Congenital Heart Defect Awareness Week: Dr Angeliki Asimaki’s story
This week is Congenital Heart Defect Awareness Week, bringing to light the various conditions that occur when the heart or its surrounding blood vessels don’t develop properly in children.
At St George’s, many of our researchers focus on understanding the function of the heart, from how sport and exercise affect its performance, to the genetics behind sudden cardiac death in young people. The results of this work can be life-changing for patients and families affected by these conditions.
Dr Angeliki Asimaki, from the Molecular and Clinical Science Institute, a researcher who was born with not one but two congenital heart defects, knows only too well how research can make a difference.
Current technology is life-saving
“The chances of being born with two heart problems were approximately 1 in 2 million,” she says.
“The first of my problems is an atrioventricular (AV) block. Essentially, no electricity can be transmitted from the upper to the lower chambers of my heart. The second problem was the presence of a hole in my heart, at a place where no hole should have been’’.
The AV block means that Dr Asimaki is pacemaker dependent – the machine sends an electrical signal down to the bottom of the heart every time a heartbeat is generated at the top. Since the age of 14, she has also been fitted with a tiny defibrillator implant.
“If we know someone is at risk of dropping dead from a heart condition, we can implant a machine to keep the patient safe,” she explains. “It will fire and restore your rhythm if your heart starts beating abnormally. In my eyes, this is lifesaving and I’m grateful the technology exists. But this acts after the event.”
And for Dr Asimaki, this isn’t enough.
In terms of her own research, Dr Asimaki’s aspirations go beyond “bringing you back to life” after the heart stops working properly. Although adamant the results of research and technology have helped her to reach her thirties, her aim is to find new ways to target these conditions before an implant is required to fire.
Developing new tests for heart conditions
Dr Asimaki’s journey towards being able to identify the mechanisms behind heritable heart diseases was invigorated when she identified the molecular basis of a disease called arrhythmogenic cardiomyopathy (ACM).
By comparing the cells from a diseased heart with those of a healthy heart, she noticed that seven proteins move to different locations in the diseased heart compared to the healthy one – either from the outer membrane of the cell to the inside or vice versa.
Moving on several years from this eye-opening discovery, Dr Asimaki has managed to develop a simple test that can identify the movement of these proteins. Previously, either a heart biopsy or a skin biopsy would be required, and although one is far less invasive than the other, both are unpleasant procedures. But now all you need is to take a cotton swab, run it along the inside of the cheek and Dr Asimaki can look at the cells on a microscope slide to identify if a patient has ACM or not.
However, for Dr Asimaki, stopping at just ACM isn’t the goal. “My goal is to diagnose more than one disease through this route,” she says. “I’m currently trying to identify mis-localised proteins in another entity that can cause sudden death; Brugada syndrome. Once I’ve figured out which proteins are re-distributed, I can translate the findings to the cheek.”
Dr Asimaki’s hope is that the process for developing the ACM test can be repeated, so a simple cheek swab could identify a whole range of heart defects.
Future technology could be death-preventing
To optimise the test so it can pick up changes at the right time, and to establish a potential order of events and mechanisms behind heart conditions, Dr Asimaki is also conducting a long-term study in children.
In collaboration with Great Ormond Street Hospital, she’s using her swab test on children carrying faulty genes associated with developing heart conditions.
“The question is, when do proteins start moving in your cheek and in your heart?” asks Dr Asimaki. “As soon as you start getting sick? A year after? Before?”
By swabbing these children over time, Dr Asimaki is looking for the timepoint when the proteins move and the signs are there that the person has an underlying heart problem. As soon as this happens, that’s when clinical investigations can start increasing in frequency and measures can be taken to prevent sudden death.
Dr Asimaki also hopes that through working out the sequence of events that occurs in the heart, it might be possible to develop new mechanism-based drugs for heart conditions. “I want to be able to stop things happening before they occur, instead of having to implant a defibrillator,” she says.
“We discovered a drug several years ago that could prevent fatal arrhythmias in zebrafish and mice. Unfortunately, it was also associated with an increased risk of developing cancer, so it could never make it to clinical trials. It did, however, pave the way so in the future we can discover further and safer mechanism-based drugs’’.
If this does happen, the outcomes for people with heritable heart diseases could be greatly improved.
Dr Asimaki doesn’t shy away from talking about growing up with heart conditions and the motivation behind her work.
“I’m not ashamed of them. I’m actually pretty proud of them,” she says. But her heart conditions weren’t immediately fixed when they were discovered as a child. She has had to deal with the complications and challenges of them into adulthood – including suffering a stroke as the result of late diagnosis of the hole in her heart.
Now the mother of a baby boy, Dr Asimaki is able to take stock of her achievements, despite significant adversity.
“I guess there’s nothing stronger than your personal motivation. The fact that I’m still here and a lot of other people at my age are not,” she says.
“There were people who could have spotted the hole earlier that didn’t, and that cost me a lot of time and grief. But there were people that took the time to find out what was wrong with me and saved me.
“They made sure I became a scientist and a mum, which is incredible for someone with a heart condition. I would ideally love that for everyone.”
Published: 14 February 2020