Myocardial iron loading in transfusion-dependent thalassemia and sickle cell disease.
Cardiac T2* (magnetic resonance imaging relaxation parameter) is abnormally low in approximately 40% of adults with thalassemia major (TM), suggesting myocardial iron deposition, but it is unknown at what age this occurs. To address this question, we measured cardiac T2* and function in 19 young patients (aged 7-26 years) with TM as well as 17 patients receiving long-term transfusions for sickle cell anemia (SCA) matched for age, sex, and liver iron content. Cardiac T2* was normal in all of the SCA patients but was low (high iron) in 8 of 19 TM patients. Abnormal T2* was observed only in the TM patients receiving transfusions for 13 years or longer and was correlated with ferritin but not liver iron levels. Cardiac dysfunction was present in 3 of the 8 patients with low T2*. Cardiac T2* changes have a long latency relative to liver iron accumulation. Total transfusional burden is a significant independent risk factor for low cardiac T2* and may partially account for differences observed between patients with SCA and TM.
Wood
John C
JC
Division of Pediatric Cardiology, Childrens Hospital Los Angeles, Los Angeles, CA 90027, USA. jwood@chla.usc.edu
Tyszka
J Michael
JM
Carson
Susan
S
Nelson
Marvin D
MD
Coates
Thomas D
TD
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000755:Anemia, Sickle Cell / Q000378:metabolism*; D001803:Blood Transfusion; D002648:Child; D005260:Female; D006454:Hemoglobins / Q000096:biosynthesis; D006801:Humans; D007501:Iron / Q000097:blood* / Q000378:metabolism*; D019190:Iron Overload; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D012737:Sex Factors; D013789:Thalassemia / Q000378:metabolism*; D013997:Time Factors
D006454:Hemoglobins; D007501:Iron