Utility of amino-terminal pro-brain natriuretic peptide testing for prediction of 1-year mortality in patients with dyspnea treated in the emergency department

Background: Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is useful for diagnosis and triage of patients with dyspnea, but its role for predicting outcomes in such patients remains undefined. Methods: A total of 599 breathless patients treated in the emergency department were prospectively enrolled, and a sample of blood was obtained for NT-proBNP measurements. After 1 year, the vital status of each patient was ascertained, and the association between NT-proBNP values at presentation and mortality was assessed. Results: At 1 year, 91 patients (15.2%) had died. Median NT-proBNP concentrations at presentation among decedents were significantly higher than those of survivors (3277 vs 299 pg/mL; P<.001). The optimal NT-proBNP cut point for predicting 1-year mortality was 986 pg/mL. In a multivariable model, an NT-proBNP concentration greater than 986 pg/mL at presentation was the single strongest predictor of death at 1 year (hazard ratio [HR], 2.88; 95% confidence interval, 1.64-5.06; P<.001), independent of a diagnosis of heart failure. Other factors associated with death included age (by decade; HR, 1.20), heart rate (by decile; HR, 1.13), urea nitrogen level (by decile; HR, 1.20), systolic blood pressure less than 100 mm Hg (HR, 1.94), heart murmur (HR, 1.92), and New York Heart Association classification (HR, 1.38 for each increase in class). The NT-proBNP concentration alone had an area under the receiver operating characteristic curve (AUC) of 0.76 for predicting mortality; the other significant covariates combined had an AUC of 0.80. The final model for predicting death, combining NT-proBNP with other covariates associated with mortality, had a superior AUC of 0.82. Conclusion: In addition to assisting in emergency department diagnosis and triage, NT-proBNP concentrations at presentation are strongly predictive of 1-year mortality in dyspneic patients.