Early urinary sodium vs B-type natriuretic peptide for predicting 30-day outcomes in acute decompensated heart...

To compare the prognostic performance of early urinary sodium (UNa) and B-type natriuretic peptide (BNP) for predicting 30-day adverse outcomes in emergency department (ED) patients with acute decompensated heart failure (ADHF).

This prospective observational study was conducted in the ED of Dokuz Eylül University Hospital, Izmir, between January 2025 and July 2025. The study enrolled adults presenting with dyspnea, diagnosed with ADHF, and treated with intravenous loop diuretics. Baseline and 2-hour spot UNa and serum BNP levels were measured. The primary outcome was a composite of intensive care unit admission at the index visit, ED revisit due to ADHF within 30 days, or 30-day all-cause mortality. Patients were compared according to the presence or absence of the composite outcome. Logistic regression and receiver operating characteristic analyses were performed.

A total of 117 patients were enrolled, and the composite outcome occurred in 41 (35.0%). Baseline BNP and UNa levels did not differ significantly between the groups. However, 2-hour UNa was significantly lower in patients with the composite outcome than in patients without it (88.0±29.1 vs 107.3±16.6 mmol/L, P<0.001), whereas 2-hour BNP was comparable between the groups. In multivariable analysis, 2-hour UNa remained independently associated with the composite outcome (adjusted odds ratio 0.963; 95% confidence interval 0.942-0.986; P=0.001), while 2-hour BNP did not. In receiver operating characteristic curve analysis, 2-hour UNa showed significant discriminative ability (area under the curve [AUC] 0.739), whereas 2-hour BNP did not (AUC 0.542). The AUC of 2-hour UNa was significantly greater than that of 2-hour BNP (P=0.003).

Lower 2-hour UNa was independently associated with 30-day adverse outcomes in ED patients with ADHF and may provide early prognostic information on natriuretic response. These findings require validation in larger multicenter studies.