title: 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: BACKGROUND
  Cardiovascular 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.
  
  
  METHODS
  Sixty-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.
  
  
  RESULTS
  Mean 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).
  
  
  CONCLUSIONS
  Native 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.
authors.forename: Silvia
authors.initials: S
authors.lastname: Pica
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Sado
authors.forename: Viviana
authors.initials: V
authors.lastname: Maestrini
authors.forename: Marianna
authors.initials: M
authors.lastname: Fontana
authors.forename: Steven K
authors.initials: SK
authors.lastname: White
authors.forename: Thomas
authors.initials: T
authors.lastname: Treibel
authors.forename: Gabriella
authors.initials: G
authors.lastname: Captur
authors.forename: Sarah
authors.initials: S
authors.lastname: Anderson
authors.forename: Stefan K
authors.initials: SK
authors.lastname: Piechnik
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Robson
authors.forename: Robin H
authors.initials: RH
authors.lastname: Lachmann
authors.forename: Elaine
authors.initials: E
authors.lastname: Murphy
authors.forename: Atul
authors.initials: A
authors.lastname: Mehta
authors.forename: Derralyn
authors.initials: D
authors.lastname: Hughes
authors.forename: Peter
authors.initials: P
authors.lastname: Kellman
authors.forename: Perry M
authors.initials: PM
authors.lastname: Elliott
authors.forename: Anna S
authors.initials: AS
authors.lastname: Herrey
authors.affiliation: The Heart Hospital, 16-18 Westmoreland Street, London W1G 8PH, UK. j.moon@ucl.ac.uk.
authors.forename: James C
authors.initials: JC
authors.lastname: Moon
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D018450:Disease Progression; D042241:Early Diagnosis; D015150:Echocardiography, Doppler; D000795:Fabry Disease / Q000150:complications* / Q000175:diagnosis / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010641:Phenotype; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016277:Ventricular Function, Left; D055815:Young Adult