Efficacy of Oral Iron Replacement Therapy in Pediatric Patients with Heart Failure

Abstract

Iron deficiency (ID) is associated with worse outcomes in children with systolic heart failure (HF). Oral iron replacement therapy (IRT) is first line therapy for ID in children but the efficacy of oral IRT in children with HF is unknown. We hypothesized that less than half of children with HF and ID would have replenishment of their iron stores with oral IRT. We performed a single center retrospective cohort study of patients aged ≤ 21 years with systolic HF and ID who received oral IRT (2-5mg/kg/day) between 01/2017 and 12/2018. ID was defined as ≥2 of the following: serum iron <50 mcg/dL, serum ferritin <20 ng/mL, transferrin >300 ng/mL, transferrin saturation <15%. Iron studies and hematologic indices pre and post IRT were compared in patients who received ≥6 weeks of therapy (to allow adequate duration of IRT to assess response) using paired-samples Wilcoxon test. Forty-two independent courses of oral IRT (in 40 patients) met inclusion criteria. The cohort was 52% male with median age 13 yrs (IQR 5 - 16 yrs). HF etiologies included cardiomyopathy (57%), congenital heart disease (31%), and history of heart transplantation with graft dysfunction (12%). Patients received ferrous sulfate (40/42) or ferrous gluconate (2/42). Median duration of IRT was 68d (IQR 32 - 145d). Twenty-nine patients received ≥6 weeks of IRT and were included for the analysis for response to oral IRT. Post IRT iron testing was available in 18 patients and post IRT hemogram was available in 26 patients. Serum iron and hematologic indices of the overall cohort as well as comparison of indices pre and post oral IRT are shown (Table). While there was an improvement in serum iron studies, 50% (9/18) of the patients remained iron deficient. This is the first report about oral IRT in children with HF. Though median values of some iron parameters increased after 6weeks of oral IRT, half of the children with HF remained iron deficient and hence non-responsive to oral IRT. Further studies are needed to find the most suitable IRT for children with HF.