Study of Cardiopulmonary Exercise Testing in Women Who Have HER2-Positive Breast Cancer With Mild Cardiotoxicity

Inclusion Criteria:

Age ≥ 18 years
Female
Diagnosed with a HER2-positive solid tumor (stage I-IV)
Left ventricular dysfunction prior to the start of HER2-targeted therapy, defined by a LVEF < 53% (or lower limit of normal), or diagnosed with mild cardiotoxicity associated with HER2-targeted therapy, defined by an absolute decrease in LVEF ≥ 10% from pre-treatment to < 53%
Planning to undergo treatment with HER2-targeted therapy (e.g. trastuzumab, pertuzumab, or ado-trastuzumab) for a minimum of 3 months (i.e. 4 cycles administered every 3 weeks).
Willing and able to comply with the requirements of the protocol

Exclusion Criteria:

Symptomatic heart failure (New York Heart Association Class III or IV)

Subjects must not have any of the following absolute contraindications to cardiopulmonary exercise testing:

Acute myocardial infarction (within 30 days of any planned study procedures),
Unstable angina
Uncontrolled arrhythmias causing symptoms or hemodynamic compromise,
Symptomatic severe aortic stenosis
Recurrent syncope
Active endocarditis
Acute myocarditis or pericarditis
Acute pulmonary embolus or pulmonary infarction (within 3 months of any planned study procedures)
Thrombosis of lower extremities (within 3 months of any planned study procedures)
Suspected dissecting aneurysm
Uncontrolled asthma
Pulmonary edema
Room air desaturation at rest ≤ 85%
Respiratory failure
Acute noncardiopulmonary disorder that may affect exercise performance or be aggravated by exercise (i.e., infection, renal failure, thyrotoxicosis)
Mental impairment leading to inability to cooperate.
Enrollment onto any other interventional investigational study
Inability to provide informed consent