Effects of angiotensin converting enzyme inhibition on neointimal proliferation in a porcine coronary injury model

To assess the effectiveness of angiotensin converting enzyme inhibition in a proliferative porcine coronary restenosis model, 35 animals received orally administered trandolapril (10 mg) or captopril (200 mg) or no drug (control group) for 6 days before and 28 days after injury by oversized metallic coils in one or more coronary arteries. Twenty arterial lesions in the trandolapril group, 17 in the captopril group, and 18 in the control group were evaluated. There was no significant difference in neointimal thickness or percentage luminal area stenosis for the groups as a whole. However, in quantitative comparisons in which vessel injury score was used as a covariate, the fractional increase in mean neointimal thickness per unit of injury was significantly less for the trandolapril group (p = 0.019) but not for the captopril group when compared with control animals. In this model, neointimal proliferation from arterial injury was inhibited by angiotensin converting enzyme inhibition with trandolapril but only modestly. Such an effect may not be clinically significant.