Inclusion Criteria: 1. Patients aged ≥ 19 and ≤ 75 years 2. Patients in whom decrease of myocardial perfusion in coronary artery territories (rest perfusion - stress perfusion: ≥ 7%) was observed by myocardial SPECT 3. Patients judged to have possibly incomplete revascularization based on the observation of the coronary artery's internal diameter of ≤ 1 mm, diffuse atherosclerosis or severe calcification on coronary angiography, or patients judged to have some myocardial perfusion territories that could not be performed Coronary Artery Bypass Graft 4. Patients who or whose legal representative can write the informed consent before the initiation of the clinical study and comply with the requirements Exclusion Criteria: 1. Patients with progressive or present heart failure 2. Patients with uncontrolled ventricular arrhythmia on electrocardiogram, or who have been treated for ventricular arrhythmia 3. Patients with current or history of malignant tumor 4. Patients with severe infectious disease 5. Patients with uncontrolled hematologic disorders 6. Patients requiring surgery for the accompanying valve diseases or left ventricular volume reduction surgery 7. Patients with current or history of proliferative retinopathy 8. Patients with remaining life of less than 1 year and severe accompanying diseases enough to die during the clinical follow-up period 9. Patients with history of drug or alcohol abuse within the recent 3 months 10. Women who are pregnant or breast feeding or postmenopausal women of childbearing age. However, women who underwent surgical sterilization including hysterectomy or bilateral tubal ligation can participate in this clinical trial. Even though they consent to the contraception, they cannot be enrolled. 11. Patients in inappropriate condition judged by investigators 12. Patients with cerebrovascular diseases (cerebral infarction, cerebral bleeding or transient ischemic attack that are currently occurring or occurred within 6 months) 13. Patients with idiopathic hypertension who are not controlled with drugs 14. Patients with severe hepatic disorders 15. Patients with severe renal disorders 16. Patients who underwent Coronary Artery Bypass Graft 17. Patients who underwent angioplasty within 1 year before their enrollment in the study