title: Increased extent of myocardial fibrosis in genotyped hypertrophic cardiomyopathy with ventricular tachyarrhythmias.
abstract: BACKGROUND
  Occurrence of malignant ventricular tachyarrhythmias such as ventricular tachycardia and fibrillation (VT/VF) in hypertrophic cardiomyopathy (HCM) can be related to the extent of myocardial fibrosis. Although late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging has been used to detect myocardial fibrosis, few data exist regarding relationships between CMR-determined myocardial fibrosis and VT/VF in genotyped HCM populations.
  
  
  OBJECTIVE
  We retrospectively investigated whether the extent of LGE can be increased in HCM patients with VT/VF compared to those without VT/VF in the genotyped HCM population.
  
  
  RESULTS
  We studied 35 HCM patients harboring sarcomere gene mutations (TNNI3=22, MYBPC3=12, MYH7=1) who underwent both CMR imaging and 24-h ambulatory electrocardiographic monitoring. VT/VF were identified in 6 patients (2 men, mean age 55.0 years). The extent of LGE was significantly increased in patients with VT/VF (n=6) compared with those without VT/VF (n=29) (18.6±14.4% vs. 8.3±11.4%, p=0.04), although the LGE extent was not an independent predictor for the occurrence of VT/VF. Applying a cut-off point ≥3.25%, episodes of VT/VF were identified with a sensitivity of 100%, specificity of 51.7%, positive predictive value of 30%, negative predictive value of 100%, and the area under the curve of 0.767 (95% confidence interval: 0.590-0.944).
  
  
  CONCLUSIONS
  These results demonstrate that myocardial fibrosis determined by CMR imaging may be increased in genotyped HCM patients with episodes of VT/VF. A further prospective study will be needed to clarify the association between the LGE extent and arrhythmic events in HCM patients harboring sarcomere gene mutations.
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujita
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan; Research and Education Center for Innovative and Preventive Medicine, Kanazawa University, Kanazawa, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Konno
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan; Division of Cardiology, Fukui Prefectural Hospital, Fukui, Japan.
authors.forename: Junichiro
authors.initials: J
authors.lastname: Yokawa
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Masuta
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Nagata
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Fujino
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Funada
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hodatsu
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Masa-aki
authors.initials: MA
authors.lastname: Kawashiri
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan; Research and Education Center for Innovative and Preventive Medicine, Kanazawa University, Kanazawa, Japan. Electronic address: myamagi@med.kanazawa-u.ac.jp.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yamagishi
authors.affiliation: Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Kenshi
authors.initials: K
authors.lastname: Hayashi
mesh_terms: D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000235:genetics* / Q000473:pathology; D003287:Contrast Media; D005355:Fibrosis / Q000473:pathology; D019786:Gadolinium DTPA; D020022:Genetic Predisposition to Disease; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000150:complications / Q000235:genetics* / Q000473:pathology
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: Hypertrophic cardiomyopathy; Magnetic resonance imaging; Myocardial fibrosis; Ventricular arrhythmia