Is intravenous (IV) iron recommended for heart failure (HF) patients with hemoglobin (Hb) levels above normal?

From the Guidelines

Intravenous (IV) iron is not recommended for heart failure patients with hemoglobin levels above normal, specifically above 150g/L, as it provides no established benefit and may potentially cause harm. IV iron therapy is primarily indicated for heart failure patients who have iron deficiency, with or without anemia. For patients with normal or elevated hemoglobin levels who don't have documented iron deficiency (typically defined as ferritin <100 μg/L or ferritin 100-299 μg/L with transferrin saturation <20%), administering IV iron provides no established benefit and may potentially cause harm, such as oxidative stress, increased infection risk, and hemosiderosis with organ damage 1. The safety of IV iron is unknown in patients with heart failure and hemoglobin > 15 g/dL, as stated in the 2016 ESC guidelines 1. Common IV iron preparations used when indicated include iron sucrose, ferric carboxymaltose, and iron dextran, but these should be reserved for patients with confirmed iron deficiency. If a heart failure patient has elevated hemoglobin levels, this could indicate other conditions like polycythemia that require different management approaches. Any iron therapy should be guided by comprehensive iron studies rather than hemoglobin levels alone, as iron deficiency can exist even with normal hemoglobin and can contribute to heart failure symptoms independently of anemia.

Key considerations for IV iron therapy in heart failure patients include:

• The presence of iron deficiency, defined by low ferritin levels or low transferrin saturation
• The absence of contraindications, such as elevated hemoglobin levels or conditions that may be worsened by iron supplementation
• The potential benefits of IV iron therapy, including improved functional capacity, quality of life, and reduced hospitalizations
• The potential risks of IV iron therapy, including oxidative stress, infection, and hemosiderosis

Recent guidelines, including the 2022 head-to-head comparison between the ESC and ACC/AHA/HFSA heart failure guidelines, emphasize the importance of individualized treatment approaches and careful consideration of the benefits and risks of IV iron therapy in heart failure patients 1.

From the Research

Intravenous Iron in Heart Failure Patients

• The use of intravenous (IV) iron in heart failure (HF) patients is a topic of ongoing research, with studies investigating its effects on patient outcomes 2, 3, 4, 5, 6.
• IV iron has been shown to improve symptoms, quality of life, and reduce hospitalizations in HF patients with iron deficiency 2, 4, 5, 6.
• However, the definition of iron deficiency in HF is still a topic of debate, with some studies suggesting that a serum ferritin <100 µg/L may not be the best indicator of iron deficiency 2.
• Transferrin saturation <20% has been proposed as a more reliable marker of iron deficiency in HF patients 2, 4, 5.

Hemoglobin Levels and IV Iron

• There is limited evidence to suggest that IV iron is beneficial in HF patients with hemoglobin (Hb) levels above 150g/L 3.
• In fact, one study suggests that a subset of patients receiving IV iron may have a worse outcome related to admissions and mortality compared to placebo, particularly if they do not have iron deficiency 3.
• The current evidence does not support the use of IV iron in HF patients with Hb levels above 150g/L, unless they have iron deficiency as defined by low ferritin or transferrin saturation levels 2, 4, 5, 6.

Recommendations

• HF patients should be screened for iron deficiency, defined as ferritin <100 µg/L or transferrin saturation <20% 4, 5.
• IV iron should be considered in HF patients with iron deficiency, particularly those with reduced ejection fraction (HFrEF) 4, 5, 6.
• However, the decision to administer IV iron should be individualized, taking into account the patient's overall clinical status and laboratory markers of iron deficiency 2, 3, 4, 5, 6.