Resolute and Xience V polymer-based drug-eluting stents compared in an atherosclerotic rabbit double injury model

Abstract

Aim: To evaluate differences in strut coverage, inflammation and endothelialization between two second-generation polymer-based drug-eluting stents (DES) in an atherosclerotic rabbit double-injury iliac artery model at 28 days follow-up.

Methods and results: Rabbits with induced atheroma received bilateral iliac artery stents: everolimus-eluting stent (Xience V EES; Abbott Vascular), zotarolimus-eluting stent (Resolute ZES; Medtronic CardioVascular), or bare-metal stent (BMS; MultiLink Vision; Abbott Vascular). After 28 days, total neointimal coverage examined by scanning electron microscopy was >98% for all three stent types. Neointimal thickness above stent struts was decreased by 50% in Xience V EES (0.06 ± 0.01 mm; P = 0.00001) compared with BMS (0.15 ± 0.03 mm) and Resolute ZES (0.12 ± 0.04 mm). Luminal area was largest for Xience V EES (3.79 ± 0.33 mm(2) ; P = 0.0003 for Xience V EES vs. BMS), followed by Resolute ZES (3.46 ± 0.45 mm(2) ; P = 0.083 for Resolute ZES vs. BMS) and BMS (3.07 ± 0.53 mm(2) ). Percentage area stenosis was smallest for Xience V EES (17.23 ± 3.64%; P = 0.00001), while BMS (30.25 ± 7.48%) and Resolute ZES (30.79 ± 7.15%) did not differ. Endothelial monolayer regrowth was significantly lower in Resolute ZES (65 ± 13%) versus BMS (79 ± 11%; P = 0.004). There was no difference between Xience V EES (74 ± 10%) and BMS. Xience V EES was further associated with a lower number of inflammatory cells surrounding the stent struts (7 ± 2 per strut) in comparison to Resolute ZES (15 ± 6; P = 0.0001) and BMS (17 ± 9; P = 0.0005).

Conclusion: In this atherosclerotic rabbit model, Xience V EES suppressed neointimal thickening better, with normal endothelial regrowth as compared with BMS, and less strut-induced inflammation.