From June 1980 to January 1989, 3,186 patients had coronary angioplasty of two (2,399 patients) or three (787 patients) of the three major epicardial coronary systems. A mean of 3.6 lesions (range 2 to 14) were dilated per patient, with a 96% success rate. Acute complications were seen in 94 patients (2.9%) and included Q wave infarction in 47 (1.4%), urgent coronary artery bypass surgery in 33 (1%) and death in 31 (1%). Multivariate correlates of in-hospital death included impaired left ventricular function, age greater than or equal to 70 years and female gender. Complete long-term follow-up data were available for the first 700 patients and the follow-up period averaged 54 +/- 15 months in duration. Actuarial 1 and 5 year survival rates were 97% and 88%, respectively, and were not different in patients with two or three vessel disease. By Cox regression analysis, age greater than or equal to 70 years, left ventricular ejection fraction less than or equal to 40% and prior coronary artery bypass surgery were associated with an increased mortality rate during the follow-up period. Repeat revascularization procedures were required in 322 patients (46%). Restenosis resulted in either repeat angioplasty or bypass surgery in 227 patients (32%). Repeat coronary angioplasty was performed for isolated restenosis in 126 patients (18%), for restenosis and disease progression at new sites in 85 patients (12%) and for new disease progression alone in 54 patients (8%). Coronary bypass surgery was required in 110 patients (16%) during the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)