Normothermic Ex-Vivo Heart Perfusion: Effects of Live Animal Blood and Plasma Cross-Circulation

Prolonged normothermic ex-vivo heart perfusion (NEVHP) could transform cardiac transplantation. To help identify perfusate components that might enable long-term perfusion, we evaluated the effects of cross-circulated whole blood and cross-circulated plasma from a live paracorporeal animal on donor porcine hearts preserved via NEVHP. Standard perfusion (n=40) utilized red blood cell/plasma perfusate and Langendorf technique for a goal of 12 hours. Cross-circulation groups used a similar circuit with the addition of cross-circulated venous whole blood (XC-Blood; n=6) or cross-circulated filtered plasma (XC-Plasma; n=7) between a live paracorporeal pig under anesthesia and the perfusate reservoir. Data included oxygen metabolism, vascular resistance, lactate production, left ventricular function, myocardial electrical impedance, and histopathologic injury score. All cross-circulation hearts were successfully perfused for 12 hours, compared to 22 of 40 standard perfusion hearts (55%; p=0.002). Both cross-circulation groups demonstrated higher oxygen consumption and vascular resistance than standard hearts from hours 3-12. No significant differences were seen between XC-Blood and XC-Plasma hearts in any variable, including left ventricular dP/dT after 12 hours (1478 ± 700mmHg/s vs. 872 ± 500; p=0.17). We conclude that cross circulation of whole blood or plasma from a live animal improves preservation of function of perfused hearts, and cross-circulated plasma performs similarly to cross-circulated whole blood.