Improvement in Left Atrial Strain Following Ferric Carboxymaltose in Heart Failure: An Analysis of the Myocardial-IRON Trial

Aims Iron deficiency (ID) is associated with an impaired cardiac function and remodelling in heart failure (HF). Treatment with ferric carboxymaltose (FCM) has been showed recently to improve biventricular systolic function and ventricular strain parameters in patients with HF with reduced ejection fraction and ID, but there is no evidence on the benefit of FCM on the left atrium (LA). In this study, we aimed to evaluate the effect of FCM on LA longitudinal strain (LA-LS). Methods and results This is a post hoc subanalysis of a double-blind, placebo-controlled, randomized clinical trial that enrolled 53 ambulatory patients with HF, left ventricular ejection fraction (LVEF) < 50%, and ID [Myocardial-IRON trial (NCT03398681)], treated with FCM or placebo. Cardiac magnetic resonance-featured tracking (CMR-FT) strain changes were evaluated before and 7 and 30 days after randomization using linear mixed regression analysis. The median age of the sample was 68 years (interquartile range: 64–76), and 20 (69%) were men. Mean ± standard deviation of LVEF was 39 ± 11%, and most (97%) were in stable New York Heart Association class II. At baseline, mean LA-LS was −8.9 ± 3.5%. At 30 days, and compared with placebo, LA-LS significantly improved in those allocated to FCM treatment arm (LA-LS = −12.0 ± 0.5 and −8.5 ± 0.6, respectively; − ∆ 3.55%, P < 0.001). Conclusions In patients with stable HF, LVEF < 50%, and ID, treatment with FCM was associated with short-term improvements in LA-LS assessed by CMR-FT. Future works should assess the potential benefit of iron repletion on LA function.