[Comparative prognostic value of plasma and urinary N-terminal pro-B-type natriuretic peptide in patients with acute destabilized heart failure].

INTRODUCTION AND OBJECTIVES Urinary concentrations of amino-terminal pro-B type natriuretic peptide (NT-proBNP) may be prognostically meaningful; however, direct comparison to plasma concentrations of this marker have not been performed in patients with acutely decompensated heart failure (ADHF). The aims of this study were to compare the prognostic value of plasma versus urinary NT-proBNP concentration for the risk stratification of patients with ADHF. METHODS Consecutive hospitalized patients with ADHF were prospectively studied. Blood and urine samples were simultaneously collected on hospital arrival to determine NT-proBNP concentrations. Clinical follow-up was obtained, and the occurrence of mortality and heart failure hospitalization was registered. RESULTS The study included 138 patients (median, 74 years [interquartile range, 67-80]; 54% men). During a median follow-up period of 387 days [interquartile range, 161-559], 65 patients (47%) suffered adverse clinical events. Plasma NT-proBNP concentration was higher among patients who presented adverse events (4561 pg/mL [2191-8631] vs 2906 pg/mL [1643-5823]; P=.03), whereas urinary NT-proBNP was similar in both groups (P=.62). After multivariable Cox regression analyses, plasma NT-proBNP concentration was associated with a higher risk of adverse events, whether considered continuously (per 100 pg/mL; hazard ratio [HR]=1.004; 95% confidence interval [CI], 1.001-1.007; P=.003) or categorically (≥3345 pg/mL; HR=2.35; 95%CI, 1.41-3.93; P=.001). In contrast, urinary NT-proBNP concentration was not associated with adverse outcomes. CONCLUSIONS Plasma NT-proBNP concentration is superior to urinary NT-proBNP concentration for the prediction of adverse clinical outcomes among unselected patients with ADHF.