Abstract 13902: Comparison of Stent Performance Between ZES and EES

Abstract

Introduction: Although drug-eluting stents (DESs) have reduced restenosis, a unique issue beyond restenosis, i.e., impairment of re-endothelialization, which may delay wound healing and cause a relapse of inflammation, leading to neoathroma formation at the stented sites, in addition to lack of neointimal coverage, has arisen. Therefore, overall stent performance should be characterized by the abilities of geometric luminal gain acquisition, neointimal coverage of the stent struts, and stabilization of the underlying inflammatory neoatheroma. Hypothesis: Our hypothesis is that stent performance would be different between 2 second generation DESs, zotarolimus-eluting stent (ZES) and everolimus-eluting stent (EES). Methods: We compared stent performance among ZES, EES and bare metal stent (BMS) using optical coherence tomography (OCT) and coronary angioscope (CA). For 37 stented coronary lesions (EES; 16 lesions, ZES; 10 lesions and BMS; 11 lesions) in 20 patients, we observed stented sites by the OCT at 6-12 months after stent placement and measured neointimal area at the site of minimal lumen area and ratio of uncovered stent strut to the whole struts. Also by the CA, neointimal coverage was observed, and neointimal color was simultaneously observed. From the CA findings, the grades of neointimal coverage and yellow color were classified into 0 to 3. Results: The neointimal area (mm 2 ) was 1.30±1.12 in the EES lesions, 2.74±1.17 in the ZES lesions (P<0.05 vs EES), and 3.76±1.01 in the BMS lesions (P<0.001 vs EES, P=0.07 vs ZES). The OCT-based uncovered ratio was 26.9% in the EES lesions, 2.1% in the ZES lesions (P<0.01 vs EES), and 1.2% in the BMS lesions (P<0.001 vs EES, P=0.9 vs ZES). Stent coverage grade by the CA findings was 0.44±0.53 in the EES lesions, 2.00±1.00 in the ZES lesions (P<0.001 vs EES), and 2.33±0.82 in the BMS lesions (P<0.01 vs EES, P=0.5 vs ZES). The yellow grade was 1.67±0.50 in the EES lesions, 0.29±0.48 in the ZES lesions (P<0.001 vs EES), and 0.17±0.41 in the BMS lesions (P<0.001 vs EES, P=0.7 vs ZES). Conclusions: ZES might be better than BMS in terms of neointimal thickening, and better than EES in terms of neointimal coverage as well as stabilization of inflammatory neoatheroma. ZES may have superior stent performance, compared to EES.