Abstract Body (Do not enter title and authors here): Background: Left atrial appendage occlusion (LAAO) is an alternative primary stroke prevention strategy for patients with atrial fibrillation (AF) who cannot tolerate anticoagulation (AC). Following LAAO implantation, patients typically undergo testing after 45 days to confirm successful occlusion and potentially discontinue AC. Some patients with LAAO may require cardioversion (CVN) due to recurrent AF. However, data is limited on whether post-CVN management in these patients should mirror that of patients without LAAO. Therefore, we report the outcomes of patients with LAAO who underwent CVN and were empirically treated with or without AC post-CVN.

Methods: Using the TriNetX database, we identified patients aged ≥ 18 years who had LAAO, underwent CVN, and were not on AC prior to the procedure. Patients were included if they received AC for at least 4 weeks after CVN (AC group) or did not receive AC (Non-AC group). Propensity score matching was performed to adjust for confounders between the two groups. Thromboembolic and bleeding outcomes were assessed at 1 year post-CVN.

Results: Among 1,086 patients, 84 (7.7%) received anticoagulation after CVN. After propensity score matching, 158 patients (79 in each group) were included, with a mean age of 71.8 ± 11.3 years (49% female) in the AC group and 70.6 ± 12.5 years (39% female) in the Non-AC group. At 1 year, the incidence of composite thromboembolic events was similar between the AC and Non-AC groups (12.7% vs. 12.7%; OR = 1.00, 95% CI: 0.39-2.55). Most thromboembolic events occurred within 2 weeks post-CVN. There were no significant differences in the composite outcomes of intracranial bleeding, gastrointestinal bleeding, or need for blood transfusion between the AC and Non-AC groups at 1 year (OR = 0.86, 95% CI: 0.30-2.25).

Conclusion: Data suggest that most patients with LAAO do not receive AC after CVN. Additionally, the use of anticoagulation post-CVN in patients with LAAO did not statistically reduce thromboembolic events nor increase bleeding risk.