title: Nonstress delayed-enhancement magnetic resonance imaging of the myocardium predicts improvement of function after revascularization for chronic ischemic heart disease with left ventricular dysfunction.
abstract: BACKGROUND
  The extent of myocardial scarring of the left ventricle (LV) is important in patients with chronic ischemic heart disease (CIHD). With delayed-enhancement magnetic resonance imaging (DE-MRI), scarred myocardium (hyper-enhanced) is easily distinguishable from viable (dark) myocardium. This investigation assessed the use of DE-MRI for predicting functional improvement after coronary artery bypass grafting (CABG) in patients with CIHD and significant LV dysfunction.
  
  
  METHODS
  The patient population (n = 29) with CIHD and LV dysfunction (ejection fraction 28% +/- 10%) underwent both DE-MRI, to delineate scarred regions before revascularization, and echocardiography (Echo), to assess segmental function before and after CABG (interval 188 +/- 57 days). Using a 16-segment model, LV myocardium was semiquantitatively analyzed for scarring based on DE-MRI and for improvements in resting function by pre- and post-CABG Echo.
  
  
  RESULTS
  Before CABG, 82% of targeted myocardial segments had abnormal contraction; 78% showed scarring, including 38% with greater than mild amounts (25%-100%). Normal contraction was found in 18% of segments before revascularization; scarred areas were identified in 42%, 84% of which had, at most, minimal amounts (0%-24%). Of segments with pre-CABG dysfunction, 82% with no evidence of scar recovered, compared to only 18% with > or =50% scarring. Amount of hyper-enhancement was a very good indicator of improvement of function, especially at the > or =50%/segment threshold; overall accuracy was 0.74 (95% CI 0.66-0.82, P <.001).
  
  
  CONCLUSIONS
  In patients with CIHD and significant LV dysfunction, DE-MRI can predict likelihood of functional improvement after revascularization.
authors.affiliation: Department of Radiology (Section of Cardiovascular Imaging), Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
authors.forename: Paulo R
authors.initials: PR
authors.lastname: Schvartzman
authors.forename: Monvadi B
authors.initials: MB
authors.lastname: Srichai
authors.forename: Richard A
authors.initials: RA
authors.lastname: Grimm
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Obuchowski
authors.forename: Donald F
authors.initials: DF
authors.lastname: Hammer
authors.forename: Patrick M
authors.initials: PM
authors.lastname: McCarthy
authors.forename: Jane M
authors.initials: JM
authors.lastname: Kasper
authors.forename: Richard D
authors.initials: RD
authors.lastname: White
mesh_terms: D000328:Adult; D000368:Aged; D009202:Cardiomyopathies / Q000473:pathology / Q000503:physiopathology; D002921:Cicatrix / Q000473:pathology / Q000503:physiopathology; D001026:Coronary Artery Bypass; D004452:Echocardiography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy; D009204:Myocardial Revascularization; D012044:Regression Analysis; D018487:Ventricular Dysfunction, Left / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy