title: Prognostic significance of myocardial fibrosis quantification by histopathology and magnetic resonance imaging in patients with severe aortic valve disease.
abstract: OBJECTIVE
  We sought to determine whether the quantitative assessment of myocardial fibrosis (MF), either by histopathology or by contrast-enhanced magnetic resonance imaging (ce-MRI), could help predict long-term survival after aortic valve replacement.
  
  
  BACKGROUND
  Severe aortic valve disease is characterized by progressive accumulation of interstitial MF.
  
  
  METHODS
  Fifty-four patients scheduled to undergo aortic valve replacement were examined by ce-MRI. Delayed-enhanced images were used for the quantitative assessment of MF. In addition, interstitial MF was quantified by histological analysis of myocardial samples obtained during open-heart surgery and stained with picrosirius red. The ce-MRI study was repeated 27+/-22 months after surgery to assess left ventricular functional improvement, and all patients were followed for 52+/-17 months to evaluate long-term survival.
  
  
  RESULTS
  There was a good correlation between the amount of MF measured by histopathology and by ce-MRI (r=0.69, p<0.001). In addition, the amount of MF demonstrated a significant inverse correlation with the degree of left ventricular functional improvement after surgery (r=-0.42, p=0.04 for histopathology; r=-0.47, p=0.02 for ce-MRI). Kaplan-Meier analyses revealed that higher degrees of MF accumulation were associated with worse long-term survival (chi-square=6.32, p=0.01 for histopathology; chi-square=5.85, p=0.02 for ce-MRI). On multivariate Cox regression analyses, patient age and the amount of MF were found to be independent predictors of all-cause mortality.
  
  
  CONCLUSIONS
  The amount of MF, either by histopathology or by ce-MRI, is associated with the degree of left ventricular functional improvement and all-cause mortality late after aortic valve replacement in patients with severe aortic valve disease.
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Clerio F
authors.initials: CF
authors.lastname: Azevedo
authors.forename: Marcelo
authors.initials: M
authors.lastname: Nigri
authors.forename: Maria L
authors.initials: ML
authors.lastname: Higuchi
authors.forename: Pablo M
authors.initials: PM
authors.lastname: Pomerantzeff
authors.forename: Guilherme S
authors.initials: GS
authors.lastname: Spina
authors.forename: Roney O
authors.initials: RO
authors.lastname: Sampaio
authors.forename: Flávio
authors.initials: F
authors.lastname: Tarasoutchi
authors.forename: Max
authors.initials: M
authors.lastname: Grinberg
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Rochitte
mesh_terms: D000328:Adult; D001024:Aortic Valve Stenosis / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D005355:Fibrosis / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D055815:Young Adult