Assessing Changes in Myocardial Tissue and Blood in Patients With Advanced Heart Disease

Hypothesis: Tissue and serum samples collected from end-stage heart failure patients receiving left ventricular assist device implantation (LVAD) or heart transplantation will provide information regarding the basic science of heart disease. Tissue and serum samples collected from a limited numbers of "healthy controls" (donor grafts that were not utilized for heart transplantation) will serve as a comparator in research database projects. Design: This is a registry project; there are no investigational treatments, drug or procedures associated with participation in registry activities. This project is an organized functional data and tissue data gathering and storing (database) endeavor with specific focus on the functional, structural, and molecular aspects of heart failure. Data collection will not immediately influence the course of treatment for any patient.

Inclusion Criteria: * \>18 years of age diagnosed with heart failure undergoing either LVAD implantation or heart transplantation * 13 to 18 years of age, specifically, older children with heart failure whose body mass index is large enough to accommodate and LVAD Exclusion Criteria: * Neither patient nor patient representative understands spoken English * Neither patient nor patient's personal representative is willing to give written consent for participation.