Smart Watches Detect Atrial Fibrillation After Stroke, Sensitivity Depends Episode Duration

Wearable devices are capable of detecting atrial fibrillation (AF) in patients with recent ischemic strokes, but sensitivity depends largely on AF episode duration and device wear time.¹

These data, the results from the Find-AF2 Watch trial, were presented at the World Stroke Congress (WSC) 2026 in Seoul, South Korea, by Tobias Uhe, MD, a specialist in internal medicine and cardiology and a senior physician at the University of Leipzig in Germany.¹

“We don’t know what amount of atrial fibrillation is key for secondary prevention of strokes – maybe longer episodes are the ones which might be more clinically significant,” Uhe told HCPLive in an exclusive interview. “And of course, we also wanted to ask a more technical question: what amount of atrial fibrillation are the variables able to find?”

Find-AF 2 Watch was a pilot study investigating the sensitivity of wearables, namely the Apple Watch Series 10 and the PulseOn device, in patients who had already been given continuous implantable event monitors (ICMs). Both devices detected AF via photoplethysmography, and the identification of an arrhythmic pulse curve was communicated through vibration.²

Patients were chosen from the Find-AF 2 trial and were required to have a recent symptomatic ischemic stroke within the last 30 days. Those with no ICM data transmission possible, poor electrocardiogram (ECG) data quality, a medical history of intracerebral bleeding, or an implanted pacemaker or cardioverter/defibrillator, among other criteria, were excluded from the study. The primary outcome was sensitivity as a function of AF duration – specifically, the probability that an AF episode will be detected, as it depends on the episode’s duration. Secondary endpoints included ECG compliance, overall sensitivity, and time to first ECG, among others.²

A total of 155 patients were enrolled in the study, of whom 60 were randomized to either wearable device. Over a median follow-up of 4 years, the team found no significant device difference between the Apple Watch and the PulseOn devices. Additionally, less frequent device charging was correlated with longer wear time and higher detection sensitivity. Patients also displayed high adherence, further demonstrating the potential feasibility of this strategy in post-stroke care.³

While the team included only German patients who were relatively healthy, limiting the generalizability of the results, Uhe and colleagues concluded that wearable use is a feasible complementary method of monitoring AF after stroke. Additionally, longer episode detection was shown to improve with less frequent charging, and no differences between the 2 devices were found.³

“We don’t yet have data that show that intensified rhythm monitoring leads to a reduction in recurrent strokes or systemic embolisms, and you should always keep in mind that anticoagulation could result in complications like bleeding,” Uhe said. “I think it first has to be shown that an intensified rhythm monitoring approach will lead to a reduction of heart endpoints.”

Editors’ Note: Uhe reports no relevant disclosures.

References

1. Uhe T. Pilot Study for Smartwatch-Driven Atrial Fibrillation Detection in Stroke Patients – Find-AF 2 Watch. Presented at the World Stroke Congress (WSC) 2026, Seoul, South Korea. October 21-23, 2026.

2. University of Leipzig. SmartWatch-driven AF Detection in Stroke Patients (Find-AF2 Watch). ClinicalTrials.gov Identifier: NCT06832579. Updated August 26, 2026. Accessed November 3, 2026. https://clinicaltrials.gov/study/NCT06832579?term=NCT06832579&rank=1

3. Vaz D. Pilot Study for SmartWatch-Driven Atrial Fibrillation Detection in Stroke Patients: Find AF-2 Trial. Day 1 clinical trials highlights at WSC 2026: WSC 2026 - 18th World Stroke congress. WSC 2026 - 18th World Stroke Congress | 18th World Stroke Congress. October 23, 2026. Accessed November 4, 2026. https://worldstrokecongress.org/day-1-clinical-trials-highlights-at-wsc-2026/