The relationship between the number of preprocedural circulating endothelial progenitor cells and angiographic restenosis following coronary artery stent placement.

OBJECTIVE: In animals, endothelial progenitor cells (EPCs) beneficially influence the repair of the coronary vessel wall after damage by stent placement. However, their role in humans is less well understood. In the present study, the authors aimed to evaluate the relationship between the number of preprocedural EPCs defined as CD34+/KDR+/CD133+ cells and angiographic late loss as a measure of the growth of in-stent intimal hyperplasia. DESIGN SETTING PATIENTS AND INTERVENTIONS: The 59 study patients were treated in the authors' clinic with a Genous EPC capturing stent, a bare metal stent (BMS) or a drug-eluting stent, and angiographic follow-up occurred between 6 and 13†months. RESULTS: The authors found no relationship between preprocedural EPCs and angiographic late loss, irrespective of stent type. Though statistically not significant, patients with a high number of preprocedural CD34 cells and treated with a Genous stent or BMS showed a numerically higher late loss (in Genous patients: 1.03±0.76†mm vs 0.71±0.50†mm, p=0.15; in BMS patients: 1.06±0.73†mm vs 0.35±0.62†mm, p=0.08). CONCLUSIONS: Considering these and other varied observations, further studies aimed at identifying the biological mechanism and the individual roles of EPCs and/or CD34 cells in endothelial repair after coronary vessel stenting are needed.