Huge heart study uses Apple Watch

Detecting but Not Diagnosing

Apple is coordinating a large heart study using the Apple Watch to detect atrial fibrillation, a heart abnormality that may cause as many as 130,000 deaths annually in the U.S. alone. “A-fib” is said to be one of the most common causes of strokes and heart failure.

Using LED lights, light-sensitive conductors and software, the watch will monitor blood flow to search for abnormalities, reported Christina Farr of CNBC. She explained, “Apple has released a first-of-its-kind Heart Study app to research whether its Apple Watch can pick up the heart rhythmic disorder. People who sign up for the study will use the watch to monitor their heart rate and heart rhythm and will consult with a physician if there's an abnormality.”

According to Apple Chief Operating Officer Jeff Williams, "This might seem like a simple study, but we think this is a really special time.  Hopefully we can save a lot of lives."

Williams said that Apple's objective is “to screen for, rather than diagnose, heart rhythm abnormalities” in a general population. While Apple does not intend for the watch to become “a regulated medical device,” it is going beyond wellness and fitness applications. Apple is “working closely with federal regulators and plans to submit the results from the study for review,” Williams added, explaining that the company decided to perform the study after hearing from numerous users that the Apple Watch saved their lives.

According to Williams, "It has been a very organic journey. We didn't wake up one day and say 'we did iPhone, then we did iPad and let's knock out health next.'"

Because many people do not experience a-fib symptoms and the condition often goes undiagnosed, finding a way to detect it could help people avoid serious illness. Additionally, with a young and healthy population rather than just at-risk populations included, the study could possibly identify situations when heart rhythm abnormalities could be problematic and when they are not.

Until now, such data were hard to obtain, because only people at high risk, such as seniors and people with a history of strokes, were monitored from home. With the Apple Watch study, anyone over age 22 with an Apple Watch Series 1 or later can sign up to be a participant. The study is being run by Stanford University's School of Medicine.

Apple has previously supported researchers in developing their own iPhone-based research studies, but this is the first time Apple has released its own app. Apple’s ResearchKit and CareKit software frameworks have been used by more than 500 outside researchers to recruit 3 million participants for various studies.

Apple Watch has always included a heart rate sensor, but it needed to monitor the heart's rhythm in order to screen for atrial fibrillation. The company used a combination of both hardware and software tools, “combining LED lights that flash hundreds of times each second and light-sensitive semiconductor devices to detect the quantity of blood flowing through the wrist,” Williams explained. The sensors gather signals from four points on the wrist, and the software algorithms seek patterns to isolate irregular heart rhythms.

If the Apple Watch detects a problem, study participants will get a notification and an offer of a free consultation with a remote doctor, provided by American Well. The doctor will ask standard questions and suggest a visit to the emergency room for further tests, or send the subject a patch called an electrocardiogram or EKG for diagnosing atrial fibrillation. In the future, a company called Alivecor will provide an interchangeable Apple Watch band with an in-built EKG to detect atrial fibrillation and other conditions.

"It's hard not to get excited," Williams concluded.