Pravastatin, Lipids, and Atherosclerosis in the Carotid Arteries (PLAC-II)

The Pravastatin, Lipids, and Atherosclerosis in the Carotid Arteries trial (PLAC-II) was initiated in 1987 and was the first double-blind, randomized clinical trial with progression of early extracranial carotid atherosclerosis as an outcome variable. We randomized 151 coronary patients to placebo or pravastatin and treated them for 3 years. B-mode ultrasound quantification of carotid artery intimal-medial thickness (IMT) was obtained at baseline and sequentially during this period. The primary outcome was the change in the mean of the maximum IMT measurements over time. Effects on individual carotid artery segments (common, bifurcation, internal carotid artery) and on clinical events were also investigated. During follow-up, plasma concentrations of total cholesterol were lower in pravastatin-treated patients compared with those of placebo-treated patients (4.81 vs 6.08 mmol/liter [186 vs 235 mg/dl]) as were concentrations of low density lipoprotein (LDL) cholesterol (3.10 vs 4.29 mmol/liter [120 vs 167 mg/dl]). Plasma concentrations of high density lipoprotein2 (HDL2) cholesterol were higher in pravastatin-treated patients than in placebo-treated patients (0.16 vs 0.14 mmol/liter [6.1 vs 5.5 mg/dl]). Active treatment resulted in a nonsignificant 12% reduction in progression of the mean-maximum IMT (from 0.068 mm/yr placebo to 0.059 mm/yr pravastatin) and a statistically significant 35% reduction in IMT progression in the common carotid (p = 0.03). Active treatment was also associated with a 60% reduction of nonfatal myocardial infarction plus death caused by coronary artery disease (p = 0.09), a 61% reduction of any fatal event plus any nonfatal myocardial infarction (p = 0.04), and an 80% reduction of fatal plus any nonfatal myocardial infarction (p = 0.03).