Professor Macdonald
Saving hearts to save lives
13 April 2023
The Institute’s Professor Peter Macdonald has lived a big life. From joining the Institute in its early days, to working in one of the most highly regarded transplant teams in the country, Professor Macdonald has much to be proud of. We talk to this accomplished clinician scientist about his decades long career and his dedication to research that is changing the face of heart disease.
33-year-old Dr Peter Macdonald is sitting in the back of a police car as it races down Sydney’s South Dowling Street.
The three-car convoy speeds through a series of coordinated green lights and in just seven minutes they’ve made it to their destination: Sydney Airport.
Dr Macdonald boards a Learjet owned by Kerry Packer. He’s with the heart transplant retrieval team from St Vincent’s Hospital, Sydney. It’s 1988 and they want Dr Macdonald as their newest cardiologist to work alongside the transplant surgeons.
The team is on its way to retrieve a donor heart from Adelaide, and as Dr Macdonald will come to learn, every minute counts.
When he recalls his first experience with heart transplants, the now Professor Macdonald's face lights up. He describes it as "quite a buzz".
More than three decades and over 1000 heart transplants later - that buzz has never left him.
“I think I got bitten by the bug at that stage,” Professor Macdonald says.
That first transplant was a success, but as is inevitable with such a complex procedure, an unsuccessful transplant followed soon after. That was when the reality of heart transplantation hit him: to save a patient, you first have to save a heart.
“When I saw that transplant, it sparked my lifelong interest in what we can do to improve both the number and the quality of donor hearts for transplantation,” Professor Macdonald says.
Staff photo, 1997
Though his original plan was to work as a cardiologist at St Vincent’s Hospital for a year before returning home to Melbourne, Professor Macdonald and his wife were won over by the Sydney lifestyle. They are still here 34 years later.
As if a thriving career as a cardiologist wasn’t enough to keep him occupied, in 1994, Professor Macdonald decided to take his interest in the heart and put it to work at the newly-opened Victor Chang Cardiac Research Institute.
In the hospital he was working on a team that saved lives; in the laboratory, he could learn how to save more.
Exploring heart transplants from the human side and the research side has given this clinician-scientist a unique perspective
“You know what the problem is in the patients you deal with in the hospital, which means you have a better sense of how you might approach things in the lab to address that problem,” Professor Macdonald says.
"Plus it’s very satisfying when we get to see something that we tested in a lab translate and make a meaningful difference in the hospital environment.”
One of those satisfying lab-to-patient projects is the ground-breaking Heart in a Box device.
In a world first, Professor Macdonald and his research team at the Institute’s Cardiac Transplantation Laboratory discovered how to transplant donor hearts that had stopped beating after death - also known as Donation After Circulatory Death (DCD) hearts.
This was made possible through the use of a preservation fluid developed in the lab and a machine that allows the heart to beat outside the body known as ‘Heart in a Box’ – a far cry from the traditional technique of transporting donor hearts in an Esky filled with ice!
Before Heart in a Box, transplant teams like the one at St Vincent’s Hospital relied on donor hearts from brain-dead patients whose hearts are still beating. With the development of Heart in a Box, DCD hearts could now be added to the donor pool – boosting the all-too-precious transit time significantly from four hours to 14 hours.
In 2014, the first DCD heart transplant was performed. As with most firsts, Professor Macdonald says it was a scary time.
“When the team retrieved the heart, flushed it with the preservation fluid, and put it in the machine it initially looked terrible,” he says.
“We thought, well, having gone this far, we should at least bring it back here to the operating theatre and see."
Thankfully, their patience was rewarded.
“Over the next two hours the heart just got better and better and by the two-hour mark it had met the viability criteria we use for heart transplants,” Professor Macdonald says.
“We watched it on the machine for a further two hours to make sure it was ok and then we went ahead with the transplant.”
It took four days for the heart to fully recover. By the one-week mark, the heart looked normal and the patient, Michelle Gribilas, was doing great.
Professor Peter Macdonald with Michelle Gribilar and Jan Damen - world's first dead heart transplant recipients
“Nine years later and Michelle’s still alive and well, and going from strength to strength,” Professor Macdonald says with a smile.
The significance of that moment was not lost on him. But like with most transplant patients, there was only one thing on this patient’s mind.
“I realised when I was explaining this new procedure that all she wanted to hear is ‘yes, we can do the transplant’,” Professor Macdonald says.
This game-changing technique has since increased the number of heart transplants by a third and is now being used not just by the team at St Vincent’s, but in countries including the US, Spain, Belgium, Austria, the Netherlands, and the UK.
“What’s amazing to see is the patient outcomes are basically the same,” Professor Macdonald says.
“Once they come out of the operating theatre you can’t tell whether this is a DCD or a DBD (Donation after Brain Death) donor.”
Though this breakthrough is more than enough for one life’s work, Professor Macdonald's research achievements haven’t stopped there
In an interesting twist of fate, another research project Professor Macdonald is involved in has discovered that venom from the deadly funnel-web spider appears to hold the answer to preventing damage to the heart.
Together with the Institute’s Professor Bob Graham and Professor Glenn King and Associate Professor Nathan Palpant from the University of Queensland, Professor Macdonald is working to develop a drug derived from a protein in the spider venom called Hi1a.
This protein blocks the acid-sensing ion channels in the heart that are activated by the build-up of lactic acid after a heart attack, blocking the death message and preventing tissue damage.
While the new drug – which the team hopes to progress to clinical trials in 2024 – could have benefits for heart attack victims, it may also help bring Professor Macdonald closer to his mission of keeping donor hearts viable for transplant for longer.
“We think that we’ll be able to extend the timeframe in which we can retrieve hearts – which could add up to 30% more hearts to the donor pool,” he says.
"We also think it will have a role for conventional brain-dead donors - if we add this drug to the preservation solution, they will be better quality hearts when we do transplant them.”
Rounding out his busy research schedule is his work on frailty
A third of the people referred for a heart transplant are classed as frail and experience worse outcomes because of this. But Professor Macdonald knows this frailty is reversible.
“I give talks on frailty quite a bit and I show this photo of a 48-year-old patient I saw in 1989 who looks like he's 70. Then I've got a photo of him two years later and he looks 48 again. So I knew a long time ago that frailty was reversible.”
These insights from his clinical experience allow Professor Macdonald to question those long-held assumptions that can impact patient outcomes.
“I think the attitude that is often taken is that these people are too sick to do anything,” he says.
“But we're going to challenge that concept by putting them through a prehabilitation program to improve their health before their transplant. I know there are things they can do - obviously there are limits, but it doesn't stop them completely.”
When he’s not seeing patients at the hospital, Professor Macdonald adds to his clinical work with monthly visits to Condobolin Aboriginal Medical Centre
He’s been visiting the remote clinic since 2006 – a dedication that has won over his patients.“They’ve been some of the happiest and most grateful patients I’ve seen,” Professor Macdonald says.
“I was going there for at least two years before I felt there was a level of trust – I think they got used to seeing doctors come and go. In the time that I’ve been there, there would have been about 20 GPs. My claim to fame in Condobolin is that I’ve been there longer than any other medical practitioner.”
With his busy clinical and research schedule complemented by golf on Sundays, gardening with his wife, and time spent enjoying his new role of grandfather, it’s hard to imagine there’s a ‘typical day’ for Professor Macdonald.
When asked instead what makes a ‘good day’, he laughs and says: “When I finish at a reasonable time,” before his thoughts turn earnest.
“If we do a transplant and it all goes well, then that's a good day at work,” he says.
“Having said that I’m always very aware that someone has to die for someone else to have a transplant - it's someone else's tragedy that you're dealing with, and you just hope that from something that is otherwise a complete disaster, something positive can come out of it for a donor family.”
On the other side of that transplant is a grateful recipient, and it’s no surprise that there’s a wealth of patients that hold high regard for Professor Macdonald and his work.
“It sure makes it easy to come to work,” Professor Macdonald laughs when told of the messages of thanks that have been left on the Institute’s social media pages from his patients and their loved ones.
“That’s part of the reason you do the job. It is really touching, and it makes me realise I’m in a very privileged position to be able to offer treatments that can be so transformative for people.”
But there’s more to it than just people who are happy to have a new heart. Professor Macdonald theorises that the respect he receives from his patients is due to the respect he offers them in return.
“I think doctors tend to talk down to patients, whereas I’ve always tried to talk to people on their level,” he says.
“I think patients warm to you when you’re like that. It’s like switching on a light bulb, people suddenly realise this person wants to help me.”
And help he does and will continue to do – for there are always hearts waiting to be saved, and people waiting to receive them.
Acknowledgement of Country
The Victor Chang Cardiac Research Institute acknowledges Traditional Owners of Country throughout Australia and recognises the continuing connection to lands, waters and communities. We pay our respect to Aboriginal and Torres Strait Islander cultures; and to Elders past and present.
