One Versus Two Months Anticoagulation After Catheter Ablation for Atrial Fibrillation in Patients Who Were Not Indicated for Long-Term OAC: A Pilot Randomized Controlled Trial (The REDUCIBLE Trial)

BACKGROUND AND OBJECTIVES: Even low-risk atrial fibrillation (AF) patients usually continue anticoagulant therapy for several months after the procedure. However, there is no solid evidence supporting this practice. The REDUCIBLE trial is designed to compare the outcomes of conventional 2- versus 1-month oral anticoagulant (OAC) therapy following successful catheter ablation (CA) in men with a CHA₂DS₂-VASc score of ≤1 and women with ≤2, where long-term OAC is not recommended. METHODS: In this pilot study, patients undergoing CA for drug-refractory paroxysmal AF were randomly divided into 2 groups. One group received OAC for 1 month, whereas the other received it for 2 months. The primary outcome was the incidence of stroke and systemic embolism within 1 year after ablation. RESULTS: A total of 220 patients were enrolled and randomly assigned to 2 groups. Baseline characteristics were similar between the groups. The AF recurrence-free survival (RFS) rate was similar (76.9% vs. 77.7%, p=0.98). During the blanking period, AF RFS was also similar (92.5% vs. 92.9%, p=0.98). No ischemic stroke or systemic embolism occurred in either group during 1-year follow-up. One patient in the 1-month group experienced a minor bleeding event when anticoagulants were not taken (7 months after ablation). CONCLUSIONS: This study found that a single month of OAC post-ablation did not significantly elevate the risk of stroke or systemic embolism in low-risk patients. Nonetheless, a larger sample size would be necessary to achieve the statistical power for definitive conclusions. Future larger prospective clinical trials are needed to address this question comprehensively. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03573037.