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

Area of Science:

• Cardiology
• Medical Imaging
• Hematology

Background:

• Cardiac magnetic resonance imaging (CMR) is the gold standard for assessing cardiac iron overload in beta-thalassemia.
• Iron overload in beta-thalassemia can lead to significant cardiac complications.
• Early detection of cardiac iron overload is crucial for timely intervention.

Purpose of the Study:

• To evaluate cardiac iron overload using four-dimensional transthoracic echocardiography (4D-TTE) in thalassemia patients.
• To compare 4D-TTE with cardiac MRI (T2* values) for detecting cardiac iron overload.
• To assess the utility of global longitudinal strain (GLS) in identifying subclinical cardiac iron overload.

Main Methods:

• A cross-sectional, observational study involving 44 patients with thalassemia major.
• Assessment of left ventricular systolic function using 4D-TTE-derived GLS and other strain indices.
• Comparison of echocardiographic findings with cardiac MRI T2* values.

Main Results:

• Left ventricular ejection fraction, volumes, and mass index were similar between patients with T2* < 20 ms and T2* > 20 ms.
• Patients with lower T2* values exhibited significantly higher GLS values (indicating impaired function).
• GLS demonstrated high sensitivity (91.7%) and negative predictive value (95.8%) at a cut-off of -18.5% for detecting cardiac iron overload.

Conclusions:

• Four-dimensional GLS can predict cardiac iron overload in thalassemia patients during the subclinical period, even without a decline in left ventricular ejection fraction.
• 4D-TTE, specifically GLS, offers a novel, non-invasive method for early detection of cardiac iron overload.
• GLS is a sensitive marker with a high negative predictive value for subclinical cardiac iron overload in beta-thalassemia.