ARBITER: Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol: a randomized trial comparing the effects of atorvastatin and pravastatin on carotid intima medial thickness.

Background: Whether marked LDL reduction to levels well below 100 mg/dL would further reduce the burden of cardiovascular disease is controversial. We compared the effects of 2 statins with widely differing potencies for LDL reduction (pravastatin 40 mg/d and atorvastatin 80 mg/d) on carotid intima-media thickness (CIMT).

Methods And Results: This was a single-center, randomized, clinical trial of 161 patients (mean age, 60 years; 71.4% male; 46% with known cardiovascular disease) that met National Cholesterol Education Program (NCEP) II criteria for lipid-lowering therapy. The effects of atorvastatin (80 mg/d; n=79) and pravastatin (40 mg/d; n=82) on CIMT were compared using blinded, serial assessments of the far wall of the distal common carotid artery. Baseline CIMT and other characteristics were similar between study groups. As anticipated, atorvastatin was substantially more potent for LDL reduction after 12 months: in the atorvastatin group, LDL cholesterol was 76+/-23 mg/dL after 12 months (-48.5%); LDL cholesterol was 110+/-30 mg/dL in the pravastatin group (-27.2%; P<0.001). Atorvastatin induced progressive CIMT regression over 12 months (change in CIMT, -0.034+/-0.021 mm), whereas CIMT was stable in the pravastatin group (change of 0.025+/- 0.017 mm; P=0.03).

Conclusions: Marked LDL reduction (<100 mg/dL) with a high-potency statin provides superior efficacy for atherosclerosis regression at 1 year. This early effect on CIMT, a surrogate for clinical benefit, suggests that marked LDL reduction with synthetic statins may provide enhanced reduction in clinical coronary event rates.