Prevalence and Risk Factors for Cardiac and Liver Iron Overload in Adults with Thalassemia in Malaysia.

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.