Impact of different coronary angioscopic findings on arterial healing one year after bioresorbable-polymer and second-generation durable-polymer drug-eluting stent implantation.

Background: The advantage of using bioresorbable-polymer drug-eluting stent (BP-DES) compared with second-generation durable-polymer drug-eluting stent (2G DP-DES) still remains controversial in clinical situations. The purpose of this study to evaluate the degree of re-endothelialization and the prevalence of high-grade yellow-colored plaque (YCP), which might concern arterial healing after BP-DES and 2G DP-DES implantation using a high-resolution coronary angioscopy (CAS).

Methods: In total, 104 DESs (52: 2G DP-DES and 52: BP-DES) were prospectively observed using CAS 12±1 months after coronary intervention. The grade of neointimal coverage (NIC) over the stent was scored on a 4-point scale from 0 (no coverage) to 3 (complete coverage). YCP grade was also scored on a 4-point scale as 0 (white) to 3 (intensive yellow). High-grade YCP was defined as maximum grade ≥2. Moreover, the prevalence of high-grade YCP and the incidence of thrombus were investigated.

Results: BP-DES revealed better dominant NIC grade and less NIC heterogeneity than 2G DP-DES (p=0.0001 and p=0.015, respectively). The prevalence of high-grade YCP was lower for BP-DES than for 2G DP-DES (p=0.05). However, the incidence of thrombus was not significantly different (p=0.41). Multivariate analysis identified that low-density lipoprotein cholesterol levels [odds ratio (OR), 1.03; 95% Confidence Interval (CI): 1.01-1.06, p=0.01] and the usage of BP-DES [OR, 0.36; 95% CI: 0.14-0.91, p=0.03] as independent predictors of high-grade YCP.

Conclusions: Compared with 2G DP-DES, BP-DES was less heterogeneous and well-covered NIC and less prevalence of the high-grade YCP implying optimal arterial healing.