Differentiation between Fabry disease and hypertrophic cardiomyopathy with cardiac T1 mapping

Purpose: To evaluate the potential of non-contrast myocardial T1 mapping on cardiovascular magnetic resonance examination (CMR) in differentiating patients with Fabry disease (FD) from those with hypertrophic cardiomyopathy (HCM) and healthy control subjects. Materials and methods: Seventeen patients with FD (8 men, 9 women; mean age, 48 years +/- 18 [range: 19-73 years]; 53% with left ventricular hypertrophy [LVH]) were matched with 36 patients with hypertrophic cardiomyopathy (HCM) (22 men, 14 women; mean age, 57 years +/- 16 [SD] [range: 22-85 years]) and 70 healthy control subjects (34 men, 36 women; mean age, 38 years +/- 15 [SD]; [range: 18-65 years]). Cardiac T1 mapping was performed using the modified Look-Locker inversion (MOLLI (R)) sequence on a 1.5-T magnet. T1 values were calculated, on mid-ventricular section, for septal left ventricular segments (S8-S9) and all mid-ventricular ones (global T1 values; S7-S12). Statistical analysis included unpaired Mann-Whitney test, receiver operating characteristic curve and likelihood ratios. Results: Septal native T1 values were significantly decreased in patients with AFD (889 +/- 61 [SD] ms; range: 784-980 ms) compared to those with HCM (995 + 48 [SD] ms; range: 935-1125 ms) P< 0.001) and versus healthy controls (965 +/- 29 [SD] ms; range: 910-1028 ms) (P< 0.001). Global native T1 values were also significantly decreased in patients with AFD (891 +/- 49 [SD] ms; range 794-970 ms) compared to those with HCM (995 +/- 34 [SD] ms; range: 952-1086 ms) (P < 0.001) and versus healthy controls (966 +/- 27 [SD] ms; range: 920-1042 ms) (P < 0.001). A septal left ventricular native T1 cutoff value of 940 ms could distinguish AFD from HCM with 88% sensitivity (95% CI: 73-100%) and 92% specificity (95% CI: 83-100%). Positive likelihood ratio was 11, negative likelihood ratio was 0.12. Compared to controls, the same threshold could distinguish AFD with 88% sensitivity (95% CI: 73-100%) and 86% specificity (95% CI: 78-94%). Positive likelihood ratio was 6.3, negative likelihood ratio was 0.14. T1 value was abnormal in 4 of 8 (50%) of FD patients who did not have LVH. Conclusion: Native T1 values are significantly lower in patients with AFD compared with HCM and healthy volunteers. (C) 2019 Societe francaise de radiologie. Published by Elsevier Masson SAS. All rights reserved.