Download Coronary Bypass Surgery Performed off Pump Does

Coronary Bypass Surgery Performed off Pump Does Not
Result in Lower In-Hospital Morbidity Than Coronary
Artery Bypass Grafting Performed on Pump
Jean-Francois Légaré, MD; Karen J. Buth, MSc; Sharon King, RN; Jeremy Wood, MD; John A. Sullivan, MD;
Camille Hancock Friesen, MD; John Lee, MD; Kier Stewart, MD; Gregory M. Hirsch, MD
Downloaded from http://circ.ahajournals.org/ by guest on June 16, 2017
Background—There is increasing evidence that cardiopulmonary bypass (CPB) may be responsible for the morbidity
associated with coronary artery bypass grafting (CABG) surgery. Recent developments in cardiac stabilization devices
have made CABG without CPB feasible. However, there is conflicting evidence to date from published trials comparing
outcomes between CABG performed with and without CPB, with some trials indicating an advantage to the avoidance
of CPB and others showing little benefit.
Methods and Results—In a single-center randomized trial, 300 patients requiring CABG surgery at a single institution
were prospectively randomized to have the procedure performed with CPB (n⫽150) or on the beating heart (n⫽150).
Exclusion criteria for the trial included emergency procedure, concomitant major cardiac procedures, ejection fraction
⬍30%, and reoperation. In-hospital outcomes were analyzed on an intention-to-treat basis. A mean of 3.0⫾0.9 grafts
were performed in the CPB group compared with 2.8⫾0.9 grafts in the beating-heart group (P⫽0.06). There were no
significant differences between the CPB group and the beating-heart group in mortality (0.7% versus 1.3%; P⫽1.0),
transfusion (8.7% versus 9.3%), perioperative myocardial infarction (0.7% versus 2.7%; P⫽0.37), permanent stroke
(0% versus 1.3%; P⫽0.50), new atrial fibrillation (32% versus 25%; P⫽0.20), and deep sternal wound infection (0.7%
versus 0%; P⫽1.0). The mean time to extubation was 4 hours, the mean stay in the intensive care unit was 22 hours,
and the median length of hospitalization was 5 days in both groups (P⫽NS).
Conclusions—In contrast to published trials, we were unable to demonstrate any advantage with CABG performed without
CPB in terms of patient morbidity. Excellent results can be obtained with either surgical approach. (Circulation. 2004;
109:887-892.)
Key Words: coronary disease 䡲 revascularization 䡲 cardiopulmonary bypass
C
oronary artery bypass grafting (CABG) performed with
cardiopulmonary bypass (CPB) has become a wellestablished treatment modality for patients with coronary
artery disease.1 However, there has been increasing evidence
that CPB may be responsible for some of the morbidity
associated with CABG surgery. The systemic inflammatory
reaction initiated by the extracorporal circuit results in mechanical trauma to blood, activation of various immunological cascades (complement, cytokines), impaired hemostasis,
and impaired neurological, renal, and gastrointestinal function.2,3 Furthermore, aortic cannulation, cross-clamping, and
CPB can result in microembolization and macroembolization
with subsequent neurological injury and other end-organ
injury, including global myocardial ischemia/reperfusion injury.4 Thus, it has been proposed that CABG surgery would
be safer if CPB could be avoided.
The development of new cardiac stabilization devices has
allowed for the creation of safe and reproducible coronary
See p 810
anastomoses on the beating heart.5–7 Several large, nonrandomized, retrospective case series comparing CABG surgery
performed on the beating heart (off pump) and conventional
CABG surgery performed with CPB (on pump) have indicated an advantage to CABG surgery without CPB; however,
selection bias toward lower-risk cases in CABG without CPB
remains an issue.8 –14 The largest randomized studies published to date are conflicting, with some demonstrating
decreased length of hospitalization and myocardial enzyme
release,15 whereas others demonstrate decreased incidence of
atrial fibrillation, length of hospitalization, and blood-product
utilization with CABG surgery performed on the beating
heart.16,17 The most recent trial demonstrated decreased
blood-product requirement, myocardial enzyme release, and
length of hospitalization in beating-heart surgery patients.18
Of the 3 published trials, 2 are single-surgeon experiences,
Received September 25, 2003; accepted November 10, 2003.
From the Division of Cardiovascular Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.
Correspondence to Dr Jean-Francois Légaré, 1796 Summer St, Room 2006, Division of Cardiovascular Surgery, New Halifax Infirmary, Halifax, Nova
Scotia, B3H 3A7, Canada. E-mail [email protected]
© 2004 American Heart Association, Inc.
Circulation is available at http://www.circulationaha.org
DOI: 10.1161/01.CIR.0000115943.41814.7D
887
888
Circulation
February 24, 2004
and as such, the potential for bias in end points that are
discretionary treatments (decision to extubate, discharge, and
transfuse) is an important consideration. Moreover, the majority of these trials excluded high-risk patients, which brings
into question the generalizability of the results.
The present study was designed and powered to detect
significant differences in the following 3 major outcomes:
blood-product requirements, length of hospitalization, and
prolonged mechanical ventilation. It is, to the best of our
knowledge, the largest single-center randomized controlled
study comparing CABG surgery performed on the beating
heart with CABG surgery using CPB.
Methods
Study Design and Patients
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Between August 1999 and March 2003, 300 patients requiring
CABG surgery at a single institution were prospectively recruited
and, after they gave informed consent, were randomized to have the
procedure performed on the beating heart (off pump) or with CPB
(on pump). Indications for CABG surgery were based on a weekly
peer review process, which involved a cardiologist, cardiac surgeons,
and cardiac radiologists. Individual patients were queued for surgery
on the basis of objective criteria as described previously.19 Exclusion
criteria for the trial included emergency procedure (requiring immediate surgery), concomitant major cardiac procedures, ejection fraction ⬍30%, and reoperation. The study was approved by the Capital
Health Research Ethics Board.
Six of 9 surgeons in this center participated in the study.
Randomization envelopes were generated by computerized block
randomization to beating-heart (off-pump) CABG surgery or surgery
with CPB (on-pump). The block size varied from 8 to 20 patients and
was unknown to the study participants. Randomization was performed intraoperatively after a preliminary inspection of the coronary artery anatomy to better ensure that a beating-heart procedure
could be performed safely. Intraoperative reasons for nonrandomization included intramyocardial vessels, very poor quality of distal
vessels, and hemodynamic instability with manipulation of the heart.
Once randomized, patients were allowed to cross over between
groups when it was judged by the treating surgeon that the procedure
assigned was unfeasible, for technical or hemodynamic reasons.
Surgical Technique
A median sternotomy was performed in all patients. Beating-heart
surgery was performed in a standardized fashion as described
previously.20 Briefly, 3 traction sutures were placed in the posterior
pericardium for retraction, followed by placement of a commercially
available tissue stabilizer (Medtronic Octopus and Coronéo Corvasc). With the advent of the Octopus III (Medtronic), posterior
pericardial traction sutures were no longer necessary. A nontraumatic, small bulldog clamp was then applied to the target vessel
proximal to the anastomotic site to achieve hemostasis after arteriotomy. All anastomoses were constructed with a continuous-suture
technique with 7-0 or 8-0 monofilament sutures.
CABG surgery performed with CPB was done in a standardized
fashion with ascending aortic cannulation and 2-stage venous cannulation of the right atrium. During CPB, the mean arterial pressure
target was set at 60 mm Hg, and body temperature was allowed to
drift to a minimum of ⬇32°C. Intermittent cold-blood cardioplegia
(1:4 blood to crystalloid with maximal K⫹ concentration 22 mEq/L)
was delivered antegrade via the aortic root unless otherwise
indicated.
In either the CPB or beating-heart approaches, the choice of
conduits and construction of composite grafts was based on surgeon
preferences rather than fixed criteria. Arterial conduits were harvested with minimal trauma (nonskeletonized internal mammary
artery), and all were treated with either a Papaverine solution or
nitroglycerin/calcium channel blocker (Verapamil) solution before
use.
Heparin was given at a dose of 300 IU/kg to achieve target
activated clotting time ⬎450 seconds in the CPB group compared
with 100 IU/kg in the beating-heart group. On completion of
anastomoses, both groups received protamine sulfate to reverse the
effects of heparin and return the activated clotting time to preoperative levels. No special blood conservation techniques were used
other than nonhemic prime, retransfusion of all contents of the
oxygenator at the end of CPB, and acceptance of normovolemic
anemia. Postoperatively, nonhemic volume expanders were used
routinely.
Postoperative Management
All postoperative cardiac surgery patients were taken to a dedicated
cardiovascular intensive care unit (ICU). Each patient was required
to meet standard criteria before extubation and before transfer to the
intermediate care unit. The need for a perioperative blood-product
transfusion was determined on an individual, patient-by-patient
basis. There was no rigid transfusion trigger for the use of homologous blood products; however, in general, patients were not transfused until serum hemoglobin was ⬍70 mg/dL, unless they were
considered at risk clinically for decreased oxygen delivery. Overall
transfusion rates were captured for blood products given intraoperatively and postoperatively. Preoperative transfusions were not
included in this analysis. Similarly, patients were generally not
transferred from the ICU if they were considered at risk clinically for
decreased oxygen delivery. Discharged patients were transferred to
an intermediate-care or general-care ward under the care of the same
team. All patients were monitored continuously for a minimum of 24
hours.
All patients received intravenous nitroglycerin (0.1 to 8 ␮g · kg⫺1
· min⫺1) infusions for the first 24 hours unless they were hypotensive
(systolic blood pressure ⬍90 mm Hg). Oral nifedipine (Adalat 10 mg
PO QID or Adalat XL 30 mg/d) was prescribed for all patients
receiving a radial artery graft beginning on day 1 after surgery for a
period of 3 to 6 months. Other routine medications included daily
aspirin and resumption of cholesterol-lowering agents, ␤-blockers,
and ACE inhibitors as appropriate.
Data Collection
Perioperative patient variables were collected prospectively by 3
full-time research assistants. An elective case was defined as a
patient waiting at home before the procedure; in-house cases were
defined as hospitalized patients requiring surgery; urgent cases were
defined as cases in which surgery was deemed necessary within 24
hours to prevent further clinical deterioration; and emergent/emergent salvage cases were those patients who required an immediate
operation. A 12-lead ECG was recorded before the operation, at 2
hours after surgery, and then when clinically indicated. ECG criteria
for perioperative myocardial infarction were new Q wave (0.04 ms)
in at least 2 leads or ECG ST changes in association with significant
creatine kinase–MB enzyme release.
Data Analysis
All analyses were performed with the Statistical Analysis Systems
software package (SAS, release 8.2). Groups were analyzed on an
intention-to-treat basis. Descriptive statistics included continuous
and discrete variables, which were analyzed accordingly with an
unpaired t test, Wilcoxon rank sum test, ␹2 test, and Fisher exact test.
Statistical significance was defined as a probability value of less than
0.05. On the basis of current literature, the present trial was powered
to detect significant differences in the following 3 major outcomes:
blood-product requirements, length of hospitalization, and prolonged
mechanical ventilation. The power calculations translated into an
absolute risk reduction of 11% in blood-product requirements
(relative risk reduction of 60%), 15% in prolonged hospitalization
(defined as ⬎6 days; relative risk reduction 40%), and 12% in
prolonged mechanical ventilation (defined as ⬎10 hours; relative
Légaré et al
Off-Pump Versus On-Pump CABG Surgery
TABLE 1.
889
Preoperative Patient Characteristics
Characteristic
CPB Group
(n⫽150)
Beating-Heart
Group
(n⫽150)
P
63.7⫾10.0
62.1⫾10.1
0.16
39–87
38–85
Age, y
Mean⫾SD
Range
Flow diagram illustrating patient recruitment during study
period. Total recruitment was 32%.
risk reduction 53%) in favor of CABG patients whose procedure was
performed on the beating heart.
⬎70 years, %
30.0
22.0
0.11
Female gender, %
20.7
18.7
0.66
Diabetes, %
0.22
36.0
29.3
Renal failure, %
2.7
4.7
0.54
Hypertension, %
60.0
70.0
0.07
Hypercholesterolemia, %
95.3
90.0
0.08
Peripheral vascular disease, %
15.3
20.0
0.29
8.0
12.0
0.25
14.0
16.7
0.52
0.0
0.0
50.7
44.7
⬎50%
84.7
86.7
30–50%
15.3
13.3
Cerebrovascular disease, %
COPD, %
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Results
A total of 933 patients were eligible for the trial during the
study period, of whom 400 patients were approached, which
resulted in 351 patients who consented to participate. Of
these, 51 were not randomized because their cases were
assigned to a nonparticipating surgeon (n⫽27) or because of
patient-related issues such as intramyocardial vessels or
intraoperative hemodynamic instability (n⫽24). A total of
300 patients were randomized to undergo CABG surgery
performed on CPB (n⫽150) or on the beating heart (n⫽150;
Figure). Twenty-one patients did not receive the assigned
intervention. Twenty were originally assigned to the beatingheart group, but because of hemodynamic instability (n⫽14),
inadequate visualization of target vessel (n⫽5), or inability to
place the stabilizer because of obesity (n⫽1), they were
crossed over to the CPB group. One patient assigned to the
CPB group was crossed over to the beating-heart group
because of extensive aortic disease. All analyses were performed on an intention-to-treat basis.
Preoperative patient characteristics were similar in both
groups and are illustrated in Table 1. For the entire cohort, the
average age of patients was 63 (range 38 to 87) years, with
26% aged ⬎70 years. Thirty-three percent of patients were
diabetic, 14% had moderate left ventricular dysfunction, 48%
had a history of previous myocardial infarction, and 71% had
3-vessel coronary artery disease. The urgency of the procedure was elective in 77%, “in-house” or hospitalized in 21%,
and urgent in 2% of the randomized patients.
A mean of 3.0⫾0.9 grafts were performed in the CPB
group compared with 2.8⫾0.9 grafts in the beating-heart
group (P⫽0.06; Table 2). There were no significant differences between CABG performed with CPB or with beating
heart with regard to complete arterial revascularization (64%
versus 68%; P⫽0.46), and avoidance of aortic proximal
anastomoses (53% versus 55%; P⫽0.64). Patients who underwent CABG with CPB had a mean pump time of 97
minutes (range 76 to 113 minutes) and clamp time of 69
minutes (range 50 to 87 minutes).
Three patients died in the hospital, for an overall mortality
rate of 1%, with no significant differences between groups
(0.7% versus 1.3%; Table 3). Similarly there were no signif-
Previous CABG, %
Previous MI, %
0.30
Ejection fraction, %
0.62
CCS class, %
I
2.7
4.0
II
20.0
24.0
III
50.6
44.0
IV
26.7
28.0
Elective
74.7
80.6
In-house
24.0
16.7
0.65
Status, %
Urgent ⬍24 hours
Current smoking, %
LM stenosis (⬎50%), %
1.3
2.7
0.21
10.0
12.7
0.47
9.3
10.7
0.70
Diseased vessels, %
Single
8.0
6.0
Double
18.0
26.7
Triple
BMI, mean (SD), kg/m2
Preoperative hemoglobin, mean (SD)
Preoperative atrial fibrillation, %
74.0
67.3
0.18
29.7 (4.2)
29.5 (4.7)
0.73
138.7 (14.7)
140.0 (16.5)
0.49
5.3
4.0
0.58
COPD indicates chronic obstructive lung disease; MI, myocardial infarction;
CCS, Canadian Cardiovascular Society; LM, left main; and BMI, body mass
index.
icant differences between the CPB group and the beatingheart group in perioperative myocardial infection (0.7%
versus 2.7%; P⫽0.37), permanent stroke (0% versus 1.3%;
P⫽0.50), new atrial fibrillation (32% versus 25%; P⫽0.20),
and deep sternal wound infection (0.7% versus 0%; P⫽1.0).
Additional morbidity outcome and composite outcome (mortality/perioperative intra-aortic balloon pump/myocardial infarction/stroke/prolonged ventilation) also failed to demonstrate significant differences between the 2 surgical
approaches (Table 3).
The use of any blood products perioperatively was similar
in both groups, with an overall transfusion rate of 9% (Table
890
Circulation
February 24, 2004
TABLE 2. Graft, Conduits, and Surgical Characteristics of
Randomized Patients
CPB Group
(n⫽150)
Patient Characteristic
Beating-Heart
Group
(n⫽150)
P
LIMA, %
96.7
97.3
1.00
RIMA, %
44.7
40.7
0.48
Radial artery, %
28.0
34.7
0.21
Complete arterial grafts, %
64.0
68.0
0.46
Zero proximals, %
52.7
55.3
0.64
1
4.0
4.7
䡠䡠䡠
2
23.3
33.3
䡠䡠䡠
3
42.0
38.0
䡠䡠䡠
4
26.7
20.7
4.0
3.3
䡠䡠䡠
0.37
3.0 (0.9)
2.8 (0.9)
3 (2–4)
3 (2–3)
Distal anastomosis, %
ⱖ5
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Mean (SD)
Median (IQR)
0.06
LIMA indicates left internal mammary artery; RIMA, right internal mammary
artery; and IQR, interquartile range.
4). The mean time to extubation was 4 hours, the mean ICU
stay was 22 hours, and the median length of hospitalization
was 5 days in both groups (P⫽NS). Similarly, the incidence
of prolonged mechanical ventilation, defined as ⬎10 hours,
was not significantly different between the CPB group (9.3%)
and the beating-heart group (12%; P⫽0.45).
Discussion
Several large case series have suggested morbidity benefit,
cost benefit, reduced length of hospitalization, and even
mortality benefit for patients undergoing beating-heart
CABG surgery compared with CABG performed with
TABLE 3.
Primary and Secondary Outcomes
CPB Group
(n⫽150)
Beating-Heart
Group
(n⫽150)
P
Combined outcome*
6 (4.0)
9 (6.0)
0.43
In-hospital mortality
1 (0.7)
2 (1.3)
1.0
Intraoperative/postoperative IABP
1 (0.7)
2 (1.3)
1.0
Perioperative MI
1 (0.7)
4 (2.7)
0.37
Stroke
0 (0.0)
2 (1.3)
0.50
Pneumonia
1 (0.7)
6 (4.0)
0.12
48 (32.0)
38 (25.3)
0.20
New postoperative atrial fibrillation
Deep sternal infection
1 (0.7)
0 (0.0)
1.0
Return to OR for bleeding
3 (2.0)
2 (1.3)
1.0
Inotropes leaving OR
18 (12.0)
19 (12.7)
0.86
Return to OR for graft occlusion
0 (0.0)
0 (0.0)
Recatheterization or angioplasty
1 (0.7)
2 (1.3)
䡠䡠䡠
1.0
IABP indicates intra-aortic balloon pump; MI, myocardial infarction; and OR,
operating room. In-hospital patient outcomes including a composite outcome
(morality, IABP, MI, stroke, or prolonged mechanical ventilation). Values are n
(%).
*Mortality/IABP/MI/stroke/long ventilation.
CPB.10,12–14,21 More recent retrospective studies, using more
sophisticated statistical tools such as case matching and
propensity score analysis, have also suggested that beatingheart surgery is associated with decreased morbidity manifested by reduction in transfusion requirement, infection,
length of hospitalization, renal failure, and encephalopathy
but not mortality.8,9 However, despite the use of sophisticated
statistical tools designed to allow valid comparisons, the
inherent bias toward fitter patients for beating-heart CABG
may not have been adequately addressed by these techniques.
To date, 3 randomized controlled trials have been performed that compared CABG surgery with or without CPB.
All of these studies have been modest in size (197 to 281
patients), 2 have been single-surgeon studies, and all have
studied relatively limited patient populations, which calls into
question the generalizability of the results to “average”
cardiac surgeons with “typical” CABG practices. Furthermore, the only significant differences in outcomes have been
nearly exclusively in discretionary therapeutic end points
(blood transfusion, time to extubation, time in ICU, and time
in hospital), for which bias concerning the assignment to onor off-pump bypass may have altered thresholds for intervention or discharge.15,16,18,22 The largest published trial (n⫽281)
was a multicenter trial limited to young patients with normal
ejection fraction and with 1- or 2-vessel coronary artery
disease. The authors reported shorter time to extubation (3
versus 9 hours) and reduced length of hospitalization (6
versus 7 days) in beating-heart patients. Transfusion rates
were lower intraoperatively (3% versus 13%) but not postoperatively (28% versus 29%). There were no other morbidity or mortality differences.15 Ascione et al16,17 reported a
concatenation of two 100-patient, single-surgeon trials in
low-risk patients with low rates of diabetes, peripheral
vascular disease, and 3-vessel coronary artery disease. This
group showed lower blood transfusion rates (33% versus
53%), reduced length of hospitalization (5 versus 7 days), and
decreased incidence of atrial fibrillation in beating-heart
patients (12% versus 37%).16,17 Most recently, Puskas et al,18
in a single-surgeon trial, attempted to address these criticisms
by randomizing 197 relatively unselected patients (no shock
patients, no redo CABG, preoperative intra-aortic balloon
pump) and reported reduced length of hospitalization (5
versus 6 days), shorter time to extubation, and lower transfusion rates (26% versus 44%). A recent meta-analysis of all
randomized controlled trials failed to show significant benefit
of CABG performed on the beating heart versus with CPB.23
The present randomized controlled trial comparing CABG
surgery performed on the beating heart versus CPB is the
largest to date, with 300 patients randomized. In the present
study, more than 30% of patients were diabetics, and the
majority had Canadian Cardiovascular Society angina class
III/IV and had critical lesions in all 3 coronary distributions.
Thus, contrary to the studies by Ascione et al16,17 and Van
Dijk et al,15 the present patient population may have been
more representative of current CABG practices, and unlike
the studies by Puskas et al18 and Ascione et al,16,17 we were
not limited to a single-surgeon experience. We report an
overall mortality rate of 1%, which was not significantly
different between groups and which compares favorably to
Légaré et al
TABLE 4.
Off-Pump Versus On-Pump CABG Surgery
891
Other In-Hospital Perioperative Outcomes
CPB Group
(n⫽150)
Beating-Heart
Group
(n⫽150)
P
8.7
9.3
0.84
RBC
8.7
8.7
1.0
Platelets
2.0
2.0
1.0
FFP
2.7
4.0
0.75
Cryoprecipitate
0.7
0.0
1.0
4 (3–7)
4 (3–8)
0.54
9.3
12.0
0.45
22 (19–25)
22 (18–26)
0.97
Blood products, % (any)
Time to extubation, median hours (IQR)
Prolonged ventilation ⬎10 hours, %
ICU stay
Median hours (IQR)
⬎24 hours, %
Postoperative stay, median days (IQR)
for patients alive at discharge
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LOS ⬎6 days, %
25.3
31.3
0.25
5 (5–7)
5 (5–7)
0.84
30.9
32.4
0.77
RBC indicates red blood cells; FFP, fresh frozen plasma; IQR, interquartile range; and LOS, length
of hospital stay.
previously published studies. In the present series, a large
proportion of patients had complete arterial revascularization
(66%), with many having no proximal anastomoses onto the
aorta (54%). The mean or median number of grafts per patient
was slightly lower for beating-heart patients (not significant),
but that may reflect the fact that a larger number of patients
did not have 3-vessel disease in the beating-heart group.
Similar findings were noted by Van Dijk et al.15
We demonstrate that very low transfusion rates (9.3%
versus 8.7%) can be achieved without special measures in
first-time isolated CABG, with no additional benefit derived
from beating-heart surgery. Our findings differed markedly
from those of existing studies, which demonstrate at least a
transient reduction in transfusion rates with beating-heart
surgery. All of those trials had markedly higher transfusion
rates than the present study, even in the beating-heart arm
(28% versus 29% in the study by van Dijk et al,15 33% versus
53% in the study by Ascione et al,16 and 26% versus 44% in
the study by Puskas et al18). It is evident that the discretionary
end point of blood-product utilization after cardiac surgery
varies tremendously despite the publication of transfusion
guidelines.24 –26
Contrary to previous published trials, we were unable to
demonstrate any differences in the time to extubation, length
of ICU stay, or length of hospitalization, which suggests little
benefit attributable to beating-heart surgery. Additionally, in
the present study, the median time to extubation of 4 hours,
ICU stay of 22 hours, and median length of hospitalization of
5 days demonstrated in both groups all compare favorably
with the previously published trials.15,16,18 Our findings suggest that excellent results can be obtained with both surgical
approaches and that the differences noted in previously
published studies may have been the result of bias in
discretionary end points despite efforts to standardize patient
care. Because length of hospitalization is one of the major
factors that affects overall cost, the present findings also
suggest that in the short term, there may be little cost benefit
to beating-heart surgery.
In the present study, 21 patients crossed over from one
treatment arm to another, a figure not significantly different
from Van Dijk et al,15 who reported 15 crossovers among 281
patients. We point out that all analysis was performed on an
intention-to-treat basis to ensure minimal impact of a crossover effect, which would have likely favored the beatingheart group. A limitation of the present trial, like all previously published, is insufficient power to evaluate subgroups
of patients more likely to benefit from beating-heart surgery,
such as patients with high risk of neurological, bleeding, or
renal complications.
In conclusion, we have shown that in a randomized
controlled trial of 300 patients to CABG surgery with or
without CPB, we have been unable to demonstrate any
significant differences in short-term mortality or morbidity
outcomes. Excellent results can be obtained with both surgical approaches, ie, CABG surgery on the beating heart or with
CPB.
Acknowledgments
This study was supported by the Maritime Heart Center. We would
like to thank the following individuals, who were instrumental in
enabling the completion of this trial: Dr Claudio Diquinzio (Head of
Cardiac Anesthesia), on behalf of all cardiac anesthesia members,
and Karen Ferrera (booking office).
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Coronary Bypass Surgery Performed off Pump Does Not Result in Lower In-Hospital
Morbidity Than Coronary Artery Bypass Grafting Performed on Pump
Jean-Francois Légaré, Karen J. Buth, Sharon King, Jeremy Wood, John A. Sullivan, Camille
Hancock Friesen, John Lee, Kier Stewart and Gregory M. Hirsch
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Circulation. 2004;109:887-892; originally published online February 2, 2004;
doi: 10.1161/01.CIR.0000115943.41814.7D
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