Continuous rhythm monitoring with implantable cardiac monitors and wearable devices with real-time smartphone alerts during AF episodes: a feasibility study

Complete

10/11/2020

South East

Device

Awarded amount: £145,485

Grant scheme: NET

Institution: Oxford University Hospitals NHS Foundation Trust

Principle Investigator: Prof Timothy Betts

---

Atrial fibrillation is the most common form of arrythmia, namely a disruption to the regular rhythm of the heart.

AF significantly increases the risk of stroke, and so those with AF are often prescribed anti-coagulant medication to try and prevent blood clots. These medications have signficant side effects in terms of excess bleeding and therefore ideally, patients would only take them when actively in AF.

However, many patients cannot tell when they are in AF and so end up taking the medication all the time. This project was designed to design a system that would continuously monitor the heart rhythm and send alerts to the participants smartphone if AF occurred. The current “gold standard” of AF detection involves a monitor implanted under the skin that sends alerts to the patient’s hospital, however these alerts have to be manually reviewed by hospital staff so are not effective in terms of dictating medication use.

This novel software works 24/7 and sends alerts automatically. The results showed that for this new system, the average time from AF episode to patient alert was 2.5 hours, considerably lower than when using the existing software system.

There are ongoing analyses to explore different wearable devices for the detection of AF, including the apple watch and a smart ring. The team intend to now move into the next phase of this study, named RESPOND-AF to examine whether this new system could allow patients to only take anti coagulant medication when needed.

This would reduce healthcare costs and side effects, whilst effectively preventing stroke. This study has formed an important step towards a future with personalised care for atrial fibrillation.

Further report received: 27/11/24

The final stage of this project focused on comparing the use of a medical monitoring system for AF with commercially available devices, the Apple Watch and the CART ring.

Overall these devices were much less sensitive than the medical device, and their alerts were less likely to be acknowledged by patients, which suggested that in their current form these devices are not suitable replacements for medical monitoring of atrial fibrillation.

Overall, however, this study demonstrated the potential of the so-called “pill in the pocket” system for tailored management of atrial fibrillation. Based on this success, the team have secured further funding from an industry partner to pilot the use of the software developed in SMART-ALERT in people with intermittent atrial fibrillation.

Recruitment for this subsequent study began in December 2024.