NPPB and Cerebral ischemia: No significant differences were noted in sex, body mass index, leukocyte count, prothrombin time, hemoglobin level, troponin-I level, NT-ProBNP level, aspartate aminotransferase level, alanine aminotransferase level, aortic regurgitation (medium or above), left ventricular ejection fraction, coronary heart disease, diabetes, hypertension, chronic obstructive pulmonary disease, acute renal insufficiency, myocardial ischemia, cerebral ischemia, operation procedure, and cardiopulmonary bypass time between the survivor and non-survivor groups.