Ferric carboxymaltose reduces the burden of arrhythmic events in heart failure with reduced ejection fraction: the role of the non-invasive arrhythmic biomarkers.

Objective: Treating iron deficiency (ID) with ferric carboxymaltose (FCM) in patients with heart failure with reduced ejection fraction (HFrEF) enhances morbidity, quality of life (QoL), and exercise capacity.

Methods: In the presented single-center, prospective follow-up study, symptomatic patients with HFrEF with ID and CIEDs scheduled for IV FCM were followed up for 12-months. Arrhythmic activity was evaluated from CIEDs and non-invasive markers from Holter recordings before and after FCM. Ventricular tachycardia/ventricular fibrillation (VT/VF) episodes, non-sustained VT (nsVT), late potentials (LPs), microvolt T-wave alternans (MTWA), heart rate variability, turbulence (HRT) QTc, and premature ventricular contractions (PVCs, number, and Lown and Wolf classification) were assessed. Left ventricular EF (LVEF), global longitudinal strain (LV GLS), QoL (KCCQ, EQ-5D-5L), 6-min walking distance (6-MWD), peak oxygen consumption, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels were also recorded.

Results: Ninety-six patients in optimal medical treatment participated (median age 71.9 [12.3] years, 83% male). After FCM treatment, the VT/VF (P = 0.043) and nsVT (P < 0.001) frequency decreased significantly. The Lown and Wolf classification improved (P = 0.002) and predicted VT/VF episodes better than other markers (AUC 0.737, P = 0.001). MTWA, LPs, and HRT improved statistically significantly after FCM. Hospitalization rates and NT-proBNP levels decreased, whereas LVEF, LV GLS, 6-MWD, QoL, and peak VO2 improved statistically significantly (P < 0.001).

Conclusion: Our study provides real-world evidence that IV FCM led to statistically significant reduction in ventricular arrhythmic episodes, as well as an improvement in non-invasive arrhythmic markers.