Onset of cardiac iron loading in pediatric patients with thalassemia major

Area of Science:

• Pediatric Cardiology
• Medical Imaging
• Hematology

Background:

• Thalassemia major patients require frequent blood transfusions, leading to iron overload.
• Cardiac iron loading is a major cause of morbidity and mortality in these patients.
• Early detection of cardiac iron is crucial for timely intervention.

Purpose of the Study:

• To determine the optimal timing for cardiac iron screening using magnetic resonance imaging (MRI) in pediatric patients with thalassemia major.
• To evaluate the relationship between patient age, transfusional iron burden, and cardiac iron levels.
• To assess the predictive value of liver iron and ferritin levels for cardiac iron loading.

Main Methods:

• Retrospective review of cardiac T2* assessments in 77 thalassemia major patients aged 2.5 to 18 years.
• Analysis of cardiac iron detection rates based on age groups.
• Correlation of cardiac iron with transfusional iron history, liver iron, and ferritin levels.

Main Results:

• No cardiac iron was detected in patients younger than 9.5 years.
• Cardiac iron was present in 36% of patients aged 15-18 years (odds ratio of 1.28 per year).
• All patients with cardiac iron had received at least 35 grams of transfusional iron; liver iron and ferritin did not predict cardiac iron.

Conclusions:

• Cardiac iron screening timing in thalassemia major should prioritize age and transfusional burden over general iron overload markers.
• MRI screening can be deferred until age 8 if chelation therapy started at birth and anesthesia is not required.
• Patients with suboptimal chelation, higher transfusion needs, or later transfusion initiation require earlier screening.