Evaluation of cardiac iron overload in transfusion-dependent adult marrow failure patients by magnetic resonance imaging.

We investigated magnetic resonance imaging T2-star (MRI-T2*) values and left ventricular ejection fraction (LVEF) in 7 adult patients with bone marrow failure with heavy transfusion to elucidate the correlation between cardiac iron overload and dysfunction. We demonstrated a positive correlation between the total volume of red blood cells (RBC) transfusion and ejection fraction. The normal T2* limit value, which represents cardiac siderosis, is probably 200 mL/kg RBC transfusion. Patients with serum ferritin levels of under 5000 ng/mL and who received 200-400 mL/kg RBC transfusion showed mild but progressive decrease of the T2* value without obvious reduction of the ejection fraction, indicating that the T2* value of MRI could be a predictor for cardiac iron deposition before the appearance of myocardial dysfunction. Transfused RBC amount of >400 mL/kg or rapid elevation of ferritin level of >5000 ng/mL might be warning sign for critical cardiac dysfunction. Since iron overload of the heart is a major factor affecting co-morbidity of bone marrow failure, MRI evaluation of cardiac iron overload and functional disturbance in adult non-thalassemic patients is essential.