Comparison of Efficacy of Oral and Intravenous Iron Replacement Therapy in Children with Systolic Heart Failure and Iron Deficiency

Abstract

Purpose Iron deficiency (ID) is associated with increased risk of ventricular assist device implantation, transplant, or death in children with systolic heart failure (HF). Oral iron replacement is standard therapy for ID. However retrospective studies in children with HF estimate its efficacy at ∼50%. There are no data comparing the efficacy of oral and intravenous (IV) iron therapy in children with systolic HF. Methods In July 2019, we instituted a screening and treatment protocol for ID in children with systolic HF. We performed a retrospective analysis of patients who were screened with this protocol between 07/2019 and 10/2020. ID was defined as the presence of ≥2 of the following 4 criteria on serum iron testing: iron 300 ng/mL, transferrin saturation Results Forty patients with systolic HF (21 male, median age 4.5 years, 28 cardiomyopathy and 12 congenital heart disease) met inclusion criteria. Nine received oral iron while 31 received IV iron. Post-therapy iron studies were available for 6/9 of the oral iron cohort and 28/31 of the IV iron cohort. The oral and IV iron cohorts were similar in terms of demographics, etiology or chronicity of HF, renal dysfunction, and mechanical ventilation. Pre-treatment serum BNP was higher in the IV iron cohort (median 1092 vs 55, p = 0.028) compared to the oral iron cohort. At 3 months, iron therapy was effective in 50% (3/6) of the oral iron cohort, compared to 86% (24/28) of those on IV iron (p = 0.086). By 6 months, ID was effectively treated in 50% (3/6) of patients on oral iron, compared to 89% (25/28) of patients on IV iron (p = 0.053). Demographics, etiology or chronicity of HF, BNP, renal dysfunction, and mechanical ventilation were not associated with efficacy of iron therapy at 3 or 6 months. Conclusion IV iron tended to be more effective than oral iron in treating ID in children with systolic HF, despite the IV iron cohort having higher BNP levels and being presumably sicker. This is the first pediatric data on the topic, although statistical significance was limited by small sample size. Larger studies are needed to guide effective therapy for ID in children with systolic HF.