Restenosis after successful percutaneous transluminal coronary angioplasty: the Montreal Heart Institute experience

Abstract

Repeat coronary angiography was performed within 6 months after successful percutaneous transluminal coronary angioplasty (PTCA) in 178 of our first 181 patients (98%). The remaining 3 patients were symptom free, had negative treadmill exercise test results and were considered not to have had restenosis. A second follow-up angiogram was performed in 107 patients (59%), including all patients with persistent or recurrent anginal symptoms, between 7 and 18 months after PTCA. Fifty-one of the 181 patients (28%) had restenosis on 51 of 205 successfully dilated segments (25%). The stenosis was greater than or equal to 70% in 49 of these 51 segments; it was 65% and 55%, respectively, in the 2 remaining patients. Restenosis was documented angiographically at a median time of 4.7 +/- 4 months. However, 47 patients (92%) had restenosis documented within 6 months, 2 between 7 and 12 months and 2 between 13 and 18 months after PTCA. Stepwise logistic regression analysis selected the following factors as independent predictors of restenosis after PTCA: variant angina, multivessel disease, severity of residual stenosis and less reduction in the diameter of the stenosis on the angiogram immediately after PTCA. Of these 4 factors, the degree of residual stenosis immediately after PTCA was by far the most significant. It is concluded that restenosis occurs in approximately 25% of patients, almost always within the first 6 months, after successful PTCA. The degree of residual stenosis after PTCA is the most important predictor of restenosis. Increased experience and improved instrumentation may eventually lead to less residual stenosis and better late results after PTCA.