Prevalence of Anemia and Iron Deficiency in Pediatric Patients on Ventricular Assist Devices

Intravenous iron therapy in pediatrics: who should get it and when is the right time?

Iron-deficiency anemia occurs most commonly in young children due to a low-iron diet and adolescent girls due to menstrual blood loss. However, children with gastrointestinal conditions such as intestinal failure, inflammatory bowel disease, celiac disease, and/or other chronic conditions, including chronic kidney disease and heart failure, also commonly have iron deficiency. Many patients with classic iron-deficiency anemia will improve with oral iron therapy. However, in children who have an incomplete response to oral iron, intravenous iron therapy is increasingly being used. Benefits of intravenous iron therapy include a rapid repletion of iron stores in addition to resolution of anemia, less gastrointestinal side effects, and relief for patients and families struggling with long-term iron supplementation. Indications for first-line therapy with intravenous iron in children with chronic conditions have also increased. Four intravenous iron formulations have approved indications in pediatrics, and many are increasingly used off-label in children as well. Here we discuss the indications and appropriate timing of intravenous iron therapy in children with a wide range of underlying etiologies.

Poor efficacy of oral iron replacement therapy in pediatric patients with heart failure

INTRODUCTION

Iron deficiency is associated with worse outcomes in children and adults with systolic heart failure. While oral iron replacement has been shown to be ineffective in adults with heart failure, its efficacy in children with heart failure is unknown. We hypothesised that oral iron would be ineffective in replenishing iron stores in ≥50% of children with heart failure.

METHODS

We performed a single-centre retrospective cohort study of patients aged ≤21 years with systolic heart failure and iron deficiency who received oral iron between 01/2013 and 04/2019. Iron deficiency 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 haematologic indices pre- and post-iron therapy were compared using paired-samples Wilcoxon test.

RESULTS

Fifty-one children with systolic heart failure and iron deficiency (median age 11 years, 49% female) met inclusion criteria. Heart failure aetiologies included cardiomyopathy (51%), congenital heart disease (37%), and history of heart transplantation with graft dysfunction (12%). Median dose of oral iron therapy was 2.9 mg/kg/day of elemental iron, prescribed for a median duration of 96 days. Follow-up iron testing was available for 20 patients, of whom 55% (11/20) remained iron deficient despite oral iron therapy.

CONCLUSIONS

This is the first report on the efficacy of oral iron therapy in children with heart failure. Over half of the children with heart failure did not respond to oral iron and remained iron deficient.

Preoperative Iron Deficiency Is Associated With Increased Blood Transfusion in Infants Undergoing Cardiac Surgery

Background

Iron deficiency (ID) is common in patients undergoing cardiac surgery, which is associated with adverse outcomes. However, the relevance of ID in congenital heart disease is still unclear. This study aimed to investigate the characteristics of preoperative ID and its association with clinical outcomes in infants undergoing cardiac surgery with cardiopulmonary bypass.

Methods

In this retrospective study, 314 patients undergoing cardiac surgery were assigned into three groups according to their preoperative ID status. Absolute ID was defined by serum ferritin <12 μg/L, and functional ID was defined by serum ferritin level at 12–30 μg/L and transferrin saturation <20%. Baseline characteristics were compared between groups and multiple logistic regression was used to identify predictors for ID. The association between ID and clinical outcomes, including allogenic blood transfusion requirements, was also evaluated.

Results

Among the 314 patients included, 32.5% were absolute ID and 28.7% were functional ID. Patients with absolute ID were more often of higher weight, cyanotic heart disease, and anemia. The presence of absolute ID was associated with an increase in postoperative blood transfusion (OR 1.837, 95% CI 1.016–3.321, p = 0.044). There was no significant difference in postoperative morbidity, mortality, and the length of hospital stay.

Conclusions

Absolute ID was associated with preoperative anemia and cyanotic heart disease, and was an independent risk factor for postoperative blood transfusion. Further research should better explore the definition of ID and its impact on outcomes in pediatric cardiac surgery.

Iron Deficiency Is Associated with Adverse Outcomes in Pediatric Heart Failure

OBJECTIVE

To evaluate the prevalence of iron deficiency and its association with outcomes in children with heart failure.

STUDY DESIGN

A single-center retrospective cohort study of patients with heart failure aged 1-21 years from July 2012 to June 2017 with available serum iron studies was performed. Subjects were analyzed in 2 groups: biventricular systolic heart failure (BiV) and single-ventricle congenital heart disease with systolic heart failure (SV). Iron deficiency was defined as ≥2 of the following: serum iron <50 μg/dL, serum ferritin <20 ng/mL, transferrin >300 ng/mL, or transferrin saturation <15%. The primary outcome was a composite adverse event (CAE) of ventricular assist device implantation, heart transplantation, or death, at 3 and 6 months from time of iron studies.

RESULTS

Of the 107 subjects (77 BiV, 30 SV) included in the study, 56% were iron deficient. Demographics, etiology of heart failure, and chronicity of heart failure symptoms were not associated with iron deficiency. On multivariable analysis, in group BiV, iron deficiency was associated with CAE at 3 months (79% iron deficiency in CAE group vs 37% iron deficiency in non-CAE, P = .001, OR 7, 95% CI 2-21) and 6 months (76% iron deficiency in CAE vs 35% iron deficiency in non-CAE, P = .002, OR 7, 95% CI 2-24). In group SV, iron deficiency was associated with CAE at 6 months (79% iron deficiency in CAE vs 29% iron deficiency in non-CAE, P = .014, OR 8, 95% CI 2-32).

CONCLUSIONS

Iron deficiency was present in 56% of the pediatric patients with heart failure who were evaluated with iron studies. Iron deficiency was associated with greater risk of ventricular assist device implantation, heart transplantation, or death.