Beneficial Effects of Combined Colestipol-Niacin Therapy on Coronary Atherosclerosis and Coronary Venous Bypass Grafts

TLDR

The CLAS trial randomized 162 nonsmoking men aged 40–59 with prior coronary bypass surgery to receive combined colestipol hydrochloride and niacin versus placebo in a two‑year, angiographic, placebo‑controlled study. Combined colestipol‑niacin therapy lowered total cholesterol by 26%, LDL by 43%, raised HDL by 37%, and significantly reduced lesion progression, new atheroma, graft deterioration, and overall coronary deterioration, with 16.2% of treated patients showing atherosclerosis regression versus 2.4% of placebo. Published in JAMA 1987;257:3233‑3240.

Abstract

The Cholesterol-Lowering Atherosclerosis Study (CLAS) was a randomized, placebo-controlled, angiographic trial testing combined colestipol hydrochloride and niacin therapy in 162 nonsmoking men aged 40 to 59 years with previous coronary bypass surgery. During two years of treatment there was a 26% reduction in total plasma cholesterol, a 43% reduction in low-density lipoprotein cholesterol, plus a simultaneous 37% elevation of high-density lipoprotein cholesterol. This resulted in a significant reduction in the average number of lesions per subject that progressed (<i>P</i>&lt;.03) and the percentage of subjects with new atheroma formation (<i>P</i>&lt;.03) in native coronary arteries. Also, the percentage of subjects with new lesions (<i>P</i>&lt;.04) or any adverse change in bypass grafts (<i>P</i>&lt;.03) was significantly reduced. Deterioration in overall coronary status was significantly less in drug-treated subjects than placebo-treated subjects (<i>P</i>&lt;.001). Atherosclerosis regression, as indicated by perceptible improvement in overall coronary status, occurred in 16.2% of colestipol-niacin treated vs 2.4% placebo treated (<i>P</i>=.002). (<i>JAMA</i>1987;257:3233-3240)