Abstract 16173: Myocardial T1 Mapping MR and Collagen Changes in Tachycardia-Induced Heart Failure

Abstract

T1 Mapping Magnetic Resonance Imaging using a modified look-locker with saturation recovery sequence was used in a tachycardia-induced heart failure (HF) swine model to assess fibrotic changes. Yorkshire swine were scanned twice at 1.5 Tesla (baseline (9), HF (6)), while allowed to spontaneously breath during image acquisition. Post mortem tissue histology used Masson Trichrome Blue. Immunochemistry assessed Collagen I, III, IV, and VI. Mean pre- and post-contrast T1 Mapping values were significantly different between baseline (pre 960 ±96 ms, post 546 ±180 ms) and HF (pre 726 ±94 ms, post 300 ±171 ms) (p = .020, p = .005, respectively). Histology of control versus HF was 0.88% and 2.60% fibrosis respectively (p < .01). Visual observation for immunochemistry currently suggests increases in Collagens I, III and VI in HF, whereas Collagen IV showed more disarray. The T1 mapping value changes were consistent with changes in collagen between healthy and HF animals. T1 mapping may be a promising technique to quantify myocardial changes in heart failure even when the patient cannot hold their breath. Changes in collagen may be a contributing factor to the dysfunction found in dilated cardiomyopathy caused by a tachycardia process. More research needs to be done to further establish the relationship between T1 mapping values and specific collagen changes.