STOP Heart Disease in Breast Cancer Survivors Trial

Inclusion Criteria:

* Female patients with newly diagnosed stage 1-3 breast cancer
* Histologically confirmed HER2, ER, and PR status
* Recommended to undergo trastuzumab treatment, with or without anthracycline. Patients will be eligible for up to 3 weeks after starting treatment.
* Age minimum 18 years
* Able and willing to read, understand, and sign an informed consent form (ICF) and medical release form
* Willing and able to comply with trial protocol and follow-up
* ECOG performance status 0-1 (Karnofsky ≥ 70%)

Exclusion Criteria:

* Prior use of statin medication within the past year
* Not using statin medication but is eligible for statin therapy based on the 2013 ACC/AHA guidelines (LDL cholesterol \>190, or LDL \<190 and ASCVD risk \>7.5%; http://tools.acc.org/ASCVD-Risk-Estimator/) and is \> 50 years old; or is eligible for statin therapy based on the 2013 ACC/AHA guidelines and is 40-50 years old and wishes to be placed on statin therapy
* History of adverse effects, intolerance, or allergic reactions attributed to statin medication
* Current use of gemfibrozil, cyclosporine, clarithromycin, itraconazole, erythromycin, the hepatitis C protease inhibitor telaprevir, HIV protease inhibitors, colchicine, or red yeast rice
* Current use of any other investigational agent
* Pregnant or intention to get pregnant during the next 18 months. Pregnant women are excluded from this study because atorvastatin is a lipid-lowering agent with the potential for teratogenic or abortifacient effects, and MRI is contraindicated in pregnant women.
* History of diabetes, severe lung disease, renal disease (creatinine \> 1.8 mg/dL or CrCl ≤ 50 mL/min), or hepatic disease (AST and ALT \> 3 times upper normal limits)
* Abnormal baseline echocardiogram or cardiac MRI (detection of congenital heart disease; ischemic heart disease; moderate or severe valvular heart disease; cardiomyopathy; EF \< 55%)
* Previously known or diagnosed heart disease (e.g. congenital; valvular; coronary artery disease; history of myocardial infarction or acute coronary syndrome; cardiomyopathy, including infiltrative, hypertensive, hypertrophic, dilated, constrictive pericarditis, or other cardiomyopathy)
* Left ventricular dysfunction (EF \< 55%)
* Prior non-cardiac illness with an estimated life expectancy \< 4 years
* Known active infection with HIV
* Allergy or contraindication to MRI testing, including claustrophobia, metallic parts in body the prohibiting MRI, prior gadolinium contrast reaction, or uncontrolled moderate hypertension (sitting blood pressure \>160/95 mm Hg with measurements recorded on at least 2 occasions).
* Has metallic breast expanders in place at the time of screening
* Concurrent illness which in the opinion of the investigators would compromise either the patient or the integrity of the data