Coronary artery disease, the leading cause of morbidity and mortality, is a continuum of events that can lead to end stage heart disease . Common to the pathogenesis of most cardiovascular diseases are the processes, called risk factors for atherosclerotic coronary artery disease, that cause pathologic change and dysfunction in the blood vessels and lead to damage of the heart. The central role played in circulatory homeostasis is by the cells that line the vascular system the endothelium. Originally considered an inert diffusional barrier between blood and vascular smooth muscle, it is now known that the endothelium has many important functions. Probably the most significant advance in cardiovascular medicine over the last two decades has been the identification of endothelial cells as a vasoactive organ. After the pioneering report 2 by the 1998 Nobel Prize winner Robert Furchgott, an impressive array of evidence has made it possible to state today that the endothelium plays a primary autocrine/paracrine regulatory role by secreting substances that control both vascular tone and structure. Moreover, accumulating evidence has indicated that the dysfunctioning endothelium, characteristic for the majority of cardiovascular risk factors, is a major promoter of atherothrombosis and, consequently, cardiovascular events. That’s why endothelial dysfunction is now considered an important target for cardiovascular treatment.