Association of plasma N-terminal pro-B-type natriuretic peptide with postoperative cardiac events in patients undergoing surgery for abdominal aortic aneurysm or leg bypass.

Postoperative cardiac events are related to myocardial ischemia and reduced left ventricular function. The utility of N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP) for preoperative cardiac risk evaluation has not been evaluated. The objective of this study was to assess whether plasma NT-pro-BNP predicts postoperative cardiac events in patients who undergo major vascular surgery in addition to clinical and dobutamine stress echocardiographic data. One hundred seventy consecutive patients scheduled for major noncardiac vascular surgery were prospectively evaluated by dobutamine stress echocardiographic and NT-pro-BNP measurements. Multivariable logistic regression analysis was performed to evaluate the predictors of cardiac death and nonfatal myocardial infarction during a follow-up of 30-days. Receiver-operating characteristic analysis was performed to determine the optimal cut-off value of NT-pro-BNP to predict outcome. Patients' mean age was 59 +/- 13 years, and 71% were men. The median NT-pro-BNP level was 110 pg/ml (interquartile range 42 to 389). Cardiac events occurred in 2 of 144 patients (1.4%) with NT-pro-BNP <533 pg/ml (i.e., the optimal cut-off value to predict cardiac events) and in 11 of 26 patients (42%) with NT-pro-BNP >or=533 pg/ml (unadjusted odds ratio 52, 95% confidence interval 11 to 256, p <0.0001). After adjustment for cardiac risk factors and dobutamine stress echocardiographic results, NT-pro-BNP remained significantly associated with cardiac events (adjusted odds ratio 17, 95% confidence interval 3 to 106, p = 0.002). In conclusion, in patients scheduled for major vascular surgery, elevated plasma NT-pro-BNP levels are independently associated with an increased risk for postoperative cardiac events. Further studies in a larger number of patients are required to confirm these findings.