Better health and less thirst with liberal fluid intake in chronic HF

ESC Heart Failure 2025 – A prespecified subanalysis of FRESH-UP among outpatients with chronic HF showed that switching from fluid restriction to liberal fluid intake resulted in a higher KCCQ – Overall Summary Score and a lower thirst distress score.

This summary is based on the presentation of Job Herrmann, MD (Nijmegen, the Netherlands) at the ESC Heart Failure Congress 2025 - The effect of a switch in fluid management on health status in heart failure patients: a prespecified subanalysis of the FRESH-UP study.

Introduction and methods

Patients with HF are often advised to limit their fluid intake because it is thought to prevent congestion and HF hospitalization. However, according to the 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic HF, more evidence is needed on the effects of fluid restriction in this population.

Previously, the FRESH-UP (Fluid REStriction in Heart Failure vs Liberal Fluid UPtake) trial showed a liberal versus restricted fluid intake for 3 months resulted in a trend towards a better health status in patients with chronic HF and significantly less thirst distress, and there were no differences in safety events, including mortality, HF hospitalization, and acute kidney injury. Interestingly, patients assigned to the liberal fluid intake arm reported drinking 1.76 L per day on average, which was only slightly more than the restricted daily intake of 1.5 L. In a prespecified subanalysis of the FRESH-UP study, the effects of the pretrial fluid intake on health status, thirst distress, and fluid intake were investigated.

The FRESH-UP trial was a multicenter open-label RCT conducted in the Netherlands in which 504 outpatients with chronic HF (NYHA class II–III HF symptoms) were randomized to liberal fluid intake or fluid restriction of 1.5 L/day for 3 months. The primary endpoint was health status, as assessed with the KCCQ – Overall Summary Score (OSS), at 3 months. Secondary endpoints included thirst distress, as assessed with the Thirst Distress Scale for patients with HF (TDS‐HF) score (range: 8–40, with higher scores indicating greater thirst distress), at 3 months and patient-reported fluid intake at 6 weeks.

Before the trial, 269 patients (53.4%) had been adhering to a fluid restriction regimen, whereas 235 (46.6%) had been liberally fluids drinking. After randomization, participants were evenly distributed over the treatment groups.

Main results

• Among the patients who had been restricting their fluid intake before the trial, participants who were assigned to liberal fluid intake had a higher mean KCCQ-OSS at 3 months than those assigned to the fluid restriction regimen (74.7; 95%CI: 71.2–78.3 vs. 73.8; 95%CI: 70.4–77.9). In the group with liberal fluid intake before the trial, a similar difference was observed (73.2; 95%CI: 69.6–76.9 vs. 70.2; 95%CI: 66.3–74.2; P across 4 groups=0.036).
• The mean TDS‐HF scores were 17.1 (95%CI: 15.6–18.5) in patients with liberal fluid intake and 18.4 (95%CI: 17.0–19.9) in those with restricted fluid intake in the pretrial fluid-restriction group and 16.7 (95%CI: 15.1–18.3) and 18.7 (95%CI: 17.1–20.3), respectively, in the pretrial liberal fluid–intake group (P across all groups=0.001).
• The largest changes in these 2 parameters between baseline and 3 months were seen in the groups that were switched to another fluid intake regimen: Patients with pretrial restricted fluid intake who were assigned to liberal fluid intake during the trial showed a slightly higher mean KCCQ-OSS and a slightly lower mean TDS‐HF score, whereas patients who went from pretrial liberal fluid intake to restricted fluid intake had a lower mean KCCQ-OSS and a higher mean TDS‐HF score.
• Among participants randomized to fluid restriction, there was no difference in fluid intake during the trial between patients with pretrial restricted fluid intake and those with pretrial liberal intake (1486 vs. 1464 mL; P=0.39), nor was there a difference among participants randomized to liberal fluid intake between the pretrial fluid management groups (1771 vs. 1757 mL; P=0.83).

Conclusion

This prespecified subanalysis of the FRESH-UP study among outpatients with chronic HF showed that switching from fluid restriction to liberal fluid intake resulted in a better health status, as assessed with the KCCQ-OSS, and less thirst distress. The fluid intake during the trial was not affected by the pretrial intake. Dr. Herrmann points out that the findings are in line with the clinical consensus statement on dietary sodium and fluid intake in HF that the ESC Heart Failure Association published in 2024, which suggested patients with chronic HF should have a normal fluid intake of 1.5–2.5 L and higher amounts are allowed.

- Our reporting is based on the information provided at the ESC Heart Failure Congress 2025 -