Cardiac involvement by CMR in different genotypic groups of thalassemia major patients

Area of Science:

• Cardiology
• Genetics
• Hematology

Background:

• Beta thalassemia major (β-TM) exhibits significant phenotypic variability.
• The relationship between specific β-TM genotypes and cardiac impairment requires further investigation.

Purpose of the Study:

• To determine if distinct genotypic groups in β-TM correlate with varying degrees of cardiac involvement.
• To assess cardiac function and myocardial iron overload across different β-TM genotypes using cardiovascular magnetic resonance (CMR).

Main Methods:

• Utilized CMR T2* technique to assess myocardial iron overload (MIO).
• Quantified biventricular function via cine imaging and evaluated myocardial fibrosis using late gadolinium enhancement (LGE).
• Categorized 671 β-TM patients into three genotypic groups: β+/β° heterozygotes, β+/β+ homozygotes, and β° homozygotes.

Main Results:

• Homozygous β+/β+ patients required fewer transfusions and had higher global heart T2* values, indicating less MIO.
• Fewer β+/β+ patients presented with a global heart T2* value < 20 ms compared to other groups.
• A lower incidence of pathological left ventricular ejection fraction (LVEF) was observed in the β+/β+ group.

Conclusions:

• The β+/β+ genotype is associated with reduced MIO and preserved systolic heart function in β-TM patients.
• Genotypic characterization is crucial for tailoring the management of β-TM patients.
• These findings highlight genotype-specific cardiac profiles in β-TM.