Catheter Ablation May Eliminate Need for Blood Thinners in Some AFib Patients, Study Finds
New research suggests successful catheter ablation for atrial fibrillation reduces stroke risk enough that many patients can safely discontinue potent blood thinners in favor of aspirin, potentially reducing bleeding complications while maintaining stroke protection.
Successful catheter ablation for atrial fibrillation significantly reduces stroke risk and may eliminate the need for ongoing blood-thinning medications in many patients, according to new research presented at the American Heart Association's Scientific Sessions 2025. The findings from the OCEAN Randomized Trial challenge current treatment guidelines that recommend continuing anticoagulants even after successful ablation procedures.
The international study followed 1,284 adults for three years after they underwent catheter ablation to treat atrial fibrillation, a condition that increases stroke risk five-fold and affects approximately five million people in the United States. According to the American Heart Association's 2025 Heart Disease and Stroke Statistics report, this number is projected to rise to more than 12 million by 2030. Participants included individuals with no evidence of irregular heart rhythm recurrence and those with moderate to high stroke risk who would typically require long-term blood thinners.
Researchers randomly assigned participants to receive either 15 mg daily of rivaroxaban, a potent blood thinner, or 75-160 mg of aspirin daily. The results revealed no significant difference in stroke protection between the two groups. The three-year risk of stroke, including covert strokes detectable only through brain imaging, was 0.8% in the rivaroxaban group compared to 1.4% in the aspirin group. Annual stroke risk measured 0.3% for rivaroxaban versus 0.7% for aspirin, differences not considered statistically significant.
However, the study found clinically relevant non-major bleeding was 3.5 times more likely with rivaroxaban than aspirin, occurring in 5.5% of rivaroxaban patients compared to 1.6% of aspirin patients. There were no notable differences in major or fatal bleeding complications between the two groups. The findings are simultaneously published in the New England Journal of Medicine and available through the American Heart Association Scientific Sessions 2025 Online Program Planner.
"We know that ablation for AFib is effective, however, we did not know if elimination of the arrhythmia also reduces the long-term risk of stroke," said study author Atul Verma, M.D., director of cardiology at McGill University Health Centre in Montreal. "Many people who have undergone successful ablation will ask 'Can I stop my blood thinners?' Until now, we have told them to continue taking blood thinners because we had insufficient evidence to suggest it was safe to stop."
The study used the CHA2DS2-VASc score to measure stroke risk, with participants averaging a score of 2.2 at enrollment. Nearly 32% of participants had a score of 3 or higher, considered high risk. All participants underwent brain magnetic resonance imaging at enrollment and again at three years to detect any covert strokes. Current American Heart Association/American College of Cardiology guidelines recommend continuing blood-thinning medications in moderate-to-high risk individuals to prevent stroke, even after successful ablation.
Researchers noted that only a small percentage of participants had a CHA2DS2-VASc score of 4 or higher, meaning the findings may not apply to higher-risk individuals. The study was conducted across healthcare centers in Canada, Australia, Germany, Belgium, Israel and China between March 2016 and July 2022. Additional information about atrial fibrillation is available through the American Heart Association's health information resources.