Neointimal hyperplasia of ultra-thin stents with microcrystalline sirolimus or durable polymer everolimus-eluting stents: 6- and 24-month results of the DESSOLVE III OCT study.

Abstract

The DESSOLVE III OCT substudy aimed to compare serially neointimal hyperplasia volume obstruction (%VO) between the thin-strut MiStent with early polymer elimination and nine-month sustained drug release from microcrystalline sirolimus and the durable polymer-coated everolimus-eluting XIENCE stent at six and 24 months after implantation. The efficacy endpoint was %VO, calculated as abluminal neointimal volume/stent volume. Thirty-six patients (MiStent 16 patients, 16 lesions; XIENCE 20 patients, 22 lesions) underwent serial OCT evaluation at both six and 24 months. At six months, mean abluminal %VO was significantly lower in the MiStent group than in the XIENCE group (14.54±3.70% vs 19.11±6.70%; p=0.011), whereas the difference in %VO between the two groups decreased at 24 months (20.88±5.72% vs 23.50±7.33%; p=0.24). There was no significant difference in percentage malapposed struts and percentage uncovered struts between the two groups at both time points. In the serial comparative OCT analysis of the MiStent versus the XIENCE, the MiStent showed a more favourable efficacy for preventing neointimal formation with comparable strut tissue coverage, as compared with the XIENCE at six months, but this difference in %VO decreased at 24 months so that the difference in neointima at 24 months was no longer significant.