Fitbit has launched the Fitbit Heart Study, its first large-scale, virtual study to validate the use of its wearable technology to identify episodes of irregular heart rhythm suggestive of atrial fibrillation (AFib), the most common form of heart rhythm irregularity. This study is part of the company’s broader strategy to make easy-to-use tools that accelerate detection of a range of conditions more accessible. The Fitbit Heart Study aims to enroll hundreds of thousands of people, and its results will support the company’s regulatory submissions globally.
 
AFib affects nearly 33.5 million people globally¹ and patients with AFib have a five times higher risk of stroke.^2 3 It can also be difficult to detect, as episodes can be sporadic and asymptomatic, and some studies suggest that as many as 25 percent of people who have an AFib-related stroke only find out they have AFib after a stroke has occurred.⁴
 
“Until recently, tools for detecting AFib had a number of limitations and were only accessible if you visited a doctor,” said Steven Lubitz, M.D., M.P.H, principal investigator of the Fitbit Heart Study, cardiologist at Massachusetts General Hospital and Associate Professor of Medicine at Harvard Medical School. “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 AFib on a large scale.”
 
Fitbit wearables have the unique potential to accelerate AFib detection because their 24/7 heart rate tracking is powered by long battery life, which allows users to wear their device for multiple days at a time. This enables long-term heart rhythm assessment, including when users are asleep. The optimal way to identify irregular rhythm through heart rate tracking technology is to screen when the body is at rest, making assessment overnight, while people sleep, ideal for detection.
 
“Since we first brought heart rate tracking to the wrist in 2015, we have continued to innovate and provide users with a deeper understanding of their heart health through features like Sleep Stages, Cardio Fitness Level and now Active Zone Minutes,” said Eric Friedman, Fitbit co-founder and chief technology officer. “The Fitbit Heart Study advances our heart health efforts. 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 AFib, which is a key to reducing the risk of a life-threatening event like stroke. 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.”
 
To track heart rate, Fitbit’s devices use photoplethysmography (PPG) technology to measure the rate of blood flow directly from a user’s wrist. Theoretically, these measurements can be used to determine a user’s heart rhythm, which Fitbit’s algorithm will analyze for irregularities in the Fitbit Heart Study. Study participants who receive a notification about an irregular heart rhythm will be connected with a doctor for a virtual appointment at no cost to get more information and may receive an electrocardiogram (ECG) patch in the mail at no cost to confirm the notification.
 
Broader Commitment to Heart Health
The Fitbit Heart Study is part of Fitbit’s broader approach to heart health innovation, which includes industry partnerships and the development of other technologies focused on raising awareness and accelerating detection of AFib to reduce the risk of stroke and improve population health. In addition to the technology being examined in the Fitbit Heart Study, the company has made significant progress in the development of a new electrocardiogram (ECG) feature for spot detection of AFib.
 
Fitbit aims to provide users with both long- and short-term AFib assessment options based on their individual needs and is developing PPG and ECG tools that could offer both long-term assessment and spot-check AFib detection. The Fitbit PPG-based heart rhythm tool is designed to identify irregular rhythm episodes with no symptoms that might otherwise go undetected, and the Fitbit ECG feature is designed to support those who want to screen themselves for possible AFib and record an ECG trace they can review with their doctor. The Company has completed a pivotal clinical trial of its new ECG feature and plans to seek review by the U.S. Food and Drug Administration (FDA) and global regulatory authorities.
 
Additionally, following FDA clearance for the PPG AFib algorithm, Fitbit will continue to work with the Bristol-Myers Squibb-Pfizer Alliance to develop programs and educational content that will help identify and support people in the U.S. at increased risk for stroke to provide a continuous and supported care pathway that extends to AFib diagnosis.
 
The study will support the clinical evaluation of the company’s PPG AFib algorithm, including whether it can successfully identify episodes of irregular heart rhythm.

References 
¹ Chugh S, Havmoeller R, Narayanan K, Singh D, Rienstra M, Benjamin E, Gillum R, Kim YH, McAnulty Jr JH, Zheng ZJ. Worldwide Epidemiology of Atrial Fibrillation: Global Burden of Disease 2010 Study. Circulation. 2014; 129: 837-847
² January CT, Wann LS, Alpert JS, et al. American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation. A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2014;64(21):e1-e76
³ Wolf PA, Abbott RD, Kannel WB. Atrial fibrillation is an independent risk factor for stroke: The Framingham Study. Stroke. 1991;22(8):983-988.
⁴ Freedman B, Potpara TS, Lip GY. Stroke prevention in atrial fibrillation. Lancet. 2016;388:806–817