One-year results of the Thrombolysis in Myocardial Infarction investigation (TIMI) Phase II Trial

The Thrombolysis in Myocardial Infarction (TIMI) Phase II Trial randomized 3,339 patients to either an invasive (INV, n = 1,681) or a conservative (CON, n = 1,658) strategy after intravenous recombinant tissue-type plasminogen activator (rt-PA) for acute myocardial infarction.

The patients assigned to the INV strategy routinely underwent cardiac catheterization, and when anatomically appropriate, percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting 18-48 hours after infarction. CON patients had these procedures only in response to the occurrence of spontaneous or provoked ischemia. One-year follow-up data are available in 3,316 patients (99.3%). The primary trial end point, death and nonfatal reinfarction, occurred in 14.7% of INV patients and in 15.2% of CON patients (p = NS). When analyzed individually, there was no difference (p = NS) in death (INV, 6.9%; CON, 7.4%) or recurrent infarction (INV, 9.4%; CON, 9.8%) between the two groups. Anginal status at 1 year was also similar. Cardiac catheterization and PTCA were performed more often in INV (98.0% and 61.2%, respectively) compared with CON (45.2% and 20.5%, respectively) patients. At 1 year, the cumulative number of patients who underwent coronary bypass surgery (INV, 17.5%; CON, 17.3%) was similar in the two groups.

The INV and CON strategies resulted in similar favorable outcomes at 1 year of follow-up. In particular, the rates of mortality and reinfarction were not different and were impressively low in both groups. One possible advantage of the INV strategy was detected in subgroup analyses. In patients with a history of myocardial infarction, the data are suggestive that 1-year mortality was lower in INV patients (10.3%) than in CON patients (17.0%) (p = 0.03).