Background: Sodium restriction is recommended for patients with heart failure (HF) despite the lack of solid clinical evidence from randomized controlled trials. Whether or not sodium restrictions provide beneficial cardiac effects is not known.
Methods: The present study is a randomized, double-blind, controlled trial of stable HF patients with ejection fraction ≤ 40%. Patients were allocated to sodium restriction (2 g of sodium/day) vs. control (3 g of sodium/day). The primary outcome was change in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 20 weeks. Secondary outcomes included quality of life and adverse safety events (HF readmission, blood pressure or electrolyte abnormalities).
Results: Seventy patients were enrolled. Median baseline sodium consumption was 3268 (2225-4537) mg/day. Adherence to the intervention based on 24-hour urinary sodium was 32%. NT-proBNP and quality of life did not significantly change between groups (p > 0.05 for both). Adverse safety events were not significantly different between the arms (p > 0.6 for all). In the per protocol analysis, patients who achieved a sodium intake < 2500 mg/day at the intervention conclusion showed improvements in NT-proBNP levels (between-group difference: -55%, 95% confidence interval -27 to -73%; p = 0.002) and quality of life (between-group difference: -11 ± 5 points; p = 0.04). Blood pressure decreased in patients with lower sodium intake (between-group difference: -9 ± 5 mmHg; p = 0.05) without significant differences in symptomatic hypotension or other safety events (p > 0.3 for all).
Conclusions: Adherence assessed by 24-hour natriuresis and by the nutritionist was poor. The group allocated to sodium restriction did not show improvement in NT-proBNP. However, patients who achieved a sodium intake < 2500 mg/day appeared to have improvements in NT-proBNP and quality of life without any adverse safety signals.
Clinicaltrials: gov Identifier: NCT03351283.
Keywords: NT-proBNP; heart failure; quality of life; sodium intake.