The TIMI phase II pilot study enrolled 288 patients with acute myocardial infarction who were treated with recombinant tissue plasminogen activator (rt-PA) within 4 hours of symptom onset and who were assigned to coronary angioplasty of the infarct-related vessel 18 to 48 hours after rt-PA treatment. The patients were followed to ascertain (1) vital status; (2) whether they suffered a recurrent myocardial infarction; (3) whether they received coronary angioplasty or bypass grafting; and (4) whether they were rehospitalized for a cardiac event. Risk factors for these events or combination of these events were identified and reported. The estimated 6-week, 6-month, and 1-year cumulative event rate of death or myocardial infarction was 9.1 +/- 1.7%, 12.9 +/- 2.0%, and 13.6 +/- 2.0%, respectively. With the exception of repeat hospital admissions, most of the above cardiac events occurred early during the patients' follow-up course. Cox proportional hazard analyses revealed that continuing chest pain after rt-PA administration, history of congestive heart failure, low systolic blood pressure at the time of initial evaluation, and history of hypertension increased the risk of death or recurrent myocardial infarction, while a history of chest discomfort at baseline evaluation and older age was predictive of future hospitalization or a revascularization procedure.