Pravastatin limitation of atherosclerosis in the coronary arteries (PLAC I): Reduction in atherosclerosis progression and clinical events

Objectives. This study was designed to evaluate the effect of pravastatin on progression of coronary atherosclerosis and ischemic events in patients with coronary artery disease and mild to moderate hyperlipidemia. Background. Few clinical trial dat support the use of lipid-lowering therapy in patients with coronary artery disease and mild to moderate elevations in cholesterol levels. Methods. Four hundred eight patients (mean age 57 years) with coronary artery disease and low density lipoprotein (LDL) cholesterol ≥130 mg/dl (3.36 mmol/liter) but <190 mg/dl ([4.91 mmol/liter]) despite diet were randomized in 3-year study to receive pravastatin or placebo. Atherosclerosis progression was evaluated by quantitative coronary arteriography. Results. Baseline mean LDL cholesterol was 164 mg/dl (4.24 mmol/liter). Pravastatin decreased total and LDL cholesterol and triglyceride levels by 19%, 28% and 8%, respectively, and increased high density lipoprotein cholesterol by 7% (p ≤ 0.001 vs. placebo for all lipid variables). Progression of atherosclerosis was reduced by 40% for minimal vessel diameter (p = 0.04), particularly in lesions <50% stenosis at baseline. There was consistent although not statistically significant effect on mean diameter and percent diameter stenosis. There were also fewer new lesions in those assigned pravastatin (p ≤ 0.03). Myocardial infarction was reduced during active treatment (8 in the pravastatin group, 17 in the placebo group; log-rank test, p ≤ 0.05; 60% risk reduction), with the benefit beginning to emerge after 1 year. Conclusions. In patients with coronary artery disease and mild to moderate cholesterol elevations, pravastatin reduces progression of coronary atherosclerosis and myocardial infarction. The time course of event reduction increases the potential for relatively rapid decrease in the clinical manifestations of coronary artery disease with lipid lowering.