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