Markers for progression of coronary disease

Endothelial cells play numerous physiologic roles including regulation of v ascular tone, regulation of hemostasis and fibrinolysis, regulation of infl ammatory processes, and maintenance of a permeability barrier to provide fo r exchange and active transport of substances into the artery wall. Pathoph ysiologic stimuli can result in localized alterations in endothelial activi ty. These changes include increased permeability to plasma lipoproteins, im balances in local thrombogenic substances causing a prothrombotic state, an d release of vasoactive compounds resulting in vaso constriction. Loss of e ndothelium-dependent vasodilatation is thought to be an early physiologic e vent in the development of arteriosclerosis, occurring before morphologic c hanges in the endothelium can be detected. Much of the effects of healthy e ndothelium appear to be produced by nitric oxide. Decreased bioavailability of nitric oxide results in endothelial dysfunction, which is the first ste p in the atherosclerotic process. Risk factor modification and pharmacologi c interventions that can reverse endothelial dysfunction have the potential to decrease cardiovascular events in patients at risk.