Abstract 174: Investigating Subclinical Cardiotoxicity in Long-term Breast Cancer Survivors Following Chemotherapy With DENSE-based 3D Strain Analysis

Abstract

This study investigated if left ventricular (LV) mechanical contractile parameters in addition to LV ejection fraction (LVEF) indicated cardiac remodeling and fibrosis in patients exposed to cardiotoxic chemotherapy agents (CCA). Cardiac deformation data were obtained using single-scan acquisitions with the Displacement Encoding with Stimulated Echoes (DENSE) MRI sequence. Contractile analysis consisted of automated myocardial boundary detection and unwrapping 3D DENSE phase images for intra-myocardial displacements, and followed by analyzing torsion and 3D strains with the meshfree Radial Point Interpolation Method (RPIM). Data were acquired on 13 CCA-exposed patients who were undergoing chemotherapy and/or care for cardiac complications. DENSE LVEF measurements in patients were validated against steady-state free precession (SSFP) MRI data, all contractility computations were compared to healthy subjects and Bland-Altman agreements established between strains computed by independent observers. A significant difference was not found between DENSE and SSFP LVEF computations (52 ± 11% vs 48 ± 15%, p=0.33). Significant differences were seen with enlarged LV diameters in patients versus healthy subjects (6.0 ± 1.1 cm vs 4.9 ± 0.7 cm, p<0.001) and similarly for torsion and longitudinal strain but not in LVEF results (p > 0.05). Bland-Altman agreements were 0.01 ± 0.06 for longitudinal strain and 0.1 ± 1.9 ° for torsion. Statistical analysis confirm changed LV size and function in patients and indicate remodeling that is otherwise not demonstrated by LVEF measurements, which may precede clinically apparent heart failure development and worsened morbidity.