Background Fluid restriction is a commonly prescribed non-pharmacological intervention in the management of heart failure (HF). However, data on its efficacy and safety are scarce. Recent randomised clinical trial (RCT) data prompt reassessment of the available evidence.

Methods CINAHL, EMBASE, PubMed and the Cochrane Library were searched up to 1 May 2025. RCTs were included if adults with HF were randomised to fluid restriction in comparison to a liberal or unrestricted intake, less strict restriction or usual care. Outcomes of interest were mortality, HF hospitalisation, quality of life (QoL), thirst distress, New York Heart Association (NYHA) class and N-terminal pro-Brain Natriuretic Peptide (CRD42022292319). No meta-analysis was performed due to high heterogeneity of the included trials.

Results In total, four RCTs were included, comprising 682 randomised inpatient, recently discharged and stable outpatient patients (ranging from 46 to 504 patients per trial). Only one study had a low risk of bias. None of the four trials found a significant difference in mortality or HF hospitalisations. For QoL, the results are contradictory, but overall, there is no clear benefit for fluid restriction, but it resulted in more thirst distress. No significant differences in NYHA class or (NT-pro)BNP were observed.