title: Myocardial fibrosis imaging based on T1-mapping and extracellular volume fraction (ECV) measurement in muscular dystrophy patients: diagnostic value compared with conventional late gadolinium enhancement (LGE) imaging.
abstract: OBJECTIVE
  Cardiac involvement with progressive myocardial fibrosis leading to dilated cardiomyopathy is a major cause of death in muscular dystrophy patients. Extracellular volume fraction (ECV) measurement based on T1-mapping pre- and post-contrast promises the detection of early 'diffuse' myocardial fibrosis that cannot be depicted by conventional contrast-imaging based on late gadolinium enhancement (LGE). With this study, we evaluated the presence of diffuse myocardial fibrosis in regions of 'normal' (LGE-negative) and 'diseased' (LGE-positive) appearing myocardium as well as its relation to the extent of left ventricular (LV) dysfunction and the occurrence of arrhythmias in Becker muscular dystrophy (BMD) patients.
  
  
  RESULTS
  Twenty-seven BMD patients (35 ± 12 years) and 17 matched male healthy controls (33 ± 8 years) underwent cardiovascular magnetic resonance (CMR) studies including ECV measurement and LGE-imaging. Ambulatory monitoring of arrhythmic events was performed by means of an external event loop recorder. Twenty BMD patients (74%) demonstrated cardiac involvement as detected by typical inferolateral presence of LGE. Twelve patients (44%) had an impaired LV ejection fraction-all being LGE-positive. Global myocardial ECV was significantly higher in the BMD group (29 ± 6%) compared with the control group (24 ± 2%, P = 0.001). Patients with cardiac involvement demonstrated higher global ECV (31 ± 6%) as well as significantly increased regional ECV not only in LGE-positive segments (34 ± 6%), but also in LGE-negative segments (28 ± 6%) compared with BMD patients without cardiac involvement and to controls, respectively (24 ± 3 and 24 ± 2%, P = 0.005). Global ECV in patients with cardiac involvement substantially correlated to LV ejection fraction (r = -0.629, P = 0.003) and to the number of LGE-positive segments (r = 0.783, P < 0.001). On univariable analysis, global ECV-but not the categorical presence of LGE per se--was significantly associated with arrhythmic events (OR: 1.97, CI: 32.22-1.21, P = 0.032).
  
  
  CONCLUSIONS
  ECV measurement by CMR is a useful tool in assessing the total extent of myocardial fibrosis as well as in depicting subtle diffuse fibrosis in areas of normal appearing myocardium on LGE-images. Thus, myocardial ECV is a potential additional quantitative tool for accurate detection of cardiac involvement and risk stratification in muscular dystrophy patients.
authors.affiliation: Department of Cardiology and Angiology, University Hospital Münster, Albert-Schweitzer-Campus 1, building A1, 48149 Münster, Germany.
authors.forename: Anca
authors.initials: A
authors.lastname: Florian
authors.affiliation: Division of Cardiology, Robert-Bosch-Krankenhaus, Stuttgart, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Ludwig
authors.affiliation: Division of Cardiology, Robert-Bosch-Krankenhaus, Stuttgart, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Rösch
authors.affiliation: Division of Cardiology, Robert-Bosch-Krankenhaus, Stuttgart, Germany.
authors.forename: Handan
authors.initials: H
authors.lastname: Yildiz
authors.affiliation: Division of Cardiology, Robert-Bosch-Krankenhaus, Stuttgart, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Sechtem
authors.affiliation: Department of Cardiology and Angiology, University Hospital Münster, Albert-Schweitzer-Campus 1, building A1, 48149 Münster, Germany ali.yilmaz@ukmuenster.de.
authors.forename: Ali
authors.initials: A
authors.lastname: Yilmaz
mesh_terms: D000328:Adult; D055424:Cardiac-Gated Imaging Techniques; D009202:Cardiomyopathies / Q000175:diagnosis* / Q000209:etiology; D003287:Contrast Media; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000150:complications*; D011446:Prospective Studies; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology
chemical_list: D003287:Contrast Media
keywords: CMR; Cardiomyopathy; LGE; Mapping; Muscular dystrophy