Evaluation of Outcomes of EES Implantation for Unprotected Left Main Coronary Artery Stenosis (PRE-COMBAT 2)

Inclusion Criteria: 1. The patient must be at least 18 years of age. 2. Significant de novo left main stenosis (\>50% by visual estimation) with or without any additional target lesions (\>70% by visual estimation) 3. Left main lesion and lesions outside LMCA (if present) potentially equally treatable with coronary stenting and CABG 4. Patients with stable (CCS class 1 to 4) or acute coronary syndromes (unstable angina pectoris Braunwald class IB, IC, IIB, IIC, IIIB, IIIC or NSTEMI) or patients with atypical chest pain or without symptoms but having documented myocardial ischemia 5. The patient or guardian agrees to the study protocol and the schedule of clinical and angiographic follow-up, and provides informed, written consent, as approved by the appropriate Institutional Review Board/Ethical Committee of the respective clinical site. Exclusion Criteria: 1. The patient has a known hypersensitivity or contraindication to any of the following medications: * Heparin * Aspirin * Both Clopidogrel and TIclopidine * Everolimus, paclitaxel, ABT 578 * Stainless steel and/or * Contrast media (patients with documented sensitivity to contrast which can be effectively pre-medicated with steroids and diphenhydramine \[e.g. rash\] may be enrolled. Patients with true anaphylaxis to prior contrast media, however, should not be enrolled). 2. Systemic (intravenous) Everolimus, paclitaxel or ABT-578 use within 12 months. 3. Any previous PCI within 1 year 4. Previous bypass surgery 5. Any previous PCI of a LMCA or ostial left circumflex artery or ostial left anterior descending artery lesion within 1 year 6. Intention to treat more than one totally occluded major epicardial vessel 7. Acute MI patients within 1 week 8. Patients with EF\<30%. 9. Patients with cardiogenic shock 10. Any disabled stroke with neurological deficit or any cerebrovascular accident within 6 months 11. Creatinine level 2.0mg/dL or dependence on dialysis. 12. Severe hepatic dysfunction (AST and ALT 3 times upper normal reference values). 13. Gastrointestinal or genitourinary bleeding within the prior 3 months, or major surgery within 2 months. 14. History of bleeding diathesis or known coagulopathy (including heparin-induced thrombocytopenia), or will refuse blood transfusions. 15. Current known current platelet count \<100,000 cells/mm3 or Hgb \<10 g/dL. 16. An elective surgical procedure is planned that would necessitate interruption of thienopyridines during the first 1 year post enrollment. 17. Non-cardiac co-morbid conditions are present with life expectancy \<1 year or that may result in protocol non-compliance (per site investigator's medical judgment). 18. Patients who are actively participating in another drug or device investigational study, which have not completed the primary endpoint follow-up period. 19. Subject unable or unwilling to follow-up with visits required by protocol 20. Female of childbearing potential, unless a recent pregnancy test is negative, who possibly plan to become pregnant any time after enrollment into this study