Improvement of heart iron with preserved patterns of iron store by CMR-guided chelation therapy

Aims T*(2) multislice multiecho cardiac magnetic resonance (CMR) allows quantification of the segmental distribution of myocardial iron overload (MIO). We evaluated whether a preferential pattern MIO was preserved between two CMR scans in regularly chelated thalassaemia major (TM) patients. Methods and results We evaluated prospectively 259 TM patients enrolled in the MIO in Thalassaemia (MIOT) network with a CMR follow-up (FU) study at 18 +/- 3 months and significant MIO at baseline. The T*(2) in the 16 segments and the global value were calculated. Four main circumferential regions (anterior, septal, inferior and lateral) were defined. We identified two groups: severe (n = 80, global T*(2) <10 ms) and mild-moderate MIO (n = 179, global T*(2) = 10-26 ms). Based on the CMR reports, 56.4% of patients changed the chelation regimen. For each group, there was a significant improvement in the global heart as well as in regional T*(2) values (P < 0.0001). At the baseline, the mean T*(2) value over the anterior region was significantly lower than the values over the other regions, and the mean T*(2) over the inferior region was significantly lower than the values over the septal and the lateral regions. The same pattern was present at the FU, with a little difference for patients with mild-moderate MIO. Conclusion A preferential pattern of iron store in anterior and inferior regions was present at both CMRs, with an increment of T*(2) values at FU due to a baseline CMR-guided chelation therapy. The anterior region seems the region in which the iron accumulates first and is removed later.