Large-Scale Assessment of a Smartwatch to Identify Atrial Fibrillation.
Abstract
BACKGROUND:Optical sensors on wearable devices can detect irregular pulses. The ability
of a smartwatch application (app) to identify atrial fibrillation during typical use
is unknown. METHODS:Participants without atrial fibrillation (as reported by the participants
themselves) used a smartphone (Apple iPhone) app to consent to monitoring. If a smartwatch-based
irregular pulse notification algorithm identified possible atrial fibrillation, a
telemedicine visit was initiated and an electrocardiography (ECG) patch was mailed
to the participant, to be worn for up to 7 days. Surveys were administered 90 days
after notification of the irregular pulse and at the end of the study. The main objectives
were to estimate the proportion of notified participants with atrial fibrillation
shown on an ECG patch and the positive predictive value of irregular pulse intervals
with a targeted confidence interval width of 0.10. RESULTS:We recruited 419,297 participants
over 8 months. Over a median of 117 days of monitoring, 2161 participants (0.52%)
received notifications of irregular pulse. Among the 450 participants who returned
ECG patches containing data that could be analyzed - which had been applied, on average,
13 days after notification - atrial fibrillation was present in 34% (97.5% confidence
interval [CI], 29 to 39) overall and in 35% (97.5% CI, 27 to 43) of participants 65
years of age or older. Among participants who were notified of an irregular pulse,
the positive predictive value was 0.84 (95% CI, 0.76 to 0.92) for observing atrial
fibrillation on the ECG simultaneously with a subsequent irregular pulse notification
and 0.71 (97.5% CI, 0.69 to 0.74) for observing atrial fibrillation on the ECG simultaneously
with a subsequent irregular tachogram. Of 1376 notified participants who returned
a 90-day survey, 57% contacted health care providers outside the study. There were
no reports of serious app-related adverse events. CONCLUSIONS:The probability of receiving
an irregular pulse notification was low. Among participants who received notification
of an irregular pulse, 34% had atrial fibrillation on subsequent ECG patch readings
and 84% of notifications were concordant with atrial fibrillation. This siteless (no
on-site visits were required for the participants), pragmatic study design provides
a foundation for large-scale pragmatic studies in which outcomes or adherence can
be reliably assessed with user-owned devices. (Funded by Apple; Apple Heart Study
ClinicalTrials.gov number, NCT03335800.).
Type
Journal articleSubject
Apple Heart Study InvestigatorsHumans
Atrial Fibrillation
Electrocardiography
Prospective Studies
Predictive Value of Tests
Confidentiality
Telemedicine
Algorithms
Adult
Aged
Middle Aged
Female
Male
Mobile Applications
Wearable Electronic Devices
Permalink
https://hdl.handle.net/10161/19577Published Version (Please cite this version)
10.1056/nejmoa1901183Publication Info
Perez, Marco V; Mahaffey, Kenneth W; Hedlin, Haley; Rumsfeld, John S; Garcia, Ariadna;
Ferris, Todd; ... Apple Heart Study Investigators (2019). Large-Scale Assessment of a Smartwatch to Identify Atrial Fibrillation. The New England journal of medicine, 381(20). pp. 1909-1917. 10.1056/nejmoa1901183. Retrieved from https://hdl.handle.net/10161/19577.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
Collections
More Info
Show full item recordScholars@Duke
Christopher Bull Granger
Donald F. Fortin, M.D. Distinguished Professor of Medicine
Research: My primary research interest is in conduct and methodology of large randomized
clinical trials in heart disease. I have led a number of large international clinical
studies in heart attacks, unstable angina, heart failure, and atrial fibrillation.
I have lead clinical studies of blood thinners and coronary intervention for heart
attacks, stroke prevention in atrial fibrillation, and prevention of heart attack
for patients with coronary artery disease. I have been co-directo

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info