View clinical trials related to Heart Transplantation.
Filter by:Bradykinin stimulates t-PA release from intact vessels, but not from endothelial cells in culture. It has been proposed that the nerves of blood vessels are the source of bradykinin stimulated t-PA release. In order tho test this hypothesis, we intend to infuse bradykinin into the brachial (arm) artery and the coronary arteries of heart transplant recipients and control subjects. This is because heart transplant recipients do not have nerves to their coronary arteries. This protocol studies the effects of bradykinin on t-PA release in the forearm of transplant recipients. The brachial artery has intact nerves. Separate protocols address coronary artery infusions in healthy subjects and transplant recipients and forearm infusions in healthy subjects.
Heart transplant recipients do not have nerves to their hearts. This protocol tests the hypothesis that bradykinin mediated t-PA release in the coronary arteries will be reduced in heart transplant recipients compared to healthy subjects. This study will compare heart transplant recipients to healthy controls who are undergoing cardiac cath for standard of care purposes (separate protocol) and compare the coronary arteries to the forearm in transplant recipients (separate protocol) and healthy controls (separate protocol).
The restoration of normal blood flow following a period of ischemia may result in ischemia / reperfusion injury (I/RI), which is characterized by inflammation and oxidative damage to tissues. Varying degrees of I/RI occur upon reperfusion of a donor heart after cold storage. Medications containing antibodies against immune cells have been used for many years as powerful immunosuppressants. These medications, called polyclonal antibody preparations, are generally only used immediately following transplantation and/or to treat rejection. At our institution, one such antibody preparation (Thymoglobulin) is used in most pediatric heart transplant recipients for 3-5 days immediately after transplantation. Because standard immunosuppressive medications (called calcineurin inhibitors) are toxic to the kidneys, the use of Thymoglobulin allows us to delay the initiation of calcineurin inhibitors until the kidneys of completely recovered from the shock of the transplant surgery. We hypothesize that Thymoglobulin may be beneficial in reducing the damage caused by I/RI. Thus, the present study seeks to evaluate the effectiveness of an intra-operative dose of Thymoglobulin (in addition to the standard doses post-operatively) at reducing the effects of I/RI. The study will be a double-bind placebo-controlled trial involving 20 subjects. Biologic markers for I/RI will be assessed at periodic intervals for six months post-transplantation. Subjects receiving intra-operative doses of Thymoglobulin will be compared to the controls in order to assess the effectiveness of intra-operative Thymoglobulin in ameliorating the effects of I/RI.
To compare results of Intravascular Ultrasound (which occurs during cardiac catheterization) with Computed Tomography (CT) scan to detect blockages or narrowing of the arteries that feed the heart. These will be studied in the cardiac transplant population.
The purpose of this research study is to apply new non-invasive, no-risk techniques to a cardiac transplant population for assessment of their reliability in detecting heart transplant rejection. Graft rejection remains a major factor limiting long-term survival despite continued advancement in the use of immunosuppression. Aggressive surveillance for the detection of acute rejection is therefore necessary. Repeated endomyocardial biopsy (EMB) (at least 11 times the first year after transplantation) remains the only reliable surveillance method available. EMB is expensive, invasive, inconvenient to the patient, and associated with a significant incidence of serious complications. Therefore, it would be very important for patient care if new no-risk methods would prove to be effective in surveillance of rejection. This research study is designed to measure non-invasive ways to assess rejection along with the standard planned endomyocardial biopsies you will have after heart transplantation. First, the investigators plan to test the effectiveness of the investigational use of the CMI 2406 Magnetocardiograph that has been approved by the U.S Food and Drug Administration (FDA). While the device used in the study is FDA-approved for the non-invasive measurements and recordings of the heart's magnetic field reflecting the heart's electrical currents, it is not yet approved for the specific use of detection of transplant rejection.