Real-time smartphone alerts during atrial fibrillation episodes with implantable cardiac monitors and wearable devices: SMART-ALERT study
Real-time smartphone alerts during atrial fibrillation episodes with implantable cardiac monitors and wearable devices: SMART-ALERT study
Background: atrial fibrillation (AF) is a major cause of stroke, with dynamic thromboembolic risk during and shortly after episodes. Implantable cardiac monitors and wearable devices have emerged as tools for real-time AF detection, yet their comparative performance in supporting anticoagulation strategies remains underexplored.
Objective: this single-center feasibility study investigated the performance of real-time AF detection and notification for episodes lasting longer than 30 minutes.
Methods: phase 1 evaluated the integration of an implantable cardiac monitor and bespoke cloud-based software (SMART-ALERT) in sending automated short message service notifications (n = 50) for episodes uploaded within 24 hours. Phase 2 evaluated the Apple Watch (n = 23) and the CART Ring (n = 23) detecting and notifying participants of AF episodes. The primary outcome was the successful AF notification rates via (1) SMART-ALERT software and (2) wearable devices. Secondary outcomes included acknowledgment rates, notification times, and adherence.
Result: among 4943 AF episodes detected in 31 participants, the SMART-ALERT software successfully notified 511 of 691 eligible AF episodes (74%), with a 99.6% acknowledgment. In contrast, wearable devices showed poor notification performance: the Apple Watch identified 76 of 389 episodes (19.5%); and the CART Ring, 72 of 474 (15.1%). This performance difference was partly explained by suboptimal device adherence (Apple Watch: 66.3%; CART Ring: 23.9%), with 24.6% and 55.7% of AF episodes missed because of devices not being worn.
Conclusion: the SMART-ALERT system demonstrated the feasibility of real-time AF detection and automated notifications, achieving a 74% notification success but facing important connectivity challenges. Wearable devices showed poor notification rates (<20%) and adherence, highlighting significant technical barriers to their current use in clinical AF monitoring.
Anticoagulation, Apple Watch, Atrial fibrillation, CART Ring, Wearable devices
Rodrigues Pontes Briosa E Gala, Andre
409c30a8-0696-4426-9f9b-2539af465dbd
Sharp, Alexander James
c534fe9f-4bcb-4d49-b72f-3d2d47ac014d
Pope, Michael Timothy Bryan
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Leo, Milena
dc45a36a-0ce3-4c7a-b38a-f4977f8f4f41
Varini, Richard Kevin
1c4158e9-951b-4efc-9155-f5b0bd63db75
Paisey, John
b1f1229b-a681-4117-bcd7-bc80210bd85b
Curzen, Nick
70f3ea49-51b1-418f-8e56-8210aef1abf4
Banerjee, Abhirup
db54813c-c926-4daa-90dd-d5d69764daca
Betts, Timothy Rider
ddd6271a-7c72-43bc-80f6-7cfd99402c9c
14 April 2025
Rodrigues Pontes Briosa E Gala, Andre
409c30a8-0696-4426-9f9b-2539af465dbd
Sharp, Alexander James
c534fe9f-4bcb-4d49-b72f-3d2d47ac014d
Pope, Michael Timothy Bryan
4e7343b7-a8c4-4ce4-a813-ff0d894b0f92
Leo, Milena
dc45a36a-0ce3-4c7a-b38a-f4977f8f4f41
Varini, Richard Kevin
1c4158e9-951b-4efc-9155-f5b0bd63db75
Paisey, John
b1f1229b-a681-4117-bcd7-bc80210bd85b
Curzen, Nick
70f3ea49-51b1-418f-8e56-8210aef1abf4
Banerjee, Abhirup
db54813c-c926-4daa-90dd-d5d69764daca
Betts, Timothy Rider
ddd6271a-7c72-43bc-80f6-7cfd99402c9c
Rodrigues Pontes Briosa E Gala, Andre, Sharp, Alexander James, Pope, Michael Timothy Bryan, Leo, Milena, Varini, Richard Kevin, Paisey, John, Curzen, Nick, Banerjee, Abhirup and Betts, Timothy Rider
(2025)
Real-time smartphone alerts during atrial fibrillation episodes with implantable cardiac monitors and wearable devices: SMART-ALERT study.
Heart Rhythm.
(doi:10.1016/j.hrthm.2025.04.015).
Abstract
Background: atrial fibrillation (AF) is a major cause of stroke, with dynamic thromboembolic risk during and shortly after episodes. Implantable cardiac monitors and wearable devices have emerged as tools for real-time AF detection, yet their comparative performance in supporting anticoagulation strategies remains underexplored.
Objective: this single-center feasibility study investigated the performance of real-time AF detection and notification for episodes lasting longer than 30 minutes.
Methods: phase 1 evaluated the integration of an implantable cardiac monitor and bespoke cloud-based software (SMART-ALERT) in sending automated short message service notifications (n = 50) for episodes uploaded within 24 hours. Phase 2 evaluated the Apple Watch (n = 23) and the CART Ring (n = 23) detecting and notifying participants of AF episodes. The primary outcome was the successful AF notification rates via (1) SMART-ALERT software and (2) wearable devices. Secondary outcomes included acknowledgment rates, notification times, and adherence.
Result: among 4943 AF episodes detected in 31 participants, the SMART-ALERT software successfully notified 511 of 691 eligible AF episodes (74%), with a 99.6% acknowledgment. In contrast, wearable devices showed poor notification performance: the Apple Watch identified 76 of 389 episodes (19.5%); and the CART Ring, 72 of 474 (15.1%). This performance difference was partly explained by suboptimal device adherence (Apple Watch: 66.3%; CART Ring: 23.9%), with 24.6% and 55.7% of AF episodes missed because of devices not being worn.
Conclusion: the SMART-ALERT system demonstrated the feasibility of real-time AF detection and automated notifications, achieving a 74% notification success but facing important connectivity challenges. Wearable devices showed poor notification rates (<20%) and adherence, highlighting significant technical barriers to their current use in clinical AF monitoring.
Text
SMART-ALERT_manuscript R1_03.04
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Accepted/In Press date: 7 April 2025
e-pub ahead of print date: 14 April 2025
Published date: 14 April 2025
Keywords:
Anticoagulation, Apple Watch, Atrial fibrillation, CART Ring, Wearable devices
Identifiers
Local EPrints ID: 501108
URI: http://eprints.soton.ac.uk/id/eprint/501108
ISSN: 1547-5271
PURE UUID: ec7b2734-ca60-4e6e-9dcd-ef6e282fa5e4
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Date deposited: 23 May 2025 16:59
Last modified: 17 Sep 2025 02:08
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Contributors
Author:
Andre Rodrigues Pontes Briosa E Gala
Author:
Alexander James Sharp
Author:
Michael Timothy Bryan Pope
Author:
Milena Leo
Author:
Richard Kevin Varini
Author:
John Paisey
Author:
Abhirup Banerjee
Author:
Timothy Rider Betts
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