The New England Journal of MedicineLarge-Scale Assessment of a Smartwatch to Identify Atrial Fibrillation

Although the probability of receiving an irregular pulse notification was low, a smartwatch app shows promise in atrial fibrillation detection, paving way for broader applications.

A study in 2019 explored the potential of a smartwatch application on Apple iPhones in identifying atrial fibrillation among users. The study employed a siteless, pragmatic design, leveraging user-owned devices for large-scale monitoring and analysis.

Study Design

• The study recruited 419,297 participants over an 8-month period.
• Participants, who reported not having atrial fibrillation, used a smartphone app for monitoring.
• If the app detected a possible atrial fibrillation, an ECG patch was mailed to the participant for further analysis.

Key Findings

• 0.52% of participants received notifications of irregular pulse.
• Among those who returned the ECG patches, 34% were found to have atrial fibrillation.
• The positive predictive value of the app was 0.84 for observing atrial fibrillation on the ECG simultaneously with a subsequent irregular pulse notification.

HCN Medical Memo
Atrial fibrillation is the most commonly diagnosed clinically significant cardiac arrhythmia and affects approximately 6 million people in the United States.

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