Residual Thromboembolic Risk and Outcomes of Oral Anticoagulation Discontinuation After Atrial Fibrillation Ablation: A Target Trial Emulation

BACKGROUND AND AIMS: Optimal management of oral anticoagulation (OAC) after atrial fibrillation (AF) ablation remains uncertain. We evaluated thromboembolic and bleeding outcomes associated with OAC discontinuation versus continuation at a clinically relevant 6-month post-ablation landmark. METHODS: This target trial emulation used data from a multicentre prospective registry in China. Patients with CHA2DS2-VA scores ≥2, no prior thromboembolism, and no atrial arrhythmia recurrence within 6 months after ablation were classified according to OAC discontinuation or continuation at the 6-month landmark. The primary outcome was the composite of stroke, systemic embolism, and major bleeding. Inverse probability weighting was applied, with intention-to-treat as the primary analysis. RESULTS: Among 8,339 patients (mean age 68 years; 40.5% women), 4,406 discontinued and 3,933 continued OAC. The risk of the primary outcome did not differ significantly between groups (weighted HR 0.93; 95% CI 0.67-1.29). Thromboembolic risk was similarly comparable (HR 0.96; 95% CI 0.69-1.35). Clinically relevant non-major bleeding occurred less frequently after OAC discontinuation (HR 0.68; 95% CI 0.47-0.97). Findings were consistent in sensitivity analyses. Annualized thromboembolic rates after discontinuation were <1% in patients with CHA2DS2-VA scores 2-3 but 1.52% in those with scores ≥4. CONCLUSIONS: Among patients without prior thromboembolism who remained arrhythmia-free at 6 months after AF ablation, OAC discontinuation was not associated with a difference in the composite outcome of stroke, systemic embolism and major bleeding, compared with OAC continuation. Residual risk remained low in patients with CHA2DS2-VA scores 2-3 but exceeded conventional thresholds in those with scores ≥4.