title: Extent of late gadolinium enhancement detected by cardiovascular magnetic resonance correlates with the inducibility of ventricular tachyarrhythmia in hypertrophic cardiomyopathy.
abstract: BACKGROUND
  Myocardial fibrosis is frequently identified in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to investigate the role of myocardial fibrosis detected by late gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) as a potential arrhythmogenic substrate in HCM. We hypothesized that the extent of LGE might be associated with the inducibility of ventricular tachyarrhythmias (VT) during programmed ventricular stimulation (PVS).
  
  
  METHODS
  We evaluated retrospectively LGE CMR of 76 consecutive HCM patients, of which 43 presented with one or more risk factors for sudden cardiac death (SCD) and were therefore clinically classified as high-risk patients. Of these 43 patients, 38 additionally underwent an electrophysiological testing (EP). CMR indices and the extent of LGE, given as the % of LV mass with LGE were correlated with the presence of risk factors for SCD and the results of EP.
  
  
  RESULTS
  High-risk patients had a significant higher prevalence of LGE than low-risk patients (29/43 [67%] versus 14/33 [47%]; p = 0.03). Also the % of LV mass with LGE was significantly higher in high-risk patients than in low-risk patients (14% versus 3%, p = 0.001, respectively). Of the 38 high- risk patients, 12 had inducible VT during EP. LV function, volumes and mass were comparable in patients with and without inducible VT. However, the % of LV mass with LGE was significantly higher in patients with inducible VT compared to those without (22% versus 10%, p = 0.03). The prevalence of LGE was, however, comparable between HCM patients with and those without inducible VT (10/12 [83%] versus 15/26 [58%]; p = 0.12). In the univariate analysis the % of LV mass with LGE and the septal wall thickness were significantly associated with the high-risk group (p = 0.001 and 0.004, respectively). Multivariate analysis demonstrated that the extent of LGE was the only independent predictor of the risk group (p = 0.03).
  
  
  CONCLUSIONS
  The extent of LGE in HCM patients correlated with risk factors of SCD and the likelihood of inducible VT. Furthermore, LGE extent was the only independent predictor of the risk group. This supports the hypothesis that the extent of fibrosis may serve as potential arrhythmogenic substrate for the occurrence of VT, especially in patients with clinical risk factors for SCD.
authors.affiliation: 1st Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. stephan.fluechter@umm.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Fluechter
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kuschyk
authors.forename: Christian
authors.initials: C
authors.lastname: Wolpert
authors.forename: Christina
authors.initials: C
authors.lastname: Doesch
authors.forename: Christian
authors.initials: C
authors.lastname: Veltmann
authors.forename: Dariusch
authors.initials: D
authors.lastname: Haghi
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
authors.forename: Tim
authors.initials: T
authors.lastname: Sueselbeck
authors.forename: Tjeerd
authors.initials: T
authors.lastname: Germans
authors.forename: Florian
authors.initials: F
authors.lastname: Streitner
authors.forename: Martin
authors.initials: M
authors.lastname: Borggrefe
authors.forename: Theano
authors.initials: T
authors.lastname: Papavassiliu
mesh_terms: D000328:Adult; D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications*; D005260:Female; D005355:Fibrosis; D005682:Gadolinium; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000209:etiology*
chemical_list: D005682:Gadolinium