Optical coherence tomography study of chronic-phase vessel healing after implantation of bare metal and paclitaxel-eluting self-expanding nitinol stents in the superficial femoral artery

BackgroundThis study aimed to assess chronic-phase suppression of neointimal proliferation and arterial healing following paclitaxel-coated (PTX) and bare metal stent (BMS) implantation in the superficial femoral artery using optical coherence tomography (OCT).MethodsTwenty-five patients with 68 stents underwent an 8-month OCT follow-up. Besides standard OCT variables, neointimal characterization and frequencies of peri-strut low-intensity area (PLIA), macrophage accumulation, and in-stent thrombi were evaluated.ResultsThe mean neointimal thickness was significantly less with PTX stents (544.9 ± 202.2 μm vs. 865.0 ± 230.6 μm, p < 0.0001). The covered and uncovered strut frequencies were significantly smaller and larger, respectively, in the PTX stent group vs. the BMS group (93.7% vs. 99.4%; p < 0.0001, 4.0% vs. 0.4%; p < 0.0001, respectively). Heterogeneous neointima was only observed in the PTX stent group (12.5% vs. 0%, p = 0.017). The frequencies of PLIA and macrophage accumulation were significantly greater in the PTX stent group (87.2% vs. 67.6%, p = 0.001 and 46% vs. 9.1%, p = 0.003, respectively).ConclusionAfter 8 months, reduced neointimal proliferation was observed with PTX stent implantation. On the other hand, delayed arterial healing was observed compared with BMS.