Left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation: a systematic review and network meta-analysis of randomized controlled trials

INTRODUCTION: Atrial fibrillation (AF) is one of the leading causes of stroke. Risks associated with oral anticoagulation (OAC) limit adherence to recommended therapy. Left atrial appendage (LA) occlusion is a treatment alternative in patients with AF. We performed a network meta-analysis (NMA) of randomized trials evaluating the efficacy of LAA occlusion compared with oral anticoagulant, antiplatelet, and placebo for stroke prevention. We also assessed the impact of LA occlusion on mortality, major bleeding, and operative time. EVIDENCE ACQUISITION: We searched MEDLINE, EMBASE, PubMed, and Cochrane Library for randomized trials comparing percutaneous or surgical LA occlusion with standard of care in AF patients. EVIDENCE SYNTHESIS: Conventional meta- analysis found no difference between groups for stroke (5 trials, 1285 patients; RR 0.78, 95% CI 0.47-1.29), and a significant reduction in mortality (5 trials, 1285 patients; RR 0.71, 95% CI 0.51-0.99) favouring LAA occlusion. NMA demonstrated a trend towards reduction in stroke (OR 0.84, 95% CrI 0.47-1.55) and mortality (OR 0.69, 95% CrI 0.44-1.10) for LA occlusion versus warfarin, but no statistically significant effect. Statistical ranking curves placed LAA occlusion as the most efficacious treatment on the outcomes of stroke and mortality when compared to warfarin, aspirin, or placebo. No significant differences between groups were seen in major bleeding or operative time for surgical trials. The overall quality of the evidence was low as assessed by GRADE. CONCLUSIONS: LAA occlusion appears to preserve the benefits of OAC therapy for stroke prevention in patients with AF, but the current evidence is of low quality.