Assessment of Left Atrial Functions in Patients With Breast Cancer Receiving Trastuzumab and/or Chemotherapy

Background: Worldwide, more women will get breast cancer (BC) than any other type of cancer. The introduction of trastuzumab (TZ) to BC therapy has greatly improved the prognosis of women with HER2-positive cancer, whether it is adjuvant or metastatic. Aim: To evaluate left atrial functions in patients with breast cancer receiving trastuzumab and or chemotherapy, and to test the hypothesis that baseline left atrial functions can predict left ventricular dysfunction due to trastuzumab and or chemotherapy. Methods: Fifty patients with a confirmed histological diagnosis of early-stage or locally advanced (stages I-IIIC) breast cancer who were treated with TZ and those who received an anthracycline-based regimen were included in this prospective trial. The patients' HER2 overexpression was carefully monitored. Results: The chemotherapy group showed substantial decreases in Simpson's biplane EF, left atrial (LA) reservoir strain, LA conduit strain, and LA contractile strain at baseline and three months later (P<0.05). Significant increases in E/A, E/e', and LAVI were seen after 3 months compared to baseline (P<0.05). After 3 months, LV mass index hadn't changed appreciably. Simpson's biplane EF, LA reservoir strain, LA conduit strain, and LA contractile strain significantly decreased in the TZ group at baseline and three months later (P<0.05). E/A ratio increased considerably at baseline and three months later (P<0.05). After 3 months, LV mass index, E/e' ratio, and LAVI were similar to baseline. Conclusions: Our findings demonstrated that La functions (LA reservoir, conduit, and contractile strains) were significantly reduced after 3 months of treatment compared to baseline values in the overall study population, regardless of the treatment type and this can help identifying patients at risk of developing heart failure even when left ventricular function appears normal.