M-A: Beta-blockers and renin–angiotensin system inhibitors may provide a modest benefit for the preservation of left ventricular function in patients with breast cancer treated with anthracyclines or trastuzumab.

A systematic review and meta-analysis of beta-blockers and renin–angiotensin system inhibitors for preventing left ventricular dysfunction due to anthracyclines or trastuzumab in patients with breast cancer – European Journal of Cardiology (link to abstract – $ for full-text)

Commentary: BBs, ACEI/ARBs to Prevent LV Dysfunction Due to Breast Cancer Drugs – American College of Cardiology