Influence of drug-eluting stent on inflammation during restenosis in a porcine coronary model

Abstract

Objective — The aim of this study is to compare anti-inflammatory and intimal hyperplasia inhibiting efficacy between the Firebird rapamycin drug-eluting stent and a bare metal stent in a porcine coronary injury model.

Methods — Twelve rapamycin drug-eluting stents (Firebird), and 12 bare metal stents (BMS) were deployed with the oversizing method into porcine coronary arteries. Coronary angiography, histopathological and immunocytochemistry analysis were carried out at week 4 after stenting.

Results — The distribution of stented vessels, diameter of reference vessels, and post-procedural minimal lumen diameter were compared between the two groups. At week 4 of follow-up, quantitative coronary angiography (QCA) showed that the minimal lumen diameter and late lumen loss were greater, and percent stenosis was less in the Firebird stent group than in the bare metal stent group. In the histopathological analysis, compared to the BMS group, injury score in the Firebird stent group (1.87 ± 0.16 vs. 1.32 ± 0.13) and inflammation score (1.86 ± 0.55 vs.1.12 ± 0.35) decreased, P < 0.05.There are significant differences for neointimal area (4.60 ± 1.39 mm² in the BMS group vs. 1.51 ± 0.45 mm² in the TCS group, P < 0.05). The lumen area in the Firebird stent group enlarged (3.24 ± 0.93 mm² in the BMS group vs. 4.34 ± 0.93 mm² in the Firebird stent group, P < 0.05). Immunohistochemistry revealed that the Firebird stent suppressed cell proliferation (Ki67) and expression of nuclear factor-kappaB (NF-κB) in the arterial wall.

Conclusion — The Firebird stent showed suppression of constrictive remodelling, inhibition of neointimal hyperplasia through antiproliferation, and anti-inflammation acts via attenuated NF-kκ activation, which has proved to be a feasible method for preventing restenosis after coronary angioplasty in pigs.

Key Words:

• Inflammation
• neointimal hyperplasia
• drug-eluting stent
• restenosis