The Impact of Intravenous Ferric Carboxymaltose on Reverse Electrical Remodeling Following Cardiac Resynchronization Therapy.

Abstract

The influence of intravenous ferric carboxymaltose (FCM) on reverse electrical remodeling (RER) in patients with heart failure with reduced ejection fraction (HFrEF) post-cardiac resynchronization therapy (CRT) is unknown. This study examines the effect of iron replacement using intravenous FCM on RER in CRT-implanted HFrEF patients with iron deficiency anemia. We retrospectively analyzed 65 patients with successful CRT-defibrillator between March 2017 and January 2020, all with iron deficiency anemia at implantation. The cohort comprised 35 patients in the FCM group and 30 in the non-FCM group. Follow-up data were obtained from visits 6 months post-CRT implantation including baseline characteristics, echocardiographic left ventricular measurements, and electrocardiograms. Changes in intrinsic QRS duration (iQRS) and left ventricular ejection fraction (LVEF) from baseline to 6 months were assessed. The FCM group showed a greater reduction in iQRS duration compared to the non-FCM group (-10.4 ± 2.2 ms vs. -3 ± 2.9 ms, p < 0.0001). Additionally, at the 6-month follow-up, the increase in LVEF was higher in the FCM group than in the non-FCM group (+3.6 ± 1.6% vs. -0.1 ± 1.7%, p < 0.0001). Correlations were found between changes in ferritin levels and iQRS duration (r = -0.725, p < 0.0001) and LVEF (r = 0.712, p < 0.0001). Multivariate regression analysis revealed that elevated ferritin independently influenced the increase in LVEF (p = 0.006, β = 0.554) and the decrease in iQRS (p < 0.001, β = -0.685). Intravenous iron treatment with FCM may reduce iQRS duration and improve LVEF and functional status in HFrEF patients with iron deficiency anemia following CRT.