Introduction: The arterial repair after bioresorbable polymer drug-eluting stent (BP-DES) implantation is expected to be different from that after durable polymer drug-eluting stent (DP-DES) because its polymer is resorbed within several months. However, the arterial repair in early phase after BP-DES implantation has not been elucidated.
Methods: We analyzed 112 stents in 99 lesions from 72 patients evaluated by angioscopy 4±1 months after the implantation. Neointimal coverage (NIC) grade, heterogeneity of NIC, yellow plaque (YP) severity and the incidence of thrombus adhesion were compared between BP-DES (11 cobalt-chromium sirolimus-eluting stents and 20 platinum-chromium everolimus-eluting stents) and DP-DES (37 cobalt-chromium everolimus-eluting stents, 4 platinum-chromium everolimus-eluting stents and 40 slow-release zotarolimus-eluting stents). NIC was graded: grade 0, struts exposed; grade 1, struts bulging into the lumen, although covered; grade 2, struts embedded in the neointima, but translucent; grade 3, struts fully embedded and invisible. NIC was defined as heterogeneous when the NIC grade variation was ≥1. YP severity was graded: grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.
Results: Baseline characteristics were similar between the two groups. NIC grade (BP-DES: grade 0, 19%; grade 1, 48%; grade 2, 26%; grade 3, 7%; DP-DES: grade 0, 9%; grade 1, 69%; grade 2, 20%; grade 3, 2%, P=0.61) and heterogeneity were similar (P=0.36). The incidence of thrombus adhesion was significantly higher in BP-DES (61% versus 33%, P=0.01, Figure) though YP grade was significantly lower in BP-DES (grade 0, 16%; grade 1, 32%; grade 2, 32%; grade 3, 20% versus grade 0, 0%; grade 1, 17%; grade 2, 52%; grade 3, 31%, P<0.01).
Conclusions: NIC is similar but the incidence of thrombus adhesion is significantly higher in BP-DES under the less severe YP status compared to DP-DES 4 months after the implantation.