Changes in epicardial adipose tissue among women treated with trastuzumab for breast cancer

Background: Epicardial adipose tissue (EAT) as an endocrine organ, secreting hormones, and inflammatory cytokines is associated with adverse cardiovascular outcomes and may have a role in trastuzumab-induced cardiotoxicity (TIC). We sought to assess changes in EAT volume and radiodensity after receiving trastuzumab and if they are associated with TIC.

Methods: A total of 185 women treated with trastuzumab for human epidermal growth factor receptor 2-positive breast cancer were retrospectively recruited. All patients underwent echocardiography and CT before and during trastuzumab therapy. The time interval between CT and echocardiography was <10 days. EAT volume and density were quantified by CT. TIC was defined as a left ventricular ejection fraction (LVEF) decrease of >10% and < 53%.

Results: Of the 185 patients, 18 (9.7%) experienced TIC. After receiving trastuzumab, EAT volume and radiodensity were increased, despite similar BMI. TIC group showed a significantly higher increment of EAT volume (21.2 ± 6.3 vs. 11.7 ± 10.5 ml, p < 0.001) and radiodensity (2.7 ± 1.8 vs. 1.5 ± 2.0HU, p < 0.05) than no TIC group. There was a high negative correlation between changes in EAT volume and LVEF (r = -0.70; p < 0.001) and a moderately negative correlation between changes in EAT radiodensity and LVEF (r = -0.50; p < 0.001). Increased EAT volume, but not radiodensity appeared to be a good imaging biomarker for TIC (AUC: 0.79 vs. 0.65, p < 0.05).

Conclusions: EAT volume and radiodensity were increased after receiving trastuzumab particularly in the TIC patients despite similar BMI. Notably, the increased EAT volume rather than radiodensity was strongly negatively associated with LVEF and appeared to be a good imaging biomarker of TIC.