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.