The correlation between preoperative patient characteristics and NT-proBNP level were shown in Table 1.Univariate analysis showed that preoperative atrial fibrillation (Af), New York heart association (NYHA) class III/IV, ejection fraction (EF), pulmonary arterial pressure, left ventricle end-diastolic diameter (LVEDD), preoperative creatinine and cTnT were significantly associated with preoperative NT-proBNP levels. This evidence concerns the gene TNNT2 and atrial fibrillation.