Atrial fibrillation (AFib) greatly increases the risk of stroke, blood clots, heart failure, and death, and millions of people in the U.S. are expected to be affected in the coming years. Current guidelines advise continuing blood thinners even after a successful catheter ablation, despite uncertainty about whether restoring normal rhythm lowers long-term stroke risk. Now, a new study suggests the procedure may reduce stroke risk enough to safely discontinue long-term anticoagulation.

In the OCEAN Randomized Trial led by the Population Health Research Institute (PHRI, Ontario, Canada), in collaboration with global trial sites, researchers evaluated nearly 1,300 adults across multiple countries to determine whether oral anticoagulation was necessary after successful ablation in patients with moderate to high stroke risk. Participants included individuals with no evidence of recurrent AFib who would normally require lifelong blood thinners.

The study followed participants for three years after ablation, using the CHA?DS?-VASc score to assess baseline stroke risk. Enrollees were on average 66 years old, with 32% scoring three or higher on the stroke-risk scale. All participants underwent brain MRI at enrollment and again at three years, and were randomly assigned either aspirin (75–160 mg daily) or rivaroxaban (15 mg daily). Researchers tracked stroke events, systemic embolism and bleeding complications.

The trial found that rivaroxaban offered no significant stroke-prevention advantage over aspirin after successful ablation. The three-year risk of stroke, including covert stroke, was 0.8% in the rivaroxaban group and 1.4% in the aspirin group, while annual stroke risk was similarly low in both arms. Rates of major or fatal bleeding were comparable, but clinically relevant non-major bleeding was 3.5 times more common with rivaroxaban.

These findings, presented at the American Heart Association’s Scientific Sessions 2025, suggest that successful catheter ablation may not only suppress recurrent AFib but also reduce long-term stroke risk to levels where continuation of potent anticoagulation may not be necessary for select patients. Lower bleeding risk with aspirin underscores the potential advantage of de-escalating therapy. Researchers conclude that individuals with moderate stroke risk may be safely advised to stop blood thinners after ablation. Future work may further refine which post-ablation patients benefit most, integrating MRI findings, AFib recurrence monitoring, and long-term outcomes across global populations.

“In essence, catheter ablation for AFib reduced the recurrence of atrial fibrillation and can also reduce the risk of stroke associated with this common heart rhythm condition,” said study author Atul Verma, M.D. “With the notably increased bleeding risk associated with rivaroxaban, we concluded that the anticoagulant did not offer any advantages in comparison to aspirin for reducing what we found to be a low stroke risk in these individuals. Now, we can advise patients that it may be safe to stop blood thinners, even if they have a moderate stroke risk.”

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