Clinical Research Directory

Inclusion Criteria: 1. Clinical 1) Patients with angina or silent ischemia and documented ischemia 2) Patients who are eligible for intracoronary stenting 3) Age \>18 years 2. Angiographic 1) De novo lesion Chronic Total Occlusion (CTO) 2) Reference vessel size ≥ 2.5 mm by visual estimation 3) At least one CTO lesions located in proximal or mid epicardial coronary artery. (If the patient has two CTO lesions, one CTO lesion should be located in proximal or mid epicardial coronary artery) 3. CTO definition: TIMI (Thrombolysis in Myocardial Infarction) flow 0 or 1 with estimated duration over 3 months * The duration of the occlusion was determined by the interval from the last episode of acute coronary syndrome, or * In patients without a history of acute coronary syndrome, from the first episode of effort angina consistent with the location of the occlusion 1. Angiographically defined total occlusion over 3 months 2. If no definite symptom with total occlusion, two experienced operators decide CTO in consideration of angiographical morphology (degree of calcification, bridging collaterals, non-tapered stump, angiographic filling from collaterals) Exclusion Criteria: 1. History of bleeding diathesis or coagulopathy 2. Pregnant state 3. Three vessel CTOs 4. Known hypersensitivity or contra-indication to contrast agent and heparin 5. ST-elevation acute myocardial infarction requiring primary stenting 6. Culprit total occlusion presented with acute coronary syndrome suggesting acute or recent occlusion 7. Characteristics of lesion 1) Left main disease 2) In-stent restenosis 3) Graft vessels 4) Distal epicardial coronary artery CTO lesions 5) Two vessel proximal segment CTOs 8. Hematological disease (Neutropenia \<3000/mm3, Thrombocytopenia \<100,000/mm3) 9. Hepatic dysfunction, liver enzyme (ALT and AST) elevation ≥ 3 times normal 10. Renal dysfunction, creatinine ≥ 2.0mg/dL 11. Contraindication to aspirin, clopidogrel or other commercial antiplatelet agent 12. Left ventricular ejection fraction \<30% 13. Patients who are actively participating in another drug or device investigational study, which have not completed the primary endpoint follow-up period. 14. Non-cardiac co-morbid conditions are present with limited life expectancy or that may result in protocol non-compliance (per site investigator's medical judgment).