Purpose: Edge restenosis has gathered focus as a main cause for restenosis after 1st generation drug-eluting stents (DES) implantation. The aim of this study was to assess the incidence of edge restenosis and to detect predictors for edge restenosis after 2nd generation DES implantation in routine clinical practice.
Methods: 2,450 lesions in 2,185 patients from several post marketing surveillances (PMS) of 2nd generation DES, everolimus-eluting etent (EES [Xience V/PROMUS, Xience Prime, Xience Prime SV, Xience Expedition SV, PROMUS Element, PROMUS Element Plus]) at 67 centres in Japan were analysed in this study. In EES PMS in Japan, quantitative coronary angiography (QCA) were conducted in an independent corelab, at pre- and post-procedure and 8–12 months follow-up with subsegmental analysis: in-stent region, proximal and distal edges.
Results: Restenosis rates of in-stent region, proximal and distal edges at follow-up were 4.5%, 2.8% and 1.3%, respectively. Late loss of in-stent region, proximal and distal edges were 0.24±0.43 mm, 0.12±0.41 mm and 0.02±0. 36mm, respectively. Probabilities of restenosis were compared between proximal and distal edges by multivariable adjusted logistic regression models including each lesion as a random effect. Risk of restenosis in distal edge was significantly lower than that in proximal edge (odds ratio [OR] 0.24 95% confidence interval [CI] 0.14 to 0.42 p≤0.001) adjusted with 12 variables as follows: post percent diameter stenosis (%DS), post reference diameter (RD), absolute difference of diameter between stent and vessel, bending >45°, stent overlap, hypertension, previous CABG, previous PCI, hemodialysis, moderate/severe calcification, age and male. Univariate and multivariable analysis of the 12 variables described above were performed in each subsegment. Multivariable analysis showed that post %DS (OR 1.04 95% CI 1.02 to 1.07 p=0.001), post RD (OR 0.50 95% CI 0.34 to 0.75 p≤0.001), stent overlap (OR 1.83 95% CI 1.17 to 2.85 p=0.008), previous CABG (OR 2.21 95% CI 1.15 to 4.28 p=0.02), previous PCI (OR 1.82 95% CI 1.21 to 2.74 p=0.004), hemodialysis (OR 5.13 95% CI 2.79 to 9.41 p≤0.001) and moderate/severe calcification (OR 2.08 95% CI 1.35 to 3.19 p≤0.001) were identified as predictors for in-stent restenosis. In proximal edge, post %DS (OR 1.09 95% CI 1.06 to 1.11 p≤0.001), post RD (OR 0.50 95% CI 0.29 to 0.88 p=0.02), bending >45° (OR 0.08 95% CI 0.01 to 0.62 p=0.02) and hemodiallysis (OR 2.71 95% CI 1.03 to 7.12 p=0.04) were the significant independent predictors, whereas only post %DS (OR 1.07 95% CI 1.04 to 1.11 p≤0.001) was significant in distal edge.
Conclusions: Multivariable analysis of 8–12 months angiographic outcomes from the EES PMS demonstrated higher restenosis risk in proximal edges than distal edges. Post %DS would be a main predictor for edge restenosis in the real-world setting. Edge restenosis might be attributed to angiographic results post-procedure rather than patient backgrounds.