Long-term effects of cholesterol lowering and angiotensin-converting enzyme inhibition on coronary atherosclerosis - The Simvastatin/Enalapril Coronary Atherosclerosis Trial (SCAT)

Background-This long-term, multicenter, randomized, double-blind, placebo-c ontrolled, 2X2 factorial, angiographic trial evaluated the effects of chole sterol lowering and angiotensin-converting enzyme inhibition on coronary at herosclerosis in normocholesterolemic patients. Methods and Results-There were a total of 460 patients: 230 received simvas tatin and 230, a simvastatin placebo, and 229 received enalapril and 231, a n enalapril placebo (some subjects received both drugs and some received a double placebo). Mean baseline measurements were as follows: cholesterol le vel, 5.20 mmol/L; triglyceride level, 1.82 mmol/L; HDL, 0.99 mmol/L; and LD L, 3.36 mmol/L. Average follow-up was 47.8 months. Changes in quantitative coronary angiographic measures between simvastatin and placebo, respectivel y, were as follows: mean diameters, -0.07 versus -0.14 mm (P=0.004); minimu m diameters, -0.09 versus -0.16 mm (P=0.0001); and percent diameter stenosi s, 1.67% versus 3.83% (P=0.0003). These benefits were not observed in patie nts on enalapril when compared with placebo. No additional benefits were se en in the group receiving both drugs. Simvastatin patients had less need fo r percutaneous transluminal coronary angioplasty (8 versus 21 events; P=0.0 20), and fewer enalapril patients experienced the combined end point of dea th/myocardial infarction/stroke (16 versus 30; P=0.043) than their respecti ve placebo patients. Conclusions-This trial extends the observation of the beneficial angiograph ic effects of lipid-lowering therapy to normocholesterolemic patients. The implications of the neutral angiographic effects of angiotensin-converting enzyme inhibition are uncertain, but they deserve further investigation in light of the positive clinical benefits suggested here and seen elsewhere.