Pill-in-the-POCKET Oral Anticoagulation Strategy After AF Catheter Ablation

Atrial fibrillation significantly increases the risk of thromboembolic complications, including stroke. Accordingly, current atrial fibrillation treatment guidelines recommend lifelong prescription of anticoagulants if the CHA2DS2-VASc score is 2 (for males) or 3 (for females) or higher (Class IA). With the recent advances in rhythm control treatment through catheter ablation in atrial fibrillation patients, increasing concerns are being raised about the need to continue anticoagulation after successful catheter ablation. However, current guidelines still require continued anticoagulation based on the baseline CHA2DS2-VASc score regardless of sinus conversion after atrial fibrillation catheter ablation.

A recently published observational study demonstrated that the risk of stroke was reduced by less than 0.7% per year in patients who discontinued anticoagulants after successful catheter ablation. Subsequent meta-analysis studies similarly suggested that anticoagulant discontinuation could be safe in patients whose rhythm was restored to sinus rhythm through catheter ablation. In addition, it was confirmed that anticoagulant discontinuation after catheter ablation was associated with only a 0.6% increase in the risk of thromboembolism as opposed to a 1.8% decrease in the risk of severe bleeding, such as intracranial hemorrhage and respiratory bleeding. Similar findings were also confirmed from large-scale non-randomized studies. However, there is still a lack of large-scale randomized study findings to support that anticoagulant discontinuation is appropriate in atrial fibrillation who are successful converted to sinus rhythm after catheter ablation.

Two single-arm pilot studies have been published about pill-in-the-pocket (PIP) anticoagulation. One is the REACT.COM (Rhythm Evaluation for Anticoagulation With Continuous Monitoring), and the other is the TACTIC-AF (Tailored Anticoagulation for Non-Continuous Atrial Fibrillation). In the above studies, continuous remote monitoring was performed using insertable cardiac monitors, dual-chamber pacemakers, or defibrillators. If atrial fibrillation persisted over a certain period during monitoring, anticoagulation was resumed for 30 days. This approach reduced the use of anticoagulants by 94% in the REACT.COM by resuming anticoagulation when atrial fibrillation recurrence persisted longer than 1 hour. TACTIC-AF observed a 75% reduction in time on anticoagulation using a threshold of 6 minutes or total burden \>6 h/d.

Conventionally, recurrence of atrial fibrillation has been confirmed through 12-lead electrocardiogram (ECG) or adhesive 24-hour (or 3-day, 7-day, 2-week) ECG monitoring. However, these methods are limited by the inability to continuously assess the exact atrial fibrillation burden during the follow-up period. As an alternative to this, implantable loop recorders (ILR) enabled with continuous heart rhythm monitoring have recently been widely used in clinical practice. These implantable loop recorders have shown desirable performance in measuring atrial fibrillation recurrence and burden. However, few studies have evaluated the role of continuous rhythm monitoring in guiding OAC in patients with AF.