P697Regional analysis of 3D-derived speckle tracking for the assessment of myocardial deformation in breast cancer patients submitted to anthracycline chemotherapy
Authors: Coutinho Cruz M , Portugal G , Moura-Branco L , Galrinho A , Timoteo A T , Feliciano J , Rio P , Gameiro-Varela F , Ilhao-Moreira R , Valentim-Goncalves A , Mendonca T , Mano T , Duarte-Oliveira S , Luz R , Cruz-Ferreira R 
Published: October 2019

Abstract

Introduction
Serial echocardiographic assessment of left ventricular ejection fraction (LVEF) and 2D left ventricular global longitudinal strain (GLS) is the gold standard in screening for cancer therapeutics-related cardiac dysfunction (CTRCD). Myocardial deformation assessed with 3D speckle tracking is not currently used in this setting, because of the lack of standardization and cut-off values, in spite of a potential for a greater reliability.

Methods
Prospective study of female breast cancer patients submitted to anthracycline chemotherapy with or without adjuvant immunotherapy and/or radiotherapy who underwent serial monitoring by 2D and 3D transthoracic echocardiography (ETT). Standard ETT measures and 3D-derived volumetric measures were assessed. Speckle tracking was used to estimate 2D-derived GLS – average and 18 segments – and 3D-derived GLS, global circumferential strain (GCS), global area strain (GAS) and global radial strain (GRS) – average and 17 segments. CTRCD was defined as an absolute decrease in 2D or 3D LVEF >10% to a value <54% or a relative decrease in 2D GLS >15%. Variables were compared using the t-student paired test and the Wilcoxon sign-rank test, when appropriate.

Results
106 patients (mean age 54.6±12.9 years, 33.0% immunotherapy, 16.5% radiotherapy, baseline LVEF 64.5% ± 8.5%, baseline 2D GLS −21.0±2.8) were included. During a mean follow-up of 16.5±9.6 months, an average of 3.9 echocardiographic examinations were performed per patient and 28 patients (26.4%) developed CTRCD. Overall, 3D regional longitudinal strain was determined in 88.9% of the segments analyzed, with lower success rates in the inferobasal (75.0%), the posterobasal (77.7%) and the laterobasal (82.4%) walls. When comparing variables before and during treatment, there was a significant difference in 2D-derived LVEF (64.5 vs. 57.6 p<0.001), 3D-derived LVEF (60.1 vs. 55.7 p 0.002), 2D-derived GLS (−20.6 vs. −18.2 p<0.001), 3D-derived GLS (−13.8 vs. −12.9 p 0.035), 3D-derived GRS (31.9 vs. 33.4 p 0.024), but not in GCS (−14.5 vs. −13.2 p 0.656) and GAS (−21.5 vs. −22.1 p 0.640). Figure 1 shows the segmental analysis of 2D and 3D strain parameters. In 2D GLS, 11 out of 18 segments showed decreased contractility during follow-up (mainly anterior septum and anterior, lateral and inferior walls). In 3D-derived strain parameters, only 3 out 17 for GLS, 2 out of 17 for GCS, 1 out 17 for GRS and none for GAS showed decreased contractility during follow-up.
Segmental analysis of 2D and 3D strain

Conclusion
In this population, there was worsening of 3D GLS and GRS, besides conventional values, such as LVEF and 2D GLS, during anthracycline-based cancer treatment. 3D-derived myocardial deformation parameters show promise in the setting of CTRCD, since 2D and 3D regional strain parameters might shed a light onto the mechanisms of CTRCD, such that subendocardial myocardial fibers seem to be more affected than medial and subepicardial fibers.