Percutaneous transluminal coronary angioplasty was performed as primary therapy in 215 consecutive patients (aged 56 +/- 11 years, 75% male) with acute myocardial infarction and single vessel coronary artery disease. Wide patency of the infarct-related artery was restored in 212 patients (99%). Complications consisted of one urgent coronary bypass operation (0.5%); there were no procedural deaths. A recurrent ischemic event before discharge occurred in eight patients (4%). The in-hospital mortality rate was 1%; five of six patients presenting with cardiogenic shock were alive at discharge. In 126 patients in whom predischarge angiography was performed, the ejection fraction improved from 55 +/- 12% to 61 +/- 12% (p less than 0.005) and increased by greater than or equal to 5% units in 66 patients (52%). Regional wall motion improved in 60 patients (48%). By multivariate analysis, a depressed initial ejection fraction, a limited increase in serum creatine kinase, young age and sustained patency of the infarct-related artery were found to be independent predictors of improvement in left ventricular function. Follow-up data were available in 214 patients (99.5%) at a mean interval of 35 months. The actuarial 3 year cardiac survival rate was 92%. By multivariate analysis, only the baseline ejection fraction correlated with long-term cardiac survival. Nine patients (4%) sustained a late nonfatal myocardial infarction, and 11 patients (5%) underwent subsequent coronary bypass surgery. At late follow-up study, 149 (77%) of 194 patients alive were free of angina. In summary, in patients with acute myocardial infarction and single vessel disease, coronary angioplasty without prior thrombolytic therapy can be performed with a high success rate and few procedural complications. After direct angioplasty, regional wall motion and global ejection fraction improve in 50% of patients, especially in those with depressed initial left ventricular function. This approach results in an excellent early and late event-free survival.