The OCEAN trial, a groundbreaking international study co-led by the University of Ottawa Heart Institute and McGill University Health Centre, provides the first evidence to address one of the most important clinical questions in modern electrophysiology: Can anticoagulation be safely discontinued after successful atrial fibrillation (AF) ablation?
Together with the international OCEAN team, in November 2025 Drs. David Birnie and George Wells published “Antithrombotic Therapy after Successful Catheter Ablation for Atrial Fibrillation” in the New England Journal of Medicine.
AF is the most common type of arrhythmia worldwide, affecting millions and significantly increasing the risk of stroke. Catheter ablation is widely used to reduce arrhythmia burden in AF patients, however, current guidelines recommend continuing anticoagulation indefinitely based on stroke risk scores, rather than ablation success because there was uncertainty about whether AF ablation also reduced the risk of stroke in these patients. The OCEAN trial’s paradigm shifting results suggest that most patients with successful AF ablation and no recurrence may safely discontinue oral anticoagulation, reducing bleeding complications and improving quality of life for ~million patients annually. Continuing anticoagulation offered no clear benefit, and in fact, increased bleeding risk, supporting the need for individualized antithrombotic strategies post-ablation. The study randomized 1284 patients at least one year post-successful AF ablation to rivaroxaban or aspirin for three years.
This study, presented as ‘Late Breaking Science’ at the American Heart Association Scientific Sessions 2025, will reshape clinical guidelines, practice, and policy, reducing healthcare costs and adverse events by avoiding unnecessary anticoagulation. The results have also received extensive media coverage, including the American College of Cardiology News, highlighting its practice-changing implications.
OCEAN results align with emerging evidence from independent studies such as ALONE-AF, published in JAMA in November 2025, which led to similar conclusions around the safety of discontinuing anticoagulation one year after AF ablation. This reproducibility across these two large, randomized trials conducted in different populations underscores the robustness of the evidence and compelling foundation for revising clinical practice worldwide. The OCEAN trial findings will transform guidelines, reduce unnecessary bleeding risk, and improve quality of life for millions of patients worldwide.
Can patients stop blood thinners after atrial fibrillation ablation? Dr. Birnie explains OCEAN trial