Reproducibility of native myocardial T1 mapping in the assessment of Fabry disease and its role in early detection of cardiac involvement by cardiovascular magnetic resonance

Abstract

BackgroundCardiovascular magnetic resonance (CMR) derived native myocardial T1 is decreased in patients with Fabry disease even before left ventricular hypertrophy (LVH) occurs and may be the first non-invasive measure of myocyte sphingolipid storage. The relationship of native T1 lowering prior to hypertrophy and other candidate early phenotype markers are unknown. Furthermore, the reproducibility of T1 mapping has never been assessed in Fabry disease.MethodsSixty-three patients, 34 (54%) female, mean age 48 ± 15 years with confirmed (genotyped) Fabry disease underwent CMR, ECG and echocardiographic assessment. LVH was absent in 25 (40%) patients. Native T1 mapping was performed with both Modified Look-Locker Inversion recovery (MOLLI) sequences and a shortened version (ShMOLLI) at 1.5 Tesla. Twenty-one patients underwent a second scan within 24 hours to assess inter-study reproducibility. Results were compared with 63 healthy age and gender-matched volunteers.ResultsMean native T1 in Fabry disease (LVH positive), (LVH negative) and healthy volunteers was 853 ± 50 ms, 904 ± 46 ms and 968 ± 32 ms (for all p < 0.0001) by ShMOLLI sequences. Native T1 showed high inter-study, intra-observer and inter-observer agreement with intra-class correlation coefficients (ICC) of 0.99, 0.98, 0.97 (ShMOLLI) and 0.98, 0.98, 0.98 (MOLLI). In Fabry disease LVH negative individuals, low native T1 was associated with reduced echocardiographic-based global longitudinal speckle tracking strain (−18 ± 2% vs −22 ± 2%, p = 0.001) and early diastolic function impairment (E/E’ = 7 [6–8] vs 5 [5–6], p = 0.028).ConclusionNative T1 mapping in Fabry disease is a reproducible technique. T1 reduction prior to the onset of LVH is associated with early diastolic and systolic changes measured by echocardiography.

T1 Mapping in Characterizing Myocardial Disease

“…91,106,107 From a clinical perspective, T1 indices can support differentiation of the infiltrative hypertrophic phenocopies in suspected cardiac amyloid infiltration: normal T1 indices can virtually exclude the presence of amyloid disease. On the contrary, significantly raised T1 indices point toward HCM or cardiac amyloid, 84,87,89 whereas low T1 values might raise the prospect of Fabry's disease in the appropriate setting.…”

Constancy of Spatial Variation in Diffuse Myocardial Disease

“…In FD, low native T1 values specify myocardial involvement from glycosphingolipid accumulation. 10,11 The international multicenter nature of this study underscores its generalizability and distinguishes the scientific rigor of this study.…”

The Role of Cardiovascular Magnetic Resonance Imaging in Heart Failure

“…In one study, native T1 was lowered in patients with genotype-positive, LVH-negative AFD, although correlation with lipid burden on biopsy was not performed. 136 Current guidelines advocate the CMR measures of LV wall thickness, mass index and LGE to guide enzyme replacement therapy in patients with AFD.…”