Endothelial dysfunction: implications for therapy of cardiovascular diseases

OBJECTIVE: To review current literature regarding endothelial dysfunction in cardiovascular diseases and examine implications of these findings for the treatment of various cardiovascular disorders. DATA SOURCE: A MEDLINE search of basic science articles pertinent to understanding the role of the endothelium in the atherosclerotic process and of clinical trials examining the presence and treatment of impaired endothelium-dependent vascular relaxation was conducted. STUDY SELECTION: Selected basic science articles and reviews were included to explain the foundation for subsequent clinical trials. All clinical trials examining the treatment of impaired endothelium-dependent vascular relaxation were reviewed. DATA SYNTHESIS: Endothelial dysfunction characterized by impaired endothelium-dependent vascular relaxation is an early physiologic event in atherogenesis. Endothelial dysfunction in peripheral vasculature serves as a marker for impairment in coronary arteries. Techniques for measuring endothelium-dependent vascular relaxation are specific and have a high positive predictive value for coronary artery disease, but low sensitivity. Various pharmacologic agents have been used in an attempt to improve endothelial function, but only lipid-lowering agents and estrogen supplementation have been shown to improve endothelium-dependent vascular relaxation consistently. Treatments used in patients with heart failure or hypertension fail to demonstrate consistent improvement. CONCLUSIONS: Endothelial dysfunction serves as a marker for cardiovascular disease, but pharmacologic treatment does not consistently restore normal endothelial function. Nevertheless, some of these agents are known to have positive clinical outcomes. Future research using these techniques will provide greater insight into the effects of many commonly used therapies for cardiovascular disease on the pathobiology of endothelial dysfunction.