Left atrial size-based anticoagulation discontinuation after catheter ablation for atrial fibrillation: a post-hoc analysis of the ALONE-AF Trial
D Kim, J Shim, E K Choi, I Y Oh, J Kim, Y S Lee, J Park, J S Ko, K M Park, J H Sung, H T Yu, T H Kim, J S Uhm, H N Pak, B JoungAbstract
Background
In the ALONE-AF (Anticoagulation One year after Ablation of Atrial Fibrillation in Patients with Atrial Fibrillation) randomized trial, discontinuation of oral anticoagulant (OAC) therapy in patients without recurrent atrial arrhythmia following ablation for atrial fibrillation (AF) resulted in a net clinical benefit, compared with continued OAC therapy.
Objective
This post-hoc analysis of the ALONE-AF trial aimed to evaluate the optimal OAC strategy after ablation among patient groups stratified by left atrial diameter (LAD), a commonly used index of atrial remodeling.
Methods
The ALONE-AF trial enrolled patient with AF who had at least 1 non–sex-related stroke risk factor (determined using the CHA2DS2-VASc score) and no documented recurrence of atrial arrhythmia for at least 1 year after catheter ablation. The patients were randomly assigned into discontinue OAC (n = 417) or continue OAC (with direct oral anticoagulants; n = 423). In this subanalysis, patients in each of the two randomly allocated groups were further divided into two groups using a median LAD of 40 mm. The cumulative incidence of the primary outcome, defined as a composite of stroke, systemic embolism, or major bleeding, was estimated at 2 years using the Kaplan–Meier method.
Results
Among 840 patients, 396 and 444 had a LAD<40 mm (mean age 64.4±8.1 years, 29.8% female) and ≥40 mm (mean age 63.8±8.1 years, 20.5% female), respectively. At 2 years, the primary outcome occurred in 5 patients (1.4%) in the patients with a LAD<40 mm and 4 patients (1.1%) in the patients with a LAD≥40 mm (log-rank P=0.664). Among the patients with LAD<40 mm, the primary outcome occurred in the 5 patients (2.8%) of the continue OAC group only (absolute difference, –2.8 percentage points [95% CI, −5.1 to -0.4]). Among those with LAD≥40 mm, the primary outcome occurred in 1 patient (0.6%) in the discontinue OAC group and 3 patients (1.7%) in the continue OAC group (absolute difference, –1.1 percentage points [95% CI, −3.3 to 1.1]).
Conclusion
No statistically significant differences in outcomes were observed between OAC strategies across LA diameter strata. These findings suggest that post-ablation anticoagulation decisions may hinge more on sustained arrhythmia-free status than on atrial structural remodeling, supporting an individualized strategy with systematic rhythm surveillance.