Assessment of Cardiac Function by Advanced Echocardiography in Breast Cancer Patients (HER2 Positive vs HER2 Negative)

Abstract

Background: Human epidermal growth factor receptor 2(HER2) is a gene that makes proteins in the breast cell. The HER2 gene is present in about 25% - 30% of patients with breast cancers. The most common side effect of drugs is left ventricular dysfunction. Evaluation of left ventricular ejection fraction (LVEF) by 2D echocardiography cannot detect subtle changes in LV systolic function. Objectives: We want to draw a comparison between two groups of breast cancer patients (HER2 positive and negative) by advanced echocardiography. Methods: We have conducted a single center prospective study at Rajaie Cardiovascular Medical and Research Center in 2018 - 2019. Results: This analysis included 58 patients with breast cancer. 15 cases (34%) were HER2 positive. Mean left ventricular ejection fraction (2D LVEF) in HER2 positive patients was 55 % at baseline and in HER2 negative patients was 55 %. In HER2 positive patients we had 10 percent decrease in LVEF during follow-up and the final LVEF was about 45% (P value < 0.05). Mean left ventricular ejection fraction by 3D echocardiography (3D LVEF) in HER positive patients was 57 % and in HER2 negative patients was 55 % at baseline. In HER2 positive patients we had about 20% decrease in 3D LVEF and the final LVEF was 40 % (P value < 0.05). Mean circumferential strain (GCS) in HER2 positive patients was -21 and in HER2 negative patients was -21 at baseline which decreased to -18 in HER positive patients and -17 in HER2 negative patients, showing clinical significance ( P value = 0.008). Conclusions: In our study HER2 positive breast cancers showed about 10% drop in 2DEF, about 20% drop in 3DLVEF and about 5% drop in HMLVEF, which all were significant (P value < 0.05). We found that GCS is more sensitive than GLS in detecting subclinical involvement, and early changes in GCS is a good predictor of subsequent development of drugs (anthracycline-transtuzumab) induced cardiotoxicity.