Abstract
Abstract 5308
Iron overload in the myocardium causes cardiomyopathy and increases the mortality of the transfusion-dependent patients with beta-thalassemia major. Myocardial T2* magnetic resonance imaging (MRI) provides a rapid and reproducible measure of cardiac iron loading and is being increasingly used worldwide for monitoring of transfusion-dependent thalassemia patients. Recent studies associate myocardial siderosis (T2* < 20 ms) with left ventricular (LV) dysfunction. However its relation with the right ventricular (RV) dysfunction has not yet been fully addressed. The aim of this study is to compare the relationship between cardiac T2* and RV function in transfusion-dependent beta-thalassemia major patients treated in a single institution in two different time points four years apart.
Hundred patients (55 men; mean age, 25.8 ± 8,28 years) systematically transfused and iron chelated with different regimens were enrolled in the study. All MRI scans were performed at the beginning of the study and 4 years later. Each scan, acquired with an imager equipped with a 1.5 T magnet, included the measurement of heart T2* (mid-septum) together with LV and RV volumes, ejection fraction (EF ) and mass using previously published techniques.
:Mean ferritin, mean T2* and mean RVEF at baseline was 1517 ± 1117 ng/ml, 33,39 ± 15,6 ms and 68 ± 5,37% respectively. There was no evident correlation between T2* and RVEF for the entire group as well as for the group with abnormal T2*. Four years later the T2* MRI was 36,64 ± 14,46 % ms expressing a statistical significant change (p<0.05). Mean ferritin and mean RVEF was 1275 ± 1045 ng/ml and 67,4±8,3% respectively. There was no other significant correlation between T2* and RESV, REDV for the entire group in the checked time points. At the beginning of the study, 20 out of the 100 patients had a T2* measurement below 20ms. At the end of the study 11 patients continued to have abnormal T2*.Four of the responders were treated with Deferiprone (out of 5), two with Deferasirox (out of 4) and three out of 5 with combination therapy (Desferrioxamine and deferiprone). All 6 patients treated with Desferrioxamine remained abnormal, although with better T2* measurements. Although there was a significant change in T2* measurements (p=0,018) in the group with abnormal T2*, RVEF did not show equally alteration.
Myocardial iron deposition by MRI does not seem to be associated with RV dysfunction. The number of responders was too small to allow conclusions for most effective therapy. The only limitation of our study is that in contrast with other reports the percentage of patients with abnormal T2* was smaller (20%). Larger studies are required to determine the relation of right ventricular function and cardiac iron overload.
Vlachaki:Novartis Hellas S.A.C.I.:. Oikonomou:Novartis Hellas S.A.C.I.:.
Author notes
Asterisk with author names denotes non-ASH members.
