Study shows Apple Watch can detect abnormal heart rate, but experts have doubts

Heart rate monitoring is an important feature of Apple Watch, but is it reliable? Stanford School of Medicine released the third batch of research data on Apple Watch.

This study is a collaborative project between Stanford School of Medicine and Apple. Researchers collected heart data from volunteers through the Apple Heart Study app to determine whether Apple Watch can detect atrial fibrillation, the validity of the test results, and the safety of the device.

      Since the research began in 2017, it did not use the Apple Watch Series 4 with ECG function released by Apple last year, but instead relied on a standard heartbeat sensor to obtain heart rhythm data.

       Atrial fibrillation is a common persistent abnormal heart rhythm and a manifestation of serious health problems in the heart, usually accompanied by a high risk of stroke. The published data showed that among a total of 419,297 participants, 0.52% (2,161) received reminders of abnormal heart rhythm during the 117-day monitoring period. About 450 of these participants wore electrode patches for further electrocardiogram testing and returned the data after two weeks of monitoring. Among these 450 people, the positive predictive value of atrial fibrillation, that is, the proportion of people who were actually confirmed to have atrial fibrillation, was 84%.

     The researchers said that the extremely low number of reminders from the Apple Watch shows that the device has a low false positive rate in healthy people. Some cases of atrial fibrillation discovered by the Apple Watch are in the early stages and the frequency is not high, so they are difficult to be detected by the electrode patch, which is more common among young people.

▲ Image from: Apple

The final conclusion is that Apple Watch can detect atrial fibrillation, and these notifications have positive effects on patients, doctors, insurance companies, etc.

It is worth mentioning that Apple is not the only technology company to enter the health detection field. Fitbit, which was acquired by Google earlier this month, just formed an alliance with US pharmaceutical companies Bristol-Myers Squibb and Pfizer in October to jointly develop technology for detecting atrial fibrillation.

However, this also brings up a problem. Doctors have no idea how to treat patients who develop atrial fibrillation, especially young patients who are still in the earliest stages and do not actually have many other risks.

"We don't know a lot about atrial fibrillation in a 35-year-old who's otherwise very healthy," New York-based cardiologist Jeff Weschler told CNBC, suggesting that if Apple were to continue the study, it should target the right population at highest risk rather than a mainstream audience.

Therefore, some experts believe that although this technology is promising, the sample is not balanced enough. Daniel Cantillon, a cardiologist at the Cleveland Clinic, pointed out that more than half of the participants were under the age of 40, and the probability of atrial fibrillation in this group is already low. "Are we trying to detect risks or are we scaring healthy people?"

But overall, doctors affirmed the positive significance of this study, which shows the potential of using new technologies to remotely monitor patients for large-scale research, thus eliminating the tediousness of door-to-door data collection, which is a good thing for the digitalization of the medical industry.