A major cause of heart transplant failure is the blockage of blood flow from lesions caused by ongoing injury and repair of the graft by the host's immune system. However, the role of T cells, antibodies, and other parts of the recipient's immune system are not well understood in transplant injury. Currently, there are no effective, noninvasive ways to detect or predict how an individual's immune system will react to a transplant. The purpose of this study is to correlate current noninvasive monitoring tests with long-term graft survival and function, and determine which tests are the most accurate predictors of this survival.

Participants in this study must currently be on the waiting list for a heart transplant and have a donor heart available to them. This study will consist of six study visits over 12 months. The baseline visit will occur on the day of transplantation. Follow-up visits will occur at Week 6 and Months 3, 6, 9, and 12 post-transplant. At each visit, a physical exam, medication tracking, assessment of graft survival, and blood and urine collection will occur. At the Week 6 and Month 12 visits, intravascular ultrasound and echocardiograms will occur. At the Week 6, Month 6, and Month 12 visits, endomyocardial biopsies will also occur. No immunosuppressive therapy will be provided by the study.