Despite launching during the COVID -19 pandemic, the Active Monitoring for AtriaL Fibrillation (AMALFI) study has recruited over 5,000 people to test a new monitor that could help detect people with abnormal heart rhythms.
Atrial fibrillation, an irregular and often abnormally fast heart rhythm, is a serious condition that affects around one in ten people aged over 65 years in the UK. People with atrial fibrillation are five times more likely to have a stroke than those without, however treatment with blood-thinning medication can effectively reduce this risk. This makes early diagnosis critically important, but this is challenging as many people with atrial fibrillation experience no symptoms at all.
Currently, atrial fibrillation is diagnosed using an electrocardiogram (ECG), but this procedure only captures the heart rate at a single point in time. This means that atrial fibrillation may not be detected if, by chance, the heart is beating regularly when the ECG is carried out. What is urgently needed is a simple method that can monitor the heart rate continuously over an extended period, as people go about their daily lives.
To address this, researchers from Oxford Population Health’s Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), in partnership with the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, launched the AMALFI study. This is testing a simple wearable sensor, the Zio Patch, which sticks to the chest and gives a continuous heart trace reading over two weeks.In AMALFI, half the participants are randomly allocated to wear the Zio Patch, whilst the remaining half do not.
After a small pilot study in 2019, the main study launched in February 2020, just a month before the first COVID-19 lockdown. But despite the pandemic effectively shutting down hundreds of clinical trials across the UK, AMALFI’s study design made it particularly suited to continue. Firstly, the participants didn’t need to visit a clinic or GP surgery, since the letters inviting people to join the study and the Zio Patch monitors were delivered directly to people’s homes. Second, the time commitment was relatively short, at just two weeks. Third, the study only required very minimal actions from GPs: once they had identified eligible people on their registers, the central AMALFI team took over.
Nevertheless, the team still had to adapt to some setbacks, as Karen Taylor, Senior Clinical Trial Manager for AMALFI, explained: ‘Our departmental postal office was closed for several months, so during this time I packaged up the monitors myself, then queued at my local post office to send them out. I was very glad when the restrictions eased and we got our own postal service back!’
The team’s efforts paid off. AMALFI originally planned to include 2,500 participants but, as recruitment was proceeding so well, the study team decided to increase this number to allow the study to be even more informative. By January 2022, they had recruited their revised target of 5,000 participants – an achievement that would be impressive even under non-pandemic scenarios.
‘The response rate was phenomenal, and we encountered so much goodwill’ said Dr Guilherme Amorim, AMALFI Clinical Coordinator. ‘I think it gave people something positive to focus on at a time when they couldn’t do most of their usual activities. And with COVID-19 and clinical research being so dominant in the media, there was more awareness of the need for people to volunteer to take part in clinical trials.’
The results of the study will be published once the five-year follow up period is complete. During this time, the study team will monitor each participant's medical record to see what happens to them during this time and whether the screening has made a difference.
Principal Investigator Professor Louise Bowman said: ‘If we find that the Zio Patch monitor is successful, we hope that this would allow more people to be put on the right treatment at an earlier stage, and so bring down their risk of having a stroke.’
Karen Taylor added: ‘We are particularly grateful to all the GPs who made time to support AMALFI, despite having to deal with the COVID-19 pandemic and the vaccination programme. And of course, we extend a very big thanks to all the participants.’