Comparative Profiles of the WATCHMAN™ and Amplatzer™ Cardiac Plug/Amplatzer™ Amulet™ Devices for Left Atrial Appendage Closure in Non-valvular Atrial Fibrillation: A Comprehensive Systematic Review and Meta-analysis.

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia marked by irregular and frequent tachycardic rhythms in the atria, affecting 1%-2% of the general population. The WATCHMAN™ device from Boston Scientific (Marlborough, MA, USA) and the Amplatzer™ Amulet™ device from Abbott (Chicago, IL, USA) are two devices used globally for left atrial appendage closure (LAAC) in non-valvular AF. A systematic search was conducted in PubMed, the Cochrane Library, and Elsevier's ScienceDirect literature databases to identify studies comparing the WATCHMAN™ procedure with Amulet™ device implantation for LAAC in patients with AF. The analyses were conducted using the random-effects model. A total of 20 studies were identified, with 18 falling into the category of observational studies and 2 being randomized controlled trials. A total of 6310 participants were included in this meta-analysis, with 3198 individuals (50.68%) assigned to the WATCHMAN™ procedure group and 3112 individuals (49.32%) allocated to the Amplatzer™ Cardiac Plug (ACP) group. The analysis revealed a higher risk of stroke associated with the WATCHMAN™ technique (relative risk [RR], 1.14), albeit without statistical significance. Conversely, the WATCHMAN™ approach led to a significantly lower risk of cardiac death (RR, 0.44; P = .04). Notably, the risks of all-cause mortality (RR, 0.89; 95% confidence interval [CI], 0.73-1.08; I 2 = 0%; P = .25) and major bleeding (RR, 0.93; 95% CI, 0.65-1.33; I 2 = 31%; P = .70) were clinically reduced with the WATCHMAN™ procedure, although statistical significance was not achieved. Compared to Amulet™ device implantation, WATCHMAN™ device implantation decreased the risk of cardiac mortality, while the risks of stroke, systemic embolism, all-cause mortality, and major bleeding were not statistically significant.

Feasibility of Amulet occluder implantation after failed left atrial appendage occlusion attempt: Insights from the EMERGE LAA postapproval study.

BACKGROUND: Although expertise in left atrial appendage occlusion (LAAO) has grown, certain intricate anatomies may pose challenges, rendering them unsuitable for LAAO with the selected device. OBJECTIVE: This analysis aimed to characterize outcomes of patients with prior failed percutaneous LAAO procedures who underwent a subsequent attempt with an Amulet occluder in the EMERGE LAA postapproval study. METHODS: Patients enrolled in the National Cardiovascular Data Registry LAAO Registry who had an Amulet occluder implantation attempt between Food and Drug Administration approval (August 14, 2021) and June 30, 2023, were evaluated. A safety end point through 7 days or hospital discharge (whichever was later) and major adverse events through 45 days were reported. RESULTS: A total of 8591 patients underwent attempted Amulet occluder implantation, of whom 244 patients had prior failed LAAO. Implantation success was 88.9% and 96.2% in patients with prior failed LAAO and index LAAO, respectively (P < .001). The safety composite end point was low, occurring in 1.6% and 0.8% of patients with prior failed LAAO and index LAAO, respectively (P = .148). Any major adverse event through 45 days occurred in 7.4% and 6.3% of prior failed LAAO and index LAAO patient cohorts, respectively (P = .497); most adverse events were similar between the groups (P > .05). At 45 days, peridevice leak ≤3 mm was achieved in >90% of patients in either group. CONCLUSION: A high degree of implantation success with a low rate of adverse events can be achieved with the Amulet occluder. The findings imply that the dual occlusive mechanism Amulet occluder facilitates successful closure, even in challenging anatomic scenarios.

Safety of Amulet Left Atrial Appendage Occluder and Watchman Device for Left Atrial Appendage Closure in Patients With Atrial Fibrillation.

BACKGROUND: Left atrial appendage (LAA) closure is an alternative to chronic anticoagulation for stroke prevention in patients with nonvalvular atrial fibrillation. Multiple devices were used for LAA closure, with the Amplatzer Amulet LAA Occluder (Abbott, Chicago, IL, USA) and Watchman device (Boston Scientific, Marlborough, MA, USA) being the most commonly used in clinical practice. In August 2021, the FDA approved the use of the Amplatzer Amulet LAA Occluder. There is still a knowledge gap in the safety profile of the Amplatzer Amulet LAA Occluder device in comparison to the Watchman device. OBJECTIVE: The aim of this study was to assess and compare the safety profile peri-procedure and post-procedure between the Amplatzer Amulet LAA Occluder and Watchman devices. METHODS: Patients who underwent LAA closure using Watchman or Amulet devices from July 2015 to August 2020 at the American University of Beirut Medical Center were included in the analysis. Primary endpoints included peri-operative and post-procedural complications (thromboembolic events, bleeding complications, vascular access complications, pericardial effusion/tamponade, device positional complications and in-hospital death). RESULTS: The study included 37 patients (21 had Watchman devices, 16 had Amplatzer Amulet LAA Occluder devices, and 28 were men, mean age 76.57 ± 9.3 years). Seven patients developed post-procedural iatrogenic atrial septal defects (four in the Watchman group vs three in the Amulet group, p-value=0.982). Three patients developed pericardial effusion (one in the Watchman vs two in the Amulet group, p-value=0.394). Only one patient developed peri-device leak (one in the Watchman group vs none in the Amulet group, p-value=0.283). One device could not be deployed (one in the Amulet group vs none in the Watchman group, p-value=0.191). None of the patients developed in-hospital death, cardiac tamponade, device embolism, device thrombosis, stroke/transient ischemic attack (TIA), cranial bleeding, or arrhythmias after the procedure. The rate of peri-operative complications was similar between both groups. Both groups displayed low rates of adverse events in the peri-operative and post-operative periods. CONCLUSION: There was no significant difference in the safety profile of Amplatzer Amulet LAA Occluders and Watchman devices. There was a low incidence of peri-operative and post-operative adverse events with the implanted devices.

Inter-atrial septal balloon dilation to facilitate intracardiac echocardiography guided left atrial appendage occlusion.

INTRODUCTION: Percutaneous left atrial appendage occlusion (LAAO) is traditionally performed under general anesthesia with trans-esophageal echocardiography guidance. Intracardiac echo (ICE)-guided LAAO closure is increasing in clinical use. The ICE catheter is crossed into LA via interatrial septum (IAS) after the septum is dilated with LAAO delivery sheath. This step can be time-consuming and requires significant ICE catheter manipulation, which increases the risk of cardiac perforation. Pre-emptive septal balloon dilation can potentially help with ICE advancement in the LA. We sought to evaluate the effect of pre-dilation of the IAS with an 8 mm balloon on the ease of crossing the ICE catheter, fluoroscopy time for crossing, and overall procedure time. METHODS: The Piedmont LAAO registry was used to identify consecutive patients who underwent LAAO. The initial 25 patients in whom balloon dilation of the IAS was performed served as the experimental cohort, and the 25 consecutive patients before that in whom balloon dilation was not performed served as controls. In the experimental group, after a trans-septal puncture, the sheath was retracted to the right atrium with a guidewire still in the LA. An 8 × 40 mm Evercoss™ over the wire balloon was inflated across the IAS. The ICE catheter was then crossed into the LA using the fluoroscopic landmark of the guide wire and the ICE imaging. The sheath was then advanced along the ICE catheter via the transseptal puncture (TSP) and the procedure continued. Follow-up compputed tomography imaging was obtained at 4-8 weeks. RESULTS: Each group consisted of 25 patients. There were no significant differences in baseline characteristics. All procedures were performed successfully under conscious sedation and ICE guidance. There was a significant reduction in the overall procedure time, fluoroscopy time, and time for transseptal puncture to ICE in LA. There was no difference in the size of the acute residual interatrial shunt, as measured via ICE, or the size and presence of iatrogenic ASD at follow-up. CONCLUSION: Balloon dilation of TSP is safe and is associated with increased efficiency in ICE-guided LAAO procedures.

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

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.

Pattern of Endothelialization in Left Atrial Appendage Occluder by Optic Coherence Tomography: A Pilot Study.

BACKGROUND: Implantation of the left atrial appendage occluder (LAAO) has been proven to prevent stroke effectively in patients with atrial fibrillation who cannot tolerate anticoagulants. Incomplete endothelization of LAAO may cause device-related thrombus, and currently no good image modality exists to clearly see LAAO endothelialization. We aimed to use coronary optic coherence tomography (OCT) to visualize LAAO endothelialization. METHODS AND RESULTS: We enrolled 14 patients (72.8±9.4 years old) undergoing pulmonary vein isolation with a preexisting LAAO implanted more than 1 year ago (5 Watchman and 9 Amulet). After pulmonary vein isolation, we did OCT via steerable sheath and coronary guiding catheter to adjust OCT probe location and injected contrast medium to visualize the LAAO surface. In vitro testing was also performed to see the bare occluder. In vitro OCT showed the surface of the bare device as an interrupted granule pattern, which included the Watchman surface polytetrafluoroethylene membrane string, Amulet disc metal strut, and inner polytetrafluoroethylene membrane string. In the implanted Watchman, OCT showed endothelialization as a smooth surface layer with noninterrupted coarser granules. In the implanted Amulet, OCT showed endothelialization as thin (early) or thick (late) endothelialization layer covering struts with OCT shadows. Among patients with Watchman, 2 showed no, 2 early, and 1 complete endothelialization. Among patients with Amulet, 2 showed no, 3 early, and 4 late endothelialization. CONCLUSIONS: We demonstrated the feasibility of OCT to visualize LAAO endothelization with high resolution. Further studies are needed to determine antithrombotic regimens if incomplete endothelization is detected. A new OCT catheter may be designed specifically for LAAO.