New cheek swab test helping to prevent sudden cardiac deaths in children

A cheap and simple test, being developed by Dr. Angeliki Asimaki, is allowing quick and safe monitoring in children with a potentially deadly heart condition at Great Ormond Street Hospital. If proven effective, the test could soon be used to guide treatment nationwide and prevent thousands of sudden cardiac deaths in children each year.

Arrhythmogenic cardiomyopathies (ACM) are a group of conditions where the cells in the heart muscle don't stick together properly, causing the walls of the heart to become weak. ACM are usually genetic, and symptoms include palpitations, breathlessness, fainting and abnormal heart rhythms that could lead to sudden cardiac death.

ACM are estimated to affect up to one in 1,000 people and research suggests they could be responsible for up to 25% of sudden cardiac deaths in children. Currently, children with ACM are monitored regularly using a combination of several heart scans and blood tests, but these can still paint an incomplete picture of the microscopic changes happening inside the heart.

Non-invasive alternative

The new cheek swab test aims to give a clearer picture of a patient's risk of dangerous heart rhythms so that sudden cardiac deaths can be prevented. It would also make the monitoring process much quicker for the people involved.

"Our test is providing a much-needed window into the minute changes happening in the hearts of ACM patients, in a totally risk-free, non-invasive way. Doctors can be warned about which of their patients are most at risk of dangerous heart rhythms and other symptoms, allowing them to tailor treatment to ensure that each patient receives the best care for them.

"Patients, particularly children, have told us they hugely prefer the speed and ease of the cotton bud cheek swab compared to alternatives like blood tests," says Dr. Angeliki Asimaki, senior lecturer at St George's, University of London.

The test that Dr. Asimaki and her team are developing takes advantage of a biological phenomenon where changes in the distribution of proteins within heart cells of a patient with ACM are mirrored in the cells inside their cheeks.

Analyzing their patient's cheek swabs will give doctors an inside look into their hearts, allowing then to monitor how their patients' condition is changing. It will also help them to spot when patients are going through a "hot phase"—where the protein changes are linked to dangerous bouts of inflammation in the heart, putting patients at highest risk of dangerous heart rhythms.

Providing reassurance

The team are already monitoring ACM in children at the Great Ormond Street Hospital (GOSH) Centre for Inherited Cardiovascular Diseases—led by Prof Juan Pablo Kaski, a co-investigator on the project, and his team—and adults at St George's Hospital. If proven to be effective, the test can continue to be rolled out to hospitals across the country.

The test is also being used for research in other locations in the UK and the Netherlands. Dr. Asimaki and her colleagues will soon start a study using the test to monitor women with ACM throughout their pregnancies in several London hospitals.

Professor Bryan Williams, Chief Scientific and Medical Officer at the British Heart Foundation said, "People with ACM often live with day-to-day worries because of the unpredictable nature of their condition, in which dangerous symptoms can start with little to no warning. The simple monitoring test being developed by Dr. Asimaki and her team has the potential to provide reassurance to patients and their families that their condition is being kept under a watchful eye by medical professionals."

With the test already showing promise in clinic, Dr. Asimaki and her team are also looking into developing a cheek swab test for diagnosing ACM. A diagnostic cheek swab test for ACM would hugely speed up and simplify the process.

If people with ACM are interested in taking part in the research, they can ask their clinical team to contact the researchers at GOSH or St George's.

Bea's story

Bea, 10, and her family are taking part in the study as part of her regular ACM check-ups at GOSH. Three years ago Bea started experiencing symptoms of an unusually fast heart rhythm, called ventricular tachycardia (VT), including shortness of breath and dizziness.

She often mistook these symptoms for anxiety but had genetic testing for ACM because Bea's father and several other family members were known to have a gene alteration that can cause the condition. Following the tests, she was diagnosed with ACM.

As part of her check-ups at GOSH, Bea has been swabbed for Dr. Asimaki's research four times. Her younger brother is now also part of the study.

Bea's mom Liz said, "The test is adding another layer of reassurance to the family that the condition is being monitored. We think it's so important to take part in this research to improve how ACM is monitored and managed for children in the future."

Bea now has an internal heart rhythm monitor fitted to alert her and her family when she is experiencing a dangerously fast heart rhythm.

Liz said, "Every time she experiences a symptom, a recording of her heart rhythm is sent to GOSH and reviewed within an hour, which gives us some reassurance. It saves her having to go for overnight monitoring in hospital and missing school every time."

"Aside from going in for regular check-ups at GOSH, we feel it's really important to not let Bea's condition get in the way of a normal childhood. She stays active by doing swimming and is in a weekly theater school."

Provided by St. George's University of London