Download PTCA registry of German community hospitals

European Heart Journal (1997) 18, 1110-1114
PTCA registry of German community hospitals
A. Vogt, T. Bonzel, D. Harmjanz, E.-R. v. Leitner, C. Pfafferott, H.-J. Engel,
W. Niederer, P.-R. Schuster, H. G. Glunz and K.- L. Neuhaus for the
Arbeitsgemeinschaft Leitender Kardiologischer Krankenhausarzte (ALKK)
study group
Medizinische Klinik II, Stadtische Kliniken Kassel gGmbH, Kassel, Germany
Background Percutaneous transluminal coronary angioplasty (PTCA) is widely used, but no quality control has
been systematically performed as yet.
Methods A registry of all PTCA procedures has been
established since October 1992 for the majority of the
German community hospitals performing PTCA, representing about one third of all PTCA activity in Germany.
Baseline demographic data, indication for PTCA, primary
success and in-hospital clinical events were recorded. Each
centre was visited at regular intervals to assure completeness and reliability of the data.
Results Of 52 453 procedures performed from October
1992 to December 1994 the catheter laboratory and discharge forms were 997% and 98-1% complete, respectively.
In 85-9% a single lesion was dilated per procedure, but
48-7% of the patients had multivessel disease. The success
rate was 66-5% in complete occlusions (residual stenosis
<70%) and 91-2% in non-occluded vessels (residual stenosis
<50%). Abrupt vessel closure occurred in 3-4%, of which
77-5% could be recanalized by repeat intervention. In
procedures not done for acute myocardial infarction, the
in-hospital mortality was 0-52%, the procedure-related
mortality 037%. In 302% of all patients a severe complication occurred (procedure-related death, myocardial
infarction or emergency bypass surgery).
Conclusion Complete recording of all PTCA procedures is
feasible even on a nationwide basis. This is a pre-requisite
for continuous quality control. The reporting of the procedures by itself very probably, has an impact on the quality
which is, however, not measurable quantitatively.
(Eur Heart J 1997; 18: 1110-1114)
Key Words: Percutaneous transluminal coronary angioplasty, quality control, success, complications.
Introduction
and seven centres are based in community hospitals
(non-university hospitals involved in the general medical
To gain knowledge about the present status of percu- care of the population), of which 62 have formed a
taneous transluminal coronary angioplasty (PTCA), and working group called 'Arbeitsgemeinschaft leitender
to control the quality of its routine application, a kardiologischer Krankenhausarzte (ALKK)'. All but
registry of all PTCA procedures from 43 centres in two of these centres participated in the registry, which
Germany was started in 1992. It now includes 68 centres, thus represents approximately 35% of all PTCA proceand the data gathered from October 1992 to December dures carried out in Germany. The number of participating centres was 43 in 1992, 59 in 1993, and 65 in 1994.
1994 are reported here.
Sixteen of the participating centres had an on-site
cardiac surgery department. The caseload was <300
procedures/year in 27, 300-600 procedures/year in 27
and >600 procedures/year in 11 centres (median value
Organization of the registry
overall 352). The average number of operators per
In 1994, more than 88 000 PTCA procedures were centre was 2-5. Each PTCA procedure was included on
performed in 190 centres in Germany1'1. One hundred an intention-to-treat basis. A single-page form, which
listed baseline demographic and angiographic data, indication for PTCA, angiographic success, and complicaRevision submitted 20 September 1996, and accepted 25 September
tions in the catheterization laboratory was transmitted
1996.
immediately after the procedure to the data centre in
Correspondence: Prof. Dr med. Albrecht Vogt, Medizinische Klinik Kassel. A second single-page form, reporting possible
II, Stadtische Kliniken Kassel gGmbH, MonchebergstraBe 41-43, complications after the patient left the catheterization
D-34125 Kassel, Germany.
0195-668X/97/071110 + 05 S18.00/0
^, 1997 The European Society of Cardiology
PTCA registry of German community hospitals
Months since start of registry
Figure 1 Procedures in the registry since its initiation in
October 1992.
laboratory, was completed and transmitted immediately
after hospital discharge.
Each centre was visited twice per year and the
local records were compared with the procedures entered into the registry to ensure completeness. This audit
revealed that 11% of PTCA procedures performed were
not reported to the data centre. Incomplete data forms
were immediately completed by telephone query from
the data centre if possible, or otherwise returned for
completion to the participating centres. Complications
were classified centrally, with respect to their relation to
the procedure, by looking up the individual case reports.
Myocardial infarction after the procedure was diagnosed when typical clinical symptoms were accompanied
by creatine kinase levels more than twice the upper
limit of normal and/or ECG changes diagnostic of
myocardial infarction.
The database was installed on a personal computer using dBase IV software (Ashton-Tate). Statistical
calculations were performed with the Statsoft CSS
software package.
Completeness of the data
From 1 October 1992 to 31 December 1994, 53 834
PTCA procedures were entered into the registry (Fig. 1).
Of these, 1381 were not performed for various reasons
(withdrawal of consent, intermittent other disease,
change in therapeutic strategy), leaving 52 453 procedures actually performed. The procedure-reporting
forms of the latter are 99-7% complete, and the discharge forms are 981% complete at the time of writing.
In 72-8%, details of the procedures were given to the
data centre in advance by fax or telephone. In this report
the procedures incompletely reported are excluded.
LAD
RCA
1111
Cx
Figure 2 Anatomical location of lesions dilated.
LAD = left
anterior descending coronary
artery,
RCA=right coronary artery, Cx=circumflex coronary
artery. • = lesions in the proximal part; 0=distally
located lesions of the respective coronary artery except for
bypass grafts, where no such differentiation was made.
4
7
10
13
16
19
22
Months of registry (1 = Oct. 1992)
Figure 3 Proportion of immediate interventions during
the primary diagnostic procedure. There is a significant
increase in the proportion of immediate PTCA from
October 1992 to December 1994.
dilated lesions. One-, two- and three-vessel coronary
disease was present in 51-3, 33-4, and 15-3% of the
procedures, respectively. Left-ventricular function was
visually classified by the operator as normal in 600%,
depressed in 35-7%, and severely depressed in 4-4% of
those who underwent ventriculography. PTCA was performed without a left ventricular angiogram in 12-7%
(6665 procedures); in 6-6% after prior coronary bypass
surgery; in 20-2% after one or more prior PTCA procedures; in 16-6% one or more recurrent stenoses were
dilated; in 299%, the procedure was performed immediately after diagnostic catheterization in the same session
(Fig. 3); in 14-1% >2 lesions were dilated in a single
session; in only 114 procedures were >3 lesions treated.
The lesion characteristics and immediate angiographic
results are specified in Table 1.
Baseline data
PTCA was performed in 43 947 patients; the mean age
was 60-7 ± 9-7 years, and 22-3% were women. Figure 2
shows the distribution of the anatomical locations of the
Indications for PTCA
The majority of the procedures was performed in symptomatic patients with stable (59-9%) or unstable angina
Eur Heart J, Vol. 18, July 1997
1112 A. Vogt et al.
Table 1 Lesion characteristics and angiographic success
n
Type of lesion (%)
A
Bl
B2
Cl
C2
Balloon size (mm)
Complete occlusion (%)
Successful recanalization (%)
Non-occluded vessels
% stenosis before PTCA
% stenosis after PTCA
% angiographic success
Table 2
Lesion 1
Lesion 2
Lesion 3
52 273
7379
935
15-8
32-6
35-9
9-6
61
2-90 ± 0-44
16-9
67-3
20-4
37-2
29-9
7-8
4-8
2-71 ±0-43
6-7
54-2
21-7
37-3
30-2
6-4
4-4
2-62 ± 0 43
5-3
500
88-2 ±8-7
27-1 ±17-8
91 -5
83-3 ± 10 7
28-3 ±18-4
89-4
82-7 ± 10-9
28-5 ± 19-4
89-2
Complications by indication for PTCA
Stable AP
n
Abrupt closure
(%)
PTCA-related MI
(%)
Emergency CABG
(%)
PTCA-related death
(%)
In-hospital mortality
(%)
PTCA-related death, MI
or emergency CABG (%)
31 300
830
(2-65)
587
(1-88)
192
(0-61)
78
(0-25)
86
(0-27)
111
(2-48)
Unstable AP
13 362
643
(4-81)
420
(3-14)
171
(1-28)
95
(0-71)
155
(1-16)
606
(4-54)
AMI
Prognostic
2879
169
(5-87)
0
4737
120
(2-53)
71
(1-50)
20
(0-42)
12
(0-5)
15
(0-32)
99
(209)
44
(1 52)
25
(0-87)
267
(9-27)
112
(3-89)
AMI = acute myocardial infarction; CABG = coronary artery bypass grafting.
pectoris (21-8%). In 5-5%, PTCA was performed in acute
myocardial infarction, and in 3-8% in severe acute
myocardial ischaemia with ECG-changes not diagnostic
for acute infarction. In 495/2879 procedures the acute
myocardial infarction and in 442/1965 the acute ischaemia leading to PTCA resulted from abrupt vessel closure
after a preceding intervention. The same is true for
1905/11 397 procedures performed for unstable angina
pectoris. In 9 1 % , PTCA was performed for prognostic
reasons in asymptomatic patients with or without
positive exercise tests.
Procedural success
In all the lesions in which an attempt to dilate was made,
15-5% were complete occlusions. Of those, 66-5% were
successfully recanalized, with a residual stenosis <70%.
If acute occlusions in the setting of myocardial infarction are excluded, the primary success rate of recanalizations was 61-8%. In non-occluded vessels, the overall
success rate was 91-2%, with a residual stenosis <50%.
Coronary stents were implanted in 2-8%. The success
Eur Heart J. Vol. 18. July 1997
rate was clearly dependent on stenosis morphology. In
type A or Bl stenosis was classified according to the
AHA/ACC criteria121, the per lesion success was 92-4%
(residual stenosis <50%), whereas in type B2 or C
stenosis it was only 810% (/><00001).
In elective interventions for stable angina or in
asymptomatic patients the success rate was 86-6% per
lesion, in unstable angina 88-1% and in acute myocardial
infarction 78-4% (/><00001). Gender had no influence
on the success rates, but in patients <65 years the
success rates were significantly higher (68-2% in occluded, 92-3% in non- occluded vessels) than in patients
>65 years (65-2% and 90-1% in occluded and nonoccluded vessels, / > <0001).
Complications
Overall, 1578 procedures (302%) caused severe complications leading to myocardial infarction, emergency
bypass surgery, or death. Of the patients with emergency
bypass surgery 8-4% eventually died. A complete listing
of complications broken down by indication for PTCA
PTCA registry of German community hospitals
1/93
111/93
1/94
Quarters of registry
111/94
Figure 4 Techniques applied in repeat interventions for
abrupt vessel closure. From October 1992 to December
1994 the proportion of standard balloon PTCA procedures
( • ) remained essentially unchanged. The use of perfusion balloons ( • ) decreased slightly in favour of the
implantation of coronary stents (D).
is given in Table 2. The majority of PTCA-related
clinical events was associated with abrupt vessel closure
documented after a total of 1762 procedures (3-4%).
Abrupt vessel closure was treated with repeat PTCA
with standard balloons in 782, with perfusion balloons
in 217, and with coronary stents in 291 cases (Fig. 4). In
87 cases other interventions (e.g. atherectomy, laser,
intracoronary thrombolysis) were performed, and in 222
cases no repeat intervention was undertaken. Of the
repeat interventions 77-5% were successful angiographically with a residual stenosis <70%. Despite this, 407
patients were referred to emergency coronary bypass
and a further 17 patients to elective coronary surgery.
Of the patients with abrupt vessel closure, 569 had
a procedure-related myocardial infarction (maximum
serum creatine kinase 603 ± 542 U/l), and 112 patients
eventually died. Procedure-related death, myocardial
infarction or emergency bypass surgery occurred in
756/1762 cases after abrupt vessel closure, i.e. 42-9%.
If the procedures done for acute myocardial
infarction are excluded, the total in-hospital mortality
is 0-52% (256 patients), and the procedure-related
mortality 037% (185 patients). Overall, 1482 patients
(30%) of those with elective PTCA had at least one
severe complication (procedure-related death, emergency bypass surgery, or procedure-related myocardial
infarction).
Discussion
The PTCA registry of the German community hospitals
was established to monitor quality control of this widely
used intervention. It was possible to record >98% complete and reliable data on all procedures in the participating centres with respect to the immediate results in
1113
the catheterization laboratory and clinical events until
discharge. The regular on-site monitoring revealed that
less than 1% procedures had not been reported to the
data centre.
Despite complete data on the whole spectrum of
PTCA procedures, the rating of appropriateness of
indication, performance and results is an unresolved
issue. In our project, an expert rating of a random subset
of 2% (stratified by centres, at least five cases per centre)
was performed. These results will be reported elsewhere.
As in the RAND study'31, roughly 5% of the procedures
were deemed inappropriate.
The rate of major PTCA complications has
decreased as compared to earlier reports'451, even
though elective as well as emergency procedures are
included. The case volume of the centres had no significant impact on the complication rate or on the immediate angiographic success rate; no significant differences
were seen when centres with <300, 300-600 and >600
procedures per year were compared. This is in contrast
to reports from the United States, where the complication rate increased in centres with lower case loads,
especially in those with less than 200 cases per year'6"81.
One reason for this may be that in Germany the work
load per operator is usually higher than in the U.S.; in
the smaller centres usually only one to three operators
perform PTCA.
While the rate of myocardial infarction after
PTCA has remained relatively constant, the rate of
emergency bypass surgery decreased from around 6%'5'
to one tenth of that in this registry. This is mainly due to
improved techniques and operator experience allowing
for successful repeat intervention in the majority of cases
even after abrupt vessel closure, whereas the incidence of
abrupt closure itself did not decrease significantly.
As in the United States'71, the majority of interventions are still single-lesion PTCA despite the many
optimistic reports on the high success rates at acceptably
low risk of multivessel interventions'9""1. Since nearly
one half of the patients in this registry had multivessel
disease it becomes clear that in a significant proportion
only partial revascularization was achieved.
The rate of immediate PTCA during a primarily
diagnostic procedure increased during the time reported
here from 23 to 40%. This is not due to an increase in
emergency interventions; the proportion of PTCA in
acute myocardial infarction remained relatively constant
at around 5% during the time reported here. There are,
however, extreme differences between centres, with proportions of immediate PTCA varying between 3 to 74%.
This demonstrates that the decision for immediate intervention in elective cases is driven by logistic rather than
medical reasons.
We conclude that complete recording of all
PTCA procedures is feasible, even on a nationwide
basis. The model project reported here covers about one
third of all procedures performed in Germany. The data
demonstrate that the risk from PTCA in the 1990s has
decreased, as compared to earlier registries, which in
turn may lead to a widening of the indications. The
Eur Heart J, Vol. 18, July 1997
1114 A. Vogt et al.
rating of appropriateness remains a largely unresolved
issue, despite complete and reliable data, since no generally accepted standards exist. Very probably the
reporting of the procedures by itself has some impact
on the quality which is, however, not measurable
quantitatively.
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