Four‑Dimensional Echocardiographic Evaluation of Cardiac Iron Overload in Patients with Beta-Thalassemia Major.

Abstract

Cardiac magnetic resonance imaging is the gold standard to detect cardiac iron overload in patients with beta-thalassemia. The aim of this study was to evaluate cardiac iron overload using four-dimensional transthoracic echocardiography in thalassemia patients with and without cardiac involvement detected by T2* value and to compare the two techniques. This cross-sectional and observational study was conducted in 44 patients diagnosed with thalassemia major. Left ventricular systolic function was assessed using four-dimensional speckle tracking echocardiography-derived global longitudinal (GLS), circumferential, radial, and area strain indices. Left ventricular ejection fraction, volumes, and mass index were similar between the patients with T2* values less than 20ms as compared to those with T2* values greater than 20ms. However, patients with lower T2* values had significantly higher GLS values (-17.0% vs. -19.8%, p < 0.001) compared with those with higher T2* values. GLS demonstrated a sensitivity of 91.7% and a specificity of 71.9% at a cut-off value of -18.5%; however, sensitivity was 75%, and the specificity was 84.4% at a cut-off value of -17.5%. For -18.5%, the positive predictive value was 55%, and the negative predictive value was 95.8%; for -17.5%, these values were 64.2 and 90%, respectively. This novel echocardiographic method, tested for the first time in our study in comparison with cardiac MRI in an adult patient group, has been shown to predict cardiac iron overload in thalassemia patients in the subclinical period without LVEF decline. Four-dimensional GLS is a marker with high sensitivity and negative predictive value.