Abstract Body (Do not enter title and authors here): Background: Left atrial appendage occlusion (LAAO) and catheter ablation (CA) for atrial fibrillation (AF) have been increasingly performed in combination. However, the effects of this combined procedure remain unknown.

Hypothesis: Combined LAAO and CA improves outcomes of patients with AF relative to isolated LAAO.

Aims: To compare the outcomes of combined LAAO and CA with isolated LAAO in patients with AF.

Methods: PubMed, Embase, and Cochrane Library were systematically searched from inception to March 2024 to identify studies comparing combined LAAO and CA versus isolated LAAO. We pooled odds ratios (OR) with 95% confidence intervals (CI) for binary endpoints. Statistical analyses were performed using R software version 4.3.1.

Results: We included eight retrospective studies comprising 51,802 patients, of whom 1,375 (2.6%) received the combined procedure, and 29,696 (57.3%) were men. Mean age of patients ranged from 63.6 to 71.4 years. Follow-up ranged from 1 to 37.6 months. Additionally, 626 (1.2%) patients had paroxysmal AF and 757 (1.4%) had persistent AF. There were no significant differences between the combined procedure and LAAO alone in terms of major bleeding (OR 0.55; 95% CI 0.09 to 3.41; p=0.52; Figure 1A), stroke (OR 1.03; 95% CI 0.35 to 3.00; p=0.96; Figure 1B), or pericardial effusion (OR 1.18; 95% CI 0.60 to 2.33; p=0.63; Figure 1C).

Conclusion: In this meta-analysis, there were no significant differences in major bleeding, stroke, or pericardial effusion when comparing combined LAAO and CA with isolated LAAO.