Echocardiographic evaluation of left atrial strain for predicting iron overload in pediatric patients with β-thalassemia with preserved ejection fraction.

Abstract

Pediatric patients with β-thalassemia (β-TM) with preserved ejection fraction may experience early myocardial damage. This prospective study aimed to investigate left atrial (LA) function restructure in pediatric patients with β-TM by two-dimensional speckle tracking echocardiography (2D-STE) and evaluate the value of LA strain for predicting myocardial iron overload (MIO). We recruited 50 β-TM pediatric patients and 30 healthy children aged 3-14 years. The patients were assigned to a normal left ventricular (LV) lesion group (n = 20) and an enlarged LV lesion group (n = 30). Subjects all underwent echocardiography to measure conventional cardiac function parameters and LA strain parameters. The results displayed that LA reservoir strain (LASr), conduit strain (LAScd), contractile strain (LASct) and strain rate were significantly reduced in pediatric patients with β-TM with preserved ejection fraction. LASr, LAScd, and LASct were negatively correlated with the E/e' ratio, of which LASr had the most significant correlation (r= - 0.69, P < 0.001). LASr and LASct correlated positively with T2* (r = 0.70 and 0.62, respectively, all P < 0.001). In the multiple regression, LASr and LASct were independent predictors for T2*. The areas under the curve for LASr and LASct were 0.87 (P < 0.001) and 0.78 (P = 0.004), respectively. Our results demonstrated that LA strains were dramatically impaired in pediatric patients with β-TM, and LASr is an efficient indicator for detecting LV early diastolic dysfunction in β-TM pediatric patients and reflects early myocardial damage. LASr and LASct were independently predictive of MIO, but LASr was a more sensitive predictor.