First Experience With Amulet in the United States: Early Insights From EMERGE LAA Postapproval Study

Abstract

Background: The Food and Drug Administration approved the Amulet occluder (Abbott) after demonstrating safety and effectiveness in the Amulet IDE (AMPLATZER Amulet LAA Occluder) trial. Objectives: The aim of the EMERGE Left Atrial Appendage study is to evaluate early postapproval outcomes of the Amulet occluder in the United States using data from the National Cardiovascular Data Registry Left Atrial Appendage Occlusion Registry. Methods: Patients with a commercial Amulet occluder implant attempt between Food and Drug Administration approval (August 14, 2021) and December 31, 2022, were included. The safety composite endpoint included all-cause death, ischemic stroke, systemic embolism, or device/procedure-related events requiring open cardiac surgery or endovascular intervention between device implantation and 7 days or hospital discharge (whichever is later). Major adverse events through 45 days were also reported and stratified by operator experience (early [<10 cases], moderate [10-29 cases], and high [30+ cases]). Results: A total of 5,499 patients underwent attempted Amulet occluder implantation. Implant success was 95.8%, and complete closure was 97.2% post–left atrial appendage occlusion and 87.1% at 45 days. A safety composite endpoint event occurred in 0.76% patients. Any major adverse event occurred in 2.9% and 5.7% of patients in-hospital and through 45 days, respectively, driven by major bleeding and pericardial effusion (PE) requiring intervention. PE requiring surgery or percutaneous intervention decreased significantly with increasing experience both in-hospital (early vs high operator experience 1.8% vs 1.1%; P = 0.006) and at 45 days (2.3% vs 1.5%; P = 0.012). Conclusions: The EMERGE Left Atrial Appendage study demonstrates favorable safety and effectiveness of the Amulet occluder in the real-world setting. More experienced operators had improved implant success and fewer PEs, suggesting a learning curve effect implanting this dual occlusive mechanism device.