Background Dietary sodium restriction remains guidelines-approved lifestyle recommendation for chronic heart failure (CHF) patients. However, its efficacy in clinical outcome improvement is dubious. Methods We performed a systematic review of the following databases: Academic Search Ultimate, ERIC, Health Source Nursing/Academic Edition, MEDLINE, Embase, Clinicaltrials.gov and Cochrane Library (trials) to find studies analysing the impact of sodium restriction in the adult CHF population. Both observational and interventional studies were included. Most considerable exclusion criteria included i.e.: sodium consumption assessment based only on natriuresis, in-hospital interventions or mixed interventions - e.g. sodium and fluid restriction in one arm only. The review was conducted following PRISMA guidelines. At least two independent reviewers screened databases and extracted the data. Meta-analysis was performed for the endpoints reported in at least 3 papers. The heterogeneity and sensitivity of the results were assessed. Analyses were conducted in Review Manager (RevMan) Version 5.4.1 The Cochrane Collaboration, 2020. Results Initially, we screened 9175 articles identified in the databases. Backward snowballing revealed 1050 additional articles. Eventually, 9 papers were evaluated in the meta-analysis. All-cause mortality, HF-related hospitalizations, and the composite of mortality and hospitalization were reported in 8, 6 and 3 articles, respectively. Sodium restriction was associated with a higher risk of composite endpoint (OR, 4.12 [95% CI, 1.23 - 13.82]) and did not significantly affect the all-cause mortality (OR, 1.38 [95% CI, 0.76 - 2.49]) or HF hospitalisation (OR, 1.63 [95% CI, 0.69 - 3.88]). Conclusions In a meta-analysis, sodium restriction in CHF patients worsened the prognosis in terms of composite of mortality and hospitalizations and did not influence all-cause mortality and HF hospitalisation rate.

The authors have declared no competing interest.

No external funding was received

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Not Applicable

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

PROSPERO https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=391133 CRD42023391133

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Not Applicable

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Not Applicable

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Not Applicable

Excel files with the screened articles and exclusion reasons at every stage are available at request. All the extracted data will be shared upon request.