Key Points:
- Atrial fibrillation (AF) increases the risk of stroke, and long-term oral anticoagulation is generally recommended for patients with atrial fibrillation and elevated stroke risk.
- However, whether there is a benefit to ongoing oral anticoagulation after successful catheter ablation of atrial fibrillation is unknown.
- OCEAN suggests that ongoing oral anticoagulation may not be beneficial after successful catheter ablation for atrial fibrillation, however these results do not apply to patients with high stroke risk.
While a lower burden of atrial fibrillation has been associated with a lower risk of stroke, it remains uncertain whether the risks of ongoing oral anticoagulation outweigh the potential benefits after successful atrial fibrillation ablation.
On November 8th, 2025, the results of “Antithrombotic Therapy after Successful Catheter Ablation for Atrial Fibrillation” were presented at the American Heart Association Scientific Sessions in New Orleans, LA, with simultaneous publication in The New England Journal of Medicine. The purpose of this trial was to determine whether ongoing oral anticoagulation offers greater protection from cerebrovascular events compared to aspirin in patients who have had a successful atrial fibrillation ablation.
This international, open-label trial randomized 1,284 adults at least one year post-successful AF ablation who had a CHADS2‑VASc score of ≥1 and no documented arrhythmia recurrence based on the absence of atrial arrythmia of >30 seconds on serial 24-hour Holter monitoring at 2-6 months post ablation, ≥ 6 months post-ablation, and 48 hours prior to enrollment. Participants were assigned in a 1:1 ratio to rivaroxaban 15mg or aspirin 75-160mg daily. The authors noted that rivaroxaban 15mg has ~80-90% pharmacokinetic overlap with the 20mg dose and that prior studies have demonstrated a lower bleeding risk with no increased stroke risk among patients with normal renal function. The primary efficacy composite endpoint was stroke, systemic embolism, or silent cerebral infarction (assessed at baseline and 3 years by MRI). The primary safety outcome was fatal and major bleeding.
This trial was stopped early because of high likelihood that it would not demonstrate a benefit for rivaroxaban. Only 4 patients were lost to follow up. Overall, 5.5% of patients exited because of repeat AF ablation and ~98% received their 3 year brain MRI. The mean age was 66 years, 71% were male, 66% had paroxysmal atrial fibrillation. The median time from ablation to enrollment was 16.4 months, the mean CHA2DS2-VASc score was 2.2, and 6% had a prior stroke or transient ischemic event.
Overall, 5 of 641 patients in the rivaroxaban arm and 9 of 643 patients in the aspirin arm experienced the primary composite outcome. The annualized risk for the primary outcome was 0.31% for rivaroxaban and 0.66% for aspirin; there was no significant difference between the two groups at 3 years (RR 0.56 [95% CI: 0.19, 1.65]). Overall, only 4% of patients had a new infarct of any size on MRI at 3 years, with no significant difference between the two groups (RR 0.89 [95% CI: 0.51, 1.55]). There was also no significant difference between rivaroxaban and the aspirin group in fatal or major bleeding (HR 2.51 [95% CI: 0.79, 7.95]). However, rivaroxaban was associated with a significant increase in clinically relevant non-major bleeding (HR 3.51 [95% CI: 1.75, 7.03]) and minor bleeding (HR 3.71 [95% CI: 2.29, 6.01]).
Potential limitations of the study include the use of aspirin rather than placebo, the use of the rivaroxaban 15mg rather than 20mg, and the lack of extended monitoring during follow-up, though all of these were intentional choices by the authors of this pragmatic trial. Most importantly, this population had a low-to-moderate stroke and bleeding risk, so the results cannot be applied to high-risk patients.
Dr. Atul Verma, of McGill University Health Center, Montreal, Canada, concluded: “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. 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.”
