The purpose of ARBITER 6 - HALTS is to compare HDL and LDL-focused strategies of lipid treatments for their effects of atherosclerosis. This study is a prospective, randomized, open-label, blinded endpoint trial comparing treatment strategies of either HDL-raising therapies or LDL reduction for dyslipidemia on carotid atherosclerosis. Subjects with known atherosclerotic coronary or vascular disease or otherwise at high cardiovascular risk through the presence of a coronary risk equivalent who are currently being treated with a statin will be eligible. Subjects will be randomly assigned in an allocation-concealed fashion to open label treatment with either Ezetimibe 10 mg/d for additional LDL-lowering OR Extended-release niacin (1 gm/d, titrated to max tolerable dose up to 2 gm/d) for HDL improvement.