Correlations between progression of coronary artery disease and circulating endothelial progenitor cells.

The pathophysiology of coronary artery disease (CAD) progression is not well understood. Endothelial progenitor cells (EPCs) may have an important role. In the present observational cohort study we assessed the number of circulating EPCs in 136 patients undergoing elective percutaneous coronary intervention and who had at least one major epicardial vessel with a nonsignificant stenosis [<50% diameter stenosis (DS)], and the relationship between plasma EPC levels and the 24-mo progression of the nonsignificant coronary artery lesion. The following cell populations were analyzed: CD34(+), CD133(+), CD34(+)/KDR(+), CD34(+)/VE cadherin(+), and endothelial cell colony-forming units (CFU-ECs). Progression was defined as a >15% DS increase of the objective vessel at follow-up. At 24 mo, 57 patients (42%) experienced significant progression. Independent predictors of disease progression were LDL cholesterol > 100 mg/dl (OR=1.03; 95% CI 1.01-1.04; P=0.001), low plasma levels of CFU-ECs (OR=3.99; 95% CI 1.54-10.37; P=0.005), and male sex (OR=3.42; 95% CI 1.15-10.22; P=0.027). Circulating levels of EPCs are significantly lower in patients with angiographic CAD progression.