Associations between endothelial progenitor cells, clinical characteristics and coronary restenosis in patients undergoing percutaneous coronary artery intervention.

OBJECTIVE: Endothelial progenitor cells (EPCs) are produced in the bone marrow and mobilized to the peripheral blood playing a key role in endothelial repair. The objective of this study was to evaluate circulating EPC before and after percutaneous coronary intervention (PCI) with stent implantation and their associations with coronary restenosis and adverse cardiovascular events. Venous blood was obtained before and the day after PCI. Quantification of total white blood count and identification of EPCs (CD45- CD34+ CD31+ CD133/2+ CD309+ ) through immunophenotyping by flow cytometry was performed. The primary outcome was either restenosis detected by new coronary angiography or angina with myocardial ischemia at the territory of the stented coronary artery. Secondary outcomes were angina without demonstrable myocardial ischemia, acute coronary syndrome or all-cause death.

RESULTS: 37 patients were followed for 1 year. The median EPC count before PCI was 320 cells/mcl and after PCI 286 cells/mcl. A decrease of EPC count was found in 65% of the patients, while 35% displayed an increase. Primary outcomes occurred in 10.8% and the secondary in 37.8% of the patients. Despite a higher level of EPC before (402 cell/mcl) and after PCI (383 cell/mcl) in patients with the secondary outcomes, there was no significant association between EPC and cardiovascular events.