[Improving donor heart preservation ex vivo]

There is a shortage of heart donors. Some available organs are lost through deterioration prior to transplantation. Indeed, from the moment of brain death until reperfusion in the recipient, cardiac grafts (and also kidney, lung and liver grafts) can undergo irreversible damage due to cardioplegia, the harvesting procedure, and hypothermic transport. The noxious phenomena occurring during cold ischaemia and myocardial reperfusion have been studied for more than 40 years. It was long believed that only the ischaemic phase was harmful, through depletion of energy stores, ionic imbalance, and metabolic disruption. We now know that the heart graft can also be damaged during the reperfusion phase, through calcium overload, free radical production, and mitochondrial changes. Preconditioning and post-conditioning procedures are being developed to protect the ischemic organ.