SCAI/HRS Technical Review on Transcatheter Left Atrial Appendage Occlusion.

Background: Nonvalvular atrial fibrillation (NVAF) is associated with an increased risk of stroke due to thrombus formation in the left atrial appendage, where over 90% of thrombi originate. While oral anticoagulation (OAC) is the standard therapy for stroke prevention, many patients cannot tolerate long-term OAC due to bleeding risks. Percutaneous left atrial appendage occlusion (LAAO) has emerged as an alternative strategy. Despite its rapid adoption, substantial variability exists in clinical practice regarding patient selection, imaging techniques, procedural guidance, and postprocedural management. This systematic review aims to collect and synthesize evidence to inform the development of new Society for Cardiovascular Angiography & Interventions (SCAI) and the Heart Rhythm Society (HRS) guidelines on LAAO. Methods: We searched PubMed, Embase, and Cochrane Library from inception through January 5, 2024, for studies of the percutaneous LAAO procedure. Eligible studies were conducted in adults with NVAF undergoing LAAO, or with peridevice leak or device-related thrombus after an occlusion procedure. Studies of surgical LAAO, double device or combined procedures, and devices that are not currently marketed in the United States were excluded. Data were extracted from studies in duplicate and summarized using meta-analysis and narrative synthesis. Risk of bias (RoB) was assessed using the RoB in nonrandomized studies of interventions tool, and version 2 of the Cochrane RoB tool for randomized trials (RoB 2.0). Overall certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Results: Our search identified 3769 titles and abstracts, of which 27 studies met eligibility criteria and contributed data to the analysis. Data were abstracted to address outcomes of LAAO for stroke prevention in patients with NVAF, in comparison to OAC, no therapy, and across various approaches including preprocedure imaging, intraprocedure guidance, and postprocedure antithrombotic regimens. Conclusions: Left atrial appendage occlusion is an effective alternative to OAC for stroke prevention in NVAF patients with bleeding risks, but uncertainties remain regarding imaging strategies and postprocedural management.