Effects of monotherapy with an HMG-CoA reductase inhibitor on the progression of coronary atherosclerosis as assessed by serial quantitative arteriography. The Canadian Coronary Atherosclerosis Intervention Trial.

BACKGROUND: 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors are widely prescribed for hyperlipidemia, yet their effect on the evolution of coronary atherosclerosis has not been defined. METHODS AND RESULTS: To address this issue, 331 patients with diffuse but not necessarily severe coronary atherosclerosis documented on a recent arteriogram and with fasting serum cholesterol between 220 and 300 mg/dL were enrolled in a randomized, double-blind, placebo-controlled trial. All patients received intensive dietary counseling. Lovastatin or placebo was begun at 20 mg/d and was titrated to 40 and 80 mg during the first 16 weeks to attain a fasting low-density lipoprotein (LDL) cholesterol or = 0.4 mm) with no regression at other sites occurred in 48 of 146 lovastatin and 76 of 153 placebo patients (33% versus 50%, P = .003). New coronary lesions developed in 23 lovastatin and 49 placebo patients (P = .001). The beneficial effect of treatment was most pronounced in the more numerous, milder lesions and in patients whose baseline total or LDL cholesterol levels were above the group median. CONCLUSIONS: Lovastatin slows the progression of coronary atherosclerosis and inhibits the development of new coronary lesions.