[Change of N-terminal pro-brain natriuretic peptide and big endothelin in patients undergoing coronary artery bypass grafting].

OBJECTIVE: To examine the change in N-terminal pro-brain natriuretic peptide (Nt-proBNP) and big endothelin (big ET) in patients undergoing coronary artery bypass grafting (CABG), and to evaluate their value in predicting postoperative mortality and complication. METHODS: Forty-seven patients undergoing coronary artery bypass grafting under on-pump (CCABG) and 43 patients undergoing off-pump bypass (OPCAB) were included for study. The levels of Nt-proBNP and big ET were determined before and 24 hours after operation in all patients. RESULTS: (1)There were no differences between two groups. The serum levels of Nt-proBNP and big ET increased significantly 24 hours after operation. Compared with those before operation, Nt-proBNP [(1 083.5 +/- 717.9) pmol/L] in CCABG group was increased [(1 579.2 +/- 719.7)pmol/L, t = -4.30, P<0.01], big ET was increased from (1.10 +/- 1.82 ) pmol/L to (1.68 +/- 1.73)pmol/L(t = -5.35, P<0.01) 24 hours after operation; Nt-proBNP [(999.6 +/- 843.6) pmol/L] in OPCAB group was increased [(1 460.8+/-830.0) pmol/L, t = -4.20, P<0.01], big ET was increased from (1.35 +/- 1.65) pmol/L to (1.73 +/- 1.50) pmol/L (t = -2.46, P=0.018) 24 hours after operation. (2)The level of Nt-proBNP before operation was showed to be negatively correlated with left ventricular ejection fraction (LVEF) (r = -0.43, P<0.001). (3)By univariate and multivariate Logistic regression analysis, the association of clinical variable with postoperative complication was assessed. Multivariable predictors, including the level of LVEF (OR = 1.045, 95%CI:0.999-1.092, P = 0.050) and Nt-proBNP 24 hours after operation (OR = 0.990, 95%CI:0.999-1.000, P = 0.014), were significantly associated with a higher postoperative mortality, lower cardiac output, and higher incidence of myocardial infarction and congestive heart failure. Receiver operating characteristic curves (ROC) for Nt-proBNP 24 hours after operation was valid for the prediction of postoperative complication, and the area under the curve was 0.698 (95% CI:0.585-0.811, P<0.003), sensitivity and specificity were 88.9% and 57.1%, respectively. CONCLUSION: Significant increase in Nt-proBNP and ET is found after CABG. BNP and LVEF are showed to be risk factors for postoperative complications in patients undergoing CABG.