Untapped potential in Australian Hospitals for organ donation after circulatory death

We thank Rakhra and colleagues,1 whose report highlighted a group of potential donors yet to be fully exploited for organ transplantation. While this untapped potential appears to largely affect kidney and lung donor pools, we must not exclude the effect that relaxing donor suitability criteria may have on the heart.

While not largely emphasised, the data collected for the heart are compelling, particularly for an organ so susceptible to ischaemic injury. Similar to the kidney and lungs, the data show that when including ideal and expanded criteria, potential donors more than doubled the number of donor hearts available for heart transplantation.1 This is an important finding, particularly if the authors have conservatively underestimated the actual potential for organ donation. In Australia, donation after circulatory death (DCD) kidney and lung donors comprise 25–30% of the total donor pool for these organs.2,3 Since 2014, the number of national and international hospitals now investigating DCD heart donation has increased, and we anticipate that DCD heart transplantation will follow the same trend as DCD lung and kidney transplant over time.

The Critical Care Research Group at the Prince Charles Hospital has developed a clinically relevant 24-hour ovine model of brain stem death,4 and these donor hearts are being used to transplant into recipient animals. Transplant clinicians and researchers from the Prince Charles Hospital, the Alfred Hospital and St Vincent’s Hospital will collaboratively employ an ex vivo hypothermic perfusion system, capable of safely storing animal hearts up to 24 hours,5 together with novel cardioprotective therapeutics to increase the allowable ischaemic times for donor hearts without impairing graft function. This technology will hopefully extend to DCD donors in the future, which are currently only preserved using a warm blood perfusion system.

By relaxing donor heart suitability criteria, and using novel machine perfusion technology to increase the storage time of the donor heart,5 thus eliminating time and travel distance constraints in Australia, the donor heart pool could be greatly increased. While the numbers may ultimately be modest, the positive effect on those recipients would be substantial.