New Apple Watch study wants to save lives by detecting strokes

(Image credit: Johnson & Johnson Health Technology)
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The Apple Watch is already an accomplished health and fitness device, but a new study is seeking to explore whether it is capable of going a step further and detecting signs of a stroke.

The Heartline Study, which also makes use of iPhones, sees Apple partner up with Johnson & Johnson. The collaboration will focus on how Apple’s smartwatch and smartphones can help enable the early detection of cardiac events such as atrial fibrillation (AFib), which is a leading cause of a stroke in the US.

Both the Apple Watch 5 and Apple Watch 4 include an ECG sensor, which - in countries where it has been authorized - is used to detect signs of arrhythmia, also known as an irregular heartbeat. Older Apple Watches can also offer irregular heart rate rhythm notifications based on readings from the heart rate monitor.

With that ability to detect irregular heartbeats, Apple’s wearable already has the potential to uncover whether you may have atrial fibrillation, which puts someone at an increased chance of a stroke. Though as Apple very clearly outlines, its heart rate sensors are not able to specifically diagnose heart conditions.

A three-year study

The study is aimed at those aged over 65 in the US and will be conducted over a three-year period. Those who are eligible will use the Heartline Study iPhone app (opens in new tab), and while some participants will just use the app on their phone, others will need a supported Apple Watch - though devices will apparently be available to borrow.

The app itself will provide ongoing tips and surveys, while the Apple Watch will deliver heart rate rhythm data to the app, where researchers will be able to evaluate the data.

That does mean that participants will have to agree to provide access to some of their medical data. For those concerned about the use of the sensitive information, it will apparently be stored in a ‘secure environment’.

This isn’t the first major health study Apple has been a part of during its push into the serious health monitoring space. Last year, it revealed the findings of its Heart Study, which was conducted with the Stanford University of Medicine. That study aimed to demonstrate the ability of wearables like the Apple Watch to detect heart rate irregularities.

At its big September event in 2019, Apple also announced three new studies focusing on heart health, women’s health, and hearing health.

Via 9to5Mac (opens in new tab)

Michael is a freelance journalist who has covered consumer technology for over a decade and specializes in wearable and fitness tech. Previously editor of Wareable, he also co-ran the features and reviews sections of T3, and has a long list of bylines in the world of consumer tech sites.


With a focus on fitness trackers, headphones, running wearables, phones, and tablet, he has written for numerous publications including Wired UK, GQ, Men's Fitness, BBC Science Focus, Metro and Stuff, and has appeared on the BBC Travel Show. Michael is a keen swimmer, a runner with a number of marathons under his belt, and is also the co-founder of YouTube channel The Run Testers.