byAmerican Heart Association

Credit: American Heart Association

A minimally invasive heart procedure to correct irregular heart rhythms called catheter ablation may reduce the risk of stroke enough that some patients can discontinue blood thinners, according to a preliminary late-breaking science presentation Saturday at the American Heart Association'sScientific Sessions 2025. The study was simultaneouslypublishedin theNew England Journal of Medicine.

In the OCEAN Randomized Trial, researchers evaluated whether long-term oral anticoagulation is needed after successful ablation in people with an increased risk of stroke. An international group of researchers enrolled nearly 1,300 adults at multiple sites in several countries and followed their progress for three years after they had ablation to treat atrial fibrillation (AFib). Participants included people with no evidence of irregular heart rhythm recurrence and those with moderate to high stroke risk, which calls for long-termblood thinners.

According to the American Heart Association, AFib increases stroke risk by five-fold and can lead to blood clots, heart failure and death. An estimated 5 million people in the U.S. live with AFib, and it is predicted that more than 12 million people will have it by 2030, per theAssociation's 2025 Heart Disease and Stroke Statistics report.

The condition can be treated withcatheter ablation, a minimally invasive nonsurgical procedure that can eliminate the electrical triggers for AFib and prevent the irregular rhythms from returning. Current American Heart Association/American College of Cardiologyguidelinesrecommend continuing blood-thinning medications in moderate-to-high risk individuals to prevent stroke, even after a successful ablation.

"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 Center 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. So, it was important to find out if successful ablation could allow discontinuing blood thinners."

Researchers prescribed half of the eligible participants 75–160 mg ofaspirin(a mild antiplatelet) daily. The other half were prescribed 15 mg daily of oral rivaroxaban, a potent blood thinner.

The study found that prescribing the blood thinner rivaroxaban after catheter ablation to treat AFib offered no major difference in stroke protection than those taking aspirin and increased bleeding risk compared to aspirin. Specifically:

"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," Verma said. "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 moderatestroke risk."

Study details, background and design:

Among the study's limitations, only a small percentage of participants a CHA2DS2-VASc score of 4 or higher. As a result, the findings may not be relevant to higher-risk individuals.

More information: Atul Verma et al, Antithrombotic Therapy after Successful Catheter Ablation for Atrial Fibrillation, New England Journal of Medicine (2025). DOI: 10.1056/nejmoa2509688 Journal information: New England Journal of Medicine

Provided by American Heart Association