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).

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.