Angiotensin Converting Enzyme Inhibitors in the Treatment of Cardiovascular Disease

The rationale for the use of angiotensin converting enzyme (ACE) inhibitors in the treatment of cardiovascular disease has changed with the course of time due to improved understanding of their mechanisms of action. Initially, hypertension and chronic heart failure (CHF) became major therapeutic targets for ACE inhibitors. The first rationale behind the use of ACE inhibitors in the treatment of heart failure was to improve left ventricular systolic function by reducing cardiac preload and afterload. But the poor correlations, found in studies, between the hemodynamic measurements and the changes in clinical class, exercise tolerance, heart size and ejection fraction suggested that ACE inhibitors can provide clinical benefit for some mechanisms other than to reduce systemic vascular resistance. Studies on experimental model myocardial infarction (MI) have shown that early administration of ACE inhibitors may limit infarct expansion and attenuate progressive left ventricular dilata-tion following acute MI. Subsequently experimental observations have also been obtained with recent MI and significantly depressed left ventricular ejection fraction. Accordingly, in the 1980s, the rationale use of ACE inhibitors for CHF changed to attenuation of left ventricular remodelling. Interestingly, unexpected data from trials on heart failure have shown that patients receiving ACE inhibitors have a reduced incidence of MI, hospitalisation for cardiovascular events and need for coronary angioplasty or bypass surgery. These data gave way to the hypothesis that the beneficial effects of ACE inhibitors can be ex-plained with vasculoprotective effects. This hypothesis was tested successfully with the multicenter, double blind and randomised studies. The current rationale for using ACE inhibitors in patients with cardiovascular disease is the vasculoprotective (antiatherogenic, antiproliferative, antiinflammatory and antithrombotic) effect. (Türk Kardiyol Dern Arş 2004; 32: 188-196)