Angiotensin-converting enzyme inhibition to enhance vascular health-clinical and research models

Protection of the endothelium, the metabolically active inner lining of the vasculature, appears to be a key factor in maintaining cardiovascular (CV) health. The endothelium responds to hemodynamic and hormonal factors by se creting substances that maintain vascular homeostasis. Damage to the endoth elium is an initial step in the development of CV disease. Angiotensin-conv erting enzyme (ACE) inhibitors, which block the formation of the vasoconstr icting substance, angiotensin II, have proved to be a key therapy for hyper tension and congestive heart failure. The activity of these agents in enhan cing vascular health appears to be a critical factor in their therapeutic e ffectiveness. Large-scale clinical trials over the past decade have shown t hat ACE inhibition is an effective therapeutic means of not only prolonging survival and reducing morbidity after acute myocardial infarction, but als o reducing all-cause mortality and morbidity in patients at high risk for C V disease, including patients with diabetes. ACE is found in far greater am ounts in tissue than in plasma. Studies indicate that ACE inhibitors act at the tissue level to provide long-term cardioprotective effects that includ e a reduction in the progression of atherosclerosis. An issue to resolve is how much ACE inhibition is needed at the tissue level to reverse or preven t further vascular damage. (C) 2001 American Journal of Hypertension, Ltd.