EXTENT OF EARLY ST SEGMENT ELEVATION RESOLUTION - A STRONG PREDICTOR OF OUTCOME IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION AND A SENSITIVE MEASURE TO COMPARE THROMBOLYTIC REGIMENS - A SUBSTUDY OF THE INTERNATIONAL JOINT EFFICACY COMPARISON OF THROMBOLYTICS (INJECT) TRIAL
R. Schroder et al., EXTENT OF EARLY ST SEGMENT ELEVATION RESOLUTION - A STRONG PREDICTOR OF OUTCOME IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION AND A SENSITIVE MEASURE TO COMPARE THROMBOLYTIC REGIMENS - A SUBSTUDY OF THE INTERNATIONAL JOINT EFFICACY COMPARISON OF THROMBOLYTICS (INJECT) TRIAL, Journal of the American College of Cardiology, 26(7), 1995, pp. 1657-1664
Objectives. This study was undertaken to assess prospectively the prog
nostic power of early ST segment elevation resolution in a large cohor
t of patients with myocardial infarction and to test the value of diff
erences in ST segment resolution as a surrogate end point. Background.
Previous studies revealed that the use of two cutoff points for three
groups of ST segment resolution within 3 h after the start of thrombo
lysis is most effective in predicting outcome. Methods. The Internatio
nal Joint Efficacy Comparison of Thrombolytics (INJECT) trial compared
mortality in 6,010 patients randomized to receive either reteplase or
streptokinase. The 1,909 German patients form the basis of this subst
udy. The three groups of ST segment resolution were defined as complet
e (greater than or equal to 70%), partial (70% to 30%) and no resoluti
on (<30% to greater than or equal to 0%). Results. In 1,398 patients p
resenting less than or equal to 6 h from onset of acute myocardial inf
arction, the 35-day mortality rate for complete, partial and no ST seg
ment resolution was 2.5%, 4.3% and 17.5%, respectively (p < 0.0001). P
eak creatine kinase levels (fraction of normal) were 9.8, 13.4 and 14.
0, respectively (p < 0.0001), When baseline characteristics were inclu
ded, ST segment resolution was the most powerful independent predictor
of 35-day mortality. The proportion of patients with complete ST segm
ent resolution was larger, and that with no ST segment resolution smal
ler, with reteplase than with streptokinase (p = 0.006). Conclusions.
No ST segment resolution, indicating failed thrombolysis, predicts ver
y high early mortality, whereas com plete resolution is associated wit
h a small infarct area and low mortality. Partial ST segment resolutio
n also predicts larger infarct areas, but early mortality is relativel
y low, Different extents of ST segment resolution may serve as a sensi
tive surrogate end point in clinical trials. (J Am Coll Cardiol 1995;2
6:1657-64)