Objective To evaluate the benefit of niacin in addition to statin therapy on plaque regression among older individuals with established atherosclerosis.

Design Randomised, controlled, double-blind clinical trial.

Setting University outpatient center.

Patients 145 patients older than 65 years, half of them older than 75 years of age, with established atherosclerosis were enrolled.

Interventions Participants received either extended release niacin (1500 mg daily) or placebo in addition to statin therapy to reach their National Cholesterol Education Program-defined low density lipoprotein (LDL) cholesterol target.

Main Outcome Measures The primary endpoint was reduction in the wall volume of the internal carotid artery (ICA) measured by MRI.

Results After 18 months, high density lipoprotein cholesterol was higher with statins plus niacin compared with statins alone (1.6±0.4 vs 1.4±0.4 mmol/L p<0.001). Both groups had significant decreases in the main outcome measure of ICA wall volume, which regressed at 0.5%/month (SEM 0.2, p=0.004) in the statins plus placebo group and at 0.7%/month in the statins plus niacin group (SEM 0.2, p<0.001). There was no difference in the rate of regression between groups (p=0.49).

Conclusions Treatment with statin therapy to presently recommended LDL levels, with or without niacin, resulted in significant atherosclerosis reduction.