Statement: There are no racial criteria for entry into the primary trial, however there are gender criteria.
Primary_evidence: INCLUSION CRITERIA   Males and Females  18 years old diagnosed with HER2 positive breast cancer   Scheduled to receive neoadjuvant or adjuvant trastuzumab (Herceptin®) therapy (anthracycline-containing regimens are permitted). Patients receiving Herceptin® with their chemotherapy are permitted for eligibility work-up. Taxanes are permitted. Trastuzumab (Herceptin®) therapy may be given with or after primary chemotherapy. Pertuzumab may be used in conjunction with trastuzumab.   Left Ventricular Ejection Fraction (LVEF)  50% by MUGA scan or echocardiogram   Adequate renal function for administration of trastuzumab-containing chemotherapy regimen.   Sitting systolic blood pressure of > 90 mm Hg   Pulse  60 beats/minute   Not pregnant or breastfeeding   Female patients of childbearing potential, who are sexually active, must have a negative pregnancy test before starting the study   Both men and women must be willing to use effective contraception during the study. Teratogenicity is documented for both active study agents   Able to swallow capsules EXCLUSION CRITERIA:   Patients with metastatic disease   Prior treatment with trastuzumab or anthracyclines prior to this chemotherapy regimen   Current treatment with angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), such as losartan, β-blockers or digoxin   Known cardiac history: heart failure, myocardial infarction, radiation-induced cardiac dysfunction   Known allergy to either ACE inhibitors or β-blockers   History of bronchial asthma or related bronchospastic conditions   Hereditary or idiopathic angioedema   History of severe hypersensitivity reactions to drugs or other causes, i.e. bee stings   This protocol does not exclude patients who are participating on other investigational studies. Refer to the local IRB guidelines.