The renin angiotensin system and endothelial dysfunction in chronic heart failure: role of endogenous fibrinolysis

Regulation of vascular tone by the endothelium is abnormal in patients with heart failure and contributes to the characteristic peripheral vasoconstriction and increased afterload. This endothelial dysfunction is mediated through several endothelium-derived factors, including nitric oxide; there is an important interplay between the endothelium and the renin angiotensin system. The benefits of ACE inhibition in heart failure relate, in part, to a reduction in ischemic events which may be mediated by improvements in endothelial function and the endothelium derived fibrinolytic parameters: tissue plasminogen activator (t-PA) and its inhibitor, plasminogen activator inhibitor type 1 (PAI-1). In addition to potential improvements in the regulation of vasomotion, ACE inhibitor therapy may increase bradykinin induced t-PA release and/or reduce angiotensin II mediated PAI-1 release. Recent evidence suggests that both angiotensin II type 1 receptor (AT(1)) antagonism and ACE inhibition improve basal fibrinolytic parameters in patients with heart failure which may facilitate the acute endogenous fibrinolytic response. 1999 by CHF, Inc.