Early thrombogenicity of coronary stents: comparison of bioresorbable polymer sirolimus-eluting and bare metal stents in an aortic rat model

BACKGROUND: Although 1-month dual antiplatelet therapy (DAPT) in patients treated with bare metal stents (BMS) is well established, the optimal duration of DAPT after implantation of a drug-eluting stent (DES) is still a matter of debate. The safety of shortened DAPT is under investigation due to concern about the risk of stent thrombosis. Data on platelet activation and prothrombotic response in vivo following bioresorbable polymer sirolimus-eluting stent (BP-SES) implantation are scarce.

OBJECTIVES: The aim of our study was to compare the early thrombogenicity of BP-SES with that of BMS in an aortic rat model.

METHODS AND RESULTS: Overall, 30 rats underwent stent implantation in the abdominal aorta: BMS (Pro-Kinetic Energy; N=15) and BP-SES (Ultimaster Tansei; N=15) were compared in terms of their early thrombogenicity. CD62P exposure at the platelet surface and fibrinogen binding at the integrin receptor were not different between BMS and BP-SES over time. The thrombus coverage of the scaffold (0 vs. 0.1%, P=0.84) was similarly low in both groups at Day 28; thrombotic deposits had totally disappeared at Day 84. The endothelial strut coverage was similarly high at 1 month (90 vs. 95%, P=0.64) and 3 months (87 vs. 97%, P=0.99) following BMS and BP-SES implantation, respectively.

CONCLUSIONS: This study demonstrates the low early thrombogenicity of a BP-SES implanted in an aortic rat model, which did not differ from a BMS. These data could be helpful to support the safety of a shortened 1-month DAPT duration following BP-SES implantation in the human coronary artery.