ramipril and Arterial-Occlusive-Diseases

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.. 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.. 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.. 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).. 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.

Topics: Angiotensin-Converting Enzyme Inhibitors; Arterial Occlusive Diseases; Carotid Artery Diseases; Carotid Artery, Common; Coronary Disease; Double-Blind Method; Female; Humans; Male; Middle Aged; Ramipril

Several studies have demonstrated the effectiveness of angiotensin I-converting enzyme (ACE) inhibitors in preventing the neointima formation found after denudation of the rat carotid artery by balloon injury. The aim of the present study was to determine the role of ACE in this model and to compare the treatment with the ACE inhibitor ramiprilat with that with the angiotensin II antagonist HR 720. The endothelial layer of the left carotid artery was removed using an inflated balloon catheter. Injured and control vessels were both submitted to histomorphological analysis and DNA content quantification at 2, 4, 6, 8, 12, and 14 days after injury. Evaluation of neointima thickening demonstrated a slow but steady increase of neointima that was significant after day 6 and reached 30% of the lumen in 2 weeks. This was paralleled by an increase in DNA content, which was significant 4 days after injury. ACE mRNA levels were quantified by polymerase chain reaction after reverse transcription. Measurement of ACE mRNA levels revealed a significant upregulation 2 and 8 days after injury, with no significant difference when compared with control tissue at later time points. ACE activity was also significantly enhanced at 2 and 8 days after injury, with no significant difference when compared with control tissue at later time points. In addition, the treatment with ramiprilat was more efficient in reducing neointima formation than that with HR 720. These data underlie the role of ACE in this model of restenosis. The early induction of ACE expression after endothelial injury but before significant changes in the vessel structure suggests that ACE activity might be one of the mechanisms that trigger neointima formation in the rat.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Arterial Occlusive Diseases; Biphenyl Compounds; Carotid Arteries; Carotid Artery Injuries; Catheterization; DNA; Enzyme Induction; Imidazoles; Male; Peptidyl-Dipeptidase A; Polymerase Chain Reaction; Ramipril; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tunica Intima; Wounds, Nonpenetrating