ABSTRACT
AIMS: Heart failure (HF) is a proinflammatory disease often associated with the onset of iron deficiency (ID). ID alters mitochondrial function, reducing the generation of cellular energy in skeletal muscle and cardiomyocytes. This study aimed to analyse the response of patients with HF to intravenous iron administration according to the type of HF: preserved ejection fraction (HFpEF) or reduced ejection fraction (HFrEF). METHODS AND RESULTS: We conducted a retrospective, single-centre study of 565 consecutive outpatients diagnosed with HF, recruited over 5 years, who were given intravenous ferric carboxymaltose (FCM) for the treatment of ID [defined as ferritin < 100 µg/L or ferritin 100-300 µg/L with transferrin saturation (TSAT) < 20%]. Clinical, laboratory, and echocardiographic parameters were analysed before and after administration. After FCM administration, overall ferritin, TSAT, and haemoglobin levels increased up to 5-fold, 1.6-fold, and 1.1-fold, respectively, relative to baseline values in HF patients with reduced and preserved ejection fraction (P < 0.0001), with a greater increase in ferritin and TSAT in HFpEF patients. The left ventricular ejection fraction of the overall series improved by 8 percentage points in both types of HF (from 40% to 48%, P < 0.0001). The percentage of patients with normalization of right ventricular function increased by 6.9 points (from 74.1% to 81%) in HFpEF patients and by 6.4 points (from 53% to 59.4%) in the HFrEF subgroup (P < 0.0001). New York Heart Association functional status slightly improved, from a median of 2.4 (interquartile range, IQR: 2-2.7) to 1.9 (IQR: 1.5-2.5; P < 0.0001) after FCM in both types of HF. No changes were noted in plasma levels of liver enzymes, creatinine, or natriuretic peptide (P > 0.05). CONCLUSIONS: Intravenous iron administration appeared to improve ejection fraction and cardiac functional status in outpatients with ID and HF with both preserved and reduced ejection fraction.