Review the data of patients who underwent coronary artery bypass grafting (CABG) at the National Center for Cardiovascular Disease, Fuwai Hospital from January 2013 to June 2023 including medical history, head CT scan, and postoperative, including 30-day mortality, arrhythmia, cerebrovascular disease and intracerebral haemorrhage, etc. Case-control and retrospective cohort studies were conducted to explore the risk factors associated with early postoperative complications, examine their relationship with postoperative management, explore independent risk factors of compound complications, and build predictive models.