Early vascular response of ultra-thin bioresorbable polymer sirolimus-eluting stents assessed by optical frequency domain imaging: the EVALUATION study

This study aimed to evaluate the early vascular response of ultra-thin strut bioresorbable polymer sirolimus-eluting stents (BP SES) using optical frequency domain imaging (OFDI). Ultra-thin strut BP SES have superior outcomes in terms of efficacy and safety endpoints when compared to other thin strut new-generation stents. However, the factors contributing to the superiority of BP SES over other thin strut new-generation stents are unclear. A total of 32 patients with multivessel disease requiring staged procedures at 1 month were enrolled from 3 cardiovascular institutions; of these, 31 were immediately assessed by OFDI (n = 31). All patients were assessed at 1 month after ultra-thin strut BP SES implantation. The primary endpoint was % of uncovered struts. A total of 1723 cross sections (17,014 struts) were analyzed at baseline and 1 month after percutaneous coronary intervention. The % uncovered struts at 1-month follow-up was 7.7% (4.0, 13.8). Furthermore, the covered strut % (88.4% and 80.4%, P = 0.013) and malapposition rate (2.7% and 4.3%, P = 0.012) were significantly different between the 60-μm and 80-μm stents. Ultra-thin strut BP SES implantation may feasibly achieve early vascular responses due to the ultra-thin struts. This may ultimately lead to lower stent thrombosis and target lesion failure rates. Clinical trial registration University Hospital Medical Information Network Clinical Trials Registry (No. UMIN000033406).