Alterations in iron status predict cardiac response to blood transfusion in $$\beta$$-thalassemia major

Despite significant advancements in the management of thalassemia, cardiac complications still represent a leading cause of disability and death. Heart dysfunction, although mainly related to myocardial iron overload (IO), might already manifest when the homeostasis of circulating iron species is altered. This study aimed to investigate the presence of heart function changes in relation to scheduled blood transfusions (BT) in transfusion-dependent thalassemic patients, to identify alterations in cardiac function early after BT or within a 7-10 days interval. Twenty patients (8 females; average age 41.65 years), followed at the Center for Hereditary Anemias, University Hospital of Modena, were enrolled to perform an echocardiographic evaluation (ECE) before scheduled BT (T0), a targeted ECE immediately after the transfusion (Tearly), and a targeted ECE 7-10 days thereafter (Tlate). Medical history, biochemical data, and parameters related to iron status including serum levels of labile plasma iron (LPI), non-transferrin-bound iron (NTBI), and 3 year-average serum ferritin, were collected to assess predictors of transfusion-related cardiac changes. Global longitudinal strain (GLS) at baseline was worse, on average, in patients with higher ferritin or lower serum calcium; early post-transfusion GLS improved significantly in patients with ferritin>1500 ng/mL or albumin-corrected calcium $$<8.4$$ mg/dL, whereas it remained stable in control groups. Notably, several early post-transfusion changes could be consistently predicted by variables related to iron homeostasis or transfusion status. Cardiac MRI T2* showed moderate IO in only one patient. In conclusion, $$\beta$$-thalassemic patients with hyperferritinemia or hypocalcemia are likely those who benefit most from BT in terms of systolic function. Even in the absence of overt myocardial IO, alterations in circulating iron status predict early dysfunctions in cardiac response after scheduled blood transfusion.