Spot urinary sodium-guided titration of intravenous diuretic therapy in acute heart failure: a pilot randomized 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 randomized controlled trial data exist to support this approach. We performed a prospective pilot trial to investigate the feasibility of this approach. Methods and results: Sixty patients with AHF (n = 30 in each arm) were randomly assigned to titration of loop diuretics for the first 48 h 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. 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 h. There was no difference in the length of hospital stay (median length of stay: 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 h. Further large-scale trials are needed to determine if the superiority of this approach translates into improved patient outcomes.