J Am Coll Cardiol. 2000 Aug;36(2):438-43. MacMahon S， Sharpe N， Gamble G， Clague A， Mhurchu CN， Clark T， Hart H， Scott J， White H. Institute for International Health and Department of Medicine， University of Sydney， NSW， Australia.

OBJECTIVES: The primary objective of this study was to investigate the effects of the angiotensin-converting enzyme (ACE) inhibitor， ramipril， on carotid atherosclerosis in patients with coronary， cerebrovascular or peripheral vascular disease.

BACKGROUND: Angiotensin-converting enzyme inhibitors have been shown to reduce the risk of coronary events in various patient groups and to prevent the development of atherosclerosis in animal models. It has been hypothesized that the clinical benefits of ACE inhibitors may， therefore， be mediated by effects on atherosclerosis. METHODS: Six hundred seventeen patients were randomized in equal proportions to ramipril (5-10 mg daily) or placebo. At baseline， two years and four years， carotid atherosclerosis was assessed by B-mode ultrasound， and left ventricular mass was assessed by M-mode echocardiography.

RESULTS: Blood pressure (BP) was reduced by a mean of 6 mm Hg systolic and 4 mm Hg diastolic in the ramipril group compared with the placebo group (p<0.001). There was no difference between groups in the changes in common carotid artery wall thickness (p = 0.58) or in carotid plaque (p = 0.93). Left ventricular mass index decreased by 3.8 g/m2 (4%) in the ramipril group compared with the placebo group (2p = 0.04).

CONCLUSIONS: The results provide no support for the hypothesis that reduced atherosclerosis is responsible for the beneficial effects of ACE inhibitors on major coronary events. It is more likely that the benefits are due to lower BP， reduced left ventricular mass or other factors such as reversal of endothelial dysfunction.