Multiparametric CMR imaging of infarct remodeling in a percutaneous reperfused Yucatan mini-pig model.
To further understanding of the temporal evolution and pathophysiology of adverse ventricular remodeling over the first 60 days following a myocardial infarction (MI) in both the infarcted and remote myocardium, we performed multi-parametric cardiac magnetic resonance (CMR) imaging in a closed-chest chronic Yucatan mini-pig model of reperfused MI. Ten animals underwent 90 min left anterior descending artery occlusion and reperfusion. Three animals served as controls. Multiparametric CMR (1.5T) was performed at baseline, Day 2, Day 30 and in four animals on Day 60 after MI. Left ventricular (LV) volumes and infarct size were measured. T1and T2mapping sequences were performed to measure values in the infarct and remote regions. Remote region collagen fractions were compared between infarcted animals and controls. Procedure success was 80%. The model created large infarcts (28 ± 5% of LV mass on Day 2), which led to significant adverse myocardial remodeling that stabilized beyond 30 days. Native T1values did not reliably differentiate remote and infarct regions acutely. There was no evidence of remote fibrosis as indicated by partition coefficient and collagen fraction analyses. The infarct T2values remained elevated up to 60 days after MI. Multiparametric CMR in this model showed significant adverse ventricular remodeling 30 days after MI similar to that seen in humans. In addition, this study demonstrated that remote fibrosis is absent and that infarct T2signal remains chronically elevated in this model. These findings need to be considered when designing preclinical trials using CMR endpoints.
Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA.
David
D
Lopez
Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA.|Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, VA, USA.
Jonathan A
JA
Pan
Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA.
Peter M
PM
Pollak
Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, VA, USA.
Samantha
S
Clarke
Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA.|Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, VA, USA.
Christopher M
CM
Kramer
Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA.|Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA, USA.
Mark
M
Yeager
Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA.|Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, VA, USA.|Department of Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, VA, USA.
Michael
M
Salerno
D000465:Algorithms; D000818:Animals; D003198:Computer Simulation; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008954:Models, Biological; D015233:Models, Statistical; D064847:Multimodal Imaging / Q000379:methods; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology*; D015428:Myocardial Reperfusion Injury / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D013552:Swine; D013556:Swine, Miniature; D020257:Ventricular Remodeling
CMR imaging; Yucatan mini-pig; multiparametric; myocardial infarction; swine; ventricular remodeling