Table 1 Patient Inclusion and Exclusion Criteria

   1. Male or female over 20 years of age

   2. Clinical indication for coronary angiography

   3. Presence of at least one significant coronary artery stenosis (>50%) requiring PCI with stent implantation and one intermediate lesion with luminal narrowing of ≥30% and <70% by visual estimation on native coronary arteries.

   4. Presence of at least one PCI target lesion (reference diameter 2.5~4 mm, lesion length ≤26 mm) with >50% diameter stenosis that can be covered with a single Zotrolimus-eluting stent (Endeavor Sprint, Medtronic Vascular Inc, Santa Rosa, CA).

   5. Able to understand and willing to provide written informed consent

Exclusion criteria

   1. Intermediate lesions that might provide difficulty for IVUS evaluation because of following reasons: heavy calcification (>90° Arc), tortuous vessel with severe angulation, total occlusion, or bifurcation lesions

   2. Previous PCI in the last 6 months

   3. Previous coronary artery bypass graft

   4. Patients with AMI undergoing primary PCI or rescue PCI after thrombolysis

   5. Cardiogenic shock

   6. Inability to take adequate antiplatelet therapy (aspirin and clopidogrel)

   7. Thrombocytopenia (platelet count <70 × 10⁹/l)

   8. Known hypersensitivity or contraindication to any of the following medications: Heparin, aspirin, clopidogrel, cilostazol, probucol, statin, contrast media

   9. History of severe ventricular arrhythmia

   10. Significant QTc prolongation (≥470 ms) on electrocardiogram

   11. Heart failure (New York Heart Association class III/IV) or left ventricular ejection fraction ≤35%

   12. Familial hypercholesterolemia

   13. Uncontrolled hypertriglyceridemia (>400 mg/dL)

   14. Chronic renal failure with serum creatinine level ≥2 mg/dL

   15. Severe liver disease or transaminase level ≥3 times the upper limit of normal.

   16. Pregnancy or women at age of childbearing potential