Background: End-stage heart and kidney failure is constrained by donor organ scarcity. This study aimed to establish a standardized protocol for combined heart–kidney xenotransplantation using multi-gene–edited porcine grafts in a non-human primate (NHP) model and to evaluate their short-term functional outcomes, providing a basis for future clinical translation.

Methods: Genetically modified Bama miniature pigs carrying five gene edits (GTKO/SdaKO/CD46/CD55/TBM) were used as organ donors, and healthy male rhesus macaques served as recipients. Donor hearts and kidneys were harvested using a standardized protocol and preserved via cold perfusion. Cardiac transplantation was performed using an intra-abdominal heterotopic approach, with end-to-side anastomosis between the donor ascending aorta and the recipient abdominal aorta, as well as between the donor pulmonary artery and the recipient inferior vena cava. Renal transplantation involved orthotopic end-to-end anastomosis of the donor renal artery and vein to the recipient's left renal vasculature. A combined immunosuppressive regimen was administered perioperatively, alongside anticoagulation, anti-infective prophylaxis, and supportive care. Recipient vital signs and cardiorenal function were continuously monitored throughout the perioperative period. Experimental endpoints were defined as cessation of renal graft perfusion or irreversible cardiac graft failure.

Results: The recipient survived 7 days and 4 hours post-transplant with stable vital signs. Both grafts demonstrated good intraoperative perfusion. The heart graft resumed beating immediately upon reperfusion, with left ventricular ejection fraction peaking at 35% on postoperative day (POD) 5 before declining. Echocardiography revealed myocardial hypertrophy and reduced contractility, but no complete cardiac failure. The kidney graft showed perfusion by POD 1, and urine output by POD 5 confirmed initial function. However, increased vascular resistance and reversed flow between POD 6 and POD 7 indicated acute graft failure. Laboratory assessments showed persistent anemia, lymphopenia, and intermittent prolongation of activated partial thromboplastin time (APTT). At necropsy, the heart graft retained structural integrity and partial function, whereas the kidney graft exhibited hemorrhagic infarction. Notably, vascular anastomoses remained intact throughout the study. Additionally, the heart graft maintained its function despite renal rejection, suggesting greater resilience to immune injury.

Conclusion: This combined xenotransplantation model demonstrated short-term graft survival, with the cardiac graft showing greater resistance to rejection than the renal graft. It offers a platform for optimizing clinically viable strategies for long-term functional xenotransplantation.