Basal natriuresis as a predictor of diuretic resistance and clinical evolution in acute heart failure

Abstract

Background: Some clinical guidelines recommend serial measurement of natriuresis to detect diuretic resistance (DR) in acute heart failure (AHF) patients, but it adds complexity to the management.

Objectives: To correlate a single measurement of basal natriuresis (BN) on admission with the development of DR and clinical evolution in AHF hospitalized patients.

Methods: Prospective and multicenter study included AHF hospitalized patients, without shock or creatinine >2.5mg%. Patients received 40mg of intravenous furosemide on admission, then BN was measured, and diuretic treatment was guided by protocol. BN was considered low if <70 meq/L. DR was defined as the need of furosemide >240mg/day, tubular blockade (TB), hypertonic saline solution (HSS) or renal replacement therapy (RRT). In-hospital cardiovascular (CV) mortality, CV mortality and AHF readmissions at 60-day post-discharge were evaluated.

Results: 157 patients were included. BN was low in 22%. DR was development in 19% (12.7% furosemide >240mg/day, 8% TB, 4% RRT). Low NB was associated with DR (44% vs 12%; p 0.0001), persistence of congestion (26.5% vs 11.4%; p 0.05), furosemide >240 mg/day (29% vs 8%; p 0.003), higher cumulative furosemide dose at 72 hours (220 vs 160mg; p 0.0001), TB (20.6 vs 4.9%; p 0.008), RRT (11.8 vs 1.6%; p 0.02), worsening of AHF (27% vs 9%; p 0.01), inotropes use (21% vs 7%; p 0.48), respiratory assistance (12% vs 2%; p 0.02) and a higher in-hospital CV mortality (12% vs 4%; p 0.1). No association was demonstrated with post-discharge endpoints.

Conclusions: In AHF patients, low BN was associated with DR, persistent congestion, need for aggressive decongestion strategies, and worse in-hospital evolution.

Keywords: Acute heart failure; Diuretic resistance; Furosemide; Mortality; Natriuresis.