Use of Intracardiac Compared With Transesophageal Echocardiography for Left Atrial Appendage Occlusion in the Amulet Observational Study

Objectives: The aim of this study was to compare patient and procedural characteristics, clinical events, and left atrial appendage (LAA) occlusion rates among implantation procedures guided either by intracardiac echocardiography (ICE) or by transesophageal echocardiography (TEE) in the Amulet Observational Study. Background: TEE is standard for intraprocedural imaging during LAA occlusion. ICE is an alternative enabling local rather than general anesthesia. Methods: The Amulet Observational Study is a prospective, multicenter, post-market study of the Amulet device in patients with atrial fibrillation at risk for thromboembolism from the LAA. Procedures were guided by ICE in the left atrium or TEE. A clinical events committee adjudicated serious adverse events. LAA closure was assessed by a core laboratory 1 to 3 months post-implantation. Results: Nine hundred fifty-five procedures were TEE guided and 130 (12%) were ICE guided. Local anesthesia was used in 93% of ICE-guided cases. Implantation success was >99% in both groups (p = 1.00). The procedure was longer (40 ± 31 min vs. 33 ± 21 min; p = 0.01) and contrast use higher (145 ± 157 ml vs. 98 ± 76 ml; p < 0.01) for ICE cases. LAA closure rate was 100% using ICE and 98% using TEE. Vascular access serious adverse events occurred in 0.8% of ICE patients and 1.5% of TEE patients (p = 0.52). Pericardial effusions or tamponade was observed at rates of 2.5% per year and 1.7% per year in ICE and TEE patients, respectively (p = 0.57). Rates of ischemic stroke (4.1% per year vs. 2.6% per year; p = 0.37) and major bleeding (8.2% per year vs. 10.6% per year; p = 0.44) did not differ significantly between ICE and TEE patients. Conclusions: Amulet LAA occlusion procedures guided by ICE and TEE resulted in comparable clinical event and LAA closure rates, without differences in procedural or vascular complications despite longer procedures and more contrast use.