A simple cheek swab test, being developed with funding from us, could detect children who have arrhythmogenic cardiomyopathy, according to research being presented at the European Society of Cardiology Congress in Madrid.
Arrhythmogenic cardiomyopathy (ACM), which is typically genetic, is responsible for more than 10 per cent of sudden cardiac deaths in children.
It is a condition caused by abnormalities in the proteins between heart cells, which leads to problems in the structure and electrical activity of the heart. Luckily, abnormalities in these proteins can also be seen in the lining of the cheeks, which may reveal what is happening in the heart.
Dangerous heart condition
Now a study suggests a simple two-minute cheek swab can detect the dangerous heart condition potentially years before someone might otherwise be diagnosed.
Researchers at City St George’s, University of London, and Great Ormond Street Hospital recruited 51 children and young people, from the age of three months to 18 years old, with a known genetic risk of ACM. They were given a cheek swab every three to six months.
Among this group, 10 went on to develop ACM, and eight of these showed abnormalities in a cheek swab before any changes were detected from other medical tests. In another group of 21 children with suspected early signs of ACM, but no genetic cause identified, five had abnormalities picked up by cheek swabs before being diagnosed.
The cheek swabs revealed changes between 1.5 and five years before children were diagnosed with ACM.
Save young lives
If a cheek swab can detect the condition early, researchers say doctors can act faster to provide extra medical care, if appropriate, which could help to save young lives by preventing a sudden cardiac arrest.
Conventional diagnosis of ACM can sometimes be challenging. The condition can progress differently in different people, with some never showing any symptoms. A diagnosis currently needs to be confirmed using a range of tests including an ECG, echocardiogram, cardiac MRI and genetic testing, meaning that a cheek swab could be a vital extra test to help diagnose children earlier.
Earlier diagnosis
Dr Sonya Babu-Narayan, our clinical director and consultant cardiologist, said: “Arrhythmogenic cardiomyopathy has the potential to develop and strike without warning and sadly can risk sudden death in children, so it’s important that research helps us discover how to diagnose it early.
“This kind of simple, pain-free cheek swab test could identify children in the early stages of ACM who need extra care, or provide reassurance to at-risk children and their families with normal test results.”
Researchers discovered a decade ago that the abnormalities of proteins in the heart are also found in the lining of the cheek. These abnormalities are important to identify, as over time the heart’s pumping function can start to fail.
A cheek swab may help to reveal if someone has ACM without a heart biopsy – which is sometimes necessary if other clinical tests are inconclusive.
Previously, cheek swabs had been used to monitor the condition of children who already have ACM. But the new early-stage findings suggest that the swabs, done using a soft brush, which comfortably sweeps cells from the lining of the cheek, could help to identify someone who may be in the early stages of ACM and not know it.
“Risk-free”
Dr Angeliki Asimaki, Reader in Cardiac Morphology and Sudden Death from the School of Health and Medical Sciences at City St George’s, University of London, is leading the research. She said: “Our test provides a window into microscopic changes happening in the heart, and it is totally risk-free and non-invasive.’’
“This has the potential to provide accurate and timely diagnosis of ACM, which could ultimately save lives.’’
“Patients, particularly children, have told us they hugely prefer the speed and ease of a cheek swab to alternatives such as blood tests.
“We are currently developing test kits which would allow children to do cheek swabs at home and post them off to researchers for analysis.”
Very beginnings
Children with one or more parents with ACM have a 50/50 chance of becoming genetic carriers of the condition, although they may never develop it. Among children with a genetic predisposition, the cheek swab test could help to detect those who do have ACM and provide reassurance for those who do not.
The study presented at ESC analysed multiple cheek swabs from children over a period of more than seven years, to study the very beginnings of ACM in the body and how the condition progresses.
The swabs missed ACM in two out of 10 children with a genetic risk who went on to develop the condition.
While this suggests a swab can reflect changes in the heart at a very early stage of ACM developing, the timescale will also be affected by these heart conditions progressing more slowly in some patients than others.
These promising findings will need to be followed with a much larger study.
To date, researchers have recruited almost 150 children for cheek swab screening, who are under the care of Professor Juan Pablo Kaski at Great Ormond Street Hospital.
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