Willing to participate in protocol procedures with signed informed consent
Assessment of LVEE via echocardiogram, cardiac MRI, or MUGA
Subjects in the cardiotoxicity group (TOX) must meet the following criteria:
History of HER2 positive breast cancer (stage I-IV)
Prior/current treatment with anthracycline based chemotherapy followed by anti-HER2 directed therapy or anti-HER2 directed therapy alone
Assessment of LVEF at baseline prior to initiation of anthracycline or anti-HER2 therapy and during anti-HER2 therapy via echocardiogram, cardiac MRI, or MUGA
Prior confirmed diagnosis of cardiotoxicity associated with anti-HER2 based therapy, defined as a decrease in LVEF \> 10% from baseline to \< 53% with symptoms of heart failure (NYHA class II-IV).
Subjects in the no cardiotoxicity group (NO-TOX) must meet the following criteria:
History of HER2 positive breast cancer (stage I-IV)
Completion of planned anthracycline and anti-HER2 therapy, or anti-HER2 therapy alone
No symptoms of heart failure (NYHA class II-IV) during and at the end of anthracycline and anti-HER2 therapy
Assessment of LVEF at baseline prior to innitiation of anthracycline or anti-HER2 therapy and during anti-HER2 therapy via echocardiogram, cardiac MRI, or MUGA
Normal LVEF \>53% at each assessment during and at the end of trastuzumab therapy.
Maximum absolute decrease in LVEF \<5% from baseline during and at the end of trastuzumab therapy.
LVEF assessment performed at baseline and at least two time points during trastuzumab therapy.
You may not be if
Unwilling or unable to give skin biopsies
Contraindications to punch biopsy including but not limited to bleeding diathesis, as determined by the investigator.
Known pre-existing CV disease prior to initiation of breast cancer therapy as determined by the investigator, including
