Impact of postangioplasty restenosis on comparisons of outcome between angioplasty and bypass grafting

Abstract

Restenosis is a major limitation of percutaneous transluminal coronary angioplasty (PTCA). In this study, we assessed the impact of restenosis on PTCA with reference to coronary angioplasty bypass grafting (CABG). In the Coronary Angioplasty versus Bypass Revascularisation Investigation (CABRI) PTCA population, those who had restenosis were defined as those needing a second revascularization at a site revascularized at the initial procedure. The 1-year clinical outcome of the nonrestenotic group (n = 437) was compared with those who underwent CABG (n = 453). There was no difference in deaths. In the nonrestenotic PTCA group, the incidence of more infarctions was insignificant (relative risk [RR] 1.9, 95% confidence intervals [CI] 0.96 to 3.75, p = 0.064), there was a much greater need for repeat revascularization (RR 8.6, CI 5.14 to 14.41, p <0.0005), and patients had a poorer angina status (RR 1.46, CI 1.01 to 2.13, p = 0.046). Using 2 measures of coronary disease, the degree of pre- and postrevascularization disease was compared between groups. There were no differences in prerevascularization disease. However, using either measure, residual postrevascularization disease was more frequent in the nonrestenotic PTCA group. Restenosis only partially accounts for the greater morbidity seen after PTCA, compared witrh CABG, in multivessel disease. The greater likelihood of residual disease post-PTCA may contribute to this greater morbidity.