The Number of Endothelial Progenitor Cell Colonies in the Blood Is Increased in Patients With Angiographically Significant Coronary Artery Disease

OBJECTIVES: The objective of this study was to determine whether the number of endothelial progenitor cells (EPCs) and circulating angiogenic cells (CACs) in peripheral blood was associated with the presence and severity of coronary artery disease (CAD) in patients undergoing coronary angiography. BACKGROUND: Previous studies have suggested an inverse relationship between levels of circulating EPCs/CACs and the presence of CAD or cardiovascular risk factors, whereas other studies have observed increased numbers of EPCs in the setting of acute ischemia. However, the criteria used to identify specific angiogenic cell subpopulations and methods of evaluating CAD varied in these studies. In the present study, we used rigorous criteria to identify EPCs and CACs in the blood of patients undergoing coronary angiography. METHODS: The number of EPCs and CACs were measured in the blood of 48 patients undergoing coronary angiography. Patients with acute coronary syndromes were excluded. RESULTS: Compared with patients without angiographically significant CAD, the number of EPCs was increased (1.11 +/- 2.50 vs. 4.01 +/- 3.70 colonies/well, p = 0.004) and the number of CACs trended higher (175 +/- 137 vs. 250 +/- 160 cells per mm(2), p = 0.09) among patients with significant CAD. The highest levels of EPCs were isolated from patients subsequently selected for revascularization (5.03 +/- 4.10 colonies/well). CONCLUSIONS: In patients referred for coronary angiography, higher numbers of EPCs, and a trend toward higher numbers of CACs, were associated with the presence of significant CAD, and EPC number correlated with maximum angiographic stenosis severity. Endothelial progenitor cell levels were highest in patients with CAD selected for revascularization.