title: In hypertrophic cardiomyopathy reduction of relative resting myocardial blood flow is related to late enhancement, T2-signal and LV wall thickness.
abstract: OBJECTIVE
  To quantify resting myocardial blood flow (MBF) in the left ventricular (LV) wall of HCM patients and to determine the relationship to important parameters of disease: LV wall thickness, late gadolinium enhancement (LGE), T2-signal abnormalities (dark and bright signal), LV outflow tract obstruction and age.
  
  
  METHODS
  Seventy patients with proven HCM underwent cardiac MRI. Absolute and relative resting MBF were calculated from cardiac perfusion MRI by using the Fermi function model. The relationship between relative MBF and LV wall thickness, T2-signal abnormalities (T2 dark and T2 bright signal), LGE, age and LV outflow gradient as determined by echocardiography was determined using simple and multiple linear regression analysis. Categories of reduced and elevated perfusion in relation to non- or mildly affected reference segments were defined, and T2-signal characteristics and extent as well as pattern of LGE were examined. Statistical testing included linear and logistic regression analysis, unpaired t-test, odds ratios, and Fisher's exact test.
  
  
  RESULTS
  804 segments in 70 patients were included in the analysis. In a simple linear regression model LV wall thickness (p<0.001), extent of LGE (p<0.001), presence of edema, defined as focal T2 bright signal (p<0.001), T2 dark signal (p<0.001) and age (p = 0.032) correlated inversely with relative resting MBF. The LV outflow gradient did not show any effect on resting perfusion (p = 0.901). Multiple linear regression analysis revealed that LGE (p<0.001), edema (p = 0.026) and T2 dark signal (p = 0.019) were independent predictors of relative resting MBF. Segments with reduced resting perfusion demonstrated different LGE patterns compared to segments with elevated resting perfusion.
  
  
  CONCLUSIONS
  In HCM resting MBF is significantly reduced depending on LV wall thickness, extent of LGE, focal T2 signal abnormalities and age. Furthermore, different patterns of perfusion in HCM patients have been defined, which may represent different stages of disease.
authors.affiliation: Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Katja
authors.initials: K
authors.lastname: Hueper
authors.forename: Antonia
authors.initials: A
authors.lastname: Zapf
authors.forename: Jan
authors.initials: J
authors.lastname: Skrok
authors.forename: Aurelio
authors.initials: A
authors.lastname: Pinheiro
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Goldstein
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.forename: Stefan L
authors.initials: SL
authors.lastname: Zimmerman
authors.forename: Ihab R
authors.initials: IR
authors.lastname: Kamel
authors.forename: Roselle
authors.initials: R
authors.lastname: Abraham
authors.forename: Frank
authors.initials: F
authors.lastname: Wacker
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.forename: Theodore
authors.initials: T
authors.lastname: Abraham
authors.forename: Jens
authors.initials: J
authors.lastname: Vogel-Claussen
mesh_terms: D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology*; D003331:Coronary Vessels / Q000503:physiopathology*; D005260:Female; D005682:Gadolinium; D006801:Humans; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow
chemical_list: D005682:Gadolinium