Aug 9 2013
A special iPhone case and app can be used to quickly and cheaply detect heart rhythm problems and prevent strokes, according to University of Sydney research presented at the Australia and New Zealand Cardiac Society conference today on the Gold Coast.
The research found the AliveCor Heart Monitor for iPhone (iECG) was a highly-effective, accurate and cost-effective way to screen patients to identify previously undiagnosed atrial fibrillation (AF) and hence help prevent strokes.
What’s more, the test is able to be used in local pharmacies and general practitioner surgeries with a single-lead ECG taken on an iPhone with a special case.
Senior author, Professor Ben Freedman, said that the device was an exciting breakthrough and would greatly assist in the challenge to improve early identification of atrial fibrillation and prevention of stroke.
“Atrial Fibrillation (AF) is the most common heart rhythm problem and is responsible for almost one third of all strokes,” he said.
“AF increases with age, affecting more than 15 per cent of people aged 85 years and over. And people with atrial fibrillation face up to a five-fold increased risk of stroke, and tend to have more severe and life-threatening strokes.
“In addition, our research showed that about 1.4 per cent of people aged over 65 (50,000 Australians) have atrial fibrillation, but do not know it. There are currently a large number of people with unknown AF who are at high risk of stroke, but who are not on any medication.
“The good news is that stroke is highly preventable with anticoagulant medication, such as warfarin, or the new oral anticoagulants, which can reduce the risk by 66 per cent.
“The iECG allows us to screen patients for atrial fibrillation in minutes, and treat people early. This is a huge boost in the fight to reduce the amount of strokes, particularly in people over the age of 65,” Professor Freedman said.
For patients in the study with a history of known atrial fibrillation, the researchers also identified both a treatment gap and a knowledge gap. The treatment gap they identified was that only 66 per cent of those eligible for stroke prevention medication were being prescribed this medication.
Lead author Nicole Lowres also said the knowledge gap of patients with AF was surprising and alarming.
"Over half of those with known atrial fibrillation in AF at the time of screening were unaware of their diagnosis even though many of them were prescribed and taking warfarin to treat their condition," she said.
“The iECG can be viewed on the phone screen and also used as an educational tool to teach people about their heart rhythm.” Ms Lowres said.
Ms Lowres also noted how cost effective screening with the iECG could be.
“Our economic analysis has shown the iECG is highly cost effective and in fact this is the first mass screening program fir AF likely to be cost effective, unlike traditional 12 lead ECGs recorded by a practice nurse,” she said.
“In addition, the iECG is extremely portable, which gives great flexibility for screening, and is simple to administer.
“In a new development, we are now getting receptionists in general practice to record an iECG before patients see their doctor,” Ms Lowres said.
The iECG
When taking a reading, the iECG can be seen on the iPhone screen in real time. In addition, the iECG is transmitted to a secure server (cloud) where a specialist can review the iECGs remotely. The website can automatically analyse the reading to make a diagnosis of AF. The researchers tested the website's automatic prediction in the SEARCH-AF study and found it correctly diagnoses atrial fibrillation 97 per cent of the time.
The researchers are currently trialing iECG screening in GP surgeries in Sydney.
The University of Sydney research was funded by a number of investigator-initiated research grants from BMS/Pfizer, Boehringer Ingelheim, and Bayer.
The National Heart Foundation provided a scholarship for lead researcher, Nicole Lowres.
“The development of the iPhone ECG device just shows how important research and fundraising is in the fight against heart disease and stroke,” Dr Robert Grenfell, the Heart Foundation’s National Director of Cardiovascular Health, said.
“Last year, the Heart Foundation directed $13.5 million in funding to support 195 researchers. This year through the Heart Foundation Big Heart Appeal, we hope to raise $5 million to continue funding this kind of world-class research.”
Iphone ECG additional information
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Screening using the iPhone ECG (iECG) was offered in 10 pharmacies across Sydney and identified unknown or unrecognized AF in 1.5 per cent of people screened.
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People with unknown AF do not usually have symptoms and may not go to their local doctor for a medical review, therefore they may remain undiagnosed and at risk of having a stroke.
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Screening can identify previously unknown AF in 1.4 per cent of people aged 65 and over, which equates to 50,000 Australians.
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Ten pharmacies across Sydney were recruited for the SEARCH-AF study. Screening ran for five months and was offered to all pharmacy customers aged 65 and over. Each screen took less than five minutes to complete, and consisted of a brief medical history, pulse check and a single lead iECG using the AliveCor Heart monitor. The iECG is transmitted to a secure server where a specialist can review the iECGs remotely, and a rhythm diagnosis is instantaneously made available by an automated algorithm the researchers have just validated.
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In total 1004 participants were screened. The researchers found previously unknown AF in 1 per cent of people screened. An additional 0.5 per cent were re-identified with AF (i.e. a history of AF previously identified, but thought to have resolved), making a total of 1.5 per cent identified with unknown AF. The automated algorithm had high accuracy for identification of AF with 97 per cent sensitivity and 92 per cent specificity. Importantly it identified all cases of previously unknown AF in the SEARCH-AF study.
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The majority of people with previously unknown AF in SEARCH did not have symptoms and had a normal resting heart rate of 77 beats per minute, yet all were at increased risk of stroke and eligible for stroke prevention therapy with oral anticoagulant medication. In the people with a known history of AF (11% of those screened), the researchers identified a treatment gap as only 66% of those eligible for stroke prevention medication were being prescribed this medication. They also identified a significant knowledge gap as 30% of those with known AF were unaware of their diagnosis even though many of them were prescribed and taking warfarin. Screening was well received by both pharmacists and the participants.
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We provide screened people with educational material from the Atrial Fibrillation Association (Australia), a lay charity that has just been set up in Australia, as part of the Arrhythmia Alliance.
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The founder of the worldwide AFA movement, Trudie Lobban, will be in Australia on 8 and 9 August to launch the Australian affiliate at Cardiac Society of Australia and New Zealand.
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