Echocardiographic Left Atrial Stiffness Index Predicts Myocardial Iron Overload in Pediatric β-Thalassemia.

Myocardial iron overload (MIO) is the leading cause of mortality among individuals with thalassemia major. This study aimed to evaluate the predictive value of the left atrial stiffness index (LASI) for MIO among β-thalassemia pediatric patients. A total of 105 children with thalassemia and 30 healthy controls were included in the study. The patients were categorized into three groups on the basis of LASI tertiles. MIO was assessed via cardiac magnetic resonance (CMR) T2* imaging. The LASI differed significantly between patients and controls (p < 0.001). The LASI and E/e' ratio were negatively correlated with the CMR T2* value (LASI: r = -0.76, p < 0.001; E/e': r = -0.48, p < 0.001), whereas left atrial reservoir strain (LASr), global longitudinal strain (GLS), and left atrial strain conduit strain (LAScd) were positively correlated with the CMR T2* value (LASr: r = 0.64, p = 0.002; GLS: r = 0.70, p < 0.001; LAScd: r = 0.57, p = 0.009). Restricted cubic spline (RCS) analysis revealed nonlinear associations between the LASI, GLS, and CMR T2* values (nonlinearity p < 0.001). In pediatric thalassemia patients, the LASI, GLS, and LASr independently predicted MIO. The LASI demonstrated the highest diagnostic accuracy (AUC = 0.90; optimal cutoff: 22.68%), outperforming GLS (AUC = 0.76; cutoff: 18.70%) and LASr (AUC = 0.80; cutoff: 37.05%) (DeLong test: p = 0.048 vs. GLS; p = 0.022 vs. LASr). The LASI is strongly correlated with the CMR T2* value and is a promising tool for predicting MIO in pediatric patients with thalassemia.