OCEAN Trial at AHA 2025: Anticoagulation After AF Ablation in High-Risk Patients

Dr. Verma: 
Hello from AHA 2025, here in New Orleans. I’m Dr. Atul Verma. I’m director of cardiology at the McGill University Health Center and I'm here today to share with you the key findings from the OCEAN trial.

So after a patient has had a successful AF ablation, one of the first questions they always ask is can I stop my blood thinner? And it was really based on that question that we decided to go ahead with this trial.

So what we did was we took 1,284 patients who were at least 1 year after a successful AF ablation. And what we did was we randomized them either to continue on oral anticoagulation with rivaroxaban or stop oral anticoagulation and go on aspirin.

All the patients had a baseline brain MRI. And then they were followed up for 3 years, at which point they had another brain MRI. Our primary outcome was a composite of stroke, systemic embolism, and covert stroke detected on MRI, and these are large embolic strokes that had to be greater than 15 mm. What we found in our patient characteristics is that this was a very typical AF ablation population. These patients were about 66 years old. They had a mean CHADS-VASC score of 2.2 and 30% of the patients had a CHADS-VASC score of 3 or more.

In terms for our primary outcome, we found that regardless of which group these patients were randomized to, the rate of our primary outcome was very low. In fact, it was extremely low. In the rivaroxaban arm, there were only 5 events in more than 600 patients. And in the aspirin arm, there were only 9 events out of more than 600 patients. So this meant that the annual rate of stroke, systemic embolism, or covert stroke was only about 0.3% in the rivaroxaban arm and 0.66% in the aspirin arm.

Now, you'll probably recall that the threshold for anticoagulation in atrial fibrillation is about 1% to 2% per year, so both of these groups were well under that.

In terms of bleeding risk, rivaroxaban did not increase the risk of major bleeding, but it did increase the risk of clinically relevant non-major bleeding and minor bleeding.

So in summary, I think the take-home message is that in patients who've had a successful AF ablation, and they have a CHADS-VASC score of 1, 2, or even 3, these patients can probably stop their oral anticoagulation and either go on aspirin or perhaps even nothing. For higher-risk patients, well, we didn't have a lot of those, and so our trial may not be directly relevant to those people.

So from AHA 2025, I'm Dr. Atul Verma, and thank you very much for watching.