Successful Resuscitation of Porcine Hearts After 12 and 24 h of Static Cold Storage With Normothermic Ex Situ Perfusion.

Background: Heart transplantation is always an emergency because the transplant needs to occur within 6 h after procurement to prevent primary graft dysfunction. Static cold storage (SCS) is the gold-standard preservation method. This study describes the outcomes of hearts preserved after prolonged SCS (12 and 24 h); those are then resuscitated with a novel normothermic ex situ heart perfusion (NEHP) system. Methods: Anesthetized piglets (n = 10) were used as heart donors. Hearts were procured and stored at 5 °C CoStorSol following standard SCS protocols. Two groups were studied: SCS-12 h and SCS-24 h. After SCS, 8 h of NEHP (37 °C blood-based perfusate) was performed at 0.7-1.0 mL/min/g of cardiac tissue. NEHP parameters were monitored continuously. Results were corroborated with 3 additional hearts transplanted orthotopically in healthy recipients (n = 3) after SCS (24 h) + NEHP (5 h). Recipients were observed for 90 min after weaning off cardiopulmonary bypass support. Results: All hearts (after 12 and 24 h of SCS) regained normal function and metabolism within 10 min and retained it throughout 8 h of NEHP. No differences were observed in NEHP parameters and histopathology between groups. Three hearts were successfully transplanted after a total ~30 h of preservation (24 h of SCS + 5 h of NEHP + 1 h of second cold ischemia time). The 3 recipients were weaned off cardiopulmonary bypass with mild vasopressor support. Conclusions: NEHP has the potential to routinely resuscitate porcine hearts that have undergone SCS for up to 24 h, restoring them to viable function. By objectively assessing heart function before transplant, NEHP may enhance the success rate of transplants. If these resuscitated hearts can be successfully transplanted, it would support the effectiveness of NEHP in ensuring heart viability.