Usefulness of N-terminal pro-B-type natriuretic peptide in patients admitted to the intensive care unit: a multicenter prospective observational study

Abstract

Background: The role of N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) as a prognostic factor in patients admitted to the intensive care unit (ICU) is not yet fully established. We aimed to determine whether NT-pro-BNP is predictive of ICU mortality in a multicenter cohort of critically ill patients. Methods: A total of 1440 patients admitted to 22 ICUs ( medical, 14; surgical, six; multidisciplinary, two) in 15 tertiary or university-affiliated hospitals between July 2010 and January 2011 were assessed. Patient data, including NT-pro-BNP levels and Simplified Acute Physiology Score ( SAPS) 3 scores, were recorded prospectively in a web-based database. Results: The median age was 64 years ( range, 53-73 years), and 906 ( 62.9%) patients were male. The median NT-pro-BNP level was 341 pg/mL ( 104-1,637 pg/mL), and the median SAPS 3 score was 57 ( range, 47-69). The ICU mortality rate was 18.9%, and hospital mortality was 24.5%. Hospital survivors showed significantly lower NT-pro-BNP values than nonsurvivors ( 245 pg/mL [ range, 82-1,053 pg/mL] vs. 875 pg/mL [ 241-5,000 pg/mL], respectively; p <0.001). In prediction of hospital mortality, the area under the curve (AUC) for NT-pro-BNP was 0.67 ( 95% confidence interval [CI], 0.64-0.70) and SAPS 3 score was 0.83 ( 95% CI, 0.81-0.85). AUC increment by adding NT-pro-BNP is minimal and likely no different to SAPS 3 alone. Conclusions: The NT-pro-BNP level was more elevated in nonsurvivors in a multicenter cohort of critically ill patients. However, there was little additional prognostic power when adding NT-pro-BNP to SAPS 3 score.