Regurgitation
Saket Agarwal, Sunil K Kaushal, Parvathi U Iyer, Poonam Khurana, Krishna S Iyer
Departments of Pediatric Surgery and Radiodiagnosis, Escorts Heart Institute and Research Centre, New Delhi
A rare case of calcified aneurysm of the ductus arteriosus with severe aortic regurgitation is presented. We
believe this is the first report of such a case in the English literature. (Indian Heart J 2005; 57: 172–174)
Key Words: Aortic regurgitation, Ductal aneurysm, Congenital heart disease
D
uctus arteriosus aneurysm is a rare condition that can
be associated with serious complications including
thromboembolism, rupture and death. To the best of our
knowledge the combination of severe aortic regurgitation
(AR) and patent ductus arteriosus (PDA) aneurysm has
not been reported. We report such a case in an adult who
was successfully treated at our institution.
compression of the right and left pulmonary arteries. No
thrombus was seen in the aneurysm (Fig. 2).
Cardiac catheterization and angiography was deferred
in view of mobile vegetations on the aortic valve and the
clarity of the anatomy obtained on CT angiogram. One
stage repair of both lesions through mid-sternotomy was
planned.
Case Report
A 27-year-old man presented with history of palpitations
for 20 years, and dyspnea on exertion (New York Heart
Association class II) of 2 years duration. He had no history
of chest pain, fatigue or syncope.
On examination he was well-built, with no pallor,
cyanosis or pedal edema. The jugular venous pressure was
within normal limits. Blood pressure was 130/40 mmHg
supine. An early diastolic decrescendo murmur was audible
in the left parasternal area.
A plain chest X-ray revealed an enlarged heart,
prominent aorta and dilated main pulmonary artery (PA)
with increased hilar vascularity. A calcified shadow was
observed in the region of the ductus (Fig. 1). A transthoracic echocardiogram (TTE) showed a dilated and
hypertrophied left ventricle (LV) with severe AR. Mobile
vegetations were seen on the aortic valve. There was a PDA
with a large aneurysm at its aortic end. The branch
pulmonary arteries were normal. The estimated PA systolic
pressure was 40 mmHg.
A multi-slice computerized tomographic (CT)
angiogram revealed a large patent ductus with a calcified
aneurysm measuring 5×4.3×3.6 cm causing splaying and
Correspondence: Dr Krishna S Iyer, Escorts Heart Institute and Research
Centre, Okhla Road, New Delhi 110025. e-mail: [email protected]
IHJ-788-04.p65
172
Fig. 1. Plain chest radiograph, left lateral view showing calcification in the middle
mediastinum, below the aortic arch in the region of the ductus.
6/21/2005, 2:46 PM
Indian Heart J 2005; 57: 172–174
Agarwal et al.
Ductal Aneurysm with Aortic Regurgitation 173
graft (Boston Scientific, Meadox Medicals Inc., Oakland, NJ)
measuring 6×4 cm using running 3/0 prolene suture.
Before tightening the suture line, blood was returned to the
patient through the arterial line and the aorta was de-aired.
Cardiopulmonary bypass was resumed and re-warming
started. The pulmonary artery was reconstructed using a
pericardial patch, while re-warming was completed. The
patient was successfully weaned off bypass on minimal
Fig. 2. CT chest angiogram, oblique sagittal reconstruction showing large patent
ductal aneurysm with peripheral calcification.
CT: computerized tomography
Operative technique: At surgery, the findings included a
mildly dilated aortic root and a tense dilated PA which was
pushed anteriorly by the calcified duct aneurysm. The
entire wall of the ductus was calcified except for a rim of
5 mm at the PA end. The branch pulmonary arteries were
normal in caliber, but stretched across the aneurysm. The
ductus was dissected and looped around the pulmonary
end. The patient was placed on cardiopulmonary bypass
with ascending aortic and two-stage venous cannulation.
The ductus was then carefully snugged and core cooling to
18°C was commenced. At 32°C the aorta was clamped, a
transverse aortotomy was done and coronary ostial
cardioplegia administered. The aortic valve was tricuspid
and there were healed mobile vegetations on its right and
non-coronary cusps. Aortic valve replacement was done
using 21M St Jude Regent valve. The aortotomy was closed
and root cardioplegia administered as core temperature
reached 18°C. Circulatory arrest was established. The
ductus was then transsected at the pulmonary end and the
pulmonary artery bifurcation was dissected free from the
anterior wall of the aneurysm. The aneurysm was then split
open anteriorly to expose the aortic opening from within.
Calcium-free margins of the aortic end were identified and
these were closed with an oval piece of Meadox vascular
IHJ-788-04.p65
173
Fig. 3. Post-operative CT chest angiogram, oblique sagittal reconstruction
showing complete occlusion of ductal aneurysm with thrombus.
CT: computerized tomography
inotropic support. Cardiopulmonary bypass time was 153
min, aortic cross clamp time was 76 min and circulatory
arrest time was 25 min.
A post-operative CT angiogram revealed satisfactory
exclusion of the aneurysm (Fig. 3).
Discussion
Surgical experience with aneurysm of the ductus arteriosus
in adult is scant. Yoshitaka et al.1 reported the case of a
giant aneurysm of the ductus arteriosus with severe mitral
regurgitation in a 58-year-old adult, which was repaired
in two stages utilizing circulatory arrest.
6/21/2005, 2:46 PM
174 Agarwal et al.
Ductal Aneurysm with Aortic Regurgitation
Aneurysm of the diverticulum of the ductus has been
reported more frequently, with surgical closure being
relatively more straightforward as only the narrow mouth
of the diverticulum has to be tackled. Mitchell et al. 2
reported successful management of 5 cases of aneurysm
of diverticulum of the ductus in adult patients.
A calcified aneurysm of the ductus is a difficult entity to
manage. The risks of thromboembolism and rupture are
real although rare, and merit early intervention. The
challenge in this case was that both lesions had to be
managed simultaneously. The AR was significant enough
to preclude prior management of the ductus aneurysm
through a thoracotomy. The mid-sternotomy approach
necessitated control of duct flow upon initiation of
cardiopulmonary bypass. We were lucky to find a small area
of non-calcified ductus at the pulmonary artery end which
could be occluded at the onset of cardiopulmonary bypass.
IHJ-788-04.p65
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Indian Heart J 2005; 57: 172–174
The pre-operative CT angiogram clearly defined the
lesion and helped us formulate a plan for management
which was efficiently executed on the operating table. It
defined the areas which were free of calcium, enabling us
to get control of the ductus, and suture the patch. We
believe this modality has certainly enhanced the accuracy
of diagnosis and should play an increasing role in the
management of such difficult patients in the future.
References
1. Yoshitaka H, Hata T, Tsushima Y, Matsumoto M, Hamanaka S,
Chikazawa G, et al. A case report of aneurysm of the ductus
arteriosus combined with mitral regurgitation. Kyobu Geka 2000;
53: 781–783
2. Mitchell RS, Seifert FC, Miller DC, Jamieson SW, Shumway NE.
Aneurysm of the diverticulum of the ductus arteriosus in the adult.
Successful surgical treatment in five patients and review of the
literature. J Thorac Cardiovasc Surg 1983; 86: 400–408
6/21/2005, 2:46 PM
Indian Heart J 2005; 57: 175–180
Khan et al. Leukotrienes and Atherosclerosis
175
Point of View
Leukotrienes and Atherosclerosis
Zeba Khan, CD Tripathi
Department of Pharmacology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi
D
eveloping drugs to treat atherosclerosis is a daunting
task. Understanding the role of mediators involved in
atherosclerosis could be of great value in managing as well
as developing new strategies for the treatment of
atherosclerosis. Recent studies of advanced human
atherosclerotic lesions have yielded new information on
potential mechanism of inflammation and immune
response. Atherosclerosis is well recognized as an
inflammatory disorder and proinflammatory role of
leukotrienes has been postulated in its pathogenesis and
progression. Lipid peroxidation, monocyte attraction,
smooth muscle proliferation and foam cell formation are
the various steps involved in atherogenesis. In this review
we summarize our current understanding of the role of
leukotrienes and their antagonists in the genesis of
atherosclerosis.
Coronary Atherosclerosis
Coronary atherosclerosis is a multifactorial disease. It is
now viewed as the outcome of hypercholesterolemia with
inflammation of the vessel wall.1 The most likely sequence
of events involved in atherosclerosis is vascular dysfunction
or injury, monocyte recruitment and macrophage
formation, lipid deposition and synthesis of extracellular
matrix. 2 Complex interactions among the resident
endothelial cells, smooth muscle cells, the infiltrating
monocytes and T lymphocytes determine the progression
of fatty streaks into vascular lesions. Recent studies have
shown that leukotrienes could influence the activities of
all the cell types involved in this process. Leukotriene
antagonists have also been tested to see their effect on
progression of atherosclerosis in appropriate animal
models. These studies suggest a previously unrecognized
role of leukotrienes and their antagonists in the genesis of
atherosclerosis.
Mammalian lipoxygenase have two principal functions,3
one is to modify membranes by peroxidation reactions by
12/15 lipoxygenase (12/15-LO), the other is to produce
signaling lipid mediators which exert effects via G-protein
Correspondence: Dr Zeba Khan, Department of Pharmacology, Vardhman
Mahavir Medical College and Safdarjung Hospital, New Delhi 110029
e-mail: [email protected]
IHJ-842-05 Point of View.p65
175
coupled plasma membrane-bound receptors by way of
5-lipoxygenase (5-LO) and its product, the leukotrienes.4-5
Accordingly, lipoxygenases may in principle contribute
to pathophysiology of atherosclerosis by oxidation of lowdensity lipoprotein (LDL) and also by production of
proinflammatory leukotrienes.6
Biosynthesis and Metabolism
of Leukotrienes
Leukotrienes are a class of biologically active lipids,
synthesized and released from leukocytes and have a variety
of proinflammatory effects (Fig.1). The synthetic pathway
for leukotrienes is initiated by the release of arachidonic
acid from the cell membrane by phospholipase A2. This free
arachidonic acid is sequestrated at the nuclear envelope and
brought into contact with 5-LO by FLAP (5LO-activating
protein), an integral membrane protein essential for
leukotriene production. The 5-LO enzyme catalyzes twostep reaction: oxygenation of arachidonate to form 5HPETE (5S-hydroxy peroxy-6, 8-trans-11, 14-cis
eicosatetranoic acid), followed by dehydration of 5-HPETE
to the labile 5,6 epoxide intermediate LTA4. The enzyme
LTA4 hydrolase can convert the unstable compound LTA4
to biologically active leukotriene LTB4 or conjugated with
reduced glutathione by action of LTC4 synthase to LTC4.
Whereas LTD4 is produced by removal of glutamic acid by
an enzyme γ glutamyl transpeptidase and LTE4 results from
subsequent cleavage of glycine by dipeptidase. LTC4 and
its metabolites are collectively known as cysteinyl
leukotrienes.7
Cellular sources of leukotrienes: In contrast to
prostaglandins, which are generated by a wide variety of
cells and tissues in response to injury and other noxious
stimuli, leukotrienes are generated by restricted range of
cell types. Leukotrienes are produced mainly by leukocytes
and endothelial cells through transcellular synthesis.
Phagocytic leukocytes, including neutrophils, monocytes
and/or macrophages and eosinophils were thought to be
the major effector cells for LTB4, and smooth muscle cells
for cysteinyl leukotrienes. However, recent discovery of
additional receptors and careful expression analysis have
resulted in considerable expression of known cellular
6/21/2005, 2:48 PM
176 Khan et al. Leukotrienes and Atherosclerosis
targets for leukotrienes.8 Various human cells produce
specific leukotrienes, the predominant leukotrienes
synthesized by human cells are given in Table 1.
Table 1. Production of leukotrienes from different human
cells
Human cells
Leukotrienes
Neutrophils
Eosinophils
Monocytes
Macrophage
Mast cell
Basophils
Endothelial cells
Smooth muscle cells
LTB4
LTC4
LTB4, C4
LTB4, C4
LTC4
LTC4
LTC4, D4-, E4
LTC4, D4-, E4
Leukotriene receptors: Receptors have been identified
for both LTB4 and cysteinyl leukotrienes. Pharmacological
characterization identified at least two subtypes of cysteinyl
leukotrienes (Cyst) receptors based on the agonist and
antagonist potency for biological responses. Molecular
identification of the human and mouse Cyst LT1 and Cyst
LT2 receptor has confirmed their structure as putative
7-membrane domain G-protein coupled receptors. 9,10
Currently known LTB4 receptors are G-protein coupled
receptors. BLT1, BLT2 and the peroxisome proliferator
activator receptor α (PPARα) are the receptors for LTB4.11-13
While BLT1 and BLT2 likely mediate the pro-inflammatory
response of LTB4, PPARα-a transcription factor-might serve
as a mediator with the anti-inflammatory effects of LTB4.14
The rank potency of leukotriene receptors for activation of
agonist and sites of expression are shown in Table 2.
Table 2. Sites of expression and rank potency for activation
of leukotriene receptors by agonists
Receptor
Agonist
Cyst LT1
LTD4 > LTC4 >LTE4 Spleen, peripheral blood leukocytes,
eosinophils, lung smooth muscle cells
and interstitial lung macrophages9,10
Site of expression
Cyst LT2
LTC4 =LTD4>LTE4
Heart, adrenal medulla, placenta and
peripheral blood leukocytes, smooth
muscle cells and macrophages9,10
BLT1
LTB4
Neutrophils, spleen and thymus15
BLT2
LTB4
Spleen, leukocytes, liver, ovary, pancreas,
heart, testis, small intestine kidney, lung,
thymus, colon and placenta15
Role of Leukotrienes in Atherosclerosis
Before understanding the role of leukotrienes in the
pathogenesis of atherosclerosis we must look briefly into
the various studies conducted to establish the role of
leukotrienes in atherosclerosis, summary of which is given
IHJ-842-05 Point of View.p65
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Indian Heart J 2005; 57: 175–180
in Table 3.
Many studies conducted on preclinical models of
atherosclerosis have shown reduction in progression by
varied mechanism. Aiello et al.21 used inbred strain of
LDLR -/- (LDL knockout) mice, MCP-1 -/- (monocyte
chemoattractant protein-1 null) mice and apoE -/(apolipoprotien E deficient) mice. These mice were treated
with a specific LTB4 receptor antagonist, CP-105, 696, for
35 days. When compared with age-matched controls, lipid
accumulation and monocyte infiltration were significantly
reduced in apo-/- mice at all time points tested. Lesion area
reduction was also demonstrated in LDLR -/- mice
maintained on high-fat diet. LTB4 antagonism had no
significant effect on lesion size in mice possessing the null
alleles for another chemotactic agent MCP-1 (MCP-1-/-X
apoE-/-), suggesting MCP-1 and LTB4 may either interact or
exert their effect by a common mechanism. Another study
on murine sepsis model by Matsukava et al.22 showed a
decreased MCP-1 production upon treatment with LTB4
receptor antagonist and decreased LTB4 production in mice
treated with a MCP-1 blocking antibody. It is further
reported that MCP-1 is the prototype of the CC- chemokine
β subfamily and exhibits the most potent chemotactic
activity for monocytes. MCP-1 is highly expressed in human
atheromatous plaque and its overexpression contributes to
the development of atherosclerosis in mouse models.23
Similar results were found in a study conducted by Porreca
et al.24 on rat vascular smooth muscle cell (VSMC) which
provides direct evidence that exogenously added 5-LO
metabolite i.e. LTD4 enhanced IL-1β production in rat
VSMC and MK-571, a specific receptor antagonist of LTD4,
antagonizes this effect and strongly inhibits mRNA
expression. An experimental drug MK-886 binds to FLAP
and blocks production of leukotrienes.7 De Code team
showed that almost 30% of 779 heart attack patients in
Iceland and 15% of 753 British heart attack patients had
alterations in a gene called ALOX5AP that cause their
arteries to produce unusually high levels of the bad
leukotrienes.25 A gene nucleotide polymorphism (SNP)
haplotype in this locus spanning the gene ALOX5AP
encoding 5-lipoxygenase activating protein (FLAP - an
integral membrane protein essential for leukotriene
production) is associated with a two times greater risk of
myocardial infarction in Iceland. This haplotype also
confers almost two times greater risk of stroke. Another
ALOX5AP haplotype is associated with myocardial
infarction in individuals from the UK. Stimulated
neutrophils from individuals with myocardial infarction
produce more leukotriene B4, a key product in the
5-lipoxygenase pathways, than do neutrophils from
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Khan et al. Leukotrienes and Atherosclerosis 177
Table 3. Summary of the studies conducted to establish role of leukotrienes in atherosclerosis
Material and Method
Result
Mehrbanian et al.16
5-LO-/- /LDLR-/-double knockout mice were developed, aortic atherosclerotic
lesion were analyzed in mice fed on high fat/cholesterol diet.
These mice showed a dramatic decrease in lesion development. Transplant
of bone marrow from 5-LO-/- mice LDLR-/- led to significant reduction in
atherogenesis suggesting the role of 5-LO in atherosclerosis.
Spanbroek et al.17
Study was conducted on coronary, carotid arteries and aorta (obtained
from 50 patients), The number of 5-LO+ macrophage foam cells and 5LO+DC foam cells were counted.
The number was found to be high in samples from advanced coronary
heart disease, presence of 5LO-activating protein FLAP, LTA4 hydrolase,
and LTC4 synthase in human atherosclerotic vessel wall was seen,
confirming the concept that 5-LO cascade generates circuits of
inflammation during critical stages of atherogenesis.
Dwyer et al.18
Degree of atherosclerosis was judged by estimating carotid intima media
thickness bilaterally in a randomly sampled cohort of 573 women and
men. Dietary arachidonic acid and marine n-3 fatty acid were measured
with the use of 6, 24-hour recalls of food intake.
Variant 5-LO genotype showed large increase in intima-media thickness
with intake of arachidonic acid while significantly inverse association was
seen with marine n-3 fatty acids. Arachidonic acid is primary substrate
for 5-LO which enhances production of leukotrienes, while marine n-3
fatty blunts this effect by competing with eicosapentanoic acid.
Harats et al.19
LDLR-/- and 15-LO overexpressing crossbred mice, fed high cholesterol/
fat diet, quantification of fatty streaks was performed at aortic sinus.
LDLR-/-/15-LO mice developed large lesions than LDLR-/-mice supporting
the hypothesis that 15-LO over expression in the vessel wall is associated
with enhanced atherogenesis.
Subbarao et al.12
Cryosections from aortic tree were analyzed for atherosclerotic lesion in
BLT1 null mice crossbred with apo E-/- mice, also LTB4- induced gene
expressions were determined in a rat basophilic leukemia cell line.
Deletion of BLT1 significantly reduced lesion formation in apoE-/- mice, LTB4
-induced up regulation of 17genes with well established association in
atherosclerosis.
Allen et al.20
Response of non atherosclerotic and atherosclerotic coronary artery ring
segment to LTC4 and LTD4 was seen in organ bath.
Non-atherosclerotic segment were unresponsive to LTC4 and LTD 4,
atherosclerotic segment showed concentration-dependent contractions
suggesting that atherosclerosis augments contractions to cysteinyl
leukotrienes and contributes to hyperreactivity of vessels.
5-LO-/-: 5-lipoxygenase null; LDLR-/-: low-density lipoprotein receptor knockout; DC: dendritic cell; FLAP: 5LO-activating protein; apo E-/-: apo-E deficient; LT: leukotriene
controls, and this difference is largely attributed to cells from
males who carry the at-risk haplotype. This suggested that
variants of ALOX5AP are involved in the pathogenesis of
both myocardial infarction and stroke by increasing
leukotriene production and inflammation in the arterial
wall predisposing to myocardial infarction. 26 De Code
mapped the gene to a locus on chromosome 13q12-13. GSK
480848 gene-based drug hits inflammation-producing
enzyme in arteries, Lp-PLA2.
These results demonstrate that in preclinical model of
atherosclerosis, leukotriene receptor blockade reduces
lesion progression and further suggest a previously
unrecognized role for leukotrienes or other oxidized lipids
in the pathogenesis of this disease.
From these independent studies we have outlined the
function of leukotrienes in the development and
progression of atherosclerosis. Mammalian lipoxygenases
have two principal functions: producing signaling lipid
mediators by 5-lipoxygenase, and modification of
IHJ-842-05 Point of View.p65
177
membranes by 12/15 lipoxygenase through peroxidation
reactions which is involved in the step of oxidation of LDL.22
The role of these two lipoxygenase enzymes is so interlinked
with each other that it is difficult to demarcate their
separate role in atherosclerosis. ALOX5AP gene located on
to a locus on chromosome 13q12-13, a four-marker singlenucleotide polymorphism (SNP) haplotype encoding 5lipoxygenase activating protein (FLAP), is involved in the
pathogenesis of atherosclerosis by increasing leukotriene
production and inflammation in the arterial wall predisposing to myocardial infarction.27
5 lipoxygenase is the rate-limiting enzyme in leukotriene
biosynthesis and is expressed primarily in leukocytes
including monocytes and macrophages.16 Leukotrienes
exert their effects via G protein-coupled plasma membranebound receptors.9,10 The leukotriene products which are
produced primarily by monocyte-macrophages or dendritic
cells (DCs) in the arterial intima foster the chemoattraction
of monocytes, T-cell or other types of circulating cells with
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Indian Heart J 2005; 57: 175–180
178 Khan et al. Leukotrienes and Atherosclerosis
in the vessel wall, increase vascular permeability or both.
These mechanisms may create a vicious circle in which
inflammatory cells, by producing these lipid mediators,
cause local vascular inflammation, perpetuating the
recruitment of inflammatory cells and the production of
mediators. This has been further substantiated by use of
LTD4 antagonist in pre-clinical models, which inhibited the
progression of atherosclerosis.22,28 LTA4 is the first product
of the 5-LO pathway; this unstable compound sits at the
crossroads of this pathway. 8 It is released from
macrophages/DCs/foam cells/mast cells and the
subsequent uptake and conversion to other leukotrienes by
neighboring cell may provide mechanism for augmentation
of transcellular leukotriene synthesis.17
The LO enzymes and its products may influence all the
major steps involved in process of atherosclerosis (Fig. 1).
Oxidation of LDL: 12,15-lipoxygenase has unique ability
to oxidize fatty acid esterified to membranes and low-density
lipoprotein (LDL) without requiring phosphorylase.21 This
lipid peroxidation in turn produces isoleukotrienes. The
oxidized LDL has been shown to increase 5-lipoxygenase
activity.29 Further reduction in atheroma lesion was seen
in mice fed on high fat diet when treated with LTB 4
antagonist.22
Nucleus
Cytoplasm
Uptake of LDL by monocytes: Formation of foam cells
is mediated by a gene which is upregulated by LTB4, fatty
acid translocase/CD36, a transmembrane protein and a
specific receptor for oxidized LDL that transports cholesterol
into monocytes thereby converting them to foam cells.30
When treated with LTB 4 antagonist apoE -/- mice were
demonstrated to accumulate less fat in monocytes.22
Chemoattraction of monocytes: LTB 4 promotes
atherosclerosis via two receptors - BLT1 and BLT2 mediate
chemotaxis, leukocyte adhesion by upregulating gene CCL2
which presumably is produced at the site of vascular lesion
and attracts monocyte to the area.30 LTB4 also interacts with
MCP-1 by increasing expression of MCP-1 mRNA which is
antagonized by LTB4 antagonist.22
Other upregulated genes are urokinase plasminogen
activator (uPA), colony stimulating factor (CSF-1) and
osteopontin, which are essential for development of
atherosclerosis. CD44, sarc-like adaptor protein (SLAP) and
protein tyrosine phosphatase (SHP-1) are among the other
genes, which are also upregulated; they may have
important function in leukocyte recruitment and signal
transduction.20
Cell membrane
Membrane phospholipids
Foam cells
LDL uptake
PLA2
Arachidonic acid
Chemotactic for
monocytes
FLAP
Atherosclerotic
plaque
5-HPETE
5-LO
Release of cytokines
LTA4 hydrolase
LTA4
LTB4
LTC4 synthase
LTC4
γ-glutamyltranspeptidase
LTB4
VSMC proliferation
Increase neutrophil
adhesion
Release of IL-1β, PAF
LTD4
LTD4 dipeptidase
LTE 4
Endothelial cells
Monocytes/macrophages
VSMC
Fig. 1. The key enzymatic and biochemical steps involved in leukotrienes synthesis pathway and important steps mediated by different leukotrienes in atherosclerosis.
PLA2: phospholipase A2; 5-LO: 5-lipoxygenase; LT: leukotriene; FLAP: 5-lipoxygenase activating protein; 5-HPETE: 5S-hydroxyperoxy-6, 8-trans-11, 14cis-eicosatetranoic acid; VSMC: vascular smooth muscle cell; LDL: low-density lipoprotein; IL: interleukine; PAF: platelet-activating factor
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Indian Heart J 2005; 57: 175–180
VSMC proliferation: Cysteinyl leukotrienes stimulate
DNA synthesis of VSMC which in turn produces IL-1β
which induces VSMC proliferation, procoagulant activity
and leukocyte adhesion molecule expression. Eicosanoids
increase cytokine production by monocytes. The major cells
of blood vessels, VSMCs and endothelial cells can transcribe
genes for several cytokines including IL-1. The expression
of mRNA is strongly antagonized by MK-571, an antagonist
to LTD4.28
VSMC contraction: The cysteinyl leukotrienes are potent
vasoconstrictor of coronary arteries in several species.
There are evidences to support that the presence of
atherosclerosis is responsible for the hyperreactivity of
coronary artery to cysteinyl leukotrienes.21
Endothelial cells: These cells in culture have shown to
produce PAF (platelet activating factor) when stimulated
by LTC4 and LTD4. This PAF, synthesized and retained by
endothelial cells may induce adherence of human
neutrophils. 30 This process may be relevant to
inflammation, thrombosis and mechanism of vascular
injury including atherosclerosis.
Role of Leukotrienes and Leukotriene Antagonists:
Future Prospects
De Code team showed that almost 30% of 779 heart attack
patients in Iceland and 15% of 753 British heart attack
patients had alterations in a gene called ALOX5AP that
cause their arteries to produce unusually high levels of the
bad leukotrienes. This high leukotriene level, De Code
researchers believe, inflame artery walls, lead to sudden
rupture of arterial plaques and cause heart attacks or
strokes.27 UCLA team recently found another leukotrieneproducing gene in 6% of Americans, that boosts the risk of
clogged arteries. De Code hopes its heart gene finding
will help heart disease patients. It has already licensed a
leukotriene-blocking drug from the German
pharmaceutical firm, Bayer and is working to bring the
drug into clinical trials. The trials will examine the efficacy
of the drug in patients with the bad gene and in high-risk
patients without the gene. Recently Pfizer published a study
showing that its experimental leukotriene blocker called
CP-105, 696 drastically decreased artery plaques in mice.
The concept of fighting heart disease with asthma drugs is
still in its infancy. It will take several years to confirm the
various gene findings and to test whether leukotrieneblockers work on human heart disease. Numerous other
approaches to reduce artery inflammation may prove more
effective. But if the leukotriene drugs prove effective, it
IHJ-842-05 Point of View.p65
179
Khan et al. Leukotrienes and Atherosclerosis 179
would provide a badly needed new option to counteract the
artery clogging.
Several pharmaceutical companies are trying to develop
leukotriene blocking drugs (i) GSK 480848 (Glaxo
SmithKline): Gene-based drug hits inflammationproducing enzyme in arteries, Lp-PLA2 (an integral
membrane protein essential for leukotriene production), (ii)
DG031 (De Code Genetics): Mystery heart attack drug
supposedly targets leukotrienes, and (iii) CP-105, 696
(Pfizer): Leukotriene antagonist, which drastically
decreased artery plaques in mice.22
Conclusions
Atherosclerosis is a complex cascade of various biochemical
reactions and the role of leukotrienes in its genesis has been
documented in a number of studies. Further advancement
in the understanding of role of leukotrienes in
atherosclerosis has been provided by studies conducted with
leukotriene antagonists. The concept of fighting heart
disease with asthma drugs is still in its infancy. It will take
several years to confirm the various gene findings and to
test whether leukotriene-blockers work on human heart
disease. Currently marketed drugs may not work because
they do not stop all types of leukotrienes; it may be
necessary to use broader-acting leukotriene blockers to help
heart patients. It is of interest to consider the physiological
role and pharmacological strategies to develop the antileukotriene drugs in prevention of atherogenesis.
Acknowledgement
The authors thank Monika Agarwal for rendering her help
in preparation of this manuscript.
References
1. Steinberg D. Atherogenesis in perspective: hypercholestrolemia and
inflammation as partners in crime. Nat Med 2002; 8: 1211-1217
2. Badimon JJ, Fuster V, Chesebro JH, Badimon L. Coronary
atherosclerosis: a multifactorial disease. Circulation 1993; 87
(Suppl 2): II3–II16
3. Brash AR. Lipoxygenases: occurrence, function, catalysis and
acquisition of substrate. J Biol Chem1999; 274: 23679–23682
4. Funk CD. Prostaglandins and leukotrienes: advances in eicosanoid
biology. Science 2001; 294: 1871–1875
5. Radmark O. Arachidonate 5-lipoxygenase. Prostaglandins Other Lipid
Mediat 2002; 68-69: 211–234
6. Radmark O. 5-lipoxygenase-derived leukotrienes, mediators also of
atherosclerotic inflammation. Arterioscler Thromb Vasc Biol 2003;
23: 1140–1142
7. Morrow JD, Roberts LJ 2nd. In: Joel G Hardman, Lee Elimbird (eds).
Lipid-derived Autacoids: Eicosanoids and platelet Activating Factor.
Goodman & Gillman’s the Pharmacological Basis of Therapeutics.
McGraw Hill, 10 ed. 2001; pp 669–685
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8. Allen SP, Yacoub MH. Role of leukotrienes in coronary artery
surgery. Curr Opin Cardiol 1995; 10: 605–613
9. Evans JF. Cysteinyl leukotrienes receptors. Prostaglandins Other Lipid
Mediat 2002; 68-69: 587–597
10. Yokomizo T, Izumi T, Chang K, A G-protein-coupled receptor for
leukotriene B4 that mediates chemotaxis. Nature 1997; 387: 620–
624
11. Yokomizo T, Kato K, Terawaki K, Takuwa Y, Shimizu T. A second
leukotriene B 4 receptor BLT2. A new therapeutic target in
inflammation and immunological disorder. J Exp Med 2000; 192:
421–431
12. Subbarao K, Jala VR, Mathis S, Suttles J, Zacharias W, Tseng MT, et
al. Role of leukotriene B 4 receptors in the development of
atherosclerosis: potential mechanisms. Arterioscler Thromb Vasc Biol
2004; 24: 369–375
13. Devchand PR, Keller H, Peters JM, Vazquez M, Gonzalez F, Wahli W,
et al. The PPAR alpha-leukotriene B4 pathway to inflammation
control. Nature 1996; 384: 39–43
14. Griffiths RJ, Pettipher ER, Koch K, Farrell CA, Breslow Smith MA, et
al. Leukotriene B4 plays a critical role in the progression of collageninduced arthritis. Proc Natl Acad Sci USA 1995; 92: 517–521
15. Brink C, Dahlen SE, Drazen J, Evans JF, Hay DW, Nicosia S, et al.
International Union of Pharmacology 37th. Nomenclature for
leukotrienes and lipoxin receptors. Pharmacol Rev 2003; 55:
195–227
16. Mehrabian M, Allayee H, Wong J, Shi W, Wang XP, Shaposh W, et al.
Identification of 5-Lipoxygenase as a major gene contributing to
atherosclerosis susceptibility in mice. Circ Res 2002; 91:120–126
17. Spanbroek R, Grabner R, Lotzer K, Hildner M, Urbach A, Ruhling K,
et al. Expanding expression of the 5-lipoxygenase pathway within
the arterial wall during human atherogenesis. Proc Natl Acad Sci
USA 2003; 100, 1238–1243
18. Dwyer JH, Allayee H, Dwyer KM, Fan J, WuH, Mar R, et al.
Arachidonate 5-lipoxygenase promoter genotype, dietary
arachidonic acid and atherosclerosis. N Eng J Med 2004; 350: 29–37
19. Harats D, Shaish A, George J, Mulkins M, Kurihara H, Le et al.
Overexpression of 15-lipoxygenase in vascular endothelium
accelerates early atherosclerosis in LDL receptor deficient mice.
Arterioscler Thromb Vasc Biol 2000; 20: 2100–2105
20. Allen S, Dashwood M, Morrison K. Yacoub M. Differential
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Leukotriene B4 receptor antagonism reduces monocytic foam cells
in mice. Arterioscler Thromb Vasc Biol 2002; 22: 443–449
Matsukawa A, Hogaboan CM, Lukacs NW, Lincoln PM, Strieter RM,
Kunkel SL. Endogenous monocyte chemo attractant protein-1
(MCP-1) protects mice in a model of acute septic peritonitis. Cross
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Caterina DR, Zampolli A. From asthma to atherosclerosis5-lipoxygenase, leukotrienes and inflammation. N Engl J Med 2004;
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Helgadottir A, Manolescu A, Thorleifsson G, Gretarsdottir S,
Jonsdottir H, Thorsteinsdottir U, et al. The gene encoding 5lipoxygenase activating protein confers risk of myocardial infarction
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Gu L, Okada Y, Clinton SK, Gerard C, Sukhova GK, Libby P, et al.
Absence of monocyte chemo-attractant protein-1 reduces
atherosclerosis in low-density lipo-protein receptor deficient mice.
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Boring l, Gosling J, Cleary M, Charo IF. Decreased lesion formation
in CCR2-/- mice reveals a role for chemokines in the initiation of
atherosclerosis. Nature 1998; 394: 894–897
McIntyre, Zimmerman GA, Prescott SM. Leukotriene C4 and D4
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Indian Heart J 2005; 57: 181–182
Bhatia et al. Multiple Coronary
and Aortic Aneurysms
181
Cardiovascular
Images
Multiple Coronary and Aortic Aneurysms in a Young
Female: A Diagnostic Dilemma
Vineet Bhatia, NO Bansal, Viswanathan V
Department of Cardiology, Grant Medical College and Sir JJ Group of Hospitals, Mumbai
Fig. 1. Aneurysm of the left main coronary artery and 90% ostial left anterior
descending artery stenosis.
Fig. 3. Descending aortogram reveals two fusiform aneurysms.
Fig. 2. Aortic root angiogram in LAO 60° shows right coronary sinus
aneurysmally dilated, ostial 90% right coronary artery stenosis and grade 1
aortic regurgitation. LAO: left anterior oblique
Fig. 4. Saccular aneurysm in suprarenal aorta.
A
upper limb was 120/70 mmHg, with no significant
difference in the BP in the other limbs. There was no skin
lesion, cervical lymphadenopathy, xanthomas or
xanthelasma. Cardiovascular, and other system
examinations were normal. Complete blood count was
normal, and ESR was 5 mm at the end of first hour. ASLO,
CRP, ANA, RA factor, and VDRL were negative. Liver and
kidney function tests, lipid profile, electrocardiogram (ECG)
n 18-year-old female presented with classical angina
pectoris and breathlessness on exertion of four months
duration. On examination she was afebrile, pulse rate was
82 beats per min, regular, and all peripheral pulsations were
equally well felt, with no bruit. Blood pressure (BP) in right
Correspondence: Dr Vineet Bhatia, Department of Cardiology, 4th Floor
Grant Medical College and Sir JJ Group of Hospitals, Mumbai 400 008
IHJ-776-04 Cardiovascular Image.p65
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6/21/2005, 2:47 PM
182 Bhatia et al. Multiple Coronary and Aortic Aneurysms
at rest, chest X-ray and fundus were normal. Twodimensional echocardiography revealed aneurysmal left
main coronary artery (LMCA) and grade 1 aortic
regurgitation. Cardiac stress test (CST) was positive at
moderate workload of 6 METs with 3 mm ST depression in
anterior leads, which persisted for 5 min into recovery.
Angiographic evaluation revealed an aneurysm of the
LMCA and 90% stenosis at the origin of the left anterior
descending artery (LAD) (Fig. 1). The left circumflex (LCx)
artery was normal. There was a large aneurysm involving
the right coronary sinus with a 90% ostial stenosis of the
right coronary artery (RCA). Aortic root angiogram
revealed grade 1 aortic regurgitation (Fig. 2). Arch
aortogram revealed the origin of all great vessels to be
normal. The descending aorta showed two saccular
aneurysms while there was a fusiform aneurysm in the
suprarenal aorta (Figs 3 and 4). Pulmonary angiogram was
normal. The patient was advised coronary artery bypass
graft surgery.
Most discrete coronary artery aneurysms are
atherosclerotic in origin; other causes include Kawasaki
disease (KD), Takayasu's arteritis [non-specific aortoarteritis
(NSAA)], polyarteritis nodosa, and systemic lupus
erythematosus. The age of presentation of this patient was in
favor of NSAA.1 Non-involvement of the subclavian vessels
ruled out type 1 and type 3 NSAA but combined type 2
(thoracoabdominal type) and type 5 (coronary) NSAA was a
strong possibility. Stenotic lesions most commonly involve
the aorta and its branches. Pure aneurysmal form of the
disease is rare and occurs in only 8.6% cases.2 Coronary
involvement occurs in 20% cases of NSAA in India. 3
Stenotic lesions are commoner and usually involve the ostia
and proximal 2-3 cm of the artery. Coronary aneurysms
are rare and only few isolated case reports are available.3,4
Coronary involvement occurs in 15-25% cases of KD.5
Aneurysms change dynamically with time with over 65%
showing resolution in 1-2 years.6 Rarely, aneurysms persist
or stenosis develops (due to myointimal proliferation).
Aneurysms outside the coronary system occur in up to 2%
of cases and involve the axillary, subclavian, common iliac,
internal iliac, femoral, pancreatic, paraovarian,
paratesticular and splenic arteries. They usually occur in
patients with coronary aneurysms and likewise show
regression in majority of cases. However, these may
progress to stenotic lesions although ischemic symptoms
are rare.7 However, involvement of the aorta was strongly
against the diagnosis of KD, as large-sized arteries are not
affected in KD.
Intravascular ultrasound (IVUS) may be helpful to
differentiate NSAA and KD. IVUS in KD with regressed
aneurysm typically shows marked intimal thickening and
lumen size similar to that at sites near the regressed
aneurysm that has an angiographically normal coronary
IHJ-776-04 Cardiovascular Image.p65
182
Indian Heart J 2005; 57: 181–182
artery (due to extensive medial smooth cell proliferation).
At sites of persistent aneurysms IVUS reveals marked
intimal thickening with calcification, but lacks increased
echogenicity in the wall or lumen (helps in differentiation
from atherosclerotic disease where, apart from intimal
thickening, increased echogenicity due to plaques or
calcification may be seen). Some intimal thickening may
occur in the vicinity of the healed aneurysm, which appears
normal on angiography. However, sites in angiographically
normal artery away from the coronary aneurysm
(persistent or regressed) demonstrate normal artery
structure.8 On the contrary, Suzuki et al.9 reported that sites
distant from the aneurysm site (persistent or healed) might
also reveal intimal involvement. Both the groups showed
that such sites show impaired vasodilatory responses to
vasodilators.8,9 Thus KD not only causes structural but also
stenotic lesions which may later complicate functional
changes at these sites.9 IVUS in NSAA typically shows
thickening and altered echogenicity of media, adventitia
and periarterial tissues and loss of aortic wall pliability in
stenosed segments. The most striking feature, however, is
that though angiogram reveals skip lesions, IVUS shows
that these areas are also affected by disease process.10 No
functional abnormalities, as seen in KD, occur in NSAA.
References
1. Ishikawa K. Diagnostic approach and proposed criteria for diagnosis
of Takayasu's arteriopathy. J Am Coll Cardiol 1988; 12: 964–972
2. Kinare S, Gandhi M, Deshpande J. Non-specific Aortoarteritis
(Takayasu Disease). Pathology and Radiology. Mumbai: Quest
Publications, 1998, p 85
3. Kinare S, Gandhi M, Deshpande J. Non-specific Aortoarteritis
(Takayasu Disease). Pathology and Radiology. Mumbai: Quest
Publications, 1998, p 37
4. Suzuki H, Daida H, Tanaka M, Sato H, Kawai S, Sakurai H, et al.
Giant aneurysm of the left main coronary artery in Takayasu aortitis.
Heart 1999; 81: 214–217
5. Takahashi M, Mason W, Lewis AB. Regression of coronary
aneurysms in patients with Kawasaki syndrome. Circulation 1987;
75: 387–394
6. Suzuki A, Kamiya T, Kuwahara A, Ono Y, Kohata T, Takahashi O, et
al. Coronary arterial lesions of Kawasaki disease: cardiac
catheterization findings of 1100 cases. Pediatr Cardiol 1986; 7: 3–9
7. Kato H, Sugimura T, Akagi T, Sato N, Hashino K, Maeno Y, et al.
Long-term consequences of Kawasaki disease: a 10- to 21- year
follow-up study of 594 patients. Circulation 1996; 94: 1379–1385
8. Sugimura T, Kato H, Inoue O, Fukuda T, Sato N, Ishii M, et al.
Congenital heart disease: intravascular ultrasound of coronary
arteries in children. Assessment of the wall morphology and the
lumen after Kawasaki disease. Circulation 1994; 89: 258–265
9. Suzuki A, Yamagishi M, Kimura K, Sugiyama H, Arakaki Y, Kamiya
T, et al. Functional behavior and morphology of the coronary artery
wall in patients with Kawasaki disease assessed by intravascular
ultrasound. J Am Coll Cardiol 1996; 27: 291–296
10. Sharma S, Sharma S, Taneja K, Bahl VK, Rajani M.Morphological
mural changes in the aorta in non-specific aortoarteritis (Takayasu's
arteritis): assessment by intravascular ultrasound imaging. Clin
Radiol 1998; 53: 37–43
6/21/2005, 2:47 PM
Letters totothe
Editor
183
Letters
the
Editor
Indian Heart J 2005; 183–185
Infra-Hisian Mobitz Type I/
Wenckebach Block
A
65-year-old lady presented with several episodes of
syncope. Clinical examination revealed occasionally
missing pulse and blood pressure was 150/80 mmHg.
There was no murmur, gallop or evidence of heart failure.
Routine hematological and biochemical examinations were
within normal limits. The electrocardiogram (ECG) showed
presence of right bundle branch block with left anterior
hemiblock. In addition, the PR interval was prolonged with
varying Wenckebach block and 3:2 and 4:3 conduction
ratios. The heart size on chest X-ray was normal, so was
the echocardiographic examination. The patient was
subjected to electrophysiological studies to ascertain the
level of block. In the baseline study, surface ECG showed
4:3 Wenckebach block, the PR interval in the first beat was
240 ms, 340 ms in second beat and 380 ms in the third
beat. The fourth P wave was not followed by QRS complex.
Simultaneous His bundle recording showed AH interval of
120 ms (normal 54-130 ms),1 H wave of 20 ms whereas
the HV interval (normal 31-55 ms) 1 showed typical
Wenckebach periodicity; 100 ms in the first beat, 200 ms
in second beat and 240 ms in the third beat. The fourth H
wave was not followed by a V wave (Fig. 1). Thus, the block
was found to be at the level below the His bundle.
Provocative maneuvers were not undertaken because the
baseline measurements showed markedly prolonged HV
Fig. 1. The upper panel shows surface electrocardiogram. There is 4:3
Wenckebach block; the PR interval being 240 ms in 1st beat, 340 ms in 2nd
and 380 ms in the 3rd beat. A QRS complex does not follow the fourth
P wave. The lower two panels show His bundle recording; the AH interval is
120 ms and the H wave is 20 ms. The HV interval is 100 ms in 1st beat, 200
ms in 2nd and 240 ms in the 3rd beat. The fourth H wave is not followed by a
V-wave. The recording speed is 50 mm/s.
IHJ-811-05 Letter-to-Editor.p65
183
intervals. Pacing from the right ventricle apex did not show
retrograde ventriculoatrial conduction. The patient was
advised to undergo permanent pacemaker implantation
and a VVI pacemaker was implanted later on.
Mobitz Type I or Wenckebach AV block was first
described by Wenckebach long before the invention of the
ECG. He described it as a form of conduction disturbance
characterized by a progressive lengthening of the interval
between the ‘a’ and the ‘c’ waves of the jugular pulse,
terminating in a dropped ‘c’ wave.2 After this, the ECG
features were characterized by Mobitz as progressive
prolongation of the PR interval until there was a dropped
ventricular beat.3 The phenomenon is usually repetitive.
Wenckebach and Winterberg further characterized this
phenomenon by describing other characteristics,
including4 : (i) Progressive lengthening of the PR interval,
(ii) The increment between the first and the second
conducted beats being the largest, (iii) Progressive decrease
in the R-R intervals because of decrease in the PR
increment, and (iv) A short ventricular pause produced by
the non-conducted P wave that is equal to the difference
between the last PR interval and the first PR interval
subtracted from twice the PP interval (during an
electrophysiologic study, this translates into an increase in
the AH interval, which parallels the PR prolongation).
The term ‘typical Wenckebach periodicity’ has been
applied to second-degree block that shows all of these
characteristics. When P wave activity is not clearly
discernible on the surface ECG, Wenckebach periodicity can
be recognized because of one of its after-effects, resultant
‘group beating’. The regular appearance of grouped QRS
complexes has been called ‘the footprints of Wenckebach’.
However, it is now generally recognized that in clinical
situations, all of the features are found in perhaps fewer
than 50% of cases. Mobitz Type I or Wenckebach block
usually occurs at the atrioventricular node. Infra-Hisian
Wenckebach block is rare and there are only anecdotal case
reports.5 When the phenomenon occurs with narrow QRS
complexes in surface ECG, the site is more likely to be above
the His bundle. With wide QRS complexes, the site is more
likely to be infra-Hisian.6 Signal-averaged ECG is another
technique, which can distinguish between the two types.7
Otherwise, invasive electrophysiologic study is the method
to differentiate the two varieties.
The present case further strengthens the concept that
Wenckebach type block in surface ECG in presence of
fascicular block is likely due to block in infra-Hisian
location.
6/21/2005, 2:49 PM
Indian Heart J 2005; 183–185
184 Letters to the Editor
References
1. Saoudi N, Rinaldi JP, Imianitoff M. et al. Atrioventricular and
intraventricular conduction disorders. In: Crawford MH et al. (eds).
Cardiology 2nd ed. 2004, Mosby, St Louis, Missouri, p 654
2. Wenckebach KF. Zur Analyse des unregelmassigen Pulses. Z Klin Med
1899; 37: 475
3. Mobitz W. Uber die unvollstandinge Storung der Erregungsuberleitung zwischen Vorhof und Kammer des menschichen
Herzens. Z Ges Exp Med 1924; 41: 180
4. Wenckebach KF, Winterberg H. Die unreglemassige Hertztatigkeit.
Leipzig: Wilhelm Enggleman; 1927
5. Gray R, Kaushik VS, Mandel WJ. Wenckebach phenomenon
occurring in the distal conducting system in a young adult. Br Heart
J 1976; 38: 204–206
6. Barbosa EC, Ginefra P, da Rocha PJ, Musse NS, Boghossian SH,
Albanesi Filho, et al. Significance of prolonged PR interval in patients
with His bundle branch block, bifascicular type. Arq Bras Cardiol
1991; 56: 355–358
7. Babuty D, Fauchier L, Tena-Carbi D, Poret P, Leche J, Raynaud M, et
al. Is it possible to identify infrahissian cardiac conduction
abnormalities in myotonic dystrophy by non-invasive methods? Heart
1999; 82: 634–637
Mukul Misra, AK Mall, M J Khan
Department of Medicine, BRD Medical College
Gorakhpur
Secondary prevention is very important. Injection
benzathine penicillin 1.2 mega units should be given once
in 3 weeks. Oral penicillin is not as effective as injection
and recurrence of RF is possible. All our patients received
injections free in the hospital. The anaphylactic reaction is
very rare. Lately, doctors are afraid to give injection
penicillin. There are other reasons also like consumer
awareness, legal problems etc. This attitude of medical
practioners must change in favour of benzathine penicillin.
My advice in that injection benzathine penicillin 1.2
mega units should be given once in 3 weeks taking all
precautions. We could bring down incidence of RF and RHD
from 8/1000 to 2/1000 in 15 years time in Alleppey during
our study (1966 to 1981). Prophylaxis should be continued
in RHD throughout life. Exception may be made depending
upon age and presence of risk factors. In RF, prophylaxis
should be continued till 20 years.
References
1. R Tadon. Is it possible to prevent rheumatic fever. Indian Heart J 2004;
56: 677-679
DV Nair
Fomerly Expert Committee Member WHO, ICMR
Kochi
Is it Possible to Prevent Rheumatic
Fever
Reply
I
must congratulate R Tandon1 for such an important
topic and also giving practical advice. It is always good
to hear from such senior people with vast experience about
such a common diseases as rheumatic fever (RF) and
rheumatic heart disease (RHD).
I would like to mention briefly my observation from my
study of RF and RHD in school children aged 5-15 years in
Alleppey district of Kerala. We covered 28,359 students
in 23 schools. This study was started in 1966.
Primordial prevention is a difficult task and good result
depends upon educating teachers of the school and also
educating the parents. Improvement in socioeconomic
status plays a major role in reducing the incidence of RF
and RHD.
Primary prevention of identifying Group A betahemolytic streptococci (GABHS) and prompt and adequate
treatment is also difficult. Most of the sore throats are not
due to GABHS. The results I got in my series were good due
to many reasons. Besides educating teachers and parents,
the doctors (of Primary Health Centre and Taluk and
District Hospitals) were also actively involved. Health care
delivery system is much better in Kerala and 95% of
children are school-going. Literacy rate is almost 100%.
Besides, all patients receive treatment free in the hospital.
IHJ-811-05 Letter-to-Editor.p65
184
I
would like to thank DV Nair for his comments since
his letter emphasizes the main purpose of my write-up,
"Is it possible to prevent rheumatic fever (RF)?"
Under active surveillance it is possible to reduce the
burden of RF/rheumatic heart disease (RHD). However, it
is not possible to eliminate the problem of RF/RHD. Nair
points out that inspite of 100% literacy and 95% children
going to school, even with active surveillance, after 15
years, the prevalence was still 2/1000 but not absent.
It is essential that three-weekly injectable penicillin is
used. Oral penicillin may not be able to prevent RF.
As far as secondary prevention is concerned, it is equal
to "closing the barn door, after the horse has escaped". It is
ethically essential and mandatory to prevent recurrences
and thus subsequent damage and worsening of RHD.
Secondary prevention will not reduce the total burden of
RHD.
Primary prevention will be feasible only with vaccine,
when it becomes available.
R Tandon
Consultant Cardiologist
Sitaram Bhartia Institute of Science & Research
New Delhi
6/21/2005, 2:49 PM
Indian Heart J 2005; 183–185
Thrombolytic Therapy for Acute
Myocardial Infarction in Acute
Lymphoblastic Leukemia
A
cute lymphoblastic leukemia (ALL) is an uncommon
malignant hematopoietic disorder in adults.
Commonly used chemotherapeutic drugs to treat this
leukemia consist of combination of anthracyclines
(daunorubicin, doxorubicin), cytarabine, cyclophosphamide, vincristine and steroids. Anthracyclines are
associated with acute toxicity in the form of atrial and
ventricular arrhythmias, but these are rarely of clinical
significance. In contrast, cumulative doses of doxorubicin
are associated with a 10% increase in incidence of chronic
cardiomyopathy.1 Another drug used in the treatment of
ALL, L-asparaginase can predispose to thrombosis by
causing clotting factor abnormalities. Though patients with
ALL are not immune to have lifestyle-related diseases like
diabetes, hypertension and coronary artery disease, the
management issues are complex when a patient of ALL
develops acute myocardial infarction (MI). Acute MI has
been reported rarely among patients of ALL usually during
therapy with L-asparaginase.2 The safety and efficacy of
thrombolysis as a treatment modality for acute MI
developing in such a setting is not known. We present a
patient of ALL who did not receive L-asparaginase and who,
in remission, developed acute MI and was successfully
thrombolyzed with streptokinase.
A 44-year-old man presented to us with epistaxis 4 years
ago. On further investigations he was found to have
pancytopenia and peripheral blood film was showing blast
cells. Bone marrow examination confirmed the diagnosis
of ALL. He was treated with modified German ALL protocol
consisting of a combination of doxorubicin, vincristine,
cytrabine and steroids.3 He was not given L-asparaginase
as he developed allergic reaction to it. During intensive
phase of chemotherapy lasting for 9 months, he received a
total of 180 mg of daunorubicin and 160 mg of
doxorubicin. He completed his maintenance chemotherapy
IHJ-811-05 Letter-to-Editor.p65
185
Letters to the Editor 185
and his last bone marrow examination was normal. The
patient remained asymptomatic for next three months.
Then, he presented to our emergency department with
acute chest pain lasting for half an hour. Electrocardiogram
(ECG) revealed changes in acute inferior wall MI. Although
the patient was in remission for ALL, there was a doubt in
the mind of treating clinicians regarding the safety of
thrombolysis in such patients. The dilemma was further
compounded due to paucity of literature on this issue. After
discussion with relatives of patient, the patient was
thrombolyzed with injection streptokinase in the dosage of
1.5 million units over one hour. Post-thrombolysis, his
pulse and blood pressure remained stable. Repeat ECG was
normal indicating successful thrombolysis. He was
discharged from hospital on day 7. Echocardiography done
before discharge showed an ejection fraction of 55%. A
stress test done at 6 weeks was positive for inducible
ischemia. A follow-up echocardiography done at 3 months
post-MI showed a normal left ventricular ejection fraction
and no regional wall motion abnormality. His hemogram
did not show any evidence of relapse. In conclusion, it can
be stated that if patient of ALL in remission develops acute
MI, he can be treated on the same lines as non-leukemia
patients and thromolysis with streptokinase is a safe option
in such patients.
References
1. Singal PK, Iliskovic N. Doxorubicin-induced cardiomyopathy. N Engl
J Med 1998; 339: 900–905
2. Fragasso G, Pastore MR, Vicari A, Chierchia SL, Pozza G. Myocardial
infarction in a patient with acute lymphoblastic leukemia during Lasparaginase therapy. Am J Hematol 1995; 48: 136–137
3. Hoelzer D, Thiel F, Loffler H, Bodenstein H, Plaumann L, Buchner T,
et al. Intensified therapy in acute lymphoblastic and acute
undifferentiated leukemia in adults. Blood 1984; 64: 38–47
Pankaj Malhotra
Department of Internal Medicine
Postgraduate Institute of Medical Education & Research
Chandigarh
6/21/2005, 2:49 PM
186 Selected
Summaries
Selected
Summaries
Indian Heart J 2005; 57: 186–189
The Effect of Cardiac Resynchronization on Morbidity and Mortality in Heart Failure
Cleland John GF et al. CARE-HF investigators
Summary
The Cardiac Resynchronization Heart Failure (CARE - HF)
study was a randomized multicenter trial undertaken with
the aim to assess effects of cardiac resynchornization
therapy (CRT) (without a defibrillator) on morbidity and
mortality in patients with symptomatic heart failure who
had objective evidence of dyssynchrony. Patients with
NYHA class III or IV heart failure due to left ventricular
(LV) systolic dysfunction and cardiac dyssynchrony who
were receiving standard pharmacologic therapy were
randomly assigned to receive medical therapy alone or with
CRT. Inclusion criteria were age ≥18 years, heart failure
for at least six weeks, and in NYHA class III or IV despite
receiving standard pharmacologic therapy, with an LV
ejection fraction (EF) < 35%, an LV end-diastolic dimension
of at least 30 mm (indexed to height), and a QRS interval
of at least 120 ms. Patients with heart failure requiring
continuous intravenous therapy were excluded. Those who
had had a recent major cardiovascular event, and those
who had conventional indications for a pacemaker or an
implantable defibrillator were also not included. Device used
was Medtronic InSync or Insync III and operators were
specifically asked to position the LV lead to pace the lateral
or posterolateral LV wall transevenously. The primary end
point was the composite of death from any cause or an
unplanned hospitalization for a major cardiovascular event
that included worsening heart failure, acute coronary
syndrome, stroke or arrhythmias. The principal secondary
end point was death from any cause and also included
NYHA class, quality of life and echocardiographic
parameters. A total of 813 patients were enrolled, 404
patients were assigned to receive medical therapy alone and
409 to receive medical therapy plus CRT and followed for a
mean period of 29.4 months ranging from 18 to 44.7
months. The primary end point was reached by 159
patients in the CRT group, as compared with 224 patients
in controls (39% v. 55%, hazard ratio, 0.63; p<0.001).
There were 82 deaths in the CRT group, as compared with
120 in the medical-therapy group (20% v. 30%, hazard
ratio 0.64; p<0.002). The mode of death was sudden in
32% of patients in the medical group and 35% in the CRT
sub group died suddenly. As compared with medical
therapy alone, CRT reduced the interventricular
mechanical delay, the end-systolic volume index and the
IHJ-Selected Sum.p65
186
N Engl J Med 2005; 352: 1539-1549
area of the mitral regurgitant jet; increased the LVEF; and
improved symptoms and the quality of life (p<0.01 for all
comparisons). The most common adverse device-related
events in CRT group were lead displacement, coronary
sinus dissection, pocket erosion, peumothorax and
infection.
Comments
Several studies in the recent past have consistently shown
improvement in the LV function manifesting in decreased
symptoms, improved quality of life and increased exercise
capacity with CRT. However, there is no clear evidence
about the effect of CRT on mortality. The recent
COMPANIAN trial showed a reduction in the composite end
point of death or hospitalization but there was no
significant reduction in the risk of death. The present study
showed that in patients with heart failure and cardiac
dyssynchrony, CRT improves symptoms and the quality of
life and reduces the risk of death. This is the first study that
proves that CRT actually reduced the risk of death.
Statistical analysis reveals that for every nine devices
implanted, 1 death and 3 hospitalizations are avoided.These
benefits are in addition to those afforded by standard
pharmacologic therapy. The overall mortality rate in this
study was relatively low compared to other studies in a
similar cohort of heart failure patients. The authors
attribute this to either the presence of relatively less severe
heart failure or to the high standard of care and close
follow-up. However, all patients were in at least NYHA class
III. It makes one think that the risk may be modified to a
greater extent among patients with less severe disease.
Another interesting point is that the hazard ratio for death
in those receiving CRT compared with medical therapy was
similar to the ratio comparing the two groups in the
COMPANIAN trial that evaluated CRT plus AICD. This
prompted the authors to consider that CRT induced
improved cardiac function, and may also reduce the risk of
sudden death; however, till a trial compares directly the two
arms it is not possible to prove the assumption. The fact
remains that 29 patients died suddenly in the CRT arm in
this study and a defibrillator would certainly have further
reduced the risk of death. However, again only a trial
specifically designed to address this issue would resolve it.
6/21/2005, 2:51 PM
Indian Heart J 2005; 57: 186–189
Selected Summaries 187
Effect of Glucose-Insulin-Potassium Infusion on Mortality in Patients with
Acute ST-Segment Elevation Myocardial Infarction
The CREATE-ECLA Trial Group Investigators
Summary
The Clinical Trial of Reviparin and Metabolic Modulation
in Acute Myocardial Infarction Treatment Evaluation
(CREATE) group of investigators used a 2x2 partial factorial
design comparing patients on reviparin versus placebo
administered for 7 days (double-blind) and those on
glucose-insulin-potassium (GIK) versus control (open)
administered for 24 hours, in addition to usual care. The
aim of the study was to find out if there is a therapeutic
benefit of using high-dose GIK infusion for patients with
ST-segment elevation myocardial infarction (STEMI). This
randomized controlled trial was conducted in 470 centers
worldwide among 20,201 patients with STEMI who
presented within 12 hours of symptom onset. Patients were
randomly assigned to receive either GIK (25% glucose, 50
U insulin/L, 80 meq/L of potassium, at a rate of 1.5 ml/kg
per hour for 24 hours) plus usual care (n=10,091) or usual
care alone (controls; n=10,110). Individuals with
contraindications for GIK infusion i.e. type 1 diabetes, renal
impairment or hyperkalemia were excluded. Primary
outcome measure was mortality while secondary outcome
measures included cardiac arrest, cardiogenic shock, or
reinfarction at 30 days after randomization. The mean age
of patients was 58.6 years, and evidence-based therapies
for STEMI were commonly used. At 30 days, 976 control
patients (9.7%) and 1004 GIK infusion patients (10.0%)
died. There were no significant differences in the rates of
cardiac arrest (1.5% in controls and 1.4% in GIK infusion),
cardiogenic shock (6.3% v. 6.6%) or reinfarction (2.4% v.
2.3%). The rates of heart failure at 7 days after
randomization were also similar between the groups
(16.9% v. 17.1%). There were no significant differences in
brady or tachyarrhythmia between two groups. The lack
of benefit of GIK infusion on mortality was consistent in
pre-specified subgroups, including in those with diabetes
(17.7%) and without diabetes (82.3%) in those presenting
with and without heart failure, in those presenting early
and later after symptom onset, and in those receiving
thrombolysis (74.1%) and not receiving thrombolytic
therapy or undergoing primary percutaneous coronary
IHJ-Selected Sum.p65
187
JAMA 2005; 293: 437-446
intervention (9.1%). In this large, international randomized
trial, high-dose GIK infusion had a neutral effect on
mortality, cardiac arrest, and cardiogenic shock in patients
with acute STEMI.
Comments
Glucose-insulin-potassium (GIK) therapy has survived
decades of clinical practice without a definitive test of its
safety and effectiveness. GIK solution was initially advocated
for the treatment of acute myocardial infarction (AMI) as
a polarizing agent to promote electrical stability and later
as an agent to provide metabolic support. Exogenous insulin
suppresses circulating levels and myocardial uptake of free
fatty acids, which are toxic to the ischemic myocardium.
Provision of high-dose glucose can improve the efficiency
of myocardial energy production during acute ischemia by
becoming the preferred fuel for the heart. Because
intracellular levels of potassium are depleted during
ischemia, provision of exogenous potassium increases levels
within the myocyte, thereby raising the threshold for
ventricular arrhythmias. Unfortunately, regardless of its
scientific rationale and the positive results of small studies,
the present study of over 20,000 patients with STEMI
demonstrated that there was no benefit (or harm) of GIK.
DIGAMI trial demonstrated in a randomized controlled trial
in 600 diabetics that initial intensive metabolic control by
insulin-glucose infusion for at least 24 hours followed by 3
months of subcutaneous insulin improved long-term
outcome. The GIPS and polish trial found no significant
benefit of GIK therapy in AMI. Though GIK per se showed
no benefit in CREATE trial, tight metabolic control using
intravenous insulin/glucose might improve outcome.
Hence it is worthwhile to test tight glycemic-control
hypothesis in patients with STEMI. This definitive trial,
combined with a previous overview that showed only a
modest potential benefit, answers the question beyond
reasonable doubt: there is no benefit of GIK therapy. Societal
resources would be better spent on evaluating other
approaches in clinical trials and using other therapies in
practice.
6/21/2005, 2:51 PM
Indian Heart J 2005; 57: 186–189
188 Selected Summaries
Effects of Reviparin, a Low-Molecular-Weight Heparin, on Mortality,
Reinfarction and Strokes in Patients with Acute Myocardial Infarction
Presenting with ST-Segment Elevation
The CREATE Trial Group Investigators
JAMA 2005; 293: 427-435
Summary
Comments
The Clinical Trial of Reviparin and Metabolic Modulation
in Acute Myocardial Infarction Treatment Evaluation
(CREATE) study was a randomized, double-blind, placebocontrolled study of 15,570 patients from 341 hospitals in
India and China with ST-segment elevation myocardial
infarction (STEMI) or new left bundle branch block (LBBB),
presenting within 12 hours of symptom onset. The primary
objective of this trial was to evaluate the effects of reviparin,
a low-molecular-weight heparin (LMWH), when initiated
early (prior to or within 15 min of thrombolytic theropy)
and given for 7 days in addition to usual therapy on the
primary composite outcome of death, myocardial
reinfarction, or strokes at 7 and 30 days. The primary
composite outcome was significantly reduced from 854
(11.0%) of 7790 patients in the placebo group to 745
(9.6%) of 7780 in the reviparin group [hazard ratio (HR),
0.87; p=0.005] at 7 days. These benefits persisted at 30
days [1056 (13.6%) v. 921 (11.8%); HR, 0.87; p=0.001)]
with significant reductions in 30-day mortality [877
(11.3%) v. 766 (9.8%); p=0.005] and reinfarction [199
(2.6%) v. 154 (2.0%); p=0.01], and no significant
differences in strokes [64 (0.8%) v. 80 (1.0%); p=0.19].
Reviparin treatment was significantly better at 7 days when
it was initiated very early after symptom onset (<2 hours:
30/1000 events prevented; 2 to <4 hours : 21/1000 events
prevented; 4 to <8 hours: 16/1000 events prevented; and
≥8 hours p=0.58; p=0.04 for trend). An increase occurred
in life-threatening bleeding at 7 days with reviparin
compared to placebo (0.2% v. 0.1%, respectively; p=0.07).
The benefits of reviparin were independent of the type of
reperfusion therapy (streptokinase, tissue plasminogen
activator or primary angioplasty and was also beneficial in
those not thrombolyzed). Thus, in patients with acute
STEMI or new LBBB, reviparin reduces mortality and
reinfarction, without a substantive increase in overall stroke
rates and with a small absolute excess of life-threatening
bleeding.
Antithrombotic therapy has become the mainstay of
treatment of acute coronary syndromes (ACS), but the
accrual of definitive evidence has been hampered by the
fact that unfractionated heparin (UFH) became standard
before the era of definitive clinical outcome trials. Trials
with unfractionated heparin (ISIS-3, GISSI-2) in patients
receiving streptokinase or tissue plasminogen activator
have not demonstrated a reduction in major vascular events
at 1 month. This lack of benefit may have been because of
the inherent limitations of unfractionated heparin or delays
in therapy after a thrombolytic agent. Trials with LMWH,
enoxaparin (v. placebo or unfractionated heparin) have
shown some reduction in reinfarctions but no impact on
mortality. There are concerns of substantial increases in
strokes when enoxaparin and some fibrin-specific agents
such as tenectoplase are used in elderly patients (ASSENT3 study and ASSENT-Plus study). However, unlike these
trials, the CREATE trial not only observed reductions in
recurrent MI and recurrent ischemic events but also
observed significant reductions in mortality. The anti-Xa/
IIa ratio for reviparin used in the present trial is about 3.3,
which is similar to enoxaparin (3.3) and nadroparin (3.0),
but higher than that of dalteparin (2.0) and tinzaparin
(1.8). The rates of intracranial hemorrhage in CREATE trial
in the reviparin group at 7 days were lower than previous
trials of enoxaparin used in conjunction with fibrin-specific
thrombolytic agents, tenecteplase (0.3% v. 0.88% in the
ASSENT-3 study). Overall, there were 17 fewer major
events (death, reinfarction, strokes or life-threatening
bleeding) per 1000 patients receiving reviparin. Therefore,
given the clearly lower mortality and reinfarction rates with
no excess in overall stroke rates, the combination of
reviparin with less expensive, non-specific thrombolytic
therapy is a reasonable option in patients with acute MI
receiving other effective therapies. CREATE advances the
field in the management of ACS by demonstrating that the
recommendation for antithrombotic therapy can now be
made with confidence. The strength of the trial lies in the
fact that it is one of the largest trials with LMWH and since
it was conducted in our country, the results are more
applicable to us.
IHJ-Selected Sum.p65
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6/21/2005, 2:51 PM
Indian Heart J 2005; 57: 186–189
Selected Summaries 189
Effectiveness and Safety of Sirolimus-Eluting Stents in the Treatment of Restenosis after
Coronary Stent Placement (TROPICAL study)
Franz-Josef Neumann et al.
Circulation 2005; 111: 2107-2111
Summary
Comments
Restenosis continues to be a significant limitation of
placement of bare metal stents for native coronary artery
lesions occurring at a rate of 15% to 50%, depending on
various factors including lesion and patient characteristics.
Treatment of in-stent restenosis (ISR) by repeat angioplasty
is confounded by a recurrence in almost half of those
treated, with repeat intervention required in about twothirds. From the several catheter-based treatment
modalities for ISR tested, only brachytherapy has been
effective to prevent recurrence. Drug-eluting stents (DESs)
inhibit neointimal proliferation which is the key mechanism
of restenosis after primary stent placement. However, there
is no large experience with the DES in the treatment of ISR.
This (TROPICAL) multicenter study was undertaken to
assess the effectiveness and safety of the sirolimus-eluting
stent in patients with ISR in a native coronary artery lesion.
This study was a prospective multicenter registry that
included 162 patients with ISR. Eligibility criteria included
a clinical indication for repeat percutaneous catheter
intervention for ISR, beyond 4 weeks after the initial
percutaneous catheter intervention. Patients with percent
diameter stenosis ≥ 60%; vessel size between 2.5 and 3.0
mm and lesion length of ≤ 45 mm were included. Exclusion
criteria were: total occlusion at the site of ISR, previous
brachytherapy, lesion in the unprotected left main,
myocardial infarction (MI) within the preceding 14 days,
contraindication to aspirin, clopidogrel, or heparin. All
lesions were stented with 1 or 2 sirolimus-eluting stents
(CYPHER, Cordis) after balloon pre-dilation. The primary
end point was in-lesion late loss at follow-up. Secondary end
points were angiographic restenosis and the rate of target
lesion revascularization. Follow-up angiography at 6
months was performed in 155 patients. There was an inlesion late loss of 0.08±0.49 mm and a binary restenosis
rate of 9.7% (15/155), which needed reintervention in
7.4% (12/162) at 9 months. The 9-month mortality rate
was 1.2% (2/162) and the rate of non-fatal MI was 1.2%
(2/162). In the subanalysis, there was no specific predictor
of restenosis like diabetes or lesion length. However there
was a trend toward higher in- lesion late loss with longer
lesions.
Aggressive neointimal proliferation is the underlying
process for the poor results achieved with conventional
treatment of ISR. Previous studies have revealed an average
late loss of around 1 mm with routine catheter-based
treatment. The most promising modality prior to the advent
of DES was brachytherapy. But even with this therapy, there
was a late loss that ranged from 0.22±0.84 to 0.64±0.69
mm depending upon the lesion characteristics and
technical factors. This is the first large multicenter
experience with sirolimus-eluting stents in the treatment
of ISR. The results of the TROPICAL study have proven the
efficacy of sirolimus-eluting stents in the treatment of ISR.
In fact the late loss (0.08±0.49 mm) measured in this study
was of the same magnitude as seen in primary stent
placement using DES. This study showed much lower inlesion late loss than previous studies. The ISAR-DESIRE
study, reported an in-lesion late lumen loss of 0.45 mm in
the 100 patients treated with sirolimus-eluting stents for
ISR. Similar in-stent late lumen loss was reported from the
Rotterdam Cardiology Hospital (RESEARCH) Registry. In
the TROPICAL study it was lower, probably due to the
exclusion of total occlusion lesions from the study.
Moreover, special care was taken to minimize balloon
trauma during pre-dilation. Care was taken to dilate only
the stenosis with minimal length balloon and to cover 5
mm safety margins at both ends. So, endothelial injury was
minimized and the injured area was adequately covered.
Although brachytherapy for ISR was superior to
conventional treatment in various studies, it is logistically
more demanding and limited by risk of edge restenosis and
late stent thrombosis. The late loss of 0.08±0.49 mm
reported in TROPICAL study is remarkable. Brachytherapy
has been the current standard of care in the treatment of
ISR. However, between these two (brachytherapy or
sirulimus eluting stent) the best treatment option for ISR is
still not answered.The ongoing Sirulimus for Instent
ReStenosis (SIRS) trial is addressing this very issue.
IHJ-Selected Sum.p65
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6/21/2005, 2:51 PM
Calendar of Conferences/CSI Executive Committee
December 1-4, 2005, 57th Annual Conference of
Cardiological Society of India and 15th Asian Pacific
Congress of Cardiology, Mumbai, India
Contact: Dr Anil Kumar, Secretary General
Bombay Hospital
# 122, 12 Marine Lines, Mumbai - 400 020
Tel: 022-2200 6848, 2206 7676 Extn. 280
Fax: 022-2203 4660/2208 0871
e-mail: [email protected]
web: www.15apccand57csi.com
or
Dr Asok Kumar Kar, President Elect
Chairman, Scientific Committee
Indian Heart House, P-60,
CIT Road, Scheme VIIM, Kankurgachi
Kolkata - 700 054
Tel: 033-2355 7837/6308
Fax: 033-2355 6308
e-mail: [email protected],
[email protected]
November 29-December 2, 2005 Asia Pacific Interventional Advances Conference, Newcastle, Australia
Contact: Ms. Lyndell Wills
PO Box 180
Morisset NSW
Australia 2264
Tel: 0661 2 4973 6573
Fax: 0061 2 4973 6609
e-mail: [email protected]
web: www.willorganise.com.au/apia
January 30 -February 2, 2006, 61st Annual Conference
of the Association of Physicians of India, Patna, India
Contact: Dr Ajay Kumar, Organizing Secretary
22, Nehru Nagar, Patna - 800 013
Tel: 0612-2265715
Fax: 0612-2278945
e-mail: [email protected]
Indian Heart J 2005; 57: 190
Cardiological Society of India
Executive Committee (2004-2005)
President
P C Manoria, Bhopal
President Elect
A K Kar, Kolkata
Honorary Editor
V K Bahl, New Delhi
Vice Presidents
Amal Kumar Banerjee, Kolkata
J C Mohan, New Delhi
Kajal Ganguly, Kolkata
Honorary General Secretary
P S Banerjee, Kolkata
Treasurer
S S Chatterjee, Kolkata
Honorary Joint Secretary
Sharad Kumar Parashar, Jahandirabad
Soumitra Kumar, Kolkata
Members
Vidhut Kumar Jain, Indore
S K Parashar, New Delhi
K Venugopal, Calicut
Shirish Hiremath, Pune
A K Khan, Kolkata
P K Deb, Kolkata
H K Chopra, New Delhi
H M Mardikar, Nagpur
Shubhendu Banerjee, Kolkata
Binoda Nand Jha, Muzaffarpur
K Sarat Chandra, Hyderabad
Santanu Guha, Kolkata
S B Gupta, Mumbai
Balram Bhargava, New Delhi
Satyendra Tewari, Lucknow
Dhiman Kahali, Kolkata
Rakesh Gupta, New Delhi
C Lakshmikantan, Chennai
A K Maity, Kolkata
Bikash Kumar Chatterjee, Kolkata
B N Shahi, New Delhi
Immediate Past President
R J Manjuran, Tiruvalla
Cal of Conference.p65
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6/21/2005, 2:20 PM