title: Native T1 mapping in transthyretin amyloidosis.
abstract: OBJECTIVE
  The aims of the study were to explore the ability of native myocardial T1 mapping by cardiac magnetic resonance to: 1) detect cardiac involvement in patients with transthyretin amyloidosis (ATTR amyloidosis); 2) track the cardiac amyloid burden; and 3) detect early disease.
  
  
  BACKGROUND
  ATTR amyloidosis is an underdiagnosed cause of heart failure, with no truly quantitative test. In cardiac immunoglobulin light-chain amyloidosis (AL amyloidosis), T1 has high diagnostic accuracy and tracks disease. Here, the diagnostic role of native T1 mapping in the other key type of cardiac amyloid, ATTR amyloidosis, is assessed.
  
  
  METHODS
  A total of 3 groups were studied: ATTR amyloid patients (n = 85; 70 males, age 73 ± 10 years); healthy individuals with transthyretin mutations in whom standard cardiac investigations were normal (n = 8; 3 males, age 47 ± 6 years); and AL amyloid patients (n = 79; 55 males, age 62 ± 10 years). These were compared with 52 healthy volunteers and 46 patients with hypertrophic cardiomyopathy (HCM). All underwent T1 mapping (shortened modified look-locker inversion recovery); ATTR patients and mutation carriers also underwent cardiac 3,3-diphosphono-1,2-propanodicarboxylicacid (DPD) scintigraphy.
  
  
  RESULTS
  T1 was elevated in ATTR patients compared with HCM and normal subjects (1,097 ± 43 ms vs. 1,026 ± 64 ms vs. 967 ± 34 ms, respectively; both p < 0.0001). In established cardiac ATTR amyloidosis, T1 elevation was not as high as in AL amyloidosis (AL 1,130 ± 68 ms; p = 0.01). Diagnostic performance was similar for AL and ATTR amyloid (vs. HCM: AL area under the curve 0.84 [95% confidence interval: 0.76 to 0.92]; ATTR area under the curve 0.85 [95% confidence interval: 0.77 to 0.92]; p < 0.0001). T1 tracked cardiac amyloid burden as determined semiquantitatively by DPD scintigraphy (p < 0.0001). T1 was not elevated in mutation carriers (952 ± 35 ms) but was in isolated DPD grade 1 (n = 9, 1,037 ± 60 ms; p = 0.001).
  
  
  CONCLUSIONS
  Native myocardial T1 mapping detects cardiac ATTR amyloid with similar diagnostic performance and disease tracking to AL amyloid, but with lower maximal T1 elevation, and appears to be an early disease marker.
authors.affiliation: The Heart Hospital, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom; National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Marianna
authors.initials: M
authors.lastname: Fontana
authors.affiliation: The Heart Hospital, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom; National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Sanjay M
authors.initials: SM
authors.lastname: Banypersad
authors.affiliation: The Heart Hospital, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Treibel
authors.affiliation: The Heart Hospital, London, United Kingdom; Department of Cardiovascular, Respiratory, Nephrologic, Anaesthesiologic and Geriatric Science, La Sapienza University of Rome, Rome, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Maestrini
authors.affiliation: The Heart Hospital, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Sado
authors.affiliation: The Heart Hospital, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom.
authors.forename: Steven K
authors.initials: SK
authors.lastname: White
authors.affiliation: The Heart Hospital, London, United Kingdom.
authors.forename: Silvia
authors.initials: S
authors.lastname: Pica
authors.affiliation: The Heart Hospital, London, United Kingdom.
authors.forename: Silvia
authors.initials: S
authors.lastname: Castelletti
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: Stefan K
authors.initials: SK
authors.lastname: Piechnik
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Robson
authors.affiliation: National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Janet A
authors.initials: JA
authors.lastname: Gilbertson
authors.affiliation: National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Dorota
authors.initials: D
authors.lastname: Rowczenio
authors.affiliation: National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: David F
authors.initials: DF
authors.lastname: Hutt
authors.affiliation: National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Helen J
authors.initials: HJ
authors.lastname: Lachmann
authors.affiliation: National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Ashutosh D
authors.initials: AD
authors.lastname: Wechalekar
authors.affiliation: National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Whelan
authors.affiliation: National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Julian D
authors.initials: JD
authors.lastname: Gillmore
authors.affiliation: National Amyloidosis Centre, University College London, London, United Kingdom.
authors.forename: Philip N
authors.initials: PN
authors.lastname: Hawkins
authors.affiliation: The Heart Hospital, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom. Electronic address: james.moon@uclh.nhs.uk.
authors.forename: James C
authors.initials: JC
authors.lastname: Moon
mesh_terms: D000686:Amyloidosis / Q000175:diagnosis*; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis*; D006801:Humans; D008297:Male
keywords: T1 mapping; amyloidosis; cardiac magnetic resonance; transthyretin