Ex Situ Set-up and Protocol 
The donor heart was then connected to the ESHP system cannulas that were suspended in a 3D-printed custom-made holder. The circuit composed a reservoir (Affinity Fusion®, Medtronic, Minneapolis, MN), an oxygenator (Affinity Fusion®, Medtronic, Minneapolis, MN) and two centrifugal pumps (560A and 540 T, Medtronic, Minneapolis, MN) working in parallel to selectively load the LV and right ventricle (RV), as described above. A heat exchanger (Sarns Dual Heater Cooler Model 11,160) maintained a stabile temperature of 37°C.
The system was primed with 2000 mL of whole autologous blood from the donor and normal saline to achieve a hematocrit > 25%. Methylprednisolone (500 mg), heparin (10,000 IU), cefazolin (1 g) and magnesium (2 g) were also added to the priming. Calcium chloride 10%, sodium bicarbonate 8.4% and dextrose 50% were added to correct calcium (1.1-1.3 mmol/L), glucose (5-10 mmol/L) and bicarbonate (24-30 mmol/L) concentrations, respectively.