Differentiation between Fabry disease and hypertrophic cardiomyopathy with cardiac T1 mapping

PurposeTo 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 methodsSeventeen patients with FD (8 men, 9 women; mean age, 48  ± 18 SD] years; 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 ± 16 SD] years; range: 22–85 years]) and 70 healthy control subjects (34 men, 36 women; mean age, 38 ± 15 SD] years; range: 18–65 years]). Cardiac T1 mapping was performed using the modified Look-Locker inversion (MOLLI®) sequence on a 1.5-T magnet. T1 values were calculated, on midventricular 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.ResultsSeptal native T1 values were significantly decreased in patients with FD (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 FD (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 FD 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 FD 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.ConclusionNative T1 values are significantly lower in patients with FD by comparison with those with HCM and healthy volunteers.