Effects of cigarette smoking on the angiographic evolution of coronary atherosclerosis - A Canadian Coronary Atherosclerosis Intervention Trial (CCAIT) substudy

Background Although smoking increases both the risk of developing coronary disease and the risk of coronary events in patients with known coronary atherosclerosis, the effect of smoking on the evolution of coronary atherosclerosis as assessed by serial angiography is poorly defined. Methods and Results Ninety smokers with coronary atherosclerosis shown on a recent angiogram and with fasting cholesterol levels between 220 and 300 mg/dL were enrolled in a randomized, double-blind, placebo-controlled trial of cholesterol-lowering therapy, along with 241 nonsmokers and ex-smokers. Lovastatin at a mean dose of 36 mg/d lowered total and LDL cholesterol by 21+/-11% and 29+/-11%, respectively, but these levels changed by <2% in placebo-treated patients. Coronary arteriography was repeated after 2 years in 72 smokers and their 557 lesions were measured blindly with an automated quantitative system, along with 1752 lesions in 227 nonsmokers. Coronary change score, the per-patient mean of the minimal lumen diameter changes for all qualifying lesions, worsened by 0.16+/-0.16 mm in smokers and by 0.07+/-0.15 mm in nonsmokers in the placebo group (P <.001). Lovastatin-treated smokers had less worsening (0.07+/-0.15 mm) than placebo-treated smokers (P=.024). One or more coronary lesions progressed in 16 of 34 lovastatin-treated smokers and in 28 of 38 placebo-treated smokers (47% versus 74%, P <.001). In the placebo group, new coronary lesions developed in 21 of 38 smokers and in 18 of 115 nonsmokers (55% versus 24%, P <.001); fewer lovastatin-treated smokers developed new lesions (15% versus 55%, P <.001). Conclusions Smoking accelerates coronary progression and new lesion formation as assessed by serial quantitative coronary arteriography. Lovastatin slows the progression of coronary atherosclerosis and prevents the development of new coronary lesions in smokers.