ObjectiveTo analyze the effect of carotid artery stenosis degree and intervention for carotid artery stenosis on the incidence of central nervous system complications after off-pump coronary artery bypass grafting (OPCABG) and explore the influencing factors. MethodsA total of 1 150 patients undergoing OPCABG in our hospital from June 2018 to June 2021 were selected and divided into two groups according to whether there were central nervous system complications, including a central nervous system complication group [n=61, 43 males and 18 females with a median age of 68.0 (63.0, 74.0) years] and a non-central nervous system complication group [n=1 089, 796 males and 293 females with a median age of 65.5 (59.0, 70.0) years]. The risk factors for central nervous system complications after OPCABG were analyzed. ResultsUnivariate analysis showed that age, smoking, hyperlipidemia, preoperative left ventricular ejection fraction, intra-aortic ballon pump (IABP), postoperative arrhythmia, postoperative thoracotomy and blood transfusion volume were associated with central nervous system complications. The incidence of central nervous system complications in patients with severe carotid artery stenosis or occlusion (11.63%) was higher than that in the non-stenosis and mild stenosis patients (4.80%) and moderate stenosis patients (4.76%) with a statistical difference (P=0.038). The intervention for carotid artery stenosis before or during the operation did not reduce the incidence of central nervous system complications after the operation (42.11% vs. 2.99%, P<0.001). Age, postoperative arrhythmia, severe unilateral or bilateral carotid artery stenosis and occlusion were independent risk factors for postoperative central nervous system complications (P<0.05). Conclusion The age, smoking, hyperlipidemia, preoperative left ventricular ejection fraction, intraoperative use of IABP, postoperative arrhythmia, secondary thoracotomy after surgery, blood transfusion volume and OPCABG are associated with the incidence of postoperative central nervous system complications in patients. Age, postoperative arrhythmia, severe unilateral or bilateral carotid artery stenosis and occlusion are independent risk factors for postoperative central nervous system complications. In patients with severe carotid artery stenosis, preoperative treatment of the carotid artery will not reduce the incidence of central nervous system complications.