Why is routine fluid restriction not recommended for patients with heart failure?

Why Routine Fluid Restriction Is Not Recommended in Heart Failure

Routine fluid restriction should not be recommended for all heart failure patients because the highest quality evidence demonstrates no benefit on quality of life or clinical outcomes in stable chronic heart failure, while it significantly increases thirst distress and reduces patient quality of life. 1

The Evidence Against Routine Fluid Restriction

The most recent and highest quality evidence comes from the 2025 FRESH-UP trial published in Nature Medicine, which directly tested liberal fluid intake versus fluid restriction (1,500 mL/day) in 504 outpatients with chronic heart failure. 1 This randomized controlled trial found:

• No improvement in health status (KCCQ-OSS) with fluid restriction compared to liberal intake (mean difference 2.17,95% CI -0.06 to 4.39; P = 0.06) 1
• Significantly higher thirst distress in the fluid restriction group 1
• No differences in safety events between groups, including death or heart failure hospitalizations 1

This aligns with the European Society of Cardiology's current position that fluid restriction should only be considered in patients with severe heart failure to relieve symptoms and congestion, while routine fluid restriction is not recommended for those with mild to moderate symptoms. 2

Why Guidelines Have Downgraded This Recommendation

The evidence supporting routine fluid restriction has always been weak:

• The American Heart Association, American College of Cardiology, and Heart Failure Society of America give fluid restriction only a Class 2b recommendation (weak) with Level C-LD evidence (limited data), indicating uncertainty about its benefit. 3
• Only two randomized studies have evaluated the effect of fluid restriction on its own, and both found that stringent fluid restriction compared to liberal fluid intake was not more beneficial with regard to clinical stability or body weight. 4
• Most evidence regarding altered sodium handling and fluid homeostasis in heart failure originates from untreated patient cohorts and physiological investigations, not from patients on contemporary guideline-directed medical therapy. 5

The Harms of Routine Fluid Restriction

Implementing routine fluid restriction can cause significant patient burden without proven benefit:

• Increased thirst distress and reduced quality of life 1
• Risk of dehydration, particularly in hot climates or low-humidity environments 3
• Increased risk of heat stroke in vulnerable populations 3
• Poor adherence due to the difficulty of maintaining strict fluid limits long-term 4

When Fluid Restriction May Be Appropriate

Rather than routine restriction, fluid management should be targeted to specific clinical scenarios:

Severe Decompensated Heart Failure

• Consider temporary fluid restriction of 1.5-2 L/day for patients with severe symptoms and persistent congestion despite optimal medical therapy 3, 2
• This should be combined with aggressive diuretic therapy and sodium restriction 3

Hyponatremia

• For patients with serum sodium <134 mEq/L, temporary fluid restriction of 1.5-2 L/day may improve hyponatremia 3, 2
• This should be monitored closely and discontinued once sodium normalizes 3

Diuretic-Resistant Patients

• Stricter fluid restriction around 1.5-2 L/day may be beneficial when combined with sequential nephron blockade (loop plus thiazide diuretics) 3
• Consider ultrafiltration if medical therapy fails 6

The Preferred Approach: Weight-Based Individualization

If fluid restriction is deemed necessary for specific clinical scenarios, weight-based fluid restriction (30 mL/kg per day, or 35 mL/kg if body weight >85 kg) is more reasonable than fixed restrictions and causes less thirst. 3, 2, 4

What Should Be Emphasized Instead

Rather than routine fluid restriction, focus on:

• Sodium restriction to ≤2 g daily, which has stronger evidence for reducing fluid retention 6, 3
• Daily weight monitoring to recognize rapid weight gain (>2 kg in 3 days) 2, 7
• Optimization of guideline-directed medical therapy (ACE inhibitors/ARBs, beta-blockers, mineralocorticoid receptor antagonists, diuretics) 3
• Progressive diuretic dose adjustment based on clinical response rather than arbitrary fluid limits 6

Common Pitfalls to Avoid

• Do not discharge patients before achieving euvolemia, as unresolved edema attenuates diuretic response and increases readmission risk 6, 3
• Do not implement fluid restriction in isolation without addressing sodium intake and optimizing medical therapy 2
• Do not continue fluid restriction indefinitely without reassessing clinical need and patient quality of life 4
• Do not apply the same fluid restriction to all patients regardless of body weight, climate, or activity level 3, 2