Outcome of target sites escaping high-grade (> 70%) restenosis after percutaneous transluminal coronary angioplasty

This study examined the fate of target sites that escaped high-grade resten osis (greater than or equal to 70% diameter narrowing) after percutaneous t ransluminal coronary angioplasty. Although favorable long-term prognosis af ter successful percutaneous transluminal coronary angioplasty is well docum ented, little is known about the stability of target sites. Long-term follo w-up (mean 6.5 years, range 1.0 to 12.0) was performed in 693 patients with 948 narrowings (stenosis <70% in diameter at. follow-vp coronary angiograp hy). Among them, 249 patients (36%) with 303 target sites received late fol low-vp coronary angiography. The relation of target sites to the culprit le sions for coronary events or newly developed angina was angiographically re viewed and progression/regression was also examined, focusing on the target sites. Regression was observed in 16 of 255 target sites in subjects with <50% stenosis and in 21 of 48 sites in the group with midgrade stenosis of 50% to 69% luminal narrowing (16 of 255, 6.3% vs 21 of 48, 43.8%, p <0.001) . Progression was observed in 33 and 4 sites (33 of 255, 12.9% vs 4 of 48, 8.3%; p = NS) in each group, respectively. The rest remained within the sam e range of stenosis. Culprit lesions for 2 acute myocardial infarctions, 7 unstable anginas, and 17 newly developed anginas were related to the origin al target sites. Three lesions developed in the midgrade stenosis group. Th ose 26 lesions were a component of 8.6% of 303 angiographically confirmed s ites and 2.7% of total target sites. Target sites that escape high-grade re stenosis frequently regress and become stable plaques and rarely trigger co ronary events. (C) 1999 by Excerpta Medico, Inc.