RESUMO
We explored the severity and risk factors for cardiac and liver iron overload (IOL) in 69 thalassemia patients who underwent T2* magnetic resonance imaging (T2* MRI) in a Malaysian tertiary hospital from 2011 to 2015. Fifty-three patients (76.8%) had transfusion-dependent thalassemia (TDT) and 16 (23.2%) had non transfusion-dependent thalassemia (NTDT). Median serum ferritin prior to T2* MRI was 3848.0 µg/L (TDT) and 3971.0 µg/L (NTDT). Cardiac IOL was present in 16 (30.2%) TDT patients and two (12.5%) NTDT patients, in whom severe cardiac IOL defined as T2* <10 ms affected six (11.3%) TDT patients. Liver IOL was present in 51 (96.2%) TDT and 16 (100%) NTDT patients, 37 (69.8%) TDT and 13 (81.3%) NTDT patients were in the most severe category (>15 mgFe/gm dry weight). Serum ferritin showed a significantly strong negative correlation with liver T2* in both TDT (rs = -0.507, p = 0.001) and NTDT (r = -0.762, p = 0.002) but no correlation to cardiac T2* in TDT (r = -0.252, p = 0.099) as well as NTDT (r = -0.457, p = 0.100). For the TDT group, regression analysis showed that cardiac IOL was more severe in males (p = 0.022) and liver IOL was more severe in the Malay ethnic group (p = 0.028) and those with higher serum ferritin levels (p = 0.030). The high prevalence of IOL in our study and the poor correlation between serum ferritin and cardiac T2* underline the need to routinely screen thalassemia patients using T2* MRI to enable the early detection of cardiac IOL.
