The long-term necessity of oral anticoagulant therapy following successful catheter ablation for atrial fibrillation (AF) remains a key clinical question. The OCEAN trial provides new data, finding no significant difference between rivaroxaban and aspirin for a composite embolic endpoint in this patient population.¹

OCEAN was an international, open-label, randomised trial with blinded outcome assessment. It enrolled 1284 patients who had undergone successful catheter ablation for AF at least one year prior and had a CHA₂DS₂-VASc score of 1 or more (or ≥2 for women or patients with vascular disease as a risk factor).¹

Participants were randomly assigned to receive either rivaroxaban (15 mg daily) or aspirin (70–120 mg daily) and were followed for three years. The primary outcome was a composite of stroke, systemic embolism, or new covert embolic stroke, defined as a new infarct of ≥15 mm on magnetic resonance imaging (MRI) at 3 years.¹

A total of 641 patients were assigned to the rivaroxaban group and 643 to the aspirin group. The primary outcome occurred in 5 patients (0.31 events per 100 patient-years) receiving rivaroxaban compared to 9 patients (0.66 events per 100 patient-years) receiving aspirin (relative risk, 0.56; 95% confidence interval [CI], 0.19 to 1.65; P=0.28).¹

The absolute risk difference at three years was −0.6 percentage points (95% CI, −1.8 to 0.5), which was not statistically significant. For the primary safety outcome, fatal or major bleeding occurred in 10 patients (1.6%) in the rivaroxaban group and in 4 patients (0.6%) in the aspirin group (hazard ratio, 2.51; 95% CI, 0.79 to 7.95).¹

New cerebral infarcts measuring less than 15 mm occurred in 3.9% of patients in the rivaroxaban group and 4.4% in the aspirin group (relative risk, 0.89; 95% CI, 0.51 to 1.55).¹

Among patients with stroke risk factors who had a successful AF ablation at least one year earlier, treatment with rivaroxaban did not result in a significantly lower incidence of the primary composite outcome compared with aspirin. A numerically higher, though not statistically significant, rate of major bleeding was observed with rivaroxaban. These findings suggest that de-escalation of antithrombotic therapy to aspirin may not be inferior to continued anticoagulation in this specific patient cohort, though bleeding risks must be considered.

This study was funded by Bayer, Abbott, Biotronik, the Canadian Institutes of Health Research, the University of Ottawa Heart Institute Accelerate funding program, the Canadian Stroke Prevention Intervention Network, the Brain-Heart Interconnectome Canada First Research Excellence Fund, and the Rosenfeld Heart Foundation.

References

1. Verma A, Birnie DH, Jiang C, et al. Antithrombotic Therapy after Successful Catheter Ablation for Atrial Fibrillation. N Engl J Med. 2025. Published online November 8, 2025. https://doi.org/10.1056/NEJMoa2509688.

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