To evaluate the predictors and likelihood of success for coronary angioplasty performed in the setting of acute myocardial infarction, 300 consecutive patients with 321 coronary stenoses were studied retrospectively. Success was defined as final diameter stenosis less than 70% and Thrombolysis in Myocardial Infarction (TIMI) flow grade greater than or equal to 2. Nine clinical variables and 15 angiographic variables were assessed. Seventy-nine percent of patients were men; the mean age was 56 +/- 11 years, and 54% of patients also received thrombolytic therapy. The mean left ventricular ejection fraction was 46 +/- 11%, and 18 patients (6%) were in cardiogenic shock. Angioplasty success in the infarct-related artery was achieved in 240 patients (80%). In 177 total occlusions (TIMI flow grade less than or equal to 1), the success rate was 75.7% and success was independently predicted by 1) an ejection fraction greater than 30% (p = 0.001); 2) no arterial bend greater than or equal to 45 degrees at the site of angioplasty (p = 0.008); and 3) no triple vessel disease (p = 0.014). In 144 subtotal occlusions (TIMI flow grade greater than or equal to 2), procedural success was achieved in 84.7% and was predicted by 1) absence of thrombus greater than 5 mm (p = 0.023), and 2) absence of other stenoses greater than or equal to 50% in the same artery (p = 0.043), whereas patency without further emergency intervention was achieved in 71.7% and was predicted only by patient age less than or equal to 60 years and absence of cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)