Vascular response to drug-eluting stent with biodegradable vs. durable polymer. Optical coherence tomography substudy of the NEXT.

BACKGROUND The aim of the present study was to compare vascular healing response between everolimus-eluting stent (EES) and biolimus-eluting stent (BES) using optical coherence tomography (OCT). METHODS AND RESULTS In the NOBORI Biolimus-Eluting Versus XIENCE V/PROMUS Everolimus-Eluting Stent Trial (NEXT), a formal OCT substudy investigated 91 patients (55 EES-treated lesions in 48 patients and 51 BES-treated lesions in 43 patients) with 8-12 months follow-up imaging at 18 centers. A total of 980 frames with 8,996 struts in EES and 907 frames with 8,745 struts in BES were analyzed. Mean neointima thickness in EES and BES was 105±82μm and 91±80μm, respectively (P<0.001). With regard to stent-treated lesions, the percentage of struts not covered by neointima (3±7% vs. 9±10%, P<0.001) and the frequency of stent-treated lesions with any uncovered struts (n=28, 51% vs. n=42, 82%; P<0.001) were significantly lower in EES compared with BES. In addition, the percentage of malapposed struts (0.2±0.8% vs. 1.3±2.8%, P=0.006) and the frequency of stent-treated lesions with any malapposed struts (n=6, 11% vs. n=14, 27%; P=0.028) were significantly lower in EES compared with BES. CONCLUSIONS Incomplete vascular healing characterized by the presence of struts not covered by neointima and malapposed struts was less common in EES compared with BES.