The anticoagulation one year after ablation of atrial fibrillation in patients with atrial fibrillation (ALONE-AF) trial: Study protocol

Background: The ideal long-term antithrombotic strategy for patients after successful catheter-based atrial fibrillation (AF) ablation is still uncertain. Presently, practices vary, and the advantages of oral anticoagulation (OAC) for the post-ablation population are not clearly established. To date, no randomized trials have addressed this therapeutic question. This study aimed to evaluate whether no OAC therapy is superior to apixaban in reducing the risk of stroke, systemic embolism, or major bleeding among patients without apparent recurrent atrial arrhythmias for at least 1 year after their AF ablation procedure. Methods: The ALONE-AF trial is a prospective, multicenter, open-label, randomized study with blinded outcome assessment. Patients with AF who have at least one non-gender stroke risk factor (as determined by the CHA2DS2-VASc score) and no documented recurrences of atrial arrhythmia for at least 12 months post-ablation will be randomly assigned to apixaban 5 mg b.i.d. or no OAC therapy. The primary endpoint is a composite outcome of stroke, systemic embolism, and major bleeding. Key secondary outcomes include clinically relevant non-major bleeding, all-cause mortality, myocardial infarction, transient ischemic attack, quality of life, and frailty analysis. Participants will be followed for a period of 2 years. The estimated total sample size is 840 subjects, with 420 subjects in each arm. Conclusion: The ALONE-AF trial aims to provide robust evidence for the optimal anticoagulation strategy for patients with stroke risk factors following successful AF ablation.