An 82-year-old male patient who had a history of ischemic heart disease (IHD) and Debranching Thoracic Endovascular Aortic Repair (TEVAR) (right axillary artery-left axillary artery-left common carotid artery) was admitted to our hospital due to sudden chest pain. The diagnosis revealed acute coronary syndrome: 2-vessel lesions, including the left main trunk (LMT) (right coronary artery (RCA) #2 75%, #3 90%, LMT #5 50%, and left anterior descending (LAD) branch #7 75%). Plain Old Balloon Angioplasty (POBA) was performed on the responsible lesion, RCA (#2-3). Off-pump Coronary Artery Bypass Grafting (OPCAB) was initially planned for the remaining lesion. However, cardiogenic shock occurred, and an emergency OPCAB (SVG-LAD, SVG-#4PD) was performed via partial sternotomy (inverted L-shaped incision on the left side), using intra-aortic balloon pumping (IABP). The patient underwent revascularization using great saphenous vein grafts due to the potential for postoperative pleuroperitoneal communication in patients undergoing peritoneal dialysis, as well as the risk of impaired internal thoracic artery (ITA) flow caused by debranching in future involving internal shunts for dialysis. It is important to consider not only the graft but also the thoracotomy, taking into account the perspectives of early weaning and the prevention of perioperative complications.