Iron chelators and nuclear magnetic resonance imaging (MRI) techniques for assessing
iron loading in liver and heart have greatly improved survival of thalassemic patients suffering
iron overload-associated
cardiomyopathy. However, the correlation between liver
iron concentration and myocardial
siderosis is ambiguous. Using an objective metric of time delay, scientists have demonstrated a lag in the loading and unloading of cardiac
iron with respect to that of the liver. In the present study, we further tested this hypothesis with different chelation treatments. We analyzed the effect of three chelating treatment approaches on liver and cardiac
iron content in 24 highly compliant patients who underwent 3 or more MRIs under each chelation treatment. Of the 84 MRIs considered, 32 were performed on
deferoxamine (DFO - 8 patients), 24 on
deferiprone (
DFP - 7 patients), and 28 on combined
therapy (DFO+DFP - 9 patients). In patients treated with DFO, changes in cardiac
iron significantly lagged changes in liver
iron but the opposite pattern was observed in patients treated with
DFP (p=0.005), while combined
therapy showed a pattern in-between DFO and
DFP. We conclude that the temporality of changes of cardiac and liver
iron is
chelator-dependent, so that
chelation therapy can be tailored to balance
iron elimination from the liver and the heart.