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Journal ArticleDOI

A clinical trial comparing primary coronary angioplasty with tissue plasminogen activator for acute myocardial infarction

14 Jun 1997-The New England Journal of Medicine (Massachussetts Medical Society)-Vol. 336, Iss: 23, pp 1621-1628
TL;DR: This trial suggests that angioplasty provides a small-to-moderate, short-term clinical advantage over thrombolytic therapy with t-PA, and should be considered an excellent alternative method for myocardial reperfusion.
Abstract: BACKGROUND: Among physicians who treat patients with acute myocardial infarction, there is controversy about the magnitude of the clinical benefit of primary (i.e., immediate) coronary angioplasty as compared with thrombolytic therapy. METHODS: As part of the Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO IIb) trial, we randomly assigned, 1138 patients from 57 hospitals who presented within 12 hours of acute myocardial infarction (with ST-segment elevation on the electrocardiogram) to primary angioplasty or accelerated thrombolytic therapy with recombinant tissue plasminogen activator (t-PA). We also randomly assigned 1012 patients to heparin or hirudin treatment in a factorial design. The primary study end point was a composite outcome of death, nonfatal reinfarction, and nonfatal disabling stroke at 30 days. RESULTS: The incidence of the primary end point in the angioplasty and t-PA groups was 9.6 percent and 13.7 percent, respectively (odds ratio, 0.67; 95 percent confidence interval, 0.47 to 0.97; P = 0.033). Death occurred in 5.7 percent of the patients assigned to angioplasty and 7.0 percent of those assigned to t-PA (P=0.37), reinfarction in 4.5 percent and 6.5 percent (P=0.13), and disabling stroke in 0.2 percent and 0.9 percent (P=0.11). At six months, there was no significant difference in the incidence of the composite outcome (13.3 percent vs. 15.7 percent, P not significant) [corrected]. The primary end point was observed in 10.6 percent of the patients in the angioplasty group assigned to heparin and 8.2 percent of those assigned to hirudin (P=0.37). CONCLUSIONS: This trial suggests that angioplasty provides a small-to-moderate, short-term clinical advantage over thrombolytic therapy with t-PA. Primary angioplasty, when it can be accomplished promptly at experienced centers, should be considered an excellent alternative method for myocardial reperfusion.

Summary (3 min read)

Introduction

  • As part of the Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO IIb) trial, the authors randomly assigned 1138 patients from 57 hospitals who presented within 12 hours of acute myocardial infarction (with ST-segment elevation on the electrocardiogram) to primary angioplasty or accelerated thrombolytic therapy with recombinant tissue plasminogen activator (t-PA).
  • The New England Journal of Medicine ternational, multicenter, randomized trial comparing primary angioplasty with thrombolytic therapy (and hirudin with heparin, in the patients treated with primary angioplasty) in the initial management of acute myocardial infarction.

Study Organization

  • This study was a prospective substudy of the Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO IIb) trial.
  • 20 Fifty-seven hospitals in nine countries participated .
  • To participate, each site was required to perform at least 200 angioplasties yearly, to have at least one cardiologist who had performed at least 50 angioplasties yearly, a 24-hour on-call team, and a system for operating-room backup if emergency bypass surgery was required.
  • Eighty-five percent of sites performed more than 400 angioplasties yearly, and 85 percent of operators performed more than 75 angioplasties yearly.

Study Patients

  • Patients presenting within 12 hours after the onset of symptoms (chest pain lasting at least 20 minutes, accompanied by electrocardiographic signs of ST-segment elevation of at least 0.2 mV in two or more contiguous leads or left bundle-branch block) were eligible for enrollment.
  • The exclusion criteria were identical to those used in the main GUSTO IIb trial.
  • All the patients gave informed consent, and the protocol was approved by the institutional review board at each hospital.

Randomization and Treatment Strategies

  • The investigators and study coordinators telephoned or faxed a 24-hour-a-day, seven-day-a-week randomization center to review the eligibility of patients and receive their assignments to treatment.
  • The protocol for the administration of the study drug in this trial has been reported previously 20 ; in brief, patients were assigned to receive an infusion of either heparin or hirudin for three to five days; the dose was adjusted to keep the activated partialthromboplastin time within the 60-to-85-second range.
  • At the recommendation of the Data and Safety Monitoring Board and the GUSTO IIb Steering Committee, enrollment in this substudy was extended, without a review of the end-point data, beyond the completion of enrollment in the GUSTO IIb trial, to January 1, 1996, in order to reach the intended sample size.
  • All the patients were also to receive standard medical care, including chewable aspirin, at the time of enrollment.

Primary Angioplasty

  • Angioplasty was performed according to local standards, with the intention of reestablishing blood flow in the infarct-related artery as soon as possible.
  • The infarct-related artery was the only target, except in patients whose hemodynamic values deteriorated despite restoration of the patency of that artery.
  • After angioplasty, the study drug was temporarily stopped to permit early removal of the sheath.
  • The study protocol acknowledged that in some patients, particularly those with stenoses of the left main artery or critical three-vessel disease, bypass surgery should be strongly considered instead of angioplasty.
  • In patients whose infarct-related arteries had Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow at first angiography, whether or not to perform angioplasty was left to the judgment of the operator.

Data Management and Quality Assurance

  • Case-report forms were forwarded to either the international coordinating center (Catholic University, Leuven, Belgium) or the main coordinating center (Duke University, Durham, N.C.) for data entry and the generation of queries about missing or inconsistent data.
  • The quality of the data was ensured by auditing 10 percent of the data forms and by having an independent Clinical Events Committee adjudicate decisions on all possible primary-end-point events.
  • A databased algorithm was developed to capture all the events that might constitute part of the primary end point and trigger a review of chart information by this committee, whose members remained unaware of the initial treatment assignments.

End Points

  • The primary end point was a composite outcome of death, nonfatal reinfarction, and nonfatal disabling stroke within 30 days, as confirmed by the Clinical Events Committee.
  • The prespecified secondary end points were mortality from all causes at 30 days; mortality from all causes and nonfatal reinfarction at 30 days; a composite end point consisting of death, reinfarction, disabling stroke, and congestive heart failure at 30 days; recurrent, medically refractory ischemia; and major bleeding.
  • 20 Follow-up electrocardiograms and creatine kinase and MB isoenzyme levels were to be obtained at the time of any suspected myocardial reinfarction.
  • 20 Computed tomography or magnetic resonance imaging of the brain was requested for all patients with suspected stroke.
  • Severe bleeding was defined as intracranial hemorrhage or bleeding that caused hemodynamic compromise.

Statistical Analysis

  • The primary study hypothesis was that immediate angioplasty would result in a lower incidence of death, nonfatal reinfarction, and nonfatal disabling stroke at 30 days than thrombolytic therapy.
  • The incidence of the primary end point in the t-PA group was expected to be approximately 12 percent.
  • Continuous data are presented as medians with 25th and 75th percentiles unless otherwise stated.
  • Selected base-line character- The New England Journal of Medicine as published by New England Journal of Medicine.
  • Downloaded from www.nejm.org at ERASMUS UNIVERSITY on July 27, 2010.

PRIMARY CORONARY ANGIOPLASTY VS. TISSUE PLASMINOGEN ACTIVATOR FOR ACUTE MYOCARDIAL INFARCTION

  • Smaller trials have reported mixed results after discharge from the hospital.31-33.
  • The speed, completeness, and durability of reperfusion, and thus outcomes for patients, will probably improve with both angioplasty and thrombolytic therapy.
  • Patients with severe hypertension, advanced age, or symptomatic cerebrovascular disease should also be treated with angioplasty, if available, to lower the risk of intracranial hemorrhage.
  • Supported in part by Guidant Corporation, Redwood City, Calif., and by Ciba–Geigy, Summit, N.J.

RESULTS

  • The median peak activated clotting time during the procedure was 381 seconds (interquartile range, 329 to 480).
  • †Data were not available for some patients.
  • Downloaded from www.nejm.org at ERASMUS UNIVERSITY on July 27, 2010.
  • As compared with t-PA, angioplasty resulted in 13 fewer deaths (95 percent confidence interval, 15 to.

After angioplasty

  • Peak intraprocedural activated clotting time — sec — 381 (329, 480) *In these patients, heparin was given before infusion of the study drug.
  • T ABLE 3. CONCOMITANT MEDICATIONS AND IN-HOSPITAL PROCEDURES IN THE STUDY GROUPS.

DISCUSSION

  • There was a relative benefit at 30 days with angioplasty with respect to all elements of the primary study end point — death, reinfarction, and disabling stroke.
  • In the light of some reports of a relation between higher volume of angioplasty and better outcome for patients,28 the results of this study should not be extrapolated to operators with lower angioplasty volumes.
  • 4,5 Subgroup analyses — from small trials in particular — should be interpreted with caution, and it will require further study to resolve this issue.

Time from the onset of

  • The New England Journal of Medicine as published by New England Journal of Medicine.
  • Downloaded from www.nejm.org at ERASMUS UNIVERSITY on July 27, 2010.

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Content maybe subject to copyright    Report

Volume 336 Number 23
1621
The New England
Journal
of
Medicine
© Copyright, 1997, by the Massachusetts Medical Society
VOLUME 336
J
UNE
5, 1997
NUMBER 23
A CLINICAL TRIAL COMPARING PRIMARY CORONARY ANGIOPLASTY WITH
TISSUE PLASMINOGEN ACTIVATOR FOR ACUTE MYOCARDIAL INFARCTION
T
HE
G
LOBAL
U
SE
OF
S
TRATEGIES
TO
O
PEN
O
CCLUDED
C
ORONARY
A
RTERIES
IN
A
CUTE
C
ORONARY
S
YNDROMES
(GUSTO IIb)
A
NGIOPLASTY
S
UBSTUDY
I
NVESTIGATORS
*
A
BSTRACT
Background
Among physicians who treat patients
with acute myocardial infarction, there is controver-
sy about the magnitude of the clinical benefit of pri-
mary (i.e., immediate) coronary angioplasty as com-
pared with thrombolytic therapy.
Methods
As part of the Global Use of Strategies to
Open Occluded Coronary Arteries in Acute Coronary
Syndromes (GUSTO IIb) trial, we randomly assigned
1138 patients from 57 hospitals who presented with-
in 12 hours of acute myocardial infarction (with
ST-segment elevation on the electrocardiogram) to
primary angioplasty or accelerated thrombolytic ther-
apy with recombinant tissue plasminogen activator
(t-PA). We also randomly assigned 1012 patients to
heparin or hirudin treatment in a factorial design.
The primary study end point was a composite out-
come of death, nonfatal reinfarction, and nonfatal
disabling stroke at 30 days.
Results
The incidence of the primary end point in
the angioplasty and t-PA groups was 9.6 percent and
13.7 percent, respectively (odds ratio, 0.67; 95 per-
cent confidence interval, 0.47 to 0.97; P
0.033). Death
occurred in 5.7 percent of the patients assigned to an-
gioplasty and 7.0 percent of those assigned to t-PA
(P
0.37), reinfarction in 4.5 percent and 6.5 percent
(P
0.13), and disabling stroke in 0.2 percent and 0.9
percent (P
0.11). At six months, there was no signif-
icant difference in the incidence of the composite
outcome (14.1 percent vs. 16.1 percent, P not signifi-
cant). The primary end point was observed in 10.6
percent of the patients in the angioplasty group as-
signed to heparin and 8.2 percent of those assigned
to hirudin (P
0.37).
Conclusions
This trial suggests that angioplasty
provides a small-to-moderate, short-term clinical ad-
vantage over thrombolytic therapy with t-PA. Primary
angioplasty, when it can be accomplished promptly
at experienced centers, should be considered an ex-
cellent alternative method for myocardial reperfu-
sion. (N Engl J Med 1997;336:1621-8.)
©1997, Massachusetts Medical Society.
Address reprint requests to Dr. Stephen G. Ellis at the Cleveland Clinic
Foundation, 9500 Euclid Ave., F-25, Cleveland, OH 44195.
Dr. Ellis assumes responsibility for the content of the article.
*The investigators and centers participating in the GUSTO IIb Angio-
plasty Substudy are listed in the Appendix.
ROMPT, complete restoration of coronary
flow is the principal mechanism by which re-
perfusion therapy improves survival and oth-
er clinical outcomes in patients with acute
myocardial infarction in whom there is electrocar-
diographic evidence of ST-segment elevation.
1-3
At
selected centers, coronary angioplasty can be per-
formed expeditiously in such patients, resulting in
better coronary flow
4,5
and 30-day survival rates
2,4-12
than are obtained with intravenous thrombolytic
therapy.
Intravenous thrombolytic therapy is, however, the
standard of care for patients with acute myocardial
infarction, because of its widespread availability, its
ability to reduce mortality, and its use in more than
a million patients over the past decade.
6,13-15
Recently,
two large studies of registry data
16,17
raised doubt
about whether the apparent superiority of angio-
plasty over thrombolytic therapy would be sustained
in general clinical practice, because treatment delays
and technical failures appear to be more common
than in the selected centers that have participated in
randomized trials.
The use of “front-loaded” (accelerated), weight-
adjusted treatment with recombinant tissue plasmin-
ogen activator (t-PA)
6
instead of other lytic regimens
used in previous trials
4,5,7-12
might further reduce the
differences in outcome between these two therapies.
Also, the adjunctive use of direct inhibitors of throm-
bin, which have several potential advantages over
heparin but have not been proved beneficial in this
setting,
18,19
might also influence the outcomes of
these two strategies. Therefore, we performed an in-
P
The New England Journal of Medicine as published by New England Journal of Medicine.
Downloaded from www.nejm.org at ERASMUS UNIVERSITY on July 27, 2010. For personal use only. No other uses without permission.
Copyright © 1997 Massachusetts Medical Society. All rights reserved.

1622
June 5, 1997
The New England Journal of Medicine
ternational, multicenter, randomized trial compar-
ing primary angioplasty with thrombolytic therapy
(and hirudin with heparin, in the patients treated
with primary angioplasty) in the initial management
of acute myocardial infarction.
METHODS
Study Organization
This study was a prospective substudy of the Global Use of Strat-
egies to Open Occluded Coronary Arteries in Acute Coronary Syn-
dromes (GUSTO IIb) trial.
20
Fifty-seven hospitals in nine countries
participated (see the Appendix). To participate, each site was re-
quired to perform at least 200 angioplasties yearly, to have at least
one cardiologist who had performed at least 50 angioplasties year-
ly, a 24-hour on-call team, and a system for operating-room back-
up if emergency bypass surgery was required. Eighty-five percent of
sites performed more than 400 angioplasties yearly, and 85 percent
of operators performed more than 75 angioplasties yearly.
Study Patients
Patients presenting within 12 hours after the onset of symp-
toms (chest pain lasting at least 20 minutes, accompanied by elec-
trocardiographic signs of ST-segment elevation of at least 0.2 mV
in two or more contiguous leads or left bundle-branch block)
were eligible for enrollment. The exclusion criteria were identical
to those used in the main GUSTO IIb trial.
20
All the patients gave
informed consent, and the protocol was approved by the institu-
tional review board at each hospital.
Randomization and Treatment Strategies
The investigators and study coordinators telephoned or faxed a
24-hour-a-day, seven-day-a-week randomization center to review
the eligibility of patients and receive their assignments to treat-
ment. Eligible patients were randomly assigned to either primary
coronary angioplasty or accelerated t-PA (an intravenous bolus of
15 mg, followed by an infusion of 0.75 mg per kilogram of body
weight [not to exceed 50 mg] over a 30-minute period and then
0.50 mg per kilogram [not to exceed 35 mg] over the next 60
minutes, for a maximal total dose of 100 mg). The first 1012
patients were also randomly assigned, in a two-by-two factorial de-
sign, to either heparin or hirudin given intravenously as part of the
GUSTO IIb trial (these patients were included in the main tri-
al).
20
The protocol for the administration of the study drug in this
trial has been reported previously
20
; in brief, patients were as-
signed to receive an infusion of either heparin or hirudin for three
to five days; the dose was adjusted to keep the activated partial-
thromboplastin time within the 60-to-85-second range.
At the recommendation of the Data and Safety Monitoring
Board and the GUSTO IIb Steering Committee, enrollment in
this substudy was extended, without a review of the end-point da-
ta, beyond the completion of enrollment in the GUSTO IIb trial,
to January 1, 1996, in order to reach the intended sample size.
All the patients enrolled thereafter were treated with heparin as
the thrombin inhibitor.
All the patients were also to receive standard medical care,
including chewable aspirin, at the time of enrollment.
20
Other car-
diac medications were administered at the discretion of the phy-
sician. Angiography within three days of study entry was discour-
aged in patients randomly assigned to t-PA, except to manage
refractory ischemia or hemodynamic deterioration.
Primary Angioplasty
Angioplasty was performed according to local standards, with
the intention of reestablishing blood flow in the infarct-related ar-
tery as soon as possible. After securing arterial access and verifying
that angioplasty was indicated, we titrated the study thrombin in-
hibitor in a double-blind fashion in increments of 3000 U of hep-
arin or 30 mg of hirudin to reach an activated clotting time of at
least 350 seconds. The infarct-related artery was the only target,
except in patients whose hemodynamic values deteriorated de-
spite restoration of the patency of that artery. After angioplasty,
the study drug was temporarily stopped to permit early removal
of the sheath. The study protocol acknowledged that in some pa-
tients, particularly those with stenoses of the left main artery or
critical three-vessel disease, bypass surgery should be strongly
considered instead of angioplasty. In patients whose infarct-relat-
ed arteries had Thrombolysis in Myocardial Infarction (TIMI)
grade 3 flow at first angiography, whether or not to perform an-
gioplasty was left to the judgment of the operator.
Angiographic Analyses
The cineangiograms obtained at study entry for all patients ran-
domly assigned to angioplasty were forwarded to the Angiographic
Core Laboratory for quantitative analyses by a validated edge-
detection method (Artrek, version 1.60, Quinton Imaging Systems,
Bothell, Wash.).
21
Technical success was defined as a residual steno-
sis of less than 50 percent and a final TIMI flow grade of 2 or 3.
Data Management and Quality Assurance
Case-report forms were forwarded to either the international
coordinating center (Catholic University, Leuven, Belgium) or
the main coordinating center (Duke University, Durham, N.C.)
for data entry and the generation of queries about missing or in-
consistent data. Patient follow-up at 30 days and 6 months was
performed by means of a self-administered questionnaire, tele-
phone interview, or follow-up visit to the physician. The quality
of the data was ensured by auditing 10 percent of the data forms
and by having an independent Clinical Events Committee adju-
dicate decisions on all possible primary-end-point events. A data-
based algorithm was developed to capture all the events that
might constitute part of the primary end point and trigger a re-
view of chart information by this committee, whose members re-
mained unaware of the initial treatment assignments.
End Points
The primary end point was a composite outcome of death,
nonfatal reinfarction, and nonfatal disabling stroke within 30
days, as confirmed by the Clinical Events Committee. The prespec-
ified secondary end points were mortality from all causes at 30
days; mortality from all causes and nonfatal reinfarction at 30 days;
a composite end point consisting of death, reinfarction, disabling
stroke, and congestive heart failure at 30 days; recurrent, medical-
ly refractory ischemia; and major bleeding.
20
Follow-up electro-
cardiograms and creatine kinase and MB isoenzyme levels were
to be obtained at the time of any suspected myocardial reinfarc-
tion.
20
Computed tomography or magnetic resonance imaging of
the brain was requested for all patients with suspected stroke. Se-
vere bleeding was defined as intracranial hemorrhage or bleeding
that caused hemodynamic compromise. Moderate bleeding was
defined as bleeding that required blood transfusion but that did
not lead to hemodynamic compromise.
Statistical Analysis
The primary study hypothesis was that immediate angioplasty
would result in a lower incidence of death, nonfatal reinfarction,
and nonfatal disabling stroke at 30 days than thrombolytic ther-
apy. The incidence of the primary end point in the t-PA group
was expected to be approximately 12 percent. Although studies
had suggested that the incidence of major end points would be
more than 60 percent lower with angioplasty than with throm-
bolytic therapy,
4,5,7-12
the size of this study population was chosen
to ensure that a relative reduction of 40 percent could be detect-
ed with an alpha error of 0.05 and a beta error of 0.20.
Continuous data are presented as medians with 25th and 75th
percentiles unless otherwise stated. Selected base-line character-
The New England Journal of Medicine as published by New England Journal of Medicine.
Downloaded from www.nejm.org at ERASMUS UNIVERSITY on July 27, 2010. For personal use only. No other uses without permission.
Copyright © 1997 Massachusetts Medical Society. All rights reserved.

PRIMARY CORONARY ANGIOPLASTY VS. TISSUE PLASMINOGEN ACTIVATOR FOR ACUTE MYOCARDIAL INFARCTION
Volume 336 Number 23
1623
istics and clinical outcomes were compared between treatment
groups by the chi-square test in the case of discrete variables and
by nonparametric analysis of variance in the case of continuous var-
iables. Odds ratios and 95 percent confidence intervals were used
to compare treatments with regard to major clinical outcomes. Kap-
lan–Meier survival curves were used to characterize the timing of
the primary study end point and its components during the follow-
up period. Logistic-regression models were used to assess prespec-
ified interactions.
Prespecified subgroups classified according to the following
variables were studied in relation to the primary and secondary end
points: age and time to randomization, as continuous variables;
and anterior as compared with nonanterior location of the infarct,
high as compared with low risk,
5
and the hospital’s experience with
angioplasty (with the number of procedures dichotomized at the
median), as discrete variables.
An interim analysis of safety was performed by an independent
Data and Safety Monitoring Board when the enrollment reached
750 patients, as specified in the protocol. Efficacy was compared
with the use of two-sided, symmetric O’Brien–Fleming boundaries
generated by the Lan–DeMets approach to group-sequential test-
ing.
22,23
All tests of significance were two-tailed, and the treatments
were compared according to the intention-to-treat principle.
RESULTS
Recruitment began on July 5, 1994, and ended
on January 1, 1996, after 1138 patients had been
enrolled. The patients tended to be middle-aged and
male, presenting without hypotension or pulmonary
edema (Table 1). Among the patients randomly as-
signed to angioplasty, 94 percent had angiography
and 82 percent had angioplasty (5 percent also re-
ceived stents); among the patients randomly as-
signed to t-PA, 98 percent received that therapy and
only 1.4 percent had primary angioplasty. Balloon
inflation was first performed in the patients under-
going angioplasty a median of 1.3 hours after ran-
domization (interquartile range, 1.0 to 1.6). The ac-
tivated partial-thromboplastin times at 6 hours were
longer in the angioplasty group because of peripro-
cedural dosing to achieve an activated clotting time
of more than 350 seconds, but the times in the two
groups were similar by 12 hours after the initial drug
therapy.
In the patients randomly assigned to angioplasty,
83 percent of the infarct-related arteries were initial-
ly occluded (TIMI grade 0 or 1 flow) according to
the on-site interpretation (Table 2). The median peak
activated clotting time during the procedure was
381 seconds (interquartile range, 329 to 480). TIMI
grade 3 flow was obtained in 73 to 88 percent of the
patients (depending on whether the angiograms were
read at the core laboratory or at the site). Seventeen
of 465 patients (3.7 percent) who were randomly as-
*Median values are given with interquartile ranges (the 25th and 75th percentiles).
†Data were not available for some patients.
‡Times shown are from the onset of symptoms.
T
ABLE
1.
C
HARACTERISTICS
OF
THE
P
ATIENTS
AT
B
ASE
L
INE
, A
CCORDING
TO
T
REATMENT
A
SSIGNMENT
.*
C
HARACTERISTIC
t-PA
(N
573)
A
NGIOPLASTY
(N
565)
H
EPARIN
PLUS
A
NGIOPLASTY
(N
247)
H
IRUDIN
PLUS
A
NGIOPLASTY
(N
256)
Median age — yr 61.9 (52.0, 70.1) 63.5 (52.5, 71.0) 64 (50, 71) 63 (54, 71)
Age
75 yr no. (%) 79 (13.8) 82 (14.5) 32 (13.0) 39 (15.2)
Female sex — no.(%) 121 (21.5) 139 (24.6) 65 (26.3) 66 (25.8)
Current smoker — no. (%)† 255 (60.9) 235 (63.7) 102 (61.1) 108 (69.2)
Diabetes no. (%)† 77 (13.4) 99 (17.5) 45 (18.2) 50 (19.5)
Median heart rate beats/min 74.5 (62, 86) 75 (63, 87) 75 (63, 87) 75 (64, 86)
Hypertension no. (%)† 218 (38.0) 225 (39.8) 100 (40.5) 101 (39.5)
Killip class no. (%)†
1
2
3
4
524 (91.4)
41 (7.2)
4 (0.7)
2 (0.3)
507 (89.7)
47 (8.3)
2 (0.4)
5 (0.9)
220 (89.1)
22 (8.9)
1 (0.4)
3 (1.2)
228 (89.1)
23 (9.0)
1 (0.4)
2 (0.8)
Prior bypass surgery no. (%) 16 (2.8) 12 (2.1) 2 (0.8) 10 (3.9)
Prior myocardial infarction
no. (%)†
85 (14.8) 73 (12.9) 25 (10.1) 38 (14.8)
Prior angioplasty no. (%) 28 (4.9) 29 (5.1) 9 (3.6) 17 (6.6)
Median systolic blood pressure
mm Hg
130 (116, 148) 130 (116, 147) 130 (118, 150) 130 (113, 144)
Median time to arrival at hospital
hr‡
1.8 (1.0, 3.1) 1.9 (1.1, 3.0) 2.0 (1.1, 3.2) 1.9 (1.2, 2.8)
Median time to treatment — hr‡ 3 (2.0, 4.3) 3.8 (3.0, 5.3) 3.9 (3.0, 5.4) 3.9 (3.0, 5.1)
Median weight kg 76 (68, 86) 75 (67, 86) 76 (67, 86) 75 (67, 86)
The New England Journal of Medicine as published by New England Journal of Medicine.
Downloaded from www.nejm.org at ERASMUS UNIVERSITY on July 27, 2010. For personal use only. No other uses without permission.
Copyright © 1997 Massachusetts Medical Society. All rights reserved.

1624
June 5, 1997
The New England Journal of Medicine
signed to angioplasty and who underwent that pro-
cedure required bypass surgery on the same day. The
results of angioplasty did not differ significantly be-
tween the patients assigned to heparin and those as-
signed to hirudin. The medications received during
hospitalization are shown in Table 3.
As compared with t-PA, angioplasty resulted in 13
fewer deaths (95 percent confidence interval,
15 to
41; P
0.37) and 41 fewer deaths, infarctions, or
disabling strokes (95 percent confidence interval, 3 to
78; P
0.033) at day 30 per 1000 patients (Tables
4 and 5). Most of the relative benefit of angioplasty
seemed to occur between days 5 and 10 (Fig. 1).
Among patients undergoing delayed elective angio-
plasty, 7 of 61 (11 percent) in the t-PA group and
2 of 5 (40 percent) in the angioplasty group subse-
quently died or had a reinfarction or a nonfatal, dis-
abling stroke. Angioplasty was associated with more
bleeding events than t-PA, with the notable exception
of intracranial hemorrhage. Death, reinfarction, or
disabling stroke occurred in 10.6 percent of patients
assigned to angioplasty and heparin, as compared
with 8.2 percent of those assigned to angioplasty and
hirudin (P
0.37). Bleeding complications in the
hirudin and heparin groups were similar.
Eighteen percent of the patients assigned to an-
gioplasty did not undergo that procedure. At least
9.3 percent had acceptable reasons for not undergo-
ing primary angioplasty: 1.2 percent died early, 6.9
percent had an open infarct-related artery, and 1.2
percent had early bypass surgery with left main or
three-vessel coronary disease. Another 3.4 percent
had early catheterization with no reason noted for
refraining from primary angioplasty; 3.6 percent
did not undergo early catheterization, had received
thrombolytic therapy before catheterization (often
because of delays in patient transfer), or both; and for
the remaining 1.6 percent, information about the
time of catheterization was missing. Among the pa-
tients assigned to primary angioplasty who did not
undergo the procedure, 14.1 percent died within 30
days and 20.7 percent died or had a nonfatal rein-
farction or nonfatal, disabling stroke.
In the angioplasty group, the correlations between
mortality within 30 days and the final TIMI flow
grades as determined in the core laboratory were as
follows: TIMI flow grade 0, 21.4 percent mortality;
grade 1, 14.3 percent; grade 2, 19.9 percent; and
grade 3, 1.6 percent (P
0.001).
The relation between the risk of death within 30
days and assignment to angioplasty or accelerated
t-PA in several prospectively defined subgroups of
patients is shown in Figure 2.
Six months after randomization, with follow-up
complete in 96.9 percent of the eligible patients, the
incidence of the composite adverse outcome was
15.7 percent in the t-PA group and 13.3 percent in
the angioplasty group (P not significant).
*Median values are given with interquartile ranges (the 25th and 75th
percentiles).
†Data were not available for some patients.
T
ABLE
2.
R
ESULTS
OF
A
NGIOPLASTY
,
AS
D
ETERMINED
IN
THE
C
ORE
L
ABORATORY
AND
AT
THE
C
LINICAL
S
ITE
.*
V
ARIABLE
†C
ORE
L
ABORATORY
C
LINICAL
S
ITE
Before angioplasty
Median percent stenosis 100 (81.9, 100) 100 (99, 100)
TIMI flow grade no. (%)
0
1
2
3
0 or 1
2 or 3
308 (60.4)
66 (12.9)
96 (18.8)
40 (7.8)
325 (70.3)
52 (11.3)
40 (8.7)
37 (8.0)
4 (0.9)
4 (0.9)
After angioplasty
Median percent stenosis
50% stenosis no. (%)
60% stenosis no. (%)
39.2 (30.7, 48.8)
343 (77.4)
406 (91.7)
23 (10, 30)
423 (91.4)
438 (94.6)
TIMI flow grade no. (%)
0
1
2
3
Open (TIMI 2 or 3, not
specified)
28 (5.5)
7 (1.4)
101 (19.9)
372 (73.2)
12 (2.7)
9 (2.0)
32 (7.1)
385 (85.4)
13 (2.9)
Peak intraprocedural activated
clotting time sec
381 (329, 480)
*In these patients, heparin was given before infusion of the study drug.
T
ABLE
3.
C
ONCOMITANT MEDICATIONS AND IN-HOSPITAL
PROCEDURES IN THE STUDY GROUPS.
MEDICATION OR PROCEDURE t-PA ANGIOPLASTY
no. of patients (%)
Angiotensin-converting–enzyme inhibitor 253 (45.1) 225 (40.3)
Aspirin 559 (98.1) 550 (98.0)
Beta-blocker
Intravenous
Oral
171 (30.1)
409 (72.7)
151 (26.9)
388 (69.9)
Calcium-channel blocker 163 (29.1) 158 (28.4)
Digitalis 61 (10.8) 72 (12.9)
Nitrate
Intravenous
Oral
491 (86.3)
427 (76.1)
468 (83.1)
410 (74.0)
Nonstudy heparin* 267 (51.1) 208 (40.7)
Warfarin 80 (14.1) 61 (11.0)
Angiography
Emergency
Elective
Specified by protocol
None
82 (14.4)
270 (47.3)
6 (1.1)
213 (37.3)
22 (4.0)
19 (3.5)
532 (94.4)
13 (2.3)
Coronary-artery bypass surgery 47 (8.3) 42 (7.5)
Intraaortic balloon pump 39 (6.8) 78 (13.8)
First angioplasty
Emergency
Elective
Specified by protocol
None
60 (16.8)
61 (17.0)
5 (1.4)
228 (63.7)
19 (3.5)
5 (0.9)
446 (81.1)
79 (14.4)
The New England Journal of Medicine as published by New England Journal of Medicine.
Downloaded from www.nejm.org at ERASMUS UNIVERSITY on July 27, 2010. For personal use only. No other uses without permission.
Copyright © 1997 Massachusetts Medical Society. All rights reserved.

PRIMARY CORONARY ANGIOPLASTY VS. TISSUE PLASMINOGEN ACTIVATOR FOR ACUTE MYOCARDIAL INFARCTION
Volume 336 Number 23 1625
*Median values are given with interquartile ranges (the 25th and 75th
percentiles).
TABLE 5. OCCURRENCE OF SECONDARY END POINTS AT 30 DAYS.
END POINT t-PA ANGIOPLASTY
Bleeding no. (%)
Any
Severe or life-threatening
Moderate
Moderate or worse
Transfusion required
195 (34.2)
11 (1.9)
44 (7.7)
54 (9.5)
51 (8.9)
227 (40.3)
15 (2.7)
57 (10.1)
69 (12.3)
64 (11.3)
Congestive heart failure no. (%) 28 (4.9) 24 (4.3)
Intracranial hemorrhage — no. (%) 8 (1.4) 0
Median length of stay — days*
Intensive care unit
Hospital
3.5 (2.5, 5)
10 (7, 14)
3 (2, 4)
8 (6, 12)
Recurrent ischemia no. (%) 48 (9.0) 29 (5.5)
Shock no. (%) 26 (4.6) 34 (6.1)
Any stroke no. (%) 11 (1.9) 6 (1.1)
Death, myocardial infarction, stroke, or
congestive heart failure no. (%)
94 (16.5) 71 (12.6)
Figure 1. KaplanMeier Curves for Survival (Panel A) and Free-
dom from the Composite End Point of Death, Reinfarction, and
Disabling Stroke (Panel B) in the Study Patients within the 30
Days after Randomization, According to Treatment Group.
TABLE 4. OCCURRENCE OF THE PRIMARY END POINT AT 30 DAYS.
END POINT t-PA ANGIOPLASTY
ODDS RATIO
(95% CONFIDENCE
INTERVAL)
P
VALUE
ANGIOPLASTY
PLUS
HIRUDIN
ANGIOPLASTY
PLUS
HEPARIN
ODDS RATIO
(95% CONFIDENCE
INTERVAL)
P
VALUE
no. (%) no. (%)
Death 40 (7.0) 32 (5.7) 0.80 (0.491.30) 0.37 12 (4.7) 15 (6.1) 0.77 (0.341.67) 0.50
Reinfarction 37 (6.5) 25 (4.4) 0.67 (0.401.12) 0.13 11 (4.3) 11 (4.5) 0.97 (0.412.27) 0.94
Disabling stroke 5 (0.9) 1 (0.2) 0.20 (0.021.73) 0.11 0 1 (0.4)
Any of the above 78 (13.6) 54 (9.6) 0.67 (0.470.97) 0.033 21 (8.2) 26 (10.6) 0.76 (0.421.39) 0.37
DISCUSSION
In this international trial comparing primary an-
gioplasty with thrombolytic therapy for acute my-
ocardial infarction, there was a relative benefit at
30 days with angioplasty with respect to all elements
of the primary study end point death, reinfarc-
tion, and disabling stroke. The aggregate outcome
occurred significantly less often in the angioplasty
group in 9.6 percent of patients, as compared
with 13.7 percent in the t-PA group (odds ratio,
0.67; P 0.033). The extent of this benefit and of
the benefit with regard to mortality alone (P 0.37)
was far less than was seen in eight previous, small,
randomized trials but larger than in recent data re-
ported from large registries.
16,17
Previous randomized trials, albeit with consider-
able apparent heterogeneity, suggested that there
was a significant improvement in major clinical out-
comes with angioplasty, with an estimated 40 lives
saved (95 percent confidence interval, 2 to 63) per
1000 patients treated.
4,5,7-12
This benefit is larger
than the benefit of streptokinase as compared with
placebo (in the Gruppo Italiano per lo Studio della
Streptochinasi nell’Infarto Miocardico trial, 23 lives
saved at 21 days; in the Second International Study
of Infarct Survival, 29 lives saved at 35 days) in the
same types of patients,
13,15
a finding that revolution-
ized the care of patients with acute myocardial in-
farction. However, these trials were performed at se-
0.90
1.00
0.98
0.96
0.94
0.92
0 5 10 15 20 25 30
Days since Randomization
Overall Survival
Angioplasty
t-PA
P
0.37
0.86
1.00
0.98
0.96
0.94
0.92
0.90
0.88
0 5 10 15 20 25 30
Days since Randomization
Freedom from
Composite End Point
Angioplasty
t-PA
P
.0.033
B
A
The New England Journal of Medicine as published by New England Journal of Medicine.
Downloaded from www.nejm.org at ERASMUS UNIVERSITY on July 27, 2010. For personal use only. No other uses without permission.
Copyright © 1997 Massachusetts Medical Society. All rights reserved.

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Abstract: Background Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes. Methods We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later. Results The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 ±0.46 vs. 1.23 ±0.48 mm, P<0.001), and a larger luminal diameter immediately after the procedure (2.49 ±0.43 vs. 1.99 ±0.47 mm, P<0.001). At six months, the patients with stented ...

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Related Papers (5)
Frequently Asked Questions (1)
Q1. What are the contributions mentioned in the paper "A clinical trial comparing primary coronary angioplasty with tissue plasminogen activator for acute myocardial infarction" ?

As part of the Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes ( GUSTO IIb ) trial, the authors randomly assigned 1138 patients from 57 hospitals who presented within 12 hours of acute myocardial infarction ( with ST-segment elevation on the electrocardiogram ) to primary angioplasty or accelerated thrombolytic therapy with recombinant tissue plasminogen activator ( t-PA ). This trial suggests that angioplasty provides a small-to-moderate, short-term clinical advantage over thrombolytic therapy with t-PA.