Impact of Residual Stenosis on the Angiographic Edge Restenosis of a Second-Generation Drug-Eluting Stent

Edge restenosis has gained attention as a main cause of restenosis after first-generation drug-eluting stent (DES) implantation. The aim of this study was to assess the incidence of edge restenosis and identify the predictors of edge restenosis after second-generation DES implantation. Data were obtained from several postmarketing surveillance (PMS) studies on a cobalt-chromium everolimus-eluting stent (CoCr-EES; Xience V/PROMUS, Xience Prime, Xience Prime SV, and Xience Expedition SV), a second-generation DES, in Japan. Angiographic analysis was conducted at the baseline and after eight months on the following subsegments: in-stent region, proximal edge, and distal edge. Restenosis was defined as ≥ 50% diameter stenosis (DS) at follow-up. We used multivariate logistic regression (with lesions as a random effect) to compare the instances of restenosis between the proximal and the distal edges. Univariate and multivariate analyses of the risk factors for restenosis were performed for each subsegment. We analyzed 1,966 lesions in 1,687 patients. The restenosis rates at the in-stent region, proximal edge, and distal edge were 4.4%, 3.0%, and 1.1%, respectively. The risk of restenosis at the distal edge was significantly lower than that at the proximal edge, when adjusted for 13 variables. The predictors of restenosis were postprocedural % diameter stenosis (%DS), postprocedural reference diameter, ≥ 45° bending, stent overlap at the proximal edge, and postprocedural %DS at the distal edge. Our analysis of eight-month angiographic outcomes from CoCr-EES PMS demonstrated that postprocedural %DS is a major predictor of edge restenosis. Edge restenosis is more likely attributable to postprocedural angiographic results than to the patient's background.