Cor Vasa 2025, 67(6):671-676

Determinants of Ineligibility for Intravenous Iron Therapy in Patients with Heart Failure and LVEF <45%: A Retrospective Cohort Study

Jozef Dodulík^{a, b}, Kristýna Podzemná^a, Klára Musiolová^a, Jiří Vrtal^{a, b}, Jiří Plášek^{a, b}, Jan Václavík^{a, b}

^a Department of Internal Medicine and Cardiology, University Hospital Ostrava, Ostrava, the Czech Republic

^b Department of Internal Medicine, Faculty of Medicine, University of Ostrava, Ostrava, the Czech Republic

Background: Intravenous iron therapy improves symptoms and reduces hospitalizations in patients with heart failure (HF) and iron deficiency (ID). Clinical trials evaluating this therapy have often excluded patients with higher hemoglobin (HGB) levels, although current European Society of Cardiology guidelines do not specify an upper HGB limit. This study aimed to assess how HGB thresholds influence eligibility for intravenous iron among real-world HF patients with left ventricular ejection fraction (LVEF) < 45%.

Methods: We retrospectively analyzed consecutive patients attending a specialized HF outpatient clinic in 2024. ID was defined as ferritin < 100 µg/L, or 100-299 µg/L with transferrin saturation (TSAT) < 20%. Eligibility for intravenous iron was simulated using various HGB thresholds ranging from ≤150 g/L to ≤160 g/L. Clinical and laboratory characteristics of eligible and non-eligible patients were compared.

Results: Among 176 patients with LVEF < 45%, 98 (55.7%) fulfilled ID criteria. Using an HGB threshold of ≤150 g/L, only 29.5% of patients were eligible for intravenous iron. Increasing the threshold to 155 g/L and 160 g/L would expand eligibility to 38.1% and 46.7%, respectively. Patients excluded based on higher HGB levels often exhibited functional ID and elevated NT-proBNP, indicating advanced HF. All patients who met the eligibility criteria during the study period received intravenous iron.

Conclusion: A substantial proportion of HF patients with LVEF < 45% and clinically relevant ID may be excluded from intravenous iron therapy based on HGB levels, despite current guidelines not imposing a strict cutoff. A modest increase in the HGB threshold may allow more symptomatic patients to benefit from guideline-recommended treatment.

Keywords: Eligibility criteria, ESC guidelines, Heart failure, Hemoglobin threshold, Intravenous iron, Iron deficiency

Received: August 17, 2025; Revised: August 17, 2025; Accepted: September 1, 2025; Prepublished online: June 2, 2012; Published: December 15, 2025  Show citation