Focal In-stent Restenosis After Drug-Eluting Stent

Inclusion Criteria: 1. The patient must be at least 18 years of age. 2. Restenosis after drug-eluting stents (\>50% by visual estimate) 3. Lesion length \< 10 mm (focal ISR) 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, amenable to stent-assisted percutaneous coronary intervention 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 * Sirolimus eluting stent * 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) Sirolimus use within 12 months. 3. Female of childbearing potential, unless a recent pregnancy test is negative, who possibly plan to become pregnant any time after enrollment into this study. 4. History of bleeding diathesis or known coagulopathy (including heparin-induced thrombocytopenia), or will refuse blood transfusions. 5. Gastrointestinal or genitourinary bleeding within the prior 3 months, or major surgery within 2 months. 6. Current known current platelet count \<100,000 cells/mm3 or Hgb \<10 g/dL. 7. 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). 8. Patients who are actively participating in another drug or device investigational study, which have not completed the primary endpoint follow-up period. 9. Patients with EF\<30%. 10. Acute MI patients within symptom onset \< 12 hours needing primary angioplasty 11. Creatinine level 3.0mg/dL or dependence on dialysis. 12. Severe hepatic dysfunction (AST and ALT 3 times upper normal reference values). 13. Patients with left main stem stenosis and left main in-stent restenosis created by DES(\>50% by visual estimate)