Studies of Neuregulin/ERBB Signaling in Human Heart

The EGF family of receptor tyrosine kinases (a.k.a. ERBB receptors) mediate the effects of
the epidermal growth factor (EGF) family including Neuregulin-1β (NRG). NRG and ERBB1-4 are
critical for cardiac development and maintenance of the adult heart. Current understanding of
the role of EGF/NRG/ERBB signaling in the cardiovascular system is rapidly evolving due to
recent findings in non-myocyte cell populations. This study is examining a population of
progenitor cells in the adult human heart that responds to EGF and NRG. Subjects are enrolled
who are scheduled to undergo heart surgery and are willing to allow for a small biopsy to be
taken from their hearts during surgery. Biopsies are taken to the laboratory where cells are
separated and analyzed by flow cytometry and grown in cell culture to understand how their
biology is regulated by NRG and EGF.

Inclusion Criteria:

- Clinical diagnosis of severe coronary artery disease scheduled to undergo coronary
artery bypass surgery.

Exclusion Criteria:

- less than 18 years of age

- unwilling or unable to provide informed consent

- known active myocarditis

- hypertrophic cardiomyopathy

- constrictive pericarditis or other significant pericardial disease

- severe pulmonary hypertension

- significant renal impairment (Cr > 2.5 mg/dL)

- severe ventricular arrhythmias

- pregnancy