N-terminal pro B-type natriuretic peptide is an independent predictor of postoperative myocardial injury in patients undergoing major vascular surgery

Objective

Myocardial ischemia and infarction after surgery remain leading causes of morbidity and mortality in patients undergoing major vascular surgery. B-type natriuretic peptide has been shown to predict early postoperative cardiac events in patients undergoing major noncardiac surgery. We aimed to determine if N-terminal pro B-type natriuretic peptide (NT-pro-BNP), with its longer half-life and greater plasma stability, can predict postoperative myocardial injury in vascular patients.

Methods

Recruited were 136 patients undergoing elective surgery for subcritical limb ischemia or abdominal aortic aneurysm (AAA) repair. Plasma NT-pro-BNP was measured preoperatively, and troponin-I was measured immediately after surgery and on postoperative days 1, 2, 3, and 5.

Results

Twenty-eight patients (20%) sustained postoperative myocardial injury (troponin-I rise of >0.1 ng/mL). The median NT-pro-BNP level of those with myocardial injury was significantly higher than those who did not (380 pg/mL [interquartile range (IQR), 223-967] vs 209 pg/mL [109-363]; P = .003). NT-pro-BNP predicted this outcome with an area under the receiver operating characteristic (ROC) curve of 68% (95% confidence interval [CI] 0.56%-0.78%). In a multivariate analysis, a NT-pro-BNP value of ≥308 pg/mL (the optimal ROC curve–derived cutoff) was associated with an increased incidence of myocardial injury (odds ratio, 3.4; 95% CI, 1.41-9.09, P =.01).

Conclusion

Elevated preoperative plasma NT-pro-BNP levels independently predict postoperative myocardial injury, which is associated with adverse outcome in the short- and long-term regardless of the presence of symptoms of acute coronary syndrome.