Progenitor cell therapy of ischemic heart disease: the new frontier

The discovery of circulating cells capable of differentiating into vascular structures (endothelial progenitor cells) has both altered our understanding of the pathophysiology of atherosclerosis and offered the possibility of using nature's reparative mechanisms to accelerate vascular restoration and regeneration. Epidemiologic studies indicate a correlation between cardiac risk factors, the presence of coronary disease and the numbers and function of endothelial progenitor cells. Preclinical animal models have demonstrated the therapeutic potential of cellular therapies for repair of ischemic myocardial damage. Several human trials investigating either the use of progenitor cells derived from bone marrow or peripheral blood, or pharmacologic therapies aimed at increasing mobilization of such cells for the treatment of ischemic heart disease, are currently underway. Some basic tenets of progenitor cell biology, key preclinical results suggesting the utility of this therapy, and the strengths and limitations of current human trials are briefly summarized, and the role of cellular therapies, today and in the future, are explored.