Heart in a Box

A heart that beats outside the body

In a world first that has already directly saved hundreds of lives, Professor Peter MacDonald and his research team at the Cardiac Transplantation Laboratory at the Victor Chang Cardiac Research Institute discovered how to transplant donor hearts that had stopped beating after death.

This was done by using a defined preservation fluid developed in the laboratory and a machine that allows the heart to beat outside the body known as ‘Heart in a Box’.

Until Heart in a Box was invented, transplant units relied solely on donor hearts from brain-dead patients whose hearts are still beating. The use of Donation after Cardiac Death (DCD) hearts, where the heart is no longer beating, represents a paradigm shift in organ donation.

This new approach extends the amount of time a donor transplant heart can spend in transit from four to 14 hours. This means donor hearts can be transported further and so be better matched with a recipient, improving the outcomes for patients, and dramatically expanding the available pool of heart donors.

How does Heart in a Box work?

The donor heart is first connected to a sterile circuit where it is kept beating and warm thereby limiting the detrimental effects of cold ischaemia (a period where the heart is dormant without oxygen and nutrients) that occurs with the standard organ preservation mode of packing the heart on ice in an Esky.

Once housed inside the portable device, the heart is reanimated, preserved with the fluid developed in the Institute’s laboratory where it can be functionally assessed until it is ready to be placed inside the recipient.

Benefits of using Heart in a Box

Until Heart in a Box was invented, transplant units relied solely on donor hearts from brain-dead patients whose hearts are still beating. The use of DCD hearts, where the heart is no longer beating, represents a paradigm shift in organ donation. This new approach extends the amount of time a donor transplant heart can spend in transit from four to 14 hours. This means donor hearts can be transported further and so be better matched with a recipient, improving the outcomes for patients, and dramatically expanding the available pool of heart donors. The unique Preservation Solution that was developed by the Institute:

• Reduces the amount of damage to the heart
• Makes the heart more resilient to transplantation
• Reduces the number of heart muscle cells that die
• Improves heart function when it is restarted
• Limits damage from a lack of oxygen
• The preservation solution took 12 years to perfect

How Heart in a Box was developed

The first DCD heart transplant was performed in 2014 – the culmination of 20 years research in donor heart preservation in the Institute’s lab.

The initial focus of this research was to improve the quality of donor hearts from brain dead donors. But when DCD donors began to be used more widely for kidney, liver and lung transplantation, Professor Macdonald started to explore the possibility of retrieving and transplanting hearts from DCD donors.

The additional challenge posed by the DCD heart is that it is non-beating at the point of retrieval so the team needed to develop a technique that allowed them to not only to preserve the heart but also which allowed them to confirm that the heart was viable and would work when transplanted.

The first Heart in a Box Transplants

Michelle Gribilas from Sydney, was the first person to ever receive a heart transplant from a DCD donor in August 2014. The donor’s heart had stopped beating 20 minutes before it was retrieved.

Ms Gribilas was suffering from heart failure due to an inherited cardiomyopathy.

The second patient, Jan Damen, 43 also suffered from a cardiomyopathy. “I feel amazing,” the father-of-three said at the time.

Both operations took place at St Vincent’s Hospital in Sydney, where Professor Macdonald is a cardiologist and senior member of the cardiothoracic transplant program.

Trials

In 2015, Professor Macdonald published the results of the world first breakthrough in The Lancet. The paper focused on the St Vincent’s Hospital patients who received a heart transplant with the new technique. Whilst their operations took place in Sydney, the hearts came from donors from other hospitals. All three recipients, including Ms Gribilas and Mr Damen, had normal cardiac function within a week of transplantation and all made a good recovery.

Since then, DCD cardiac transplantation has been progressively taken up worldwide as a now proven and reliable means to increase the cardiac transplant organ donor pool.

Collaboration

The transplant of DCD hearts is the result of years of combined research between the Victor Chang Cardiac Research Institute and St Vincent’s Hospital. Funding came from an NHMRC Program Grant, St Vincent’s Clinic Foundation, John T Reid Charitable Trust and a NSW OMHR Senior Researcher Grant.

Outcomes and impact

There are around 5,000 heart transplants performed per year around the world. This technique is expected to see the figure rise by an extra 1,000 transplants annually. At St Vincent’s in Sydney almost a third of transplants now use the Heart in a Box procedure with DCD cardiac transplantation. It is also now being used by surgeons in the US, the UK and Europe. Professor Macdonald is now working closely with the University of Queensland on the use of minute quantities of funnel web spider venom to further extend the life of donor hearts.