Abstract 14645: Three Dimensional Ejection Fraction is More Strongly Determined by Strain Than by Torsion in a Cohort of Breast Cancer Patients Undergoing Anthracycline-Based Chemotherapy

Abstract

Introduction: Anthracycline cardiotoxicity affects approximately 10-20% of treated individuals, representing a significant health burden. Three dimensional (3D) echocardiographic measures of myocardial mechanics have the potential to improve our understanding of the functional changes that occur with anthracyclines, and may play an important role in cardiotoxicity risk prediction. Our objective was to define the relationships between 3D myocardial deformation parameters and left ventricular ejection fraction (LVEF) in a longitudinal, prospective cohort of patients with breast cancer. Methods: We performed 3D echocardiograms at standardized intervals in a longitudinal cohort of women with breast cancer undergoing doxorubicin therapy with or without trastuzumab. We acquired all 3D images at a minimum of 22 frames per second and excluded from analysis all images that had poor tracking of greater than 3 myocardial segments, dropout of the apex, or stitch artifact. Two readers used a vendor-independent analysis platform (TomTec Cardiac Performance Analyses, Unterschleissheim, Germany) to measure 3D LVEF and the following 3D deformation parameters: principal strain, global longitudinal strain (GLS), global circumferential strain (GCS), and left ventricular torsion. Spearman correlation analyses were performed to understand the relationships amongst these parameters. Results: We analyzed 270 total echocardiograms from 87 women (mean age 49). Conventional 3D strain parameters were highly correlated with 3D LVEF (principal strain, r=-0.95, p<0.001; GLS, r=-0.85, p<0.001; GCS r=-0.97, p<0.001). In contrast, left ventricular torsion was only modestly correlated with 3D LVEF (r=0.51, p<0.001). Conclusions: Three dimensional principal strain, GLS, and GCS were all strongly correlated with 3D LVEF. However, left ventricular torsion was only weakly correlated to LVEF, suggesting that LVEF is determined less by torsion than by 3D strain. With further study, 3D strain may play an important role in chemotherapy cardiotoxicity risk prediction.