Wearable-Detected Atrial Fibrillation in Asymptomatic Adults: Managing the Referrals a Consumer Device Generates
DOI:
https://doi.org/10.5281/zenodo.22386625Keywords:
Atrial fibrillation, Wearable devices, Smartwatch, Photoplethysmography, Screening, Health equityAbstract
Three landmark studies -- the Apple Heart Study (419,297 participants), the Huawei Heart Study (187,912 participants), and
the Fitbit Heart Study (455,699 participants) -- have now shown that consumer smartwatches can flag possible atrial
fibrillation (AF) in asymptomatic adults with a positive predictive value of 84%, 91.6%, and 98.2% respectively against
ambulatory ECG or clinical confirmation. Applied across hundreds of thousands of otherwise healthy users, even a low
per-person alert rate (0.23-1.0%) generates a large absolute stream of referrals: in the Apple Heart Study, 2,161 people were
notified, but only 153 (34% of the 450 who returned an analyzable ECG patch) were ultimately confirmed to have AF, and a
notified user under 40 had only an 18% chance of confirmed AF versus 34.8% across all ages. A separate study of established
AF patients found that wearable ownership itself is associated with more AF-related clinic visits, more ECGs and ablations,
and more messages to providers, and that 20% of wearable users report intense fear or anxiety after an irregular-rhythm
notification. Meanwhile, ownership of the devices generating these referrals skews toward younger, wealthier, more educated,
urban, and privately insured adults, while older, lower-income, and rural adults -- who carry the higher baseline AF risk that
makes a true-positive alert more likely -- consistently lag in ownership. This review sets these findings side by side to
characterize the referral surge wearable-detected AF is generating for cardiology, and the system-capacity and equity
tensions it exposes that neither device accuracy alone, nor a one-sided promotional reading of these trials, resolves.
References
Perez MV, Mahaffey KW, Hedlin H, et al. "Large-Scale Assessment of a Smartwatch to Identify Atrial Fibrillation" (Apple Heart Study). N Engl J Med 381(2019):1909-1917.
Guo Y, Wang H, Zhang H, et al. "Mobile Photoplethysmographic Technology to Detect Atrial Fibrillation" (Huawei Heart Study). J Am Coll Cardiol 74(2019):2365-2375.
Lubitz SA, Faranesh AZ, Selvaggi C, et al. "Detection of Atrial Fibrillation in a Large Population Using Wearable Devices: The Fitbit Heart Study". Circulation 146(2022):1415-1424.
Rosman L, et al. "Wearable Devices, Health Care Use, and Psychological Well-Being in Patients With Atrial Fibrillation". J Am Heart Assoc 13(2024):e033750.
Nagappan A, Krasniansky A, Knowles M. "Patterns of Ownership and Usage of Wearable Devices in the United States, 2020-2022: Survey Study". J Med Internet Res 26(2024):e56504.
Barrera N, et al. "Accuracy of Smartwatches in the Detection of Atrial Fibrillation: A Systematic Review and Diagnostic Meta-Analysis". JACC Adv 4(2025):102133.
