T2 mapping as a marker of active myocardial injury in Anderson-Fabry disease patients

Abstract Background In Anderson-Fabry Disease (AFD) with cardiac involvement, left ventricular hypertrophy (LVH) is often associated with myocardial scarring by cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) imaging. Myocardial inflammation, detected as increased T2 weighted/T2 mapping (T2m) signal, has also been reported, although its role in disease progression is still unclear. Purpose To investigate the relationship between T2m and LGE/LVH progression in AFD patients. Methods 67 paired CMR scans (1.5T) from 30 AFD patients were included. Three groups were defined according to LGE: no LGE at either scan (LGE-/-); LGE at baseline, unchanged at follow-up (LGE+/-); LGE at follow-up, appeared or increased compared to baseline (LGE+/+). T2m was measured in the infero-lateral basal segment in all scans; in LGE+ scans only, LGE was also manually contoured (ROI_LGE), and the ROI_LGE copied and pasted on the matching T2m image (T2m_ROI_LGE). See Figure 1. Troponin I (TnI) was also dosed at each scan. A univariate repeated measures analysis of variance was used to compare the groups and Tukey-Kramer correction was applied. Results As expected, the presence of LGE was strongly associated with older age, higher global and regional T2m, left ventricular (LV) mass and TnI values. As a novelty, in the LGE+/+ scans (scar appearance/progression) T2m in the ROI_LGE was higher than in the LGE+/- scans (scar unchanged) (p value 0.02). None of the other parameters, such as LV mass, TnI and global T2m values, differ between the the LGE+/+ compared to the LGE +/- group. See Table 1. Conclusions In our AFD patients’ cohort, scar progression was associated with focal increase in T2m values, i.e. T2m may identify patients with active myocardial injury. The potential implication on management/disease progression monitoring needs to be tested in future research, with longer follow-up. The role of sex, with females known to have higher average T2m values, will also need to be explored in a wider patient’s cohort.