Imagine being able to make a 3D model of a patient’s artery and use it to predict if and when they will have a heart attack. It may sound far-fetched but it’s nearer than you think. In this feature we speak to interventional cardiologist Professor Peter Barlis from St Vincent’s hospital in Melbourne about his work advancing innovative technology that could one day make this a reality.
Australia leading the way
Australia may be a small, if somewhat isolated country – especially when it comes to the field of science – but that has not stopped Australian researchers and clinicians from being at the forefront of world-class innovation.
In fact we have led the way for almost a century.
Many of these innovations are recorded in history books as some of the most significant medical discoveries and innovations of our time.
One of the earliest innovators was Dr Mark Lidwell, a physician who specialised in anaesthesiology and cardiology and became the first to create a pacemaker.
In 1926 he was treating a newborn baby with heart problems at Sydney’s Crown Street Women’s Hospital. In an impromptu bid to encourage a regular heartbeat, he connected the baby’s heart to electrodes which stimulated the heartbeat with electric pulses.
And then there was Howard Florey, Adelaide scientist who paved the way in the 1940s for penicillin to be used to treat infections in humans, and Melbourne otolaryngologist Dr Graeme Clark who pioneered the development of the world’s first bionic ear.
The list goes on. Taking folate prior to and during early pregnancy to prevent spina bifida, ultrasound for screening and diagnosis, IVF, spray-on skin for burns treatment and a vaccine to prevent certain types of human papillomavirus. These are all Australian innovations that have changed the world in a big way.
Virtual snapshots of living arteries
Innovation seems to be in our blood, just ask University of Melbourne Associate Professor Peter Barlis, an interventional cardiologist with St Vincent’s and Northern Hospitals in Melbourne.
He leads a team of doctors, researchers and engineers at University of Melbourne who are using supercomputers to create 3D models of arteries from patients with heart disease, with photos from a camera that is thinner than a human hair.
This allows them to examine the artery in depth while minimising risk to the patient, and can be used to pinpoint problem areas and even simulate potential treatments.
It is easy to see why Professor Barlis is so enthusiastic about the potential this offers, both from a research point of view and a patient outcomes perspective.
“It’s certainly exciting stuff,” he told the limbic. “I think this is very compelling technology and we really can go a long way with it. We’ve almost got a virtual snapshot inside a living artery”.
How it works is simple and yet doesn’t even get close to revealing the many thousands of hours that have gone into research and development to get to this point.
Crucial clues into the behaviour of blood flow
Images taken of a patient’s heart during an angiogram are entered into a super computer and so begins the recreation of the artery as a 3D model.
At the moment it takes about 24 hours to complete the model of a patient’s artery in 3D, and from this model cardiologists are able to discover crucial clues into the behaviour of blood flow and the precise structure of the artery from the inside.
Professor Barlis said it was also possible to detect so-called ‘hot spots’ for plaque, which can sometimes be difficult to see using traditional methods because no two arteries are shaped the same, nor does plaque build up in the same areas.
Once the blockage has been identified, the model can then be used to test the various stents to see which one is the most effective, before the stent is implanted, using the 3D model as a guide.
“It’s a try before you buy opportunity,” he said. “Customising the therapy to suit the patient will hopefully prevent complications which is a win for patients”
Moving towards 3D printing in unstable patients
The process is still in its infancy and suitable for use only in stable patients, because it takes time to build the models. Professor Barlis however believes it has potential to be used in unstable patients who require emergency intervention.
“I would envisage having access to this in the cath lab,” he said. “Who’s to say we’re not going to have a super computer in our cath lab where we can do the modelling in urgent cases”.
Professor Barlis co-authored a review article published last month in the European Heart Journal which examines recent advances in this field.
Another promising development is in the use of image-based computational modelling that can not only identify plaque progression but also highlight features of plaques most prone to symptomatic rupture.
“It’s still early days but we are looking at the possibility of using this technology to predict certain parts of arteries that are most at risk,” he said.
Not only could this be invaluable in improving prevention and early detection rates, but it could also be a useful tool in helping to educate patients.
Scanning the arteries using a super-high resolution camera, known as optical coherence tomography (OCT), has made it easier to image cholesterol plaques, but it still isn’t clear which of these plaques will go on to cause heart attacks.
The potential to predict heart attacks
Professor Barlis brought the OCT technology to Australia in 2009 and has been working to refine the technology. He hopes to be able to predict where plaques could form in arteries in the future.
“The ultimate goal is to be able to predict heart attacks,” he told the limbic.
He and his research team have two Australian Research Council grants to work with the University of Melbourne’s Engineering School, to find a biocompatible polymer to print heart stents in 3D to precisely match a person’s physical makeup and reduce the risk of stent collapse or complications.
They are also collaborating with the Imperial College in London and Harvard University in Boston on a project looking at new polymers that will allow the stent to slowly disintegrate over time and deliver drugs directly to the location of the plaque.
“Australia has been at the forefront of so many innovations, like the Cochlear implant, and we see this as a new high-end manufacturing industry opportunity for Australia,” he said.
He also believes the technology has the potential to be adapted into other speciality areas, including bypass surgeries and even aneurysm grafts.
“The sky’s the limit,” he said.