Role of N-terminal pro B-type natriuretic peptide in identifying patients at high risk for adverse outcome after emergent non-cardiac surgery.

ABSTRACT

BACKGROUND: Patients undergoing emergency surgery continue to be at very high risk, but accurate risk identification for the individual patient remains difficult. This study tested the usefulness of perioperative N-terminal pro B-type natriuretic peptide (NT-proBNP) for in-hospital and long-term risk stratification. METHODS: We conducted a prospective single-centre observational cohort study in an Austrian university hospital. Two hundred and ninety-seven consecutive patients >50 yr of age undergoing a variety of emergency non-cardiac procedures were included. The primary endpoint was a composite of non-fatal myocardial infarction (MI), acute heart failure, or death between index surgery and 3 yr follow-up. The secondary endpoint was in-hospital major adverse cardiac events (MACE), defined as non-fatal MI, acute heart failure, or cardiac death. RESULTS: During a median follow-up of 34 months (inter-quartile range 16-39), 31% of subjects reached the primary endpoint. A preoperative NT-proBNP ≥725 pg ml(-1) was associated with a 4.8-fold univariate relative risk [95% confidence interval (CI) 3.1-7.6] and a postoperative NT-proBNP ≥1600 pg ml(-1) was associated with a four-fold univariate relative risk (95% CI 2.7-6.2) for reaching the primary endpoint. Moreover, preoperative NT-proBNP remained a significant and independent (hazards ratio 1.91, 95% CI 1.08-3.37, P=0.027) predictor in a multivariate Cox proportional hazards model. A preoperative NT-proBNP ≥1740 pg ml(-1) was associated with a 6.9-fold univariate relative risk (95% CI 3.5-13.4) for MACE during the index hospital stay, but did not remain significant in a multivariate logistic regression model. CONCLUSIONS: Preoperative NT-proBNP can help identify patients at high risk for adverse long-term outcome after emergency surgery.