Current approaches to the prevention of cardioembolic complications in patients with the nonvalvular atrial fibrillation

Percutaneous left atrial appendage (LAA) closure has been proposed as an alternative to long-term administration of oral anticoagulants (OACs) in non-valvular atrial fibrillation, but there is insufficient comparative evidence-based data on this issue. Objective. To analyze data from studies comparing the efficacy and safety of using left atrial appendage occluding devices and direct oral anticoagulants for the prevention of cardioembolic complications in patients with atrial fibrillation. Materials and methods. A search for randomized studies for the period up to March 1, 2025, in which devices that occlude LAA were compared with the administration of OACs, was carried out in PubMed database. The selection of studies was done using the following keywords: «atrial fibrillation», «cardioembolism», «oral anticoagulation», «left atrial appendage closure». Results. The paper considers various methods for preventing cardioembolic events in non-valvular atrial fibrillation, including OACs, LAA occlusion and factor XIa inhibitors. The largest study to date, PRAGUE-17, comparing occluder implantation with OACs, showed that mechanical occlusion of the LAA is not inferior to therapy with direct OACs for the prevention of cardioembolic events, cardiovascular mortality, clinically significant bleeding or postoperative occluder-associated complications, but safety remains an open question. Similar data on efficacy and safety in smaller randomized controlled trials included in this work also indicate comparable results of using the two methods with a tendency to superiority of LAA occlusion. Conclusion. Implantation of devices occluding the left atrial appendage as a non-pharmacological alternative in atrial fibrillation is characterized by the same efficacy and safety as the use of oral anticoagulants. Further research in larger studies is needed.