Cardiac transplantation for hypoplastic left heart syndrome

Abstract

Future improvements can be expected in cardiac transplantation in children. We continue to advance our understanding of the immune system, and to develop more specific immunosuppressive agents. Ultimately, the future for recipients may be improved by strategies such as induction therapy or donor-derived chimeric destined transfusions, designed to enhance the tolerance of the host to a human leukocyte antigen incompatible graft. Improvements in tolerance of the host would allow for reduction or elimination of many, if not all, of the immunosuppressive agents, and for longevity extending well into the adulthood. Survival, particularly for infants, has improved dramatically in the last decade. The most recent results from the registry of the International Society of Heart and Lung Transplantation/United Network for Organ Sharing show that recipients less than one year old at transplantation, who survive the first year, have greater than a 95% survival to four years (Fig. 1). As late outcomes continue to improve, transplantation will provide a better quality and duration of life for infants with hypoplastic left heart syndrome. It is possible, nonetheless, that some infants will require retransplantation, since the half life of a transplanted heart in children has been about 12 years. The alternative is conventional surgery with multiple palliative operations, and the need for later transplantation as end-stage cardiac function is reached. Efforts to increase potential donors and donor utilization can be supported by innovative schemes, such as ABO incompatible transplants. Additional efforts are made more urgent when the current data indicate excellent outcomes after transplantation, but a high mortality while waiting for transplantation.

Hypoplastic Left Heart Syndrome

“…Infants and children waiting for hearts in the United States have the highest waitlist mortality of all solid organ recipients (17%) and has increased progressively over the past 2 decades (141). Though a preferred therapeutic modality in a few centers (32, 142), given that waiting times for neonates in most regions approach several months and Stage 1 reconstructive palliation at most centers carry acceptable results, primary heart transplant for HLHS is rarely offered in this era, and is, in general, limited to neonates with severe RV dysfunction and/or moderate-to- severe tricuspid regurgitation. Because the limited supply of donor organs contributes to significant mortality while patients are waiting for a suitable donor, attempts have been made to increase the donor pool through the use of ABO-incompatible donors (143).…”

Heart Cells with Regenerative Potential from Pediatric Patients with End Stage Heart Failure: A Translatable Method to Enrich and Propagate

“…In the pediatric age group, CHD and cardiomyopathies are the predominate causes of heart failure leading to heart transplantation [ 8 ], with far fewer due to ischemic heart disease when compared with the adult age group [ 8 ]. Unfortunately, since most children have undergone surgical repairs for their CHD, they frequently have high levels of antibodies to HLA antigens that increases their risk of heart transplantation [ 9 , 10 ]. For many pediatric patients with heart failure, an autologous cell-based regenerative strategy would be a better therapeutic option than allogeneic heart transplantation [ 11 ].…”

Cost-effectiveness of Pediatric Heart Transplantation

“…Infants may have a longer time on the wait-list but greater graft longevity-presumably due to tolerance. 31 A multicenter study would be helpful in the assessment of infants and re-transplant recipients because these sub-sets of patients at any single institution are limited.…”