Wearables giant Fitbit Inc. has kicked off its first large-scale, virtual study to evaluate how well its wrist-worn technology can spot episodes of irregular heart rhythm that might indicate atrial fibrillation (AF). The study, part of a broader plan to equip Fitbit devices with new tools to speed the detection of a range of conditions, is open to people in the U.S. ages 22 and older who own a Fitbit that tracks heart rate.
Fitbit aims to enroll hundreds of thousands of people in the study, which is expected to run through 2020. The results will be used to support the submissions to the U.S. FDA and other international regulatory bodies.
Large patient base
Nearly 33.5 million people have AF worldwide, a condition that increases the risk of stroke but is often hard to detect, because episodes are often sporadic and asymptomatic. In the U.S.., more than 454,000 people are hospitalized each year with a primary diagnosis of AF, and its role in U.S. deaths has been rising for more than two decades, according to the CDC.
“Until recently, tools for detecting AF had a number of limitations and were only accessible if you visited a doctor,” said Steven Lubitz, a cardiologist at Massachusetts General Hospital and associate professor of medicine at Harvard Medical School, who is leading the Fitbit Heart Study. “My hope is that advancing research on innovative and accessible technology, like Fitbit devices, will lead to more tools that help improve health outcomes and reduce the impact of AF on a large scale.”
The Fitbit Heart Study will track heart rate using photoplethysmography (PPG) technology, which measures a person’s blood flow directly from the wrist. Fitbit’s PPG algorithm will search for irregularities in the user’s heart rhythm that might signal AF.
If a pattern of irregular heart rhythms is detected, subjects will be notified and connected with a doctor for a virtual visit at no cost. Fitbit may also mail an electrocardiogram (ECG) patch to users suspected of having AF to confirm the results.
Fitbit markets a number of wearables that track heart rate, including its Ionic, Versa, Charge 3, Charge 4 and Inspire HR.
Round-the-clock tracking aids in detection
“Long-term passive heart rhythm assessment with our wide range of affordable devices powered by 24/7 heart rate tracking technology has the potential to improve earlier identification of AF, which is a key to reducing the risk of a life-threatening event like stroke,” said Eric Friedman, Fitbit’s co-founder and chief technology officer. “By doing this important research, we have the opportunity to develop and provide access to technology that may be able to improve public health and save lives.”
The Fitbit Heart Study is the company’s latest effort to target AF. It has completed a pivotal clinical trial of an ECG tool that enables users concerned about AF to record an ECG that can be shared with their doctor.
The company is working with the FDA to determine the most appropriate pathway for its new detection tools – de novo, 510(k) clearance or precertification, a spokesperson said.
Tech companies like Fitbit and Apple Inc. have increasingly focused on add-ons like ECG as a way to leverage their devices in the digital health space. In October, Fitbit teamed up with pharma companies Bristol-Myers Squibb Co. and Pfizer Inc. to develop educational content for people at high risk of AF. The aim is to catch AF patients earlier and reduce their likelihood of stroke.
In 2018, Fitbit updated its wearables with Spo2 sensing to detect changes in blood oxygen levels, which could suggest problems like sleep apnea and asthma, and added enhanced sleep tracking to Charge 3. The company also released a new feature to track women’s menstrual cycles and has hinted at a personal coaching program to help people manage chronic conditions like diabetes.
In April, Fitbit reported a research collaboration with The Scripps Research Institute and Stanford Medicine aimed at using Fitbit data to help detect, track and contain infectious diseases such as COVID-19. The consortium brings together research already underway at Scripps and Stanford that leverages data collected from wearables.
Meanwhile, Stanford University and Apple published mixed results from a virtual study of more than 400,000 people in the U.S. to screen wearers participants for heart irregularities via their Apple Watch. Those with identified issues were monitored with an ECG patch.
The results from the Apple Heart Study, published in the Nov. 14, 2019, issue of the New England Journal of Medicine, found that of 419,297 participants followed for eight months, only 2,161 (0.52%) received notifications of irregular heart rate. All participants with an irregular pulse were offered ECG patches, but just 450 accepted. Of those who did, 34% were determined not to have AF.
Alphabet Inc. subsidiary Google LLC took aim at Apple Watch in a November 2019 bid to buy Fitbit for $2.1 billion in cash. The proposed merger with the fitness tracking company, with its increasing focus on health care applications, comes as Google’s and Alphabet’s have been ramping their health care game. Last fall, Alphabet hired ex-FDA commissioner Robert Califf to head up strategy and policy at its Google Health and Verily Life Sciences subsidiaries.
That deal, which was expected to close this year, has reportedly triggered added scrutiny from the U.S. Department of Justice, which has requested additional documents from both companies. A Fitbit spokesperson declined to comment to BioWorld on the status of the proposed transaction.