The risk of early heart failure after a heart transplant is lower if a donor's heart is stored in a so-called heart-in-a-box rather than in a regular cooler with ice, according to the findings of a study now published by researchers at the University of Gothenburg.
The established method of storing donated hearts before transplantation is to store them in a potassium solution in an iced cooler at 4 degrees Celsius. Handling the heart is a race against time, as matching, transport and surgery must be completed within four hours to avoid increased risk of complications for the transplant patient.
Studies have shown that transport times of up to nine hours are not an issue if static, refrigerated storage is replaced with hypothermic oxygenated machine perfusion (HOPE), or a “heart in a box.” Inside the box, the heart is kept at a temperature of 8 degrees and oxygenated using a pump, set of tubing, reservoir and fluid circulated through the heart at rest while it awaits transplant.
The aim of the study, published in The Lancet, was to compare the “heart-in-the-box” technique with the cooler technique in terms of safety and health outcomes 30 days after heart transplantation. It is the first so-called randomized controlled study of its kind.
8 European countries
The study involved 204 adult patients who registered for heart transplants at 15 different clinics in eight European countries. Half the participants were randomly assigned to receive a “heart in a box” treated heart, while the other half received a heart that had been stored in cold storage using standard procedures. All hearts came from brain-dead donors.
Results showed that heart transplant patients were significantly less likely to experience heart failure with their new hearts if their hearts were handled with the “heart-in-a-box” method before transplantation compared with standard refrigerated storage. The risk of severe organ failure, or primary graft dysfunction (PGD), was 11% in the heart-in-a-box group and 28% in patients whose hearts were preserved with the standard method.
“There were no other differences in clinical events between the two groups during the follow-up period. The researchers will later publish the results of their analysis of participants' health outcomes one year after their heart transplant.”
The driving force behind the study was author Andreas Varinder, MD, now medical director of the Swedish company XVIVO AB, who developed the “heart in a box” concept together with Stig Steen, senior professor at Lund University.
“The oxygen supply to the heart inside the box is crucial. During normal refrigerated storage and transport, there is no oxygen supply or circulation to the cells, but with the box, oxygen-rich, nutrient-rich fluid is continuously pumped to the heart, improving its function and reducing complications for the patient after transplant,” he says.
More transplants coming soon
Göran Delgren, professor of transplant surgery at Sahlgrenska Academy, University of Gothenburg and cardiothoracic surgeon at Sahlgrenska University Hospital, is the Swedish lead investigator of the study, which involves around 20 participants.
“This finding represents a groundbreaking advance in transplantation and has the potential to expand the field of transplantation. If used correctly, the boxed heart could reduce many complications that often lead to suffering, poor outcomes and, at worst, premature death, and high costs,” he said.
“In terms of time, organs can now be transported over longer distances, increasing the number of organs available for transplantation. It could also enable the use of less ideal organs from older donors, potentially increasing the number of heart transplants,” Göran Delgren concludes.
sauce:
Journal References:
Rega, F., et al. (2024). Hypothermic oxygen perfusion of donor hearts in heart transplantation: short-term results of a randomized, controlled, open-label, multicenter clinical trial. The Lancet. doi.org/10.1016/s0140-6736(24)01078-x.
