·The related articles were obtained from PubMed, Embase, Cochrane Library, Wanfang database and CNKI, from the establishment of databases to July 2020. English retrieval method was as follows: ("atrial fibrillation" or "AF" or "nonvalvular AF") and ("left atrial appendage closure" or "LAAC") and ("new oral anticoagulants" or "NOAC" or "novel oral anticoagulants" or "non-vitamin K antagonist oral anticoagulants" or "warfarin"). Chinese keywords were "心房颤动""左心耳封堵术""新型口服抗凝剂" and "华法林". The articles were screened according to inclusion and exclusion criterias, and the quality evaluation and data extraction were carried out. The RevMan 5.3 software was used for meta-analysis of the data. The primary efficacy and safety endpoints were the incidence of embolism events, bleeding events, all-cause mortality events and sudden cardiac death (SCD).

·Finally, nine articles was included, including three randomized controlled trials and six non-randomized controlled trials, consisting of 2 429 patients. The result of meta-analysis showed that there was no significant difference in compound embolism events in patients with AF treated with LAAC, compared with oral anticoagulant therapy (OR=0.90, 95%CI 0.62?1.31, P=0.59). There was no significant difference in all-cause mortality events in patients with AF treated with LAAC, compared with oral anticoagulant therapy (OR=1.11, 95%CI 0.48?2.59, P=0.81). There was no significant difference in SCD patients with AF treated with LAAC, compared with oral anticoagulant therapy (OR=0.90,95%CI 0.38?2.11, P=0.81). Compared with warfarin and NOAC, the incidence of bleeding events in patients treated with LAAC was decreased significantly (OR=0.48, 95%CI 0.35?0.65, P=0.000).

·There is no significant difference in embolism and death in patients of non-valvular AF treated with LAAC, compared with oral anticoagulants. But it has a lower risk of bleeding.