Abstract
Left atrial appendage occlusion (LAAO) offers an alternative to oral anticoagulation for stroke prevention in atrial fibrillation. We performed a systematic review and meta-analysis comparing Watchman (Boston Scientific Corporation, Marlborough, MA) with oral anticoagulants (OACs) and alternative LAAO devices. PubMed, EBSCO, and ClinicalTrials.gov were searched (January 2005 to August 2025) for randomised trials and observational studies comparing Watchman with OACs or other devices in adults with atrial fibrillation (minimum one-month follow-up). Twenty-one studies (eight randomised, 13 observational; n=12,357) were analysed. Results reflect combined randomised and observational evidence, with heterogeneity addressed using random-effects models. Most comparators were warfarin; DOAC-specific data were limited. Versus OACs, LAAO reduced transient ischaemic attack (odds ratio (OR) 0.72), haemorrhagic stroke (OR 0.41), all-cause mortality (OR 0.73), and cardiovascular mortality (OR 0.57), with similar ischaemic stroke rates (OR 1.09). Ten studies contributed device-device comparisons. Versus other devices, Watchman had fewer complications (OR 0.67) but more major peridevice leaks (OR 1.84). Watchman showed a consistently more favourable safety profile compared to others. Device-related complications were significantly lower (OR 0.67), including markedly reduced device embolisation (OR 0.45) and procedural bleeding (OR 0.68). Watchman also demonstrated fewer major procedural complications and a lower rate of pericardial effusion requiring intervention. Efficacy outcomes, including ischaemic stroke, transient ischaemic attack (TIA), haemorrhagic stroke, and systemic embolism, were comparable across devices, with no significant differences detected. Follow-up duration varied across studies, though absolute event rates remained low. Publication bias and residual confounding may influence mortality estimates, as device-generation reporting was incomplete. In conclusion, LAAO reduces haemorrhagic stroke and mortality compared with OACs while maintaining equivalent ischaemic stroke protection. Among devices, Watchman demonstrates superior procedural safety but increased leak rates.