Stanford Medicine publishes its long-awaited Apple Heart Study, which is one of the largest research efforts of its kind, relying on consumer devices to better understand human health.
A paper published Wednesday in the New England Journal of Medicine looked at how the Apple Watch can be used to detect atrial fibrillation, a condition that is associated with an increased risk of stroke.
The researchers explained that Apple sponsored the survey and owns the data, but the survey data is stored in Stanford. As standard for research studies, the protocol and methods are approved by a central institutional review board to ensure that patient confidentiality is protected.
Atrial fibrillation affects about 6 million people in the United States alone, and many do not know they have it. It can also be potentially detected using sensors and algorithms, making it a prime target for wearable device manufacturers. For example, Apple has an electrocardiogram sensor baked into its Apple Watch Series 4 and Series 5 devices to monitor heart rate and return health information directly to users.
For the study, researchers recruited more than 400,000 participants in the eight months that Apple Watch had. This is an amazing number for medical research. About 0.5% of participants, or just over 2000 people, received an irregular heartbeat notification. Among this group, about a quarter completed the patch-wearing protocol to monitor the rhythm of their heart for two weeks before sending it back.
Here are some of the other key findings from the study:
- Among those who were identified by the Apple Watch as having an irregular heartbeat and then continued to return an electrocardiogram patch, 84% of their subsequent notifications were confirmed as atrial fibrillation. This indicates that this type of passive monitoring can be effective, although further studies are needed.
- Of participants over 65, more than 3% received notices, indicating that the condition is far more common among older users. This is already widely understood in the medical community.
- Some of the atrial fibrillation detected by the Apple Watch is in its early stages, meaning that it has rarely happened that the subsequent patch did not take it. This does not necessarily mean that researchers believe there are many false positives. This is especially true among the younger participants.
- Many participants sought medical help outside the study.
- Fewer people returned the stickers than expected. Just a quarter did what shows that getting people to stick with monitoring when it's more active (wearing a patch and sending it back against just wearing a watch) was a challenge.
- Researchers have repeatedly noted that they did not intend to prove that the Apple Watch can be a screening tool for the health status of a large population.
The results of the study are promising but have not yet convinced cardiologists that the Apple Watch and other wearable devices are an appropriate tool for monitoring people for signs of atrial fibrillation.
For starters, the standard treatment for the condition is blood thinners. But this comes with risks and potential side effects, so cardiologists have a method of evaluating whether a patient should be treated. These factors include things like the patient's age (elderly are at increased risk), their medical history, and whether they have previously had strokes.
So cardiac doctors worry that while the Apple Watch can identify many who really have atrial fibrillation, the medical community will not know how to treat them. And this is especially true with young people or those who have the disease in the earliest stages and do not have many other risk factors.
"We just don't understand atrial fibrillation in 35-year-olds, an otherwise healthy person," says Jeff Wesler, a cardiologist based in New York who is also the founder of Heartbeat Cardiology Clinics.
Wesler is already treating patients who are came to his clinics based on the data they received, their Apple Watch, which he says will become an increasingly common event over time, but he also notes that these types of health monitoring tools the heart develops faster than the medical
Wesler said that a follow-up study, if Apple sponsors additional research, would involve finding the right population that is most at risk, but that would deviate from the typical Apple approach that is to develop tools for the general population, in which case the Apple Heart Study app was available to anyone who could download and use the App Store if they were a US resident and over 22 years of age.
Another potential problem with finding more people with atrial fibrillation is that the medical system is still not properly treating all people who are known to be at high risk. Some patients do not want to take blood thinners, and some doctors are still cautious about prescribing them or do not correctly characterize the risks.
"Too many people in the study and in many atrial fibrillation clinics are not doing much or anything about it," notes Venck Murty, a cardiologist at the Michigan Cardiovascular Center Frankel.
In other words, doctors have not yet sufficiently treat the atrial fibrillation population, let alone a new group that may
In general, cardiologists such as Wessler say the study is positive, indicating that there is great potential for large-scale studies using a combination of tools and remote sensing technologies on the This is good for the growing digital healthcare sector as a whole.
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