A randomized, open-label clinical trial using optical coherence tomography to compare two sirolimus-eluting stents, one with a biodegradable polymer and the other with a permanent polymer.

Intimal hyperplasia appears to differ after implanting a drug-eluting stent (DES) with a biodegradable or a permanent polymer. The aim of the present study was to compare biodegradable with permanent polymer DES, since the available data are limited. One hundred patients with de novo coronary artery stenosis were included in this study. The patients were classified into 2 groups: DES with a biodegradable polymer (n=50) and DES with a permanent polymer (n=50). Optical coherence tomography (OCT) examination was performed before and after stent implantation. A follow‑up OCT, performed 1 year after stent implantation, compared the morphologies of intimal hyperplasia in the 2 groups. The frequencies of uncovered stent struts (2.27 vs. 1.87%, P=0.145) and stent strut malapposition (1.9 vs. 2.02%, P=0.655) upon the first-year follow-up were not significantly different. Average neointimal thickness was lower in the biodegradable compared with the permanent polymer group (106.12±80.65 vs. 181.20±146.96 µm, P<0.001). The frequencies of neointimal thickness <100 µm were significantly higher in the biodegradable compared with the permanent polymer group (62.1 vs. 35.9%, P<0.001). The average intimal thickness was also lower in the biodegradable compared with the permanent polymer group (57.7±24.6 vs. 67.6±22.4 µm, P<0.001). In conclusion, biodegradable polymer DES resulted in significantly lower intimal hyperplasia and had well-proportioned intimal coverage compared with permanent polymer DES.