Restenosis remains a critical limitation after percutaneous transluminal coronary angioplasty (PTCA). The clinical experience with restenosis was reviewed in 1,490 patients who had restenosis of at least 1 site within 1 year of their PTCA. The source of data was the clinical database at Emory University. Patients who had previous coronary bypass surgery or PTCA and patients who underwent PTCA in the setting of acute myocardial infarction were excluded. When restenosis was angiographically documented, 363 were treated medically, 1,051 with repeat PTCA, and 76 with coronary bypass surgery. In the repeat PTCA group there were 778 patients who originally had 1-vessel disease and 273 with multiple vessel disease. Re-dilatation of restenotic sites was performed in 95%. Angiographic success of all lesions dilated was achieved in 99%. Coronary bypass surgery was required in 2.5% of patients with restenosis first treated with repeat PTCA. One patient with multiple vessel disease died. Coronary bypass surgery was performed in fewer patients aged greater than or equal to 65 years, but more patients with multiple vessel disease. Two (2.6%) of the coronary bypass surgery patients had Q-wave myocardial infarction and there were no deaths. In the PTCA group, 5-year actuarial survival was 95%, and cardiac survival 96%. Freedom from cardiac events or further revascularization procedures was 51% at 5 years. Patients treated with PTCA and medically treated patients had similar cardiac survival rates. The most important correlates of cardiac survival were age and the presence of diabetes mellitus. At 5 years, cardiac survival without diabetes was 97 and 83% with diabetes (p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)