Rivaroxaban does not change stroke risk after successful AF catheter ablation
AHA 2025 – In OCEAN, rivaroxaban did not lower the risk of stroke, systemic embolism, or new covert embolic stroke compared with aspirin in patients with increased stroke risk ≥1 year after successful AF ablation. However, it did increase the risk of nonmajor bleeding events.
This summary is based on the presentation of Atul Verma, MD (Montreal, Canada) at the AHA Scientific Sessions 2025 - The Need for Ongoing Oral Anticoagulation in Patients with Clinical Stroke Risk Factors After Successful Catheter Ablation of Atrial Fibrillation: The OCEAN Randomized Trial.
Introduction and methods
It remains uncertain whether effective catheter ablation sufficiently reduces AF burden to lower the risk of stroke and eliminate the need for long-term OAC. In fact, current guidelines recommend continuing OAC for life after AF ablation based on the CHA₂DS₂-VASc score, regardless of the apparent success of the procedure. The researchers of the OCEAN (Optimal Anticoagulation for Higher Risk Patients Post-Catheter Ablation for Atrial Fibrillation Trial) trial therefore hypothesized that continued OAC is superior to antiplatelet therapy in reducing stroke risk after successful ablation for AF.
In this international, open-label, blinded-outcome-assessment, phase 4 RCT conducted at 56 sites across 6 countries, 1284 patients who had undergone successful AF ablation ≥1 year prior and had a CHA₂DS₂-VASc score ≥1 (≥2 if female sex or vascular disease present) were randomized to rivaroxaban 15 mg daily or low-dose aspirin (70–120 mg). Brain MRI was performed at baseline and 3 years.
The primary endpoint was a composite outcome of stroke, systemic embolism, or new covert embolic stroke (defined as ≥1 new infarct measuring ≥15 mm on MRI) at 3 years. The primary safety endpoint was a composite outcome of fatal of major bleeding events, defined according to the International Society on Thrombosis and Haemostasis criteria.
In May 2022, the Data and Safety Monitoring Board recommended terminating the trial early because of the high likelihood that it would not demonstrate a benefit for rivaroxaban over aspirin.
Main results
- The primary endpoint occurred in 5 of 641 patients treated with rivaroxaban (annualized risk: 0.31%) and 9 of 643 patients receiving aspirin (annualized risk: 0.66%) (relative risk (RR): 0.56; 95%CI: 0.19–1.65; P=0.28). These events were mostly strokes (annualized risk: 0.31% vs. 0.58%; RR: 0.72; 95%CI: 0.23–2.25).
- There was no systemic embolism, and covert embolic stroke was observed in 2 patients in the aspirin arm (annualized risk: 0.08%) and none of the rivaroxaban-treated patients.
- New cerebral infarcts measuring <15 mm on MRI occurred in 22 of 568 patients (3.9%) in the rivaroxaban group and 26 of 590 patients (4.4%) in the aspirin group (RR: 0.89; 95%CI: 0.51–1.55).
- This meant that 96% of the participants had no new infarct of any size on MRI at 3-year follow-up.
- The cumulative incidence of fatal or major bleeding events did not differ between the rivaroxaban and aspirin groups (1.6% vs. 0.6%; HR: 2.51; 95%CI: 0.79–7.95).
- However, rivaroxaban did increase the cumulative event rates of clinically relevant nonmajor bleeding (HR: 3.51; 95%CI: 1.75–7.03) and minor bleeding (HR: 3.71; 95%CI: 2.29–6.01) compared with aspirin.
Conclusion
Rivaroxaban treatment did not reduce the risk of the composite outcome of stroke, systemic embolism, or new covert embolic stroke compared with aspirin in patients who had undergone successful AF catheter ablation ≥1 year prior and had increased stroke risk. Although there was no difference in the occurrence of major bleeding events between the groups, rivaroxaban did increase the risks of clinically relevant nonmajor and minor bleeding events. Dr. Verma pointed out that in this trial, “the annualized rate of stroke, systemic embolism, and covert stroke is very low after successful AF ablation and falls below the threshold for OAC.”
- Our reporting is based on the information provided at the AHA Scientific Sessions 2025 and publication of the data in N Engl J Med. -