Researchers at Northwestern Medicine in Chicago are trying to find out if wearable devices, such as an Apple Watch, can reduce the need for continuous blood thinners for patients with atrial fibrillation.

Atrial fibrillation, orAFib, is the most common type of heart arrhythmia impacting more than five million people in the USA, a number that is anticipated to reach 12.1 million by 2030. The heart rhythm condition is characterised by fast and irregular heartbeats from the upper chambers of the heart.

People with AFib are at increased risk of stroke, heart failure, dementia and premature death. To reduce risk of stroke from blood clots, many patients with AFib are treated with life-long oral anticoagulation therapy, yet blood thinning medications come with their own risks, including excessive bleeding. Individuals with AFib may now be eligible to enrol in a clinical trial that will study if wearable technology can help reduce the reliance on these medications.

“For both patients and physicians, it can be challenging to balance the risk and benefits of continuous anticoagulation therapy,” said Rod Passman, cardiac electrophysiologist at Northwestern Medicine Bluhm Cardiovascular Institute. “Currently, standard of care for AFib leaves many patients on blood thinners for the rest of their lives even if they experience very infrequent arrhythmias either on their own or as the result of medications or ablation treatment.”

The seven-year trial will recruit participants at more than 80 sites nationwide, randomising them to receive the current standard of care of continuous blood thinners or the pill-in-pocket treatment directed by a study app on Apple Watch. The trial will also examine whether this approach can reduce major bleeding events compared with continuous therapy.

Passman is leading a clinical trial that, if successful, could potentially provide a more personalised approach to preventing AFib-related stroke. The Rhythm Evaluation for AntiCoagulaTion (React-AF, clinicaltrials.gov/study/NCT05836987) trial will monitor a participant’s AFib episodes to attempt to reduce patients’ continuous and lifelong reliance on blood-thinning medication.

“We know that risk of stroke is greatest in the weeks following an episode of AFib then returns to a low level, which suggests the potential for anticoagulant therapy only as needed rather than every day of the year,” said Passman. “However, many patients have no symptoms of AFib, so treating in the moment is challenging. That’s where wearable technology comes in.”

The trial will use a custom study app on Apple Watch that uses its heart health features to monitor heart activity and notify patients when they’re entering an episode. When alerted to an episode, participants will start blood-thinning medications only for a few weeks when they are considered at highest risk for stroke.

“If we can show this pill-in-pocket strategy is equally protective against stroke and also reduces bleeding caused by these blood thinners, that could potentially save lives, reduce cost, improve quality of life and fundamentally change the standard of care for millions of patients living with AFib,” said Passman.

To participate in the clinical trial, individuals must have an iPhone. Apple Watch devices are provided to participants through a contribution from Apple (www.apple.com).

“This is an exciting opportunity to better understand how this technology can help us better personalise patient care,” said Passman. “Why should patients expose themselves to the risk and cost of these drugs when they may not be benefiting?”

For more information about Northwestern Medicine, visit news.nm.org.