Right Ventricle Strain changes in patients with breast cancer during anthracycline therapy

Background: Cardiotoxicity has become a significant adverse effect of cancer therapy, with Anthracyclines (ANT) in particular. There is a crucial need for the early subclinical detection of cardiotoxic effect. We aimed to evaluate Right ventricle (RV) two-dimensional speckle tracking echocardiography (2D-STE) changes during ANT therapy and to assess the correlation between RV 2D-STE and the routine echocardiographic RV parameters.

Methods: Data were prospectively collected as part of the Israel Cardio-Oncology Registry (ICOR). All female patients with breast cancer, planned for ANT therapy were included. All patients underwent serial echocardiography exams including baseline RV 2D-STE (before chemotherapy, T1) and shortly after the completion of ANT therapy (T3). RV 2D-STE was evaluated using the apical 4 chamber (4C) RV-focused view, assessing both the combined RV free wall and inter-ventricular septum (RV GLS) and solely the RV free wall strain (RV FWLS). Significant reduction in both RV GLS and RV FWLS was determined by either a relative reduction of > 10% or an absolute value of >-25% for RV GLS and >-29% for RV FWLS.

Results: From September 2016 to June 2019, 40 patients were evaluated with a mean Doxorubicin (type of ANT) dose of 238.5±9.4 mg/m2. RV FWLS showed significant correlation to Tricuspid annular plane systolic excursion. At T3, significant reduction in both RV GLS and RV FWLS was observed among 77% and 62% of the patients with a mean RV GLS and RV FWLS reduction from -26.8(±4.7) % to -21.5(±4.4) % and -28.9(±5.1) % to -25.6(±5.9) % (p<0.001, p=0.002), respectively. Left ventricle (LV) ejection fraction and LV GLS were within the normal range.

Conclusions: RV GLS and RV FWLS reduction are frequent and occur early in the course of ANT therapy, preceding LV dysfunction, which may imply for the role of RV 2D-STE in the detection of early cardiotoxicity.