Aims: The study sought to define the long-term angiographic and clinical outcome of a bio-engineered stent, able to sequester endothelial progenitor cells (EPC) to the stent to promote the post-stenting vascular repair response.
Methods and results: The HEALING-II was a multicentre, prospective registry, including 63 patients treated with the implantation of a Genous™ EPC capture stent. Serial quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) analysis was performed at 6 and 18 month. The 18 month composite MACE rate was 7.9%, whereas 6.3% clinically justified target lesion revascularisations were observed. Although patients received one month of clopidogrel, no (sub)acute or late angiographic stent thrombosis occurred. At 6 month follow-up, in-stent late luminal loss was 0.78±0.39 mm and percent in-stent volume obstruction was 22.9±13.7% (mean±sd). Serial angiographic and IVUS analyses were available in 30 event-free patients at post-procedure, 6 months and 18 months. From 6 months to 18 months follow-up, a significant late regression of neointimal hyperplasia was observed on QCA (late luminal loss 0.59±0.31, 24.4% reduction or 16.9% by matched serial analysis) and IVUS (percent in-stent volume obstruction 20.3±14.3%, 11.4% reduction or 9.6% by matched serial analysis). The relative increase in circulating EPC titers at long-term follow-up correlated with neointimal compaction in individual patients, suggestive of an EPC-mediated vascular repair response.
Conclusions: The HEALING II study suggests that the EPC capture stent, aimed to stimulate the coronary vascular repair response, significantly promotes late regression of neointimal hyperplasia up to 18 months after stent implantation.