Arterial Healing 10 Months After Implantation of an Ultrathin-Strut, Biodegradable-Polymer, Sirolimus-Eluting Stent　― An Angioscopic Study ―

Background: The Orsiro(TM) ultrathin-strut, biodegradable-polymer, sirolimus-eluting stent (O-SES) has specific characteristics regarding its components and has demonstrated comparable clinical outcomes compared with durable-polymer, drug-eluting stents (DES). However, arterial repair following deployment of the O-SES has not been elucidated to date. Methods and Results: Using data from the Kansai Rosai Hospital database between November 2010 and September 2020, we analyzed coronary angioscopy (CAS) findings a mean (±SD) of 10±2 months after implantation of an O-SES, a durable-polymer everolimus-eluting stent (Xience(TM); X-EES), or a biodegradable-polymer everolimus-eluting stent (Synergy(TM); S-EES). Neointimal coverage (NIC), yellow color intensity of the stented segment, and the incidence of thrombus adhesion were compared between the O-SES (66 stents from 42 patients), X-EES (119 stents from 87 patients), and S-EES (132 stents from 88 patients). NIC was significantly thinner for the O-SES than S-EES (P<0.001), but was similar between the O-SES and X-EES (P=0.25). Yellow color intensity was significantly greater for the O-SES than X-EES (P<0.001), but similar between the O-SES and S-EES (P=0.51). The incidence of thrombus adhesions was similar in all 3 groups. Conclusions: O-SES and X-EES resulted in similar inhibition of NIC and both resulted in a thinner NIC than with S-EES. In addition, O-SES exhibited a similar degree of thrombus adhesion as the other DES, suggesting similar thrombogenicity.