AFib Ablation May Eliminate Need for Blood Thinners, Study Finds

In groundbreaking research presented at the American Heart Association's Scientific Sessions 2025, an international study reveals that catheter ablation for atrial fibrillation (AFib) may significantly reduce stroke risk to the point where many patients can safely discontinue potent blood thinners. The OCEAN Randomized Trial, involving nearly 1,300 adults across multiple countries, followed participants for three years after successful ablation procedures. Researchers found that prescribing the blood thinner rivaroxaban offered no significant advantage over aspirin in stroke prevention while carrying substantially higher bleeding risks. The study, simultaneously published in the New England Journal of Medicine, challenges current American Heart Association guidelines that recommend continuing blood thinners even after successful ablation in moderate-to-high risk individuals.

Led by Dr. Atul Verma of McGill University Health Centre, the research specifically examined whether successful catheter ablation could eliminate the need for long-term oral anticoagulation in AFib patients. The study enrolled participants with an average CHA2DS2-VASc score of 2.2, with nearly 32% having scores of 3 or higher indicating high stroke risk. Participants were randomly assigned to receive either 75-160 mg of aspirin daily or 15 mg of rivaroxaban daily. The findings showed remarkably low stroke rates across both groups—just 0.8% in the rivaroxaban group and 1.4% in the aspirin group over three years, translating to annual risks of 0.3% and 0.7% respectively. These minimal differences suggest that ablation itself dramatically reduces stroke risk, making potent anticoagulants potentially unnecessary for many patients.

Most notably, the study revealed that rivaroxaban users experienced clinically relevant non-major bleeding events at 3.5 times the rate of aspirin users (5.5% versus 1.6%). This increased bleeding risk without corresponding stroke protection advantages led researchers to conclude that aspirin provides adequate protection for patients who have undergone successful catheter ablation. The findings are particularly significant given that AFib increases stroke risk five-fold and affects approximately five million Americans, with projections suggesting over 12 million will have the condition by 2030 according to the Association's 2025 Heart Disease and Stroke Statistics report. This research could transform clinical practice by allowing many patients to avoid the bleeding risks and lifestyle limitations associated with long-term potent blood thinners.