new trial Challenges Long-Held beliefs About Blood Thinners After Atrial Fibrillation Ablation
A landmark study presented at the American Heart AssociationS 2025 Scientific Sessions suggests some patients may be able to safely discontinue blood thinners after successful treatment for atrial fibrillation (AF), a common heart rhythm disorder.
For decades, medical guidelines have recommended long-term oral anticoagulation following catheter ablation for AF, a procedure designed to restore a normal heartbeat. However, results from the OCEAN trial, concurrently published in the New England Journal of Medicine, are prompting a reevaluation of this standard practice, particularly for lower-risk individuals.
The OCEAN trial compared the effectiveness of aspirin to the direct oral anticoagulant rivaroxaban (Xarelto) in 1,284 patients who had undergone successful AF catheter ablation at least one year prior to the study. Participants, with a mean age of 66, were monitored for three years to assess the incidence of stroke, systemic embolism, and covert embolic strokes detected by MRI.
“I think when you look at the totality of the evidence, there are some patients who can stop oral anticoagulation after successful ablation,” stated the lead investigator of the OCEAN trial, Atul Verma, MD, during a press conference. He further clarified that patients with a CHA2DS2-V
The findings align with those of the recent ALONE-AF study, which also demonstrated improved clinical outcomes in patients who stopped oral anticoagulation after successful AF ablation. though,Christine Albert,MD,of Cedars-Sinai Medical Center,cautioned that concerns about silent AF and the potential for stroke continue to drive the practice of long-term anticoagulation in many cases.
The OCEAN trial’s design, which compared aspirin to rivaroxaban, has also drawn scrutiny. Investigators initially chose aspirin as a comparator as, at the time the trial began 10 years ago, they were uncomfortable randomizing patients to no treatment. Though,as one investigator noted,the evidence supporting aspirin’s stroke-preventive benefits in low-risk patients has diminished,making it function more like a placebo in the context of the ALONE-AF trial.
The study included patients with a CHA2DS2-VASc score of 1 or more (2 or more for women or those with vascular disease), with a mean score of 2.2. Participants were randomized to either 70-120 mg of aspirin daily or a 15-mg dose of rivaroxaban for a median of 16.4 months post-ablation.The trial was halted in 2022 by its data safety and monitoring board due to the high probability of no meaningful difference in outcomes.
While the trial showed a nonsignificant increase in major bleeding with rivaroxaban (1.6% vs. 0.6% with aspirin; HR 2.51; 95% CI 0.79-7.95), experts suggest that option direct oral anticoagulants (DOACs) like apixaban (Eliquis) may offer a more favorable bleeding profile. Furthermore, procedures like left atrial appendage occlusion (LAAO) are emerging as potential alternatives to long-term anticoagulation, as demonstrated in the OPTION study.
Michael Ghannam, MD, of the University of Michigan Health, emphasized that these findings shoudl not be interpreted as a blanket proposal to discontinue anticoagulation. “I certainly wouldn’t use these data to justify discontinuing anticoagulants at large, particularly among patients who have a high burden of cardiovascular disease and elevated stroke risk,” he stated. “Nevertheless, it’s captivating to see that the overall event rates postablation were low.”
The OCEAN trial represents a significant step forward in understanding the optimal post-ablation management of AF, opening the door to more personalized treatment strategies.As the prevalence of AF continues to rise, these findings will undoubtedly shape future clinical guidelines and, most importantly, empower physicians to have more informed conversations with their patients about the risks and benefits of continuing or discontinuing blood thinners.
