1. Stains have demonstrated consistent benefits to reduce cardiovascular events in several primary and secondary prevention trials. The suppression of plaque progression or regression may be a part of mechanism of clinical benefit. The intravascular ultrasound studies demonstrated that intensive statin therapy can regress or inhibit the progression of coronary atherosclerosis.
2. Unregulated renin-angiotensin system is important in the pathogenesis of cardiovascular disease. Angiotensin receptor antagonists (ARB) have been reported to improve clinical outcomes in patients with heart failure, left ventricular dysfunction, myocardial infarction, and high-risk patients. Several small studies showed that ARBs were effective to inhibit the progression of coronary atherosclerosis by intravascular ultrasound examination.
3. The combined therapy with statins and ARBs may be additive or synergistic effects on the atherosclerosis regression as well as to improve endothelial dysfunction and insulin resistance in addition to lowering cholesterol levels and blood pressure when compared with either monotherapy in patients.
4. Serial computed tomography angiography (CTA) can be utilized to assess the effect of treatment on coronary plaque morphology. In addition to the assessment of luminal stenosis, CTA also allows characterization of plaque morphology.

Inclusion Criteria:

1. Subjects must be at 19 years~70 years of age
2. Patients undergoing coronary CTA with coronary artery stenosis 30~70%
3. Informed consent
4. Appropriate CT resolution enough to measure of plaque volume
5. Patients who are stain and renin-angiotensin system blocker naïve at least for 1 year

Exclusion Criteria:

1. Patients with>=70% luminal stenosis or requiring percutaneous coronary intervention(PCI)
2. Severely calcifiedcoronary artery
3. Patients who have a history of previous PCI or coronary artery bypass grafting surgery.