Heart Transplant Failure and Rejection

The investigators will evaluate for early evidence of cardiac allograft dysfunction by cardiac MRI and single cell sequencing to determine underlying molecular and macroscopic causes.

The purpose of this study is to compare the safety and efficacy of letermovir with valganciclovir for prevention of Cytomegalovirus (CMV) viremia in moderate to high risk serostatus heart transplant recipients.

Prospective cohort clinical study, registry-based, multicenter, national, with the consecutive inclusion of patients with a history of Heart Transplantation in Brazil. The clinical registry will involve the participation until 25 centers. Patients will be included up to 30 days after Heart Transplant surgery and will be followed for one year. Laboratory tests and clinical parameters wil be collected in two clinical visits (6mo and 12 mo). The outcomes evaluate will be the total hospitalizations and all-cause death. It is expected to include 730 patients with a 12-month follow-up from the day of the transplant surgery. The findings of the HESTIA Registry may guide the management of post-heart transplant patients, aiming at reducing morbidity and mortality within 12 months after heart transplant surgery.

Abnormal lipid metabolism is a common complication after organ transplantation, with pathological changes in lipid parameters occurring in approximately 60-80% of cardiac transplant recipients receiving triple immunotherapy with cyclosporine, imid azathioprine, and methylprednisolone. With the significant increase in long-term survival and increasing age of transplant patients, atherosclerotic cardiovascular diseases, such as those caused by dyslipidemia, have become a major cause of transplant organ failure and recipient death. However, the causes of dyslipidemia after organ transplantation, as well as the effects and mechanisms of dyslipidemia on transplant rejection, are unknown. Previous studies have found that 1. increased lipid levels occur in recipients after heart transplantation; 2. during rejection, hepatic PCSK9 expression is increased in recipients; 3. a high-fat environment increases the immunoreactivity of human peripheral blood lymphocytes. It is suggested that PCSK9-lipid disorder-immune cell interactions may be associated with the development of transplant rejection. In this project, we propose to (1) establish a long-term follow-up system for postoperative cardiac transplantation patients in our department to track the characteristics of lipid changes in transplantation patients, to clarify the link between dyslipidemia and rejection, and to provide a strong evidence-based medical basis for the management of lipids during the perioperative period and in the postoperative period; (2) expand the dimensions of lipid-related assays under the support of the above system, and to incorporate transcriptomic, proteomic, and metabolomic research methods to elucidate transplantation rejection in a multidimensional manner. (ii) Expanding the dimensions of lipid-related assays to include transcriptomic, proteomic, and metabolomic studies to elucidate the relationship between PCSK9 and dyslipidemia in transplant patients; (iii) Adopting single-cell sequencing technology to deeply reveal the potential mechanism by which changes in lipids affect T-cell-mediated rejection of cardiac transplants. The mechanism of T-cell-mediated cardiac transplantation rejection is revealed by single-cell sequencing.