The first 169 patients in whom percutaneous transluminal coronary angioplasty was performed have now been followed for five to eight years. The procedure was technically successful in 133 patients (79 percent). In the follow-up period, nine of the 133 patients died (five of cardiac disease), and actuarial cardiac survival was 96 percent at six years. All patients were symptomatic before angioplasty, but 67 percent of the 133 who had technically successful procedures were asymptomatic at the last follow-up evaluation. Exercise stress testing, positive in 97 percent before angioplasty, was positive at the last follow-up study in only 10 percent of the patients who had technically successful procedures. Stenosis recurred during the first six months in 30 percent of the patients, and six more recurrences were observed among the 41 patients who had follow-up angiograms at two to seven years. A second angioplasty was required in 27 patients, and coronary bypass surgery was subsequently needed in 19. Actuarial event-free survival (freedom from death, myocardial infarction, and coronary bypass surgery) was 79 percent at six years. Follow-up of patients with multivessel disease showed a higher mortality from cardiac causes and a lower rate of long-term success than occurred among patients with single-vessel disease. These long-term results indicate that most episodes of restenosis occurred within six months of angioplasty, but some late recurrences were seen. Patients with single-vessel disease had a better long-term outcome after angioplasty than those with multivessel disease.