Abstract 15974: Cardiac Magnetic Resonance Imaging Technique to Assess Constructive Myocardial Regeneration of a Tissue Engineered Cardiac Patch
Introduction: Extracellular matrix (ECM) scaffolds have been applied to repair myocardium. However the assessment of regional functions such as contractility and perfusion during remodeling process has not been well established. In this study, we evaluated the remodeled scaffolds using Cardiac Magnetic Resonance (CMR) with strain-encoding (SENC), rest perfusion, and T1 Mapping by modified Look-Locker inversion recovery for extracellular volume fraction (ECV) calculation.
Methods and Results: The tissue-engineered cardiac patch, derived from porcine small intestinal submucosa ECM incorporated with basic fibroblast growth factor, was implanted into the porcine right ventricle (RV) to repair a surgically created full-thickness defect. CMR and histology was performed at 60 days post-implant. (N=4). Dacron patched pigs served as control (N=5; histology).
Histology: Remodeled ECM consisted of well-organized repopulated host cells including a monolayer of endocardial endothelial cells, as well as scattered isolated islands of cardiomyocytes. Only foreign body reaction was seen in the Dacron patch, which was supported by the capillary density analysis (ECM: 27.9 ± 10.1/mm2, Dacron: 18.5± 5.2/mm2; p <0.0001 ).
CMR: SENC showed contractility in the ECM patch area (peak longitudinal strain: -13.6 ± 1.7 %, vs self-controlled normal RV: -17.9 ± 1.6%). Perfusion revealed reasonably restored blood perfusion in the ECM (relative maximum upslope: 11.5 ± 1.1, vs self-controlled normal RV: 16.0 ± 2.2). ECV of the patch region was visualized and calculated, yielding 78 ± 14 % in the patch; whereas self-controlled ECV value was 27 ± 3 % in normal RV.
Conclusions: The ECM patch demonstrated constructive repopulation of host cells and early signs of restoring regional myocardial function with positive contractility and blood perfusion. CMR using our protocol showed efficacy to assess the regional and biological myocardial function of a remodeled tissue engineered scaffold
Author Disclosures: A. Tanaka: Research Grant; Modest; AHA Scientist Development Grant, Astellas Researh Grant. Other Research Support; Modest; Philips. K. Kawaji: None. A. Patel: Research Grant; Modest; Astellas. Other Research Support; Modest; Philips. T. Ota: Research Grant; Modest; AHA Scientist Development Grant.
This research has received full or partial funding support from the American Heart Association.
- © 2014 by American Heart Association, Inc.