Impact of iron replacement therapy on six minutes walking test (functional state) in patients with heart failure with reduced ejection fraction and iron deficiency

Abstract

Background and objective: Iron deficiency may impair aerobic performance. This study aimed to assess whether intravenous iron (ferric carboxymaltose) will improve symptoms in patients with heart failure with reduced left ventricular ejection fraction and iron deficiency or not, depending on serum ferritin or transferrin saturation with or without anemia. Methods: We enrolled 100 patients with heart failure with reduced ejection fraction (less than 40%) and iron deficiency (serum ferritin less than 100 ng/ml, or between 100-299 ng/ml but transferrin saturation less than 20%). The patient received an intravenous iron supplement of ferric carboxymaltose (1000-2500mg) until the correction of their iron status. We checked the 6-minute walking test, New York Heart Association functional class, and ejection fraction for each patient at baseline, 12 weeks, and 24 weeks after intervention. Results: Our study showed a significant improvement in the patient's functional status. The 6-minute walking test, New York Heart Association functional class, improved significantly in patients at 12 weeks and continues to improve beyond 24 weeks with or without anemia. The left ventricular ejection fraction in our study was not improved significantly. Conclusion: Treatment with intravenous iron supplement (ferric carboxymaltose) in patients with chronic stable heart failure and iron deficiency, with or without anemia, improves symptoms, functional capacity, and quality of life. Keywords: Iron replacement therapy; Six minute walking test; Heart failure; Ejection fraction; Iron deficiency.