Specific Aim 1 To identify a patient population seen in the University of California, San Diego general internal medicine and cardiology subspecialty clinics as well as referrals from community physicians who are hyporesponsive to statin therapy (defined as an initial LDL reduction of <25% in response to 10mg of atorvastatin or 20mg of simvastatin- expected mean reduction is 35% -37% for starting dose simvastatin and atorvastatin).~Specific Aim 2 To test the hypothesis, with a prospective study, that a hyporesponse to statin therapy may be related to increased cholesterol absorption, and that this hyporesponse may be overcome by the addition of ezetimibe, a specific cholesterol absorption inhibitor.~Specific Aim 3 To evaluate whether patients with less than 25% LDL reduction on 10 mg of atorvastatin (or 20 mg of simvastatin) would achieve significantly greater LDL reduction with combination therapy (atorvastatin/ezetimibe) than with statin dose titration (using atorvastatin).
Response to statin therapy for elevated low density lipoprotein is variable and may be influenced by cholesterol absorption. This study will evaluate whether combination therapy with atorvastatin/ezetimibe will be superior to atorvastatin alone in subjects who have less than 25% LDL reduction on starting dose statin (eg, atorvastatin 10 mg daily or simvastatin 20 mg daily).