Background: Progress in the treatment of breast cancer has led to substantial improvement in survival, but at the cost of increased side effects, with cardiotoxicity being the most significant one. The commonly used definition is cancer therapeutics-related cardiac dysfunction (CTRCD), defined as a left ventricular ejection fraction reduction of > 10%, to a value below 53%. Recent studies have implied that the incidence of CTRCD among patients with breast cancer is decreasing due to lower doses of anthracyclines and low association to trastuzumab and pertuzumab treatment.

Objectives: To evaluate the prevalence of CTRCD among patients with active breast cancer and to identify significant associates for its development.

Methods: Data were collected as part of the Israel Cardio-Oncology Registry, which enrolls all patients who are evaluated at the cardio-oncology clinic at our institution. Patients were divided to two groups: CTRCD and no-CTRCD.

Results: Among 103 consecutive patients, five (5%) developed CTRCD. There were no significant differences in the baseline cardiac risk factors between the groups. Significant correlations of CTRCD included treatment with trastuzumab (P = 0.001) or pertuzumab (P < 0.001), lower baseline global longitudinal strain (GLS) (P = 0.016), increased left ventricular end systolic diameter (P < 0.001), and lower e’ septal (P < 0.001).

Conclusions: CTRCD is an important concern among patients with active breast cancer, regardless of baseline risk factors, and is associated with trastuzumab and pertuzumab treatment. Early GLS evaluation may contribute to risk stratification and allow deployment of cardioprotective treatment