Partial Heart Transplant Update: Where Are We In 2025?

Abstract

Partial heart transplantation (PHT) creates a new and innovative approach to allow for patient and disease tailored intervention with the ability to treat a larger patient base. It offers the growth capacity of a heart transplantation without the need for high dose immunosuppression. The importance of a valve replacement with the potential of growth is imperative in the pediatric population as these patients will otherwise outgrow their new valves requiring repeat and high-risk interventions. Adaptive valve growth has been observed prior to PHT, in the case of orthotopic heart transplantation and Ross pulmonary autografts. The first human PHT was performed in April of 2022 at Duke. The recipient was a 17-day old infant with truncus arteriosus and severe truncal valve regurgitation. The operation was a success and the transplanted PHT conduit showed appropriate adaptive valve growth. Due to the low immunogenicity and recipient endothelialization of the transplanted PHT graft, the immunosuppressive requirements for PHT patients are low. One of the benefits of PHT is that it utilizes hearts which would otherwise not be suitable for orthotopic heart transplantation. Furthermore, the prospect of domino and split root PHT increases the potential of ethical and efficient organ stewardship. Currently PHT is regulated by the Food and Drug Administration, a ruling which was released in early 2024 as human cells, tissues, or cellular or tissue-based products (HCT/Ps). This means it does not compete with hearts suitable for orthotopic heart transplantation which are regulated as organs under the Organ Procurement and Transplantation Network (OPTN).