Endothelial Progenitor Cells in Coronary Artery Disease: The 5-Year Experience at a Single Center

Endothelial progenitor cells (EPCs) are a heterologous population of bone marrow-derived cells that play a key role in maintaining homeostasis of the endothelium, as they home to areas of endothelial injury, replace damaged endothelium, and participate in neovascularisation. The relationship between EPCs number and the severity of atherosclerosis is still a matter of debate. Abnormalities in EPCs have been associated with coronary artery disease, as experimental investigations have shown that a decrease in the endogenous pool of EPCs may accelerate the course of atherosclerosis, and the number of EPCs has been reported to be reduced in patients with atherosclerosis and in apparently healthy subjects without overt disease. On the opposite, other studies have found that the number of EPCs in the blood is increased in patients with angiographically significant coronary artery disease. The potential exists that EPCs constitute a therapeutic target, because persistent stimulation of EPCs by pharmacological intervention may, at least theoretically, repair endothelial injury and prevent the progression of atherosclerosis in patients at risk. Indeed, experimental and clinical studies have revealed that the number of EPCs can be increased by several pharmacological interventions such as hormones, statins, recombinant human EPO, and blockage of the angiotensin converting enzyme system. This review addresses the clinical correlates and prognostic significance of EPCs in a large cohort of patients with coronary artery disease that has been evaluated at a single Academic center in Italy.