In-hospital mortality is associated with high NT-proBNP level

Objective To compare in-hospital mortality in unselected adult patients according to N-terminal probrain natriuretic peptide (NT-proBNP) levels. Method Retrospective study including 3833 adult patients (median age 72 years, 45% women) hospitalized between January 2013 and April 2015 in a Swiss university hospital, with at least one NT-proBNP level measurement during hospitalization. Patients were categorized in quintiles regarding their highest NT-proBNP level. In-hospital mortality and length of stay (LOS) were compared between the highest and the other quintiles. Results In-hospital mortality rate and LOS (average +/- standard deviation) were higher in the fifth quintile than in the others (6.5% vs 20.3%, and 20.8 +/- 24.0 vs. 14.9 +/- 26.5 days respectively, both p<0.001). After multivariate adjustment on age, gender, principal diagnoses, stage 5 renal failure and type of management, patients in the fifth quintile had a hazard ratio [95% confidence interval] of 1.97 [1.57-2.46] for in-hospital mortality and an adjusted LOS (average +/- standard error) of 20.4 +/- 1.0 vs. 14.9 +/- 0.5 days for the other quintiles (p<0.001). Further stratification on the main diagnosis at discharge led to similar findings. Conclusion Patients with high levels of NT-proBNP are at higher risk of in-hospital mortality and longer LOS, regardless of their clinical characteristics. NT-proBNP level can be a helpful tool for predicting in-hospital patient outcome in unselected adult patients.