What are the guidelines for iron supplementation in patients with Congestive Heart Failure (CHF)?

Iron Supplementation in Patients with Congestive Heart Failure

Intravenous iron supplementation is recommended for patients with heart failure who have iron deficiency (defined as ferritin <100 μg/L or ferritin 100-300 μg/L with transferrin saturation <20%), regardless of anemia status, to improve functional capacity, symptoms, and quality of life. 1

Screening and Diagnosis

• All patients with heart failure should undergo routine evaluation for iron deficiency as part of their initial workup and follow-up care 1
• Iron deficiency is common in CHF patients (prevalence 37-57%) and is associated with worse outcomes, even in non-anemic patients 2, 3
• Diagnostic criteria for iron deficiency in heart failure:
  • Serum ferritin <100 μg/L (absolute iron deficiency), or
  • Serum ferritin 100-300 μg/L with transferrin saturation <20% (functional iron deficiency) 1

Treatment Recommendations

Intravenous Iron Therapy

• IV ferric carboxymaltose (FCM) is the recommended form of iron supplementation for CHF patients with iron deficiency (Class IIa recommendation, Level of Evidence A) 1
• Clinical trials (FAIR-HF, CONFIRM-HF, EFFECT-HF) have demonstrated that IV iron improves:
  • Exercise capacity (6-minute walk test)
  • NYHA functional class
  • Quality of life
  • Potential reduction in HF hospitalizations 1
• Benefits occur in both anemic and non-anemic patients with iron deficiency 1, 4

Dosing of IV Ferric Carboxymaltose

• For patients with heart failure and iron deficiency, dosing is based on weight and hemoglobin levels 5:
  • For patients <70 kg:
    • Hb <10 g/dL: 1000 mg on day 1,500 mg at week 6
    • Hb 10-14 g/dL: 1000 mg on day 1, no dose at week 6
    • Hb >14 to <15 g/dL: 500 mg on day 1, no dose at week 6
  • For patients ≥70 kg:
    • Hb <10 g/dL: 1000 mg on day 1,1000 mg at week 6
    • Hb 10-14 g/dL: 1000 mg on day 1,500 mg at week 6
    • Hb >14 to <15 g/dL: 500 mg on day 1, no dose at week 6
• Maintenance dose of 500 mg at 12,24, and 36 weeks if ferritin remains <100 ng/mL or ferritin 100-300 ng/mL with transferrin saturation <20% 5

Administration

• IV FCM can be administered as:
  • Undiluted slow IV push (100 mg/min, or 15 minutes for 1000 mg)
  • Infusion (diluted in 0.9% sodium chloride) 1, 5
• Maximum recommended cumulative dose is 1000 mg iron/week 1
• Monitor patients for at least 30 minutes after administration for adverse reactions 1

Oral Iron Therapy

• Oral iron supplementation is NOT recommended for iron deficiency in heart failure patients 1
• The IRONOUT-HF trial showed that oral iron:
  • Minimally replenished iron stores
  • Did not improve exercise capacity or heart failure symptoms
  • Is poorly tolerated with gastrointestinal side effects in up to 60% of patients 1

Monitoring

• Re-evaluate iron status 3 months after IV iron administration 1
• Avoid early re-evaluation (within 4 weeks) as ferritin levels increase markedly following IV iron administration 1
• Consider routine evaluation of iron parameters 1-2 times per year in CHF patients 1
• Re-evaluate iron status if:
  • Patients remain symptomatic despite optimal heart failure therapy
  • Hemoglobin levels decrease 1

Contraindications and Cautions

• Contraindications for IV FCM include:
  • Hypersensitivity to FCM or its components
  • Known hypersensitivity to other parenteral iron products
  • Non-iron deficiency anemia
  • Iron overload or disturbances in iron utilization 1
• Use with caution in patients with:
  • Acute or chronic infection (stop treatment in ongoing bacteremia)
  • History of drug allergies, severe asthma, eczema, or atopic allergies
  • Immune or inflammatory conditions 1
• Not evaluated in patients with Hb >15 g/dL 1

Clinical Implications

• Iron deficiency in CHF is associated with:
  • Reduced exercise capacity
  • Worse NYHA functional class
  • Poorer quality of life
  • Increased risk of hospitalization and mortality 1, 2
• Despite its importance, iron status is often undertested in CHF patients (tested in only 39% of hospitalized CHF patients in one study) 3
• Treatment of iron deficiency should be considered independently of anemia status 1, 4, 6