Inclusion Criteria:  Patients who received CABG at the Department of Cardiac Surgery in our hospital from March 2020 to March 2021. Surgery that patients received includes both isolated and combined CABG surgery. Includes both cardiopulmonary and non-cardiopulmonary bypass.  Exclusion Criteria:  Without complete preoperative examination data, such as carotid-cerebral artery CTA, head CT imaging results and so on. Without complete baseline medical history and 7 day post-surgery record.