Novel anticoagulation therapy using apple watch after catheter ablation for atrial fibrillation-Up to AF trial: Design and rationale

Background: Continuous anticoagulation based on the CHA2DS2-VASc score is recommended to prevent embolism caused by atrial fibrillation (AF), but it does not consider AF episodes. The Apple Watch's continuous heart rhythm monitoring and fast-acting direct oral anticoagulants (DOACs) could enable precise, episode-tailored anticoagulation, reducing bleeding risks while preventing stroke. This study evaluates Apple Watch-guided personalized anticoagulation therapy, adjusting DOAC usage based on real-time AF detection.

Methods: This multicenter prospective single-arm study will enroll patients who have maintained sinus rhythm post-ablation and are on DOACs. The target enrollment is 50 patients free of AF for at least 30 days following the initiation of Apple Watch monitoring. If no AF occurs for the first 30 days of monitoring, anticoagulants will be discontinued on day 31. If AF is confirmed after day 31, DOAC administration will be resumed and continued until the end of the observation period. The primary endpoint is the reduction in the total number of days with DOACs from day 31 to day 360 compared to the conventional method of continuing anticoagulation. Secondary endpoints include all-cause mortality, stroke, systemic thromboembolism, bleeding events, and Apple Watch malfunctions.

Results: Enrollment of a total of 50 patients was completed in April 2024. Follow-up of the last enrolled patient will be completed in April 2025 and primary results are expected to be available in late 2025.

Conclusions: The Up to AF trial is the first trial to evaluate Apple Watch-guided personalized anticoagulation therapy. This trial represents a potential advancement in personalized medicine for AF management.