Discontinuing OAC After AF Catheter Ablation Reduces Bleeding Without Increasing Stroke Risk: ALONE-AF Trial
核心洞察
The ALONE-AF trial found that discontinuing oral anticoagulation one year after successful AF catheter ablation reduced the composite of stroke, systemic embolism, or major bleeding compared with continuing OAC (0.3% vs 2.2%, p=0.02).
The benefit was driven by a significant reduction in major bleeding events, with no major bleeds in the discontinuation group versus five events (1.4%) in the continuation group (p=0.03).
Stroke rates were similar between groups (0.3% vs 0.8%, p=0.34), suggesting OAC discontinuation does not increase thromboembolic risk in patients free of atrial arrhythmias post-ablation.
Discontinuing oral anticoagulation (OAC) in patients with elevated stroke risk who remain free of atrial arrhythmias one year after catheter ablation for atrial fibrillation (搜索) (AF) significantly reduces the composite risk of stroke, systemic embolism, or major bleeding compared with continuing OAC, according to findings from the ALONE-AF trial. The benefit was driven primarily by a statistically significant reduction in major bleeding events, with no increase in stroke risk observed.
The ALONE-AF (Anticoagulation One Year After Ablation of Atrial Fibrillation (搜索) in Patients With Atrial Fibrillation) trial was an open-label, randomized clinical study conducted across 18 centers in South Korea. A total of 840 patients with AF who underwent catheter ablation and remained free of recurrence of atrial arrhythmias after one year were randomized 1:1 to discontinue OAC (n=417) or continue OAC (n=423) with apixaban or rivaroxaban.
Primary Endpoint Results
In the intention-to-treat analysis at two-year follow-up, the primary composite endpoint of stroke, systemic embolism, or major bleeding occurred in one patient (0.3%) in the discontinue OAC group and eight patients (2.2%) in the continue OAC group, yielding an absolute difference of −1.9% (95% CI, −3.5 to −0.3; p=0.02).
Per-protocol analysis produced similar estimates: 0.3% in the discontinue OAC group versus 2.3% in the continue OAC group, with an absolute difference of −2.0% (95% CI, −3.7 to −0.3; p=0.023).
The number needed to treat via OAC discontinuation to prevent one primary outcome event was 53 patients (95% CI, 29 to 333 patients).
Stroke and Bleeding Outcomes
The cumulative incidence of stroke or systemic embolism at two-year follow-up was not significantly different between groups, occurring at a rate of 0.3% in the discontinue OAC group versus 0.8% in the continue OAC group (absolute difference, −0.5%; 95% CI, −1.6 to 0.6; p=0.34).
In contrast, major bleeding events showed a significant difference favoring OAC discontinuation. No major bleeding events occurred in the discontinue OAC group, compared with five events (1.4%) in the continue OAC group, for an absolute difference of −1.4% (95% CI, −2.6 to −0.2; p=0.03). One of these events was a permanently disabling hemorrhagic stroke.
Clinically relevant nonmajor bleeding occurred in five patients (1.4%) in the no-OAC group versus seven patients (1.9%) in the OAC group. There were no reported cases of all-cause mortality or myocardial infarction in either group. Approximately 10% of patients experienced AF recurrence and restarted anticoagulation.
Study Limitations and Population Considerations
The trial has several important limitations. The open-label design can introduce both ascertainment and reporting bias. The overall event rate was low and skewed toward a higher absolute number of bleeding events, which may bias the composite endpoint. In subgroup analysis, a statistically significant difference was not observed among patients younger than 65 years (46.9% of the study population) or in women (24.9%).
Additionally, most participants were of East Asian descent, and only 30.5% of patients had a CHA₂DS₂-VASc score greater than 2, with a mean score of 2.1. Patients with higher CHA₂DS₂-VASc scores, who carry both elevated thromboembolic and bleeding risk regardless of OAC intake, have not been extensively evaluated in randomized trials.
Context Within the Broader Evidence Landscape
The ALONE-AF findings align with results from the ODIn-AF and OCEAN trials, which together open the pathway for OAC discontinuation after AF ablation. The ODIn-AF trial found no difference in cerebral embolic events when comparing OAC with dabigatran to OAC discontinuation in patients with a mean CHA₂DS₂-VASc score of 2.6. The OCEAN trial demonstrated that in patients with a mean CHA₂DS₂-VASc score of 2.2 and successful AFCA one year earlier, rivaroxaban did not result in a significantly lower incidence of the composite of stroke, systemic embolism, or new covert embolic stroke compared with aspirin.
Ongoing trials are now evaluating individualized OAC management guided by documented AF recurrences detected through continuous rhythm monitoring using implantable loop recorders, as in the POCKET-OAC trial, or wearable technologies such as smartwatches, as in the DIAMOND-AF and REACT-AF trials. These results have the potential to inform future guideline updates and significantly influence contemporary clinical practice.
As the study authors note, more research is required prior to establishing clinical practice guidelines, but the ALONE-AF trial provides continuing evidence supporting the discontinuation of long-term anticoagulation in patients post-AFCA who remain free of atrial arrhythmias in the year following their indexed ablation.