The aim of this prospective, open-label, randomized, single center study is to compare the effect of usual dose rosuvastatin plus ezetimibe and high-dose rosuvastatin on modifying atherosclerotic plaque.

High-intensity statin therapy have shown improved clinical outcomes compared to placebo or moderate-intensity statin therapy. Based on these results, 2013 American College of Cardiology/American Heart Association(ACC/AHA) guideline on treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk in adults recommended high-intensity statin therapy to patient with coronary artery disease for secondary prevention. However, high-intensity statin therapy was known to increase risk of diabetes mellitus and complication such as hepatotoxicity and myalgia. An alternative to high-intensity statin therapy is reducing the dose of statin and using drug that can improve blood cholesterol level by a different mechanism than statin. Ezetimibe acts on Niemann-Pick C1-like protein then inhibits cholesterol absorption in the intestine, which can reduce low-density lipoprotein(LDL) cholesterol more effectively when administered with statin. In IMPROVE-IT study, simvastatin plus ezetimibe decreased ischemic events more than simvastatin alone in patients with acute coronary syndrome. Although this study could confirm the additional effect of ezetimibe by using the same amount of simvastatin in both groups, it could not compare the effect of statin plus ezetimibe and high dose statin monotherapy. Moreover, there were few data on the efficacy of ezetimibe added to rosuvastatin which is one of the effective statin recommended by various guidelines. One study reported that rosuvastatin 2.5 mg plus ezetimibe 10 mg was superior to rosuvastatin 5 mg monotherapy in reducing LDL cholesterol. Another study reported that adding rosuvastatin 5 mg to ezetimibe 10 mg was more effective than rosuvastatin 5 mg alone in reducing coronary atherosclerotic lesions as measured by intravascular ultrasound. However, the previous studies did not compare the efficacy of combination therapy of usual dose rosuvastatin and ezetimibe to high-dose statin monotherapy. Therefore, investigators aimed to compare the effect of rosuvastatin 10 mg plus ezetimibe 10 mg to rosuvastatin 20 mg alone on the reduction of coronary atherosclerosis in patient with coronary artery disease. If this study shows that the combination of usual dose rosuvastatin and ezetimibe is not inferior to high dose rosuvastatin monotherapy in anti-atherosclerotic effect and safety, it would provide a basis for effective and safe cholesterol treatment.

Inclusion Criteria:

• Subject must be at least 19 years of age
• Subject with suspected ischemic heart disease undergoing coronary angiography and have intermediate coronary artery stenosis (30-70% by visual estimation) whose revascularization was deferred based on invasive physiologic assessment using fractional flow reserve (>0.80) or intravascular ultrasound (minimum lumen area> 4mm2)
• Subject can verbally confirm understandings of risks, benefits and treatment alternatives of receiving statin or ezetimibe and he/she or his/her legally authorized representative provides written informed consent prior to any study related procedure.

Exclusion Criteria:

• Subject has calculated creatinine clearance <30 mL/min or dialysis within 30 days.

• Subject has active liver disease or persistent unexplained serum transaminase elevations (x2 x upper limit of normal [ULN]).

• Subject requires the following concomitant medications: cyclosporine, danazol, niacin, fibrates as concomitant medications

• Subject requires any of the potent CYP3A4 inhibitors, itraconazole, ketoconazole, erythromycin, clarithromycin, and telithromycin, HIV protease inhibitors, nefazodone, probucol, resins, and any investigational drugs.

• Subject has an allergy/sensitivity to any statin, ezetimibe, and/or their excipients.

• Subject with history of myopathy or family history of myopathy

• Untreated hypothyroidism

• Subject has a history of alcohol and/or drug abuse.

• Subject is a pregnant or lactating woman, or woman intending to become pregnant.

• Non-cardiac co-morbid conditions are present with life expectancy <2 year or that may result in protocol non-compliance (per site investigator's medical judgment).

• Unwillingness or inability to comply with the procedures described in this protocol.

  • Eligible patients will be randomly assigned to treatment arms, stratified by diagnosis on admission(acute coronary syndrome or stable ischemic heart disease) and presence of chronic statin use (more than one month)

After publication of first manuscript and trial results, the de-identified data will be shared by permission of principle investigator, when asked.

The obtained intravascular ultrasound(IVUS) data will be stored through the storage device in the core lab of Heart Center of Heart Vascular Stroke Institute in Samsung Medical Center, and the treatment group to which the patient belongs would not be known. Subsequent baseline and follow-up IVUS data will be analyzed together by independent experts without knowledge of the patient's treatment group.