IMPACT OF TREATMENT STRATEGY ON PREDISCHARGE EXERCISE TEST IN THE THROMBOLYSIS IN MYOCARDIAL-INFARCTION (TIMI) II-TRIAL

Predischarge supine bicycle ergometry was used to assess persistent myocardial ischemia in postinfarction patients who received thrombolytic therapy and were randomized to an invasive versus conservative strategy in the Thrombolysis in Myocardial infarction (TIMI) II trial. The frequency of ischemic responses in both strategies, and the 1-year prognostic importance of the different exercise test outcomes were examined. At 14 days, the percentage of patients with any adverse outcome (including death, presence of exercise-induced ST-segment depression, or inability to perform the exercise test) was 33.7% of 1,681 randomly assigned to the invasive strategy compared with 34.6% of 1,658 randomly assigned to the conservative strategy (p = 0.57). The 1-year mortality was greater in patients who did not perform the predischarge exercise test (7.7%) than in those who did (1.8%) (p < 0.001); the former were older, and a greater proportion were women, had a more frequent history of myocardial infarction, and more extensive coronary artery disease (p < 0.01 for each comparison). The 1-year mortality in patients with exercise-induced ST-segment depression or chest pain was only 1.4% (3 of 222) among those randomly assigned to the conservative strategy where coronary angiography and revascularization were recommended if the test result was abnormal (relative risk compared with those without ST-segment depression or chest pain 0.6; 99% confidence interval 0.1 to 2.9). Among patients randomly assigned to the invasive strategy, exercise-induced ST-segment depression or chest pain was associated with a 1-year mortality of 2.5% (4 of 161) (relative risk compared with those without ST-segment depression or chest pain 2.1; 99% confidence interval 0.5 to 9.4). Thus, in postinfarct patients treated with thrombolytic therapy and a conservative strategy, the recommendation of performing cardiac catheterization and coronary revascularization when the predischarge exercise test is abnormal results in a low 1-year mortality for those with exercise-induced angina or ST-segment depression, which is parable to that for patients who do not have these findings.