RESTENOSIS AFTER DELAYED CORONARY ANGIOPLASTY OF THE CULPRIT VESSEL IN PATIENTS WITH A RECENT MYOCARDIAL-INFARCTION TREATED BY THROMBOLYSIS

Background Clinical follow-up after percutaneous transluminal coronary angioplasty (PTCA) of an infarct-related lesion has demonstrated a low incidence of recurrent symptoms and repeated revascularization. In the absence of systematic angiographic follow-up, this low rate of clinical restenosis may reflect either a truly lower incidence of anatomic restenosis or the lack of recurrent symptoms in patients with extensive infarction in the territory of the restenotic vessel. Methods and Results We studied 300 consecutive patients who, after a thrombolysis for myocardial infarction, underwent delayed (10.5+/-6 days after the myocardial infarction) PTCA of the infarct-related lesion. Procedural success was obtained in 253 patients (84%), and angiographic follow-up was performed in 205 of this group (81%) at a mean of 7.3+/-1.9 months. Restenosis (defined as the recurrence of >50% stenosis) was present in 105 patients (51%). Only 34 of the 105 patients (32%) with angiographic restenosis were symptomatic; the other 68% had clinically silent restenosis. Of these 105 patients, 27 (13% of the total population undergoing follow-up angiography) had reocclusion at the dilated site at follow-up. The severity of the stenosis at follow-up and the late loss in minimal lumen diameter followed a nearly Gaussian distribution if the lesions that were totally occluded at follow-up were excluded. By multivariate analysis, two independent predictors of reocclusion were identified: a small reference diameter (P<.0005) and the presence of collateral vessels before the procedure (P<.01). Only one factor was associated with restenosis in the 178 patients who did not have reocclusion at follow-up: a Thrombolysis in Myocardial Infarction grade less than or equal to 2 before the procedure (P<.0001). At follow-up, there was a significantly (P<.01) higher ejection fraction in patients without restenosis (56.1+/-13.4%) and in patients with restenosis without total occlusion (56.0+/-13.8%) than in patients with reocclusion (46.4+/-13.0%). Conclusions Despite a satisfactory clinical outcome, delayed PTCA of an infarct-related lesion is associated with a high rate of angiographic recurrence. Two distinct mechanisms account for recurrent stenosis: progressive luminal renarrowing as documented after angioplasty of stable lesions and reocclusion of the infarct-related lesion. Only reocclusion is associated with a deterioration in left ventricular function at follow-up.