Effect of Fluid Restriction in Heart Failure: A Meta-Analysis of Randomized Controlled Trials

Fluid restriction is frequently recommended for patients with heart failure (HF) to prevent volume overload, yet its clinical benefit remains uncertain. This meta-analysis compared the efficacy and safety of fluid restriction versus liberal fluid intake in HF by systematically searching PubMed, Scopus, and Cochrane CENTRAL through May 2025 for randomized controlled trials evaluating fluid restriction (≤1.5 L/d) compared with liberal intake in adults with HF. Outcomes included re-hospitalization, mortality, weight, thirst, quality of life (QoL), intravenous diuretic use, and serum biomarkers such as sodium, creatinine, and brain natriuretic peptide. Ten randomized controlled trials involving 1465 participants (731 fluid restriction; 734 liberal intake) were included. Fluid restriction was associated with a 29% relative reduction in re-hospitalization (relative risks [RR] 0.71; 95% confidence interval [CI], 0.50-1.02; P = 0.06; I2 = 52%) and mortality (RR 0.71; 95% CI, 0.43-1.18; P = 0.19; I2 = 0%), although neither reached statistical significance. Weight reduction favored fluid restriction (weighted mean difference [WMD] -1.58 kg; 95% CI, -3.92 to 0.76), but findings varied across studies. No significant differences were observed for thirst (WMD 4.96), QoL (standardized mean difference [SMD] 0.15), intravenous diuretic use, sodium levels (WMD 0.90 mmol/L), creatinine (WMD -0.10 mg/dL), or brain natriuretic peptide (WMD -51.41 pg/mL). Subgroup analysis showed that liberal fluid intake significantly reduced creatinine in chronic compensated HF, whereas no benefit was found in acute decompensated HF. Sensitivity analyses identified one outlier trial as the primary source of heterogeneity. Overall, fluid restriction does not significantly improve outcomes in HF, and liberal fluid intake appears safe, supporting more individualized fluid strategies.