108 patients with acute myocardial infarction (MI), aged 70 years or younger, underwent left ventriculography and coronary arteriography (mean one month) after infarction and were followed up for an average period of 22 months (range 5-47 months). The contribution of angiographic variables to a first cardiac event (death, recurrent infarction, coronary artery bypass grafting or congestive heart failure) was evaluated with Kaplan-Meier survival curve analysis and long-rank test. Patients with cardiac events had left ventricular dilation, systolic dysfunction, multivessel coronary disease and lack of residual flow to the infarct region. Multivariate analysis showed that left ventricular end-systolic volume (P less than 0.001), end-diastolic volume (P less than 0.01) and the number of the diseased coronary vessels (P less than 0.05) were of significance in predicting the outcome. This prospective study indicates that in survivors of first acute transmural MI, cardiac catheterization performed one month after infarction can provide additive prognostic information that can be used to stratify risk.