Sodium Restriction in Patients With Heart Failure: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Background: Sodium restriction is a nonpharmacologic treatment suggested by practice guidelines for the management of patients with heart failure (HF). In this study, we synthesized the data from randomized controlled trials (RCTs) evaluating the effects of sodium restriction on clinical outcomes in patients with HF.

Methods: In this aggregate data meta-analysis, Cochrane Central, MEDLINE (Medical Literature Analysis and Retrieval System Online), Embase Ovid, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) Plus databases were searched up to April 2, 2022. RCTs were included if they investigated the effects of sodium/salt restriction as compared to no restriction on clinical outcomes in patients with HF. Outcomes of interest included mortality, hospitalization, change in New York Heart Association functional class, and quality of life (QoL).

Results: Seventeen RCTs were identified (834 and 871 patients in intervention and control groups, respectively). Sodium restriction did not reduce the risk of all-cause death (odds ratio, 0.95 [95% CI, 0.58-1.58]), hospitalization (odds ratio, 0.84 [95% CI, 0.62-1.13]), or the composite of death/hospitalization (odds ratio, 0.88 [95% CI, 0.63-1.23]). The results were similar in different subgroups, except for the numerically lower risk of death with reduced sodium intake reported in RCTs with dietary sodium at the 2000 to 3000 mg/d range as opposed to <2000 mg/d (and in RCTs with versus without fluid restriction as a co-intervention). Among RCTs reporting New York Heart Association change, 2 RCTs (which accounted for two-thirds of the data) showed improvement in New York Heart Association class with sodium restriction. Substantial heterogeneity existed for QoL: 6 RCTs showed improvement of QoL and 4 RCTs showed no improvement of sodium restriction on QoL.

Conclusions: In a meta-analysis of RCTs, sodium restriction was not associated with fewer deaths or hospitalizations in patients with HF. Dietary sodium restriction may be associated with improvements in symptoms and QoL.