Abstract Body (Do not enter title and authors here): Background: Optimal fluid management is central to heart failure (HF) care, yet the clinical efficacy of fluid restriction remains inconclusive. This updated systematic review and meta-analysis evaluates the impact of fluid restriction compared to liberal fluid intake on cardiovascular and patient-centered outcomes in individuals with HF.

Methods: This study adhered to PRISMA guidelines. Ten randomized controlled trials involving 1,465 HF patients were included (731 fluid restriction; 734 liberal intake). Primary and secondary outcomes assessed were HF re-hospitalization, all-cause mortality, weight change, quality of life (QOL), thirst, intravenous (IV) diuretic use, and laboratory markers (serum sodium, creatinine, brain natriuretic peptide (BNP). Pooled estimates were calculated using a random-effects model. Subgroup analyses were conducted by HF subtype, clinical status (acute vs. chronic), and sodium restriction.

Results: Fluid restriction showed a trend toward reduced HF re-hospitalizations compared to liberal fluid intake, although the difference was not statistically significant (RR: 0.71; 95% CI: 0.50 to 1.02; p = 0.06; Figure 1A). No significant difference was observed in all-cause mortality (RR: 0.71; 95% CI: 0.43 to 1.18; p = 0.19; Figure 1B). Similarly, weight change (WMD: –1.58 kg; 95% CI: –3.92 to 0.76; p = 0.19; Figure 1C), QOL (SMD: 0.15; 95% CI: –0.14 to 0.44; p = 0.30; Figure 2B), thirst (WMD: 4.96; 95% CI: –4.05 to 13.97; p = 0.28; Figure 2A), and IV diuretic use (WMD: 3.50; 95% CI: –5.80 to 12.80; p = 0.46; Figure 2C) did not differ significantly between groups. Laboratory outcomes also showed no significant differences: serum sodium (WMD: 0.90 mmol/L; 95% CI: –0.79 to 2.58; p = 0.30; Figure 3A), serum creatinine (WMD: –0.10 mg/dL; 95% CI: –0.22 to 0.01; p = 0.08; Figure 3B), and BNP (MD: –51.41; 95% CI: –171.44 to 68.61; p = 0.40; Figure 3C). Subgroup analyses revealed significant benefits in patients with chronic HF for both re-hospitalization (p = 0.01) and serum creatinine levels (p < 0.01).

Conclusions: Fluid restriction may reduce re-hospitalization risk and provide modest clinical benefits in patients with chronic HF. However, no statistically significant improvements were seen in mortality or broader clinical outcomes. These findings support a selective approach to fluid restriction in HF management and highlight the need for further large-scale trials to confirm subgroup-specific efficacy and safety.