title: Cardiovascular magnetic resonance characterization of peri-infarct zone remodeling following myocardial infarction.
abstract: BACKGROUND
  Clinical studies implementing late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) studies suggest that the peri-infarct zone (PIZ) contains a mixture of viable and non-viable myocytes, and is associated with greater susceptibility to ventricular tachycardia induction and adverse cardiac outcomes. However, CMR data assessing the temporal formation and functional remodeling characteristics of this complex region are limited. We intended to characterize early temporal changes in scar morphology and regional function in the PIZ.
  
  
  RESULTS
  CMR studies were performed at six time points up to 90 days after induction of myocardial infarction (MI) in eight minipigs with reperfused, anterior-septal infarcts. Custom signal density threshold algorithms, based on the remote myocardium, were applied to define the infarct core and PIZ region for each time point. After the initial post-MI edema subsided, the PIZ decreased by 54% from day 10 to day 90 (p = 0.04). The size of infarct scar expanded by 14% and thinned by 56% from day 3 to 12 weeks (p = 0.004 and p < 0.001, respectively). LVEDV increased from 34.7. ± 2.2 ml to 47.8 ± 3.0 ml (day 3 and week 12, respectively; p < 0.001). At 30 days post-MI, regional circumferential strain was increased between the infarct scar and the PIZ (-2.1 ± 0.6 and -6.8 ± 0.9, respectively;* p < 0.05).
  
  
  CONCLUSIONS
  The PIZ is dynamic and decreases in mass following reperfused MI. Tensile forces in the PIZ undergo changes following MI. Remodeling characteristics of the PIZ may provide mechanistic insights into the development of life-threatening arrhythmias and sudden cardiac death post-MI.
authors.affiliation: Johns Hopkins School of Medicine, Division of Cardiology, 1042 Ross Building, Baltimore, MD 21205, USA.
authors.forename: Karl H
authors.initials: KH
authors.lastname: Schuleri
authors.forename: Marco
authors.initials: M
authors.lastname: Centola
authors.forename: Kristine S
authors.initials: KS
authors.lastname: Evers
authors.forename: Adam
authors.initials: A
authors.lastname: Zviman
authors.forename: Robert
authors.initials: R
authors.lastname: Evers
authors.forename: João A C
authors.initials: JA
authors.lastname: Lima
authors.forename: Albert C
authors.initials: AC
authors.lastname: Lardo
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D006352:Heart Ventricles / Q000473:pathology* / Q000503:physiopathology; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D013552:Swine; D013556:Swine, Miniature; D020257:Ventricular Remodeling