Comparison Of Neointimal Coverage Of Zotarolimus-Eluting Stent And Everolimus-Eluting Stent At 1, 2 And 3-Month Follow-Up: Evaluation By Optical Coherence Tomography

BACKGROUND: Confirming complete neointimal coverage after drug-eluting stents (DES) implantation is clinically important, because incomplete stent coverage is responsible for stent thrombosis. Previous study using optical coherence tomography (OCT) demonstrated that stent struts of first-generation DES still remain uncovered 3 months after deployment. On the other hand, the ENDEAVOR OCT showed 99.9% of the stent struts were covered with neointima at 3 months after zotarolimus-eluting stent (ZES; Endeavor Sprint) implantation. However, the time-course up to 3 months analyses of neointimal coverage in patients with second-generation DES, such as ZES and everolimus-eluting stent (EES; Xience V and PROMUS), has not been reported. The aim of this study was to compare vessel responses at 1, 2 and 3-month follow-up after ZES or EES implantation using OCT. METHODS: A total of 33 stents (16 ZES and 17 EES) in 26 patients with de novo native coronary lesions were enrolled in this study. OCT examination was performed at 1-month (n=12), 2-month (n=14) and 3-month (n=7) follow-up after ZES or EES implantation. Cross-sectional OCT images were analyzed at 1 mm intervals. The strut apposition to the vessel wall and neointimal coverage on struts were evaluated by OCT. Mean neointimal hyperplasia (NIH) was also measured. RESULTS: Neointimal coverage was almost completed at 3 months after ZES implantation. In addition, 70% of ZES struts were covered with neointima at even 1-month follow-up. Whereas, the rate of neointimal coverage was 37%, 46% and 60% at 1, 2 and 3-month follow-up after EES implantation, respectively (Table). Thrombus was observed in 3 stents (1 ZES vs. 2 EES). CONCLUSIONS: Within 3 months after implantation, vessel healing was better with second-generation DES. Especially, the rate of neointimal coverage was greater in ZES compared with in EES.