The purpose of the LDL-Apheresis Regression Study (LARS) group, which included 13 institutions in Japan, was to investigate the effects on coronary atherosclerosis of LDL-apheresis combined with cholesterol-lowering drugs. Changes in coronary artery stenosis were assessed angiographically in 37 patients with familial hypercholesterolemia (7 homozygotes and 25 heterozygotes) and hypercholesterolemia which had not been defined as familial hypercholesterolemia (5 patients) by visual judgement and computer analysis. Definite regression was observed in 14 cases, including 4 homozygotes and 10 heterozygotes and others. Regression occurred as often in patients with severe coronary artery disease (2 or more vessel disease) as in those having less severe disease. Our results encourage initiation of aggressive cholesterol-lowering therapy to produce regression of coronary atherosclerosis in FH patients at high risk for cardiovascular events.