title: Clinical significance of global two-dimensional strain as a surrogate parameter of myocardial fibrosis and cardiac events in patients with hypertrophic cardiomyopathy.
abstract: OBJECTIVE
  Late gadolinium enhancement (LGE) on contrast-enhanced magnetic resonance imaging (MRI) in hypertrophic cardiomyopathy (HCM) has been reported to be associated with myocardial fibrosis and cardiac events. In patients with HCM, two-dimensional (2D) strain can identify subclinical global systolic dysfunction despite normal left ventricular (LV) chamber function. Therefore, this study tested the hypothesis that global 2D strain could detect subtle myocardial fibrosis and serve as a novel prognostic parameter in HCM patients.
  
  
  RESULTS
  Echocardiography and MRI were performed in 48 consecutive patients with HCM and normal chamber function. We measured global longitudinal strain (GLS) in apical two-chamber, four-chamber, and long-axis views using speckle-tracking analysis. The extent of LGE (%LGE = LGE volume/total LV volume) and LV mass index were calculated by MRI using Simpson's rule and custom software. All patients were followed up for major cardiac events. Global longitudinal strain in patients with LGE was significantly lower than that without LGE (-11.8 ± 2.8 vs. -15.0 ± 1.7%, P < 0.001). Multivariate analysis showed that GLS was an independent predictor of %LGE (standard coefficient = 0.627, P < 0.001). During a mean follow-up period of 42 ± 12 months, five patients had cardiac events. When the patients were stratified based on the median level of GLS (-12.9%), all events were observed in the worse GLS group (P = 0.018).
  
  
  CONCLUSIONS
  These results suggest that global 2D strain might provide useful information on myocardial fibrosis and cardiac events in HCM patients with normal chamber function.
authors.affiliation: Department of Cardiology,  Kitaishikai Hospital, Ozu,  Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Saito
authors.forename: Hideki
authors.initials: H
authors.lastname: Okayama
authors.forename: Toyofumi
authors.initials: T
authors.lastname: Yoshii
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Higashi
authors.forename: Hiroe
authors.initials: H
authors.lastname: Morioka
authors.forename: Go
authors.initials: G
authors.lastname: Hiasa
authors.forename: Takumi
authors.initials: T
authors.lastname: Sumimoto
authors.forename: Shinji
authors.initials: S
authors.lastname: Inaba
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Nishimura
authors.forename: Katsuji
authors.initials: K
authors.lastname: Inoue
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Ogimoto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Shigematsu
authors.forename: Mareomi
authors.initials: M
authors.lastname: Hamada
authors.forename: Jitsuo
authors.initials: J
authors.lastname: Higaki
mesh_terms: D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003287:Contrast Media; D015150:Echocardiography, Doppler; D004719:Endomyocardial Fibrosis / Q000150:complications* / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012044:Regression Analysis
chemical_list: D003287:Contrast Media