The golden standard revisited
Up until today, cold storage on ice is the golden standard for storing donor hearts. But this method increases the change of heart failure once the heart is out of the body for more than three hours. This is a disadvantage, especially in the case of complex heart transplantation that take longer and are being performed more often nowadays.
Therefore, in an international study led by UZ Leuven, researchers compared the standard technique with an innovative method, in which the heart is preserved using a machine and a specially developed cold fluid (HOPE, hypothermic oxygenated machine perfusion). The storage machine allows a constant ideal temperature to be maintained and additional nutrients to be administered. The heart can be stored to up to 24 hours and will continue to function properly after that.
Breakthrough
The international study took place between November 2019 and May 2023. Spread over 8 European countries and 15 centres, 204 patients were randomly assigned: one half received a heart preserved with a machine (HOPE), the other half a donor heart preserved on ice.
The results show that all donor hearts preserved with HOPE, were suitable for transplantation. The new preservation technique is therefore not only safe and effective, it is also better than storage on ice in a few areas:
- The effect of the use of HOPE appears to be the biggest the first 24 hours, where the risk of failure of the donor hears was reduces with 61%.
- The risk of major complications that may accompany heart transplantation was 44% lower in the HOPE group.
This research underlines the potential of HOPE as the new standard in heart transplant medicine.
Prof. dr. Filip Rega
Prof. dr. Filip Rega, cardiac surgeon at UZ Leuven and principal investigator of the study: "After almost 60 years, we finally have a better preservation method for the heart pending transplantation. This research underlines the potential of HOPE as the new standard in heart transplany medicine. The method improves the patients' recovery considerably, because damage to the heart is less than when stored on ice.”
Increasing the donor pool
The findings of this study are especially relevant for the long waiting lists for heart transplants: there is still a major shortage of donor organs. The current acceptance criteria for donor organs were developed on the basis of the use of storage on ice. As a result, some donor hearts do not qualify, e.g. because of the donor's age or another underlying disorder. HOPE could further increase the pool of available donor hearts and offer more patients the chance of a life-saving transplant.
Other organs, such as kidneys have long been preserved via machine perfusion, with good results. However, a heart muscle cell is a complex cell. It is a lot more sensitive to oxygen deficiency than liver, kidney or lung cells, whick explains why it takes longer to introduce new techniques for the heart.