Left ventricular ejection fraction recovery in patients with heart failure treated with intravenous iron: a pilot study.

AIMS: In patients with heart failure with reduced ejection fraction (HFrEF) and iron deficiency, treatment with intravenous iron has shown a clinical improvement regardless of anaemic status. Cardiac magnetic resonance (CMR) T2* sequence has shown a potential utility for evaluating myocardial iron deficiency. We aimed to evaluate whether T2* sequence significantly changes after ferric carboximaltose (FCM) administration, and if such changes correlate with changes in left ventricle ejection fraction (LVEF).

METHODS AND RESULTS: In this pilot study, we included eight patients with chronic symptomatic (New York Heart Association II-III) HFrEF and iron deficiency. A CMR, including T2* analysis, was performed before and at a median of 43 days (interquartile range = 35-48) after intravenous FCM administration. Pearson or Spearman correlation coefficient (r) was used for bivariate contrast as appropriate. A partial correlation analysis was performed between ΔLVEF and ΔT2* while controlling for anaemia status at baseline. Anaemia was present in half of patients. After FCM administration, T2* decreased from a median of 39.5 (35.9-48) to 32 ms (32-34.5), P  = 0.012. Simultaneously, a borderline increase in median of LVEF [40% (36-44.5) to 48.5% (38.5-53), P  = 0.091] was registered. In a bivariate correlational analysis, ΔT2* was highly correlated with ΔLVEF ( r  = -0.747, P  = 0.033). After controlling for anaemia at baseline, the association between ΔT2* and ΔLVEF persisted [ r (partial): -0.865, R 2 (partial): 0.748, P  = 0.012]. A median regression analysis backed-up these findings.

CONCLUSIONS: In a small sample of patients with HFrEF and iron deficiency, myocardial iron repletion assessed by CMR was associated to left ventricular remodelling. Further studies are warranted.