Patients with cardiomyopathy and/or LVEF < LLN. Prior or current cardiomyopathy including but not limited to the following: known hypertrophic cardiomyopathy, known arrhythmogenic right ventricular cardiomyopathy, previous moderate or severe impairment of left ventricular systolic function (left ventricular ejection fraction [LVEF] < 45% on echocardiography or equivalent on multigated acquisition scan [MuGA]) even if full recovery has occurred Documented cardiomyopathy; Active cardiomyopathy Hypertrophic cardiomegaly or restrictive cardiomyopathy from prior treatment or other causes Has significant cardiovascular disease with New York Heart Association (NYHA) class III or IV symptoms, or hypertrophic cardiomyopathy, or restrictive cardiomyopathy, or myocardial infarction within 3 months prior to enrollment, or unstable angina, or unstable arrhythmia as determined by history and physical examination Patients with clinically significant cardiomyopathy requiring treatment Hypertrophic cardiomegaly or restrictive cardiomyopathy from prior treatment or other causes Patients with LVEF =< 40% from treatment with anthracyclines for all malignancies at any dose without evidence of other causes of cardiomyopathy History of familial cardiomyopathy History of infiltrative cardiomyopathy or restrictive cardiomyopathy Transthyretin amyloid (ATTR) cardiomyopathy (CM) Cardiomyopathy primarily caused by non-amyloid diseases (e.g. ischemic heart disease; valvular heart disease) Symptomatic cardiomyopathy Patients with LVEF =< 40% documented from treatment with anthracyclines for any malignancy at any dose at any time without evidence of other causes of cardiomyopathy History of familial cardiomyopathy History of infiltrative cardiomyopathy or restrictive cardiomyopathy Documented cardiomyopathy Documented cardiomyopathy Hypertrophic cardiomegaly or restrictive cardiomyopathy from prior treatment or other causes Known history of cardiomyopathy Patients with clinically significant cardiomyopathy requiring treatment Documented cardiomyopathy Significant cardiovascular disease with New York Heart Association (NYHA) class III or IV symptoms, ejection fraction (EF) =< 40% or hypertrophic cardiomyopathy, or restrictive cardiomyopathy, or myocardial infarction within 6 months prior to enrollment, or unstable angina, or unstable arrhythmia as determined by history and physical examination. Echocardiogram will be performed during screening evaluation Has significant cardiovascular disease with New York Heart Association (NYHA) class III or IV symptoms, ejection fraction (EF) =< 40% or hypertrophic cardiomyopathy, or restrictive cardiomyopathy, or myocardial infarction within 6 months prior to enrollment, or unstable angina, or unstable arrhythmia as determined by history and physical examination; echocardiogram will be performed during screening evaluation Has significant cardiovascular disease with New York Heart Association (NYHA) class III or IV symptoms, ejection fraction (EF) =< 40% or hypertrophic cardiomyopathy, or restrictive cardiomyopathy, or myocardial infarction within 6 months prior to enrollment, or unstable angina, or unstable arrhythmia as determined by history and physical examination; echocardiogram will be performed during screening evaluation Hypertrophic cardiomegaly or restrictive cardiomyopathy from prior treatment or other causes Prior history of cardiomyopathy. Uncontrolled hypertension or cardiomyopathy Uncorrected primary obstructive or severe regurgitative valvular disease, nondilated (restrictive) or hypertrophic cardiomyopathy, or significant systemic ventricular outflow obstruction Any grade immune-related pneumonitis, cardiomyopathy, or hepatitis Have cardiomyopathy Receiving treatment for cardiomyopathy or heart failure Uncorrected primary obstructive or severe regurgitative valvular disease:\r\n* Nondilated (restrictive); or\r\n* Hypertrophic cardiomyopathy; or\r\n* Significant systemic ventricular outflow obstruction Patients with any of the following cardiac conditions:\r\n* Symptomatic restrictive cardiomyopathy\r\n* Dilated cardiomyopathy\r\n* Unstable angina within 4 months prior to enrollment\r\n* New York Heart Association functional class III-IV heart failure on active treatment\r\n* Symptomatic pericardial effusion History of myocardial disease, such as myocarditis, cardiomyopathy, congestive heart failure, ischemic cardiomyopathy Pre-existing ischemic heart disease (includes angina if documented in electronic medical record [EMR]) or ongoing cardiomyopathy. Cirrhosis, cardiomyopathy, restrictive heart disease, or bronzing of the skin