Losartan in Prevention of Radiation-Induced Heart Failure

This study is being done to see if losartan affects the chances of developing radiation-induced heart failure in patients who are receiving radiation therapy as part of standard of care treatment for breast cancer.The interventions involved in this study are:LosartanRadiation Therapy (standard of care)

Inclusion Criteria:->18 years of ageNon-metastatic Breast Cancer patients who are scheduled to receive conventional left breast/chest wall RT inclusive of treatment to the internal mammary lymph nodes (IMNs)Prior chemotherapy is permittedPatients must have Left-sided Breast CancerAbility to understand and the willingness to sign a written informed consent documentNo contraindication to MRIExclusion Criteria:Person who is pregnant or breastfeeding.Patient unable to swallow oral medication.Patients receiving any other investigational agent will not be excluded from study eligibility, unless the patient is already enrolled in an interventional study evaluating cardiac toxicityPatients already receiving ACE/ARBs.Patients with a history of allergic reactions to Losartan biosimilars.