Spot urinary sodium guided titration of intravenous diuretic therapy in acute heart failure: A pilot randomised controlled trial.

Background: Spot urinary sodium concentration (UNa) is advocated in guidelines to assess diuretic response and titrate dosage in acute heart failure (AHF). However, no randomised controlled trial data exists to support this approach. We performed a prospective pilot trial to investigate the feasibility of this approach.
Methods: 60 patients with AHF (n = 30 in each arm) were randomly assigned to titration of loop diuretics for the first 48 hours of admission according to UNa levels (intervention arm) or based on clinical signs and symptoms of congestion (standard care arm). Diuretic insufficiency was defined as UNa < 50 mmol/L. Endpoints relating to diuretic efficacy, safety and AHF outcomes were evaluated.
Results: UNa-guided therapy patients experienced less acute kidney injury (20% vs 50%, p = 0.01) and a tendency towards less hypokalaemia (serum K+<3.5 mmol, 7% vs 27%, p = 0.04), with greater weight loss (3.3 kg vs 2.1 kg, p = 0.01). They reported a greater reduction in the clinical congestion score (-4.7 vs -2.6, p < 0.01) and were more likely to report marked symptom improvement (40% vs 13.3%, p = 0.04) at 48 hours. There was no difference in the length of hospital stay (median LOS: 8 days in both groups, p = 0.98), 30-day mortality or readmission rate.
Conclusion: UNa-guided titration of diuretic therapy in AHF is feasible and safer than titration based on clinical signs and symptoms of congestion, with more effective decongestion at 48 hours. Further large-scale trials are needed to determine if the superiority of this approach translates into improved patient outcomes.
(© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)