Study shows that method reduces the risk of early heart failure

The risk of early heart failure after a heart transplant is lower if the donor heart is stored in a so-called heart-in-a-box instead of in the usual cooling box with ice. This is the result of a study by researchers at the University of Gothenburg.

The common method of storing donated hearts prior to transplantation is to keep them in a potassium solution at 4°C in a cooler with ice. Handling is a race against time, as allocation, transport and surgery must be completed within four hours to avoid increasing the risk of complications for the recipient.

Studies have shown that transport times of up to nine hours are no longer an obstacle when hypothermic oxygen machine perfusion (HOPE) or a “heart-in-a-box” is used instead of static cold storage. In the box, the heart is kept at 8°C and oxygenated using a pump, a series of tubes, a reservoir and fluid that circulates through the resting heart while awaiting transplantation.

The aim of the current study, published in The LancetThe aim was to compare the “Heart-in-the-Box” and Cooler methods in terms of safety and health effects in heart recipients in the first 30 days after the transplant. The study is the first randomized controlled study of its kind.

Eight countries in Europe

The study involved 204 adult patients registered for heart transplantation at 15 different clinics in eight European countries. Half of the participants were randomly assigned to receive hearts treated in a “heart-in-a-box” setting, while the other half received hearts from cold static storage using standard procedures. All hearts came from brain-dead donors.

The results show that heart recipients were significantly less likely to experience heart failure in their new heart if it was treated in a “heart-in-a-box” system before transplantation, compared to standard cold static storage. The risk of severe organ failure, primary graft dysfunction (PGD), was 11% in the heart-in-a-box group and 28% in those whose hearts were stored using standard procedures.

Otherwise, there were no differences in clinical events between the groups during the observation period. The researchers will later present analyses of the health effects of the participants in the first year after the heart transplant.

One of the driving forces behind the study is author Andreas Wallinder, MD, Ph.D., a cardiothoracic surgeon and now medical director of the Swedish company XVIVO AB, who developed the “Heart-in-a-Box” concept used together with Stig Steen, senior professor at Lund University.

“The oxygenation of the heart that occurs in the box is crucial. With normal cold storage and transport, we have no oxygenation or circulation in the cells, but when we use the box, oxygen- and nutrient-rich fluid is continuously pumped through the heart, allowing the heart to function better and leading to fewer complications in the recipient after the transplant,” he says.

More transplants in sight

Göran Dellgren is a professor of transplant surgery at the Sahlgrenska Academy at the University of Gothenburg and a cardiothoracic surgeon at Sahlgrenska University Hospital. He is the Swedish principal investigator of the study, which is responsible for about 20 participants. “The results represent a breakthrough in transplantation that could expand the field.”

“If used correctly, the heart-in-a-box can reduce a number of complications that otherwise often lead to suffering, poor outcomes, in the worst case premature death and also high costs. From a time perspective, organs can also be transported over longer distances, making more organs available for transplant.

“We can probably also use less ideal organs from older donors, which could increase the number of heart transplants,” he says.