A randomized clinical trial has found that restricting fluid intake in patients with chronic heart failure provides no significant health status benefits compared to a more liberal approach, challenging a common clinical recommendation.
The Fluid REStriction in Heart failure vs. liberal fluid UPtake (FRESH-UP) trial investigated whether the widely practiced recommendation of fluid restriction for heart failure patients actually improves outcomes or quality of life.
Trial Design and Patient Population
The FRESH-UP study enrolled patients with chronic, symptomatic heart failure (NYHA class II-III). Participants were randomized to either a liberal fluid intake approach or a restricted fluid intake regimen and followed for three months.
The study population was primarily male, Caucasian, and of European descent, which may limit generalizability to other demographic groups. The behavioral intervention successfully influenced patient fluid consumption, with the liberal group reporting significantly higher daily fluid intake (1,764 mL vs. 1,483 mL, p<0.001).
Primary Outcome Shows No Significant Benefit from Restriction
The primary outcome measure was the Kansas City Cardiomyopathy Questionnaire-Overall Summary Score (KCCQ-OSS), a validated tool for assessing heart failure-related health status. After three months, the liberal fluid intake group scored 74.0 compared to 72.2 in the fluid restriction group.
After adjusting for baseline scores, the mean difference between groups was 2.17 points (95% CI, -0.06 to 4.39, p=0.06), which did not reach statistical significance. This suggests that fluid restriction does not meaningfully improve health status in this patient population.
Reduced Thirst Distress with Liberal Fluid Intake
Notably, patients allowed liberal fluid intake experienced significantly less thirst distress as measured by the Thirst Distress Scale for patients with heart failure (TDS-HF). The liberal group scored 16.9 versus 18.6 in the restricted group, with an adjusted mean difference of -2.29 (95% CI, -1.09 to 3.49, p<0.001).
This finding is particularly relevant as thirst is a common and distressing symptom reported by heart failure patients, potentially affecting quality of life and treatment adherence.
Safety Outcomes Show No Increased Risk
The trial found no statistically significant differences in safety endpoints between the liberal and restricted fluid intake approaches:
- Mortality: 1 vs. 2 patients
- All-cause hospitalization: 20 vs. 15 patients
- Heart failure hospitalization: 4 vs. 4 patients
- IV loop diuretic usage: 5 vs. 7 patients
- Acute kidney injury: 3 vs. 4 patients
However, researchers noted that the overall number of clinical safety events was low, limiting statistical power to detect meaningful differences. This was likely due to the modest sample size and relatively short follow-up period of three months.
Clinical Implications for Heart Failure Management
"The results of FRESH-UP suggest that liberal fluid intake is safe in patients with chronic heart failure and may improve their well-being," noted the study investigators. "It challenges providers to reconsider widespread fluid restrictions for all patients with heart failure and consider a more individualized approach."
The findings align with a growing body of evidence questioning the universal application of fluid restriction in heart failure management. Recent guidelines from the Heart Failure Association of the European Society of Cardiology have already begun to acknowledge the limited evidence supporting strict fluid restriction for all heart failure patients.
Dr. Johannes Herrmann, one of the study authors, commented, "For years, we've been telling heart failure patients to limit their fluid intake without strong evidence. This study suggests we may need to rethink this approach, particularly for stable patients with mild to moderate symptoms."
Limitations and Future Research Directions
Despite its important findings, the FRESH-UP trial had several limitations. The study population was relatively homogeneous, with underrepresentation of women and non-Caucasian patients. Additionally, only 34% of patients in the liberal arm consumed more than 2,000 mL of fluid daily, limiting conclusions about very high fluid intake levels.
The researchers emphasized that future studies should investigate the effects of fluid intake in patients with more advanced heart failure (NYHA class IV) and those with acute decompensated heart failure, as these populations were not included in the current trial.
The study also had a relatively short follow-up period of three months, which may not capture long-term effects of different fluid intake strategies.
Balancing Patient Comfort and Clinical Outcomes
The FRESH-UP trial highlights the importance of balancing clinical recommendations with patient comfort and quality of life. While fluid restriction has been a standard recommendation for heart failure patients, the evidence suggests it may increase thirst distress without providing meaningful clinical benefits for many patients.
As heart failure management continues to evolve, this study provides valuable evidence to support more personalized approaches to fluid intake recommendations, potentially improving patient comfort without compromising safety or outcomes.
