ObjectiveTo compare clinical outcomes between coronary artery bypass grafting (CABG)and off-pump coronary artery bypass grafting (OPCAB)for high-risk coronary artery disease (CAD)patients with high European System for Cardiac Operative Risk Evaluation (EuroSCORE). MethodsA total of 211 CAD patients undergoing surgical treatment in the Department of Cardiovascular Surgery, Anhui Provincial Hospital Affiliated to Anhui Medical University from June 2007 to July 2013 were enrolled into this study, including 52 patients receiving CABG and 159 patients receiving OPCAB. Predicted risk of operative mortality (PROM)of each patient was calculated by EuroSCORE. Patients with PROM≥6 were stratified into high-risk subgroups. Clinical outcomes were compared between CABG and OPCAB patients, as well as incidence of cardiovascular events, angina and stroke within 30 postoperative days in high-risk subgroup patients. ResultsOPCAB and CABG group patients had similar left main disease. There was no statistical difference in the number of distal anastomosis between OPCAB (2.75±0.82)and CABG group patients (2.83±0.58) (P > 0.05). Operation time[ (3.92±0.79)hour vs. (6.83±1.53)hour], thoracic drainage[ (983.14±802.39)ml vs. (1 620.40±879.32)ml], blood transfusion[ (1 289.30±668.08)ml vs. (2 325.30±491.98)ml], length of ICU stay[ (3.90±1.33)days vs. (5.08±1.78)days], and mechanical ventilation time[ (9.63±3.32)h vs. (13.76±3.79)h] of OPCAB group patients were significantly shorter or lower than those of CABG group patients (P < 0.05). There was no statistical difference in 30-day mortality between OPCAB and CABG group patients (1.26% vs. 3.85%, P > 0.05). Among high-risk subgroup patients, the odds ratio of stroke within 30 postoperative days in CABG was 5.7 (95%CI 1.28-25.09, P < 0.05)compared with OPCAB group patients, and the incidence of cardiovascular events and angina within 30 postoperative days were similar between the 2 subgroups. ConclusionsPostoperative mortality and number of distal anastomosis are not significantly different between CABG and OPCAB patients, but OPCAB can significantly reduce operation time, thoracic drainage, blood transfusion, length of ICU stay and mechanical ventilation time compared with CABG. For high-risk patients with high EuroSCORE, OPCAB can better reduce the incidence of postoperative stroke compared with CABG.