title: Relationship between native papillary muscle T1time and severity of functional mitral regurgitation in patients with non-ischemic dilated cardiomyopathy.
abstract: BACKGROUND
  Functional mitral regurgitation is one of the severe complications of non-ischemic dilated cardiomyopathy (DCM). Non-contrast native T1mapping has emerged as a non-invasive method to evaluate myocardial fibrosis. We sought to evaluate the potential relationship between papillary muscle T1time and mitral regurgitation in DCM patients.
  
  
  METHODS
  Forty DCM patients (55 ± 13 years) and 20 healthy adult control subjects (54 ± 13 years) were studied. Native T1mapping was performed using a slice interleaved T1mapping sequence (STONE) which enables acquisition of 5 slices in the short-axis plane within a 90 s free-breathing scan. We measured papillary muscle diameter, length and shortening. DCM patients were allocated into 2 groups based on the presence or absence of functional mitral regurgitation.
  
  
  RESULTS
  Papillary muscle T1time was significantly elevated in DCM patients with mitral regurgitation (n = 22) in comparison to those without mitral regurgitation (n = 18) (anterior papillary muscle: 1127 ± 36 msec vs 1063 ± 16 msec, p < 0.05; posterior papillary muscle: 1124 ± 30 msec vs 1062 ± 19 msec, p < 0.05), but LV T1time was similar (1129 ± 38 msec vs 1134 ± 58 msec, p = 0.93). Multivariate linear regression analysis showed that papillary muscle native T1time (β = 0.10, 95 % CI: 0.05-0.17, p < 0.05) is significantly correlated with mitral regurgitant fraction. Elevated papillary muscle T1time was associated with larger diameter, longer length and decreased papillary muscle shortening (all p values <0.05).
  
  
  CONCLUSIONS
  In DCM, papillary muscle native T1time is significantly elevated and related to mitral regurgitant fraction.
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.|Department of Cardiology, Yokohama City University Hospital, Yokohama, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Kato
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.
authors.forename: Shiro
authors.initials: S
authors.lastname: Nakamori
authors.affiliation: Biomedical Engineering Department, King's College London, London, UK.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Roujol
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.
authors.forename: Francesca N
authors.initials: FN
authors.lastname: Delling
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.
authors.forename: Shadi
authors.initials: S
authors.lastname: Akhtari
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.
authors.forename: Jihye
authors.initials: J
authors.lastname: Jang
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.|Biomedical Engineering Department, Cairo University, Giza, Egypt.
authors.forename: Tamer
authors.initials: T
authors.lastname: Basha
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.
authors.forename: Sophie
authors.initials: S
authors.lastname: Berg
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.
authors.forename: Kraig V
authors.initials: KV
authors.lastname: Kissinger
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.
authors.forename: Beth
authors.initials: B
authors.lastname: Goddu
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA.|Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Warren J
authors.initials: WJ
authors.lastname: Manning
authors.affiliation: Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA. rnezafat@bidmc.harvard.edu.
authors.forename: Reza
authors.initials: R
authors.lastname: Nezafat
mesh_terms: D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D005355:Fibrosis; D006801:Humans; D016014:Linear Models; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008536:Meglumine / Q000008:administration & dosage / Q000031:analogs & derivatives; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D015999:Multivariate Analysis; D009200:Myocardial Contraction; D009942:Organometallic Compounds / Q000008:administration & dosage; D010210:Papillary Muscles / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016277:Ventricular Function, Left
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine