Left atrial appendage closure using the Amulet device: an initial experience with the second generation amplatzer cardiac plug

Risk factors, clinical implications, and management of peridevice leak following left atrial appendage closure: A systematic review

BACKGROUND

Left atrial appendage closure (LAAC) is a treatment modality for stroke prevention in patients with atrial fibrillation (AF). One of the potential complications of LAAC is a peri-device leak (PDL), which could potentially increase the risk of thromboembolism formation.

METHODS

This systematic review was done according to PRISMA guidelines. Using four databases, all primary studies through April 2022 that met selection criteria were included. Outcomes of interest were studies reporting on PDL characteristics, risk factors and management.

RESULTS

A total of 116 studies met selection criteria (97 original studies and 19 case reports/series). In the original studies (n = 30,133 patients), the weighted mean age was 72.0 ± 7.4 years (57% females) with a HAS-BLED and CHA2DS2-VASc weighted means of 2.8 ± 1.1 and 3.8 ± 1.3, respectively. The most common definition of PDL was based on size; 5 mm: major, 3-5 mm: moderate, < 1 mm minor, or trivial. Follow up time for PDL detection was 7.15 ± 9.0 months. 33% had PDL, irrespective of PDL severity/size, and only 0.9% had PDL of greater than 5 mm. The main risk factors for PDL development included lower degree of over-sizing, lower left ventricular ejection fraction, device/LAA shape mismatch, previous radiofrequency ablation, and male sex. The most common methods to screen for PDL included transesophageal echocardiogram and cardiac CT. PDL Management approaches include Amplatzer Patent Foramen Ovale occluder, Hookless ACP, Amplatzer vascular plug II, embolic coils, and detachable vascular coils; removal or replacement of the device; and left atriotomy.

CONCLUSION

Following LAAC, the emergence of a PDL is a significant complication to be aware of. Current evidence suggests possible risk factors that are worth assessing in-depth. Additional research is required to assess suitable candidates, timing, and strategies to managing patients with PDL.

Preoperative Planning for Structural Heart Disease

Preoperative assessment with computed tomography (CT) is critical before transcatheter interventions for structural heart disease. CT provides information for device selection, device sizing, and vascular access approach. The interpreting radiologist must have knowledge of appropriate CT protocols, how and where to obtain the important measurements, and know additional imaging characteristics that are important to describe for optimal support of the interventionalist. CT is the modality of choice for pre-operative evaluation in patients undergoing transcatheter aortic valve replacement and left atrial appendage occlusion, and is also useful before transcatheter mitral valve replacement, which is an ongoing area of research.

Short-Term Antiplatelet Versus Anticoagulant Therapy After Left Atrial Appendage Occlusion: A Systematic Review and Meta-Analysis

OBJECTIVES

The aim of this study was to compare bleeding, thromboembolic, device-related thrombus (DRT), and all-cause mortality events between patients treated with short-term oral anticoagulation (OAC) and those treated with short-term antiplatelet therapy (APT) following left atrial appendage occlusion (LAAO).

BACKGROUND

Short-term OAC is recommended for patients following LAAO. However, in practice many patients receive APT rather than OAC because of excessive bleeding risk. However, the safety and efficacy of APT compared with OAC have been debated.

METHODS

A search was conducted of databases for studies comparing OAC with APT following LAAO. The outcomes of interest were all-cause stroke, major bleeding, DRT, and all-cause mortality. Noncomparative studies were pooled into a single study to generate comparisons of the studies' outcomes. Effects measure were pooled using the random-effect model.

RESULTS

A total of 83 studies with 12,326 patients (APT, n = 7,900; OAC, n = 4,151) were included. Mean CHA2DS2-VASc and HAS-BLED scores were 4.1 ± 1.6 and 3.0 ± 1.3, respectively. There were no significance differences between the APT and OAC groups with regard to stroke (risk ratio [RR]: 1.04; 95% confidence interval [CI]: 0.54 to 1.98; p = 0.91; I2 = 31%), major bleeding (RR: 1.12; 95% CI: 0.68 to 1.84; p = 0.65; I2 = 53%), DRT (RR: 1.33; 95% CI: 0.74 to 2.39; p = 0.33; I2 = 36%), and all-cause mortality (RR: 1.29; 95% CI: 0.40 to 4.09; p = 0.18; I2 = 36%). These findings persisted in multiple secondary analyses: 1) excluding studies that reported no events; 2) including comparative studies only; 3) excluding patients who were treated with single APT; and 4) removing one study at a time to assess the effect of each study on the overall effect size. There was also no difference in the studies' endpoints among patients who received different LAAO devices.

CONCLUSIONS

In a meta-analysis of observational data, there were no differences in the occurrence of stroke, major bleeding DRT, and all-cause mortality in patients treated with short-term OAC or APT following LAAO.

Epicardial versus Endocardial Closure: Is One Better than the Other?

Left atrial appendage occlusion is an evolving technology with demonstrable benefits of stroke prophylaxis in patients with atrial fibrillation unsuitable for anticoagulation. This has resulted in the development of a plethora of transcatheter devices to achieve epicardial exclusion and endocardial occlusion. In this review, the authors summarize the differences in technique, target patient population, outcomes, and complication profiles of endocardial and epicardial techniques.

Left Atrial Appendage Occlusion: The Current Device Landscape and Future Perspectives

Since the first percutaneous left atrial appendage occlusion (LAAO), many studies have shown the safety and efficacy of this technique to prevent embolic strokes in nonvavular atrial fibrillation. The design, characteristics, and clinical data of the most frequently used devices for LAAO are reviewed, including the Amplatzer cardiac plug and Amulet (Abbott Vascular), the Watchman (Boston Scientific), and the LARIAT device (SentreHEART). Similarly, newer closer devices, such as Ultraseal (Cardia), LAmbre (Lifetech), and Coherex WaveCrest (Johnson & Johnson), are also discussed. Finally, new technologies still in the stage of preclinical study or in the initial clinical experience are also reviewed.

Initial experience of percutaneous left atrial appendage closure using the LAmbre device for thromboembolic prevention

AIMS

Stroke due to atrial fibrillation has been associated with a high risk of disability and mortality. Percutaneous left atrial appendage (LAA) closure has been established as an alternative strategy for stroke prevention in patients not eligible for oral anticoagulation. The LAmbre is a novel occluder, specifically designed for LAA closure adaptive to various LAA anatomies. The aim of this study was to demonstrate feasibility and initial experience in a nonprescreened patient cohort for LAA occlusion using the novel LAmbre occluder.

METHODS

The device was implanted in 11 patients with nonvalvular atrial fibrillation. Follow-up included transesophageal echocardiography and an outpatient visit at 6 weeks and 6 months after implantation.

RESULTS

All devices were implanted successfully. Device sizes ranged from 16/22 to 22/34 mm. Patients' mean CHA2DS2-VASc and HAS-BLED scores were 3.3 ± 1.0 and 3.2 ± 1.0, respectively. Two out of 11 patients had previously been rejected for Watchman occluder implantation by reasons of too small LAA. At 6 weeks and 6 months, there were no deaths, strokes, systemic thromboembolism or severe bleeding complications. There was no device-related thrombus or pericardial effusion seen with transesophageal echocardiography. In one out of 11 patients, a minimal peridevice flow (less than 5 mm) was present at 6-week follow-up.

CONCLUSION

The LAmbre occluder is a novel LAA-closure device with features that provide many options for LAA-closure to physicians, particularly in patients with challenging anatomies. From our initial experience, implantation is associated with a good success rate and clinical outcome.

Percutaneous Left Atrial Appendage Occlusion for the Prevention of Stroke in Patients with Atrial Fibrillation: Review and Critical Appraisal

The authors review the current status of percutaneous left atrial appendage (LAA) occlusion therapy in patients with atrial fibrillation with the goal to prevent ischemic stroke and systemic embolism and to reduce oral anticoagulation associated bleeding. While we cover the historical and also surgical background, and all tested devices, the main focus rests on the single currently U.S. Food and Drug Administration (FDA) approved LAA occluder, the WATCHMAN device, and its approval process. The authors also give a critical appraisal beyond the review of mere facts, trying to put the current data into perspective.

Safety and feasibility of interventional left atrial appendage closure without contrast agent

AIMS

Interventional left atrial appendage closure (LAAC) is routinely performed under both echocardiographic and angiographic guiding. However, adverse outcomes, e.g., kidney injury and cerebral embolism, might be associated with injections of contrast agent into the LAA. Therefore, this prospective registry investigated the safety and feasibility of LAAC without the support of angiographic images as the default approach.

METHODS AND RESULTS

This single-centre registry included a total of 46 non-selected, consecutive patients. In the first 25 patients (54%), LAAC with the Amulet device was performed routinely with LAA angiography prior to implantation and after release of the device. The following 21 patients (46%) were treated without the use of contrast agent. The combination of successful implantation and lack of procedural complications was regarded as the primary endpoint. Procedure time, number of recapture manoeuvres, change of device size, compression, leakage, dose area product and late thrombosis on the device were investigated as secondary endpoints. Besides the longer fluoroscopy time and duration of the procedure in the group using angiography, no significant differences could be found. Major complications occurred equally often in both cohorts.

CONCLUSIONS

Interventional LAAC with the Amulet device can be performed safely without the use of contrast agent. This approach might help to enhance the use of LAAC in patients at high risk of contrast-induced nephropathy and procedural stroke.

Left atrial appendage occlusion with the AMPLATZER Amulet device: periprocedural and early clinical/echocardiographic data from a global prospective observational study

AIMS

The global, prospective AMPLATZER Amulet observational study documents real-world periprocedural, transoesophageal echocardiographic (TEE) and clinical outcomes from left atrial appendage occlusion (LAAO) using the AMPLATZER Amulet device. The aim of this report is to describe the periprocedural and early clinical/TEE results from this study.

METHODS AND RESULTS

This multicentre prospective real-world registry included 1,088 patients (75±8.5 years, 64.5% male, CHA2DS2-VASc: 4.2±1.6, HAS-BLED: 3.3±1.1) with non-valvular atrial fibrillation; 82.8% of patients were considered to have an absolute or relative contraindication to long-term anticoagulation and 72.4% had had a previous major bleeding. Periprocedural results, clinical outcomes up to the first three months and the available TEE results from the first scheduled follow-up (one to three months post implant) are reported. Successful device implantation was achieved in 99.0% of patients. During the procedure and index hospitalisation, major adverse events occurred in 3.2% of patients. Patients were discharged on a single antiplatelet agent (23.0%), dual antiplatelets (54.3%) or an oral anticoagulant (18.9%). TEE follow-up 67±23 days post procedure in 673 patients showed adequate (<3 mm jet) occlusion of the appendage in 98.2% of patients and device thrombus in 10 patients (1.5%), as evaluated by core laboratory analysis.

CONCLUSIONS

This large real-world prospective registry of catheter-based LAAO using the AMPLATZER Amulet device reports a high implant success rate and a low periprocedural complication rate in a population with a high risk of stroke and bleeding. Transoesophageal echo data confirm good closure rates during follow-up and low rates of device-associated thrombus.

Left Atrial Appendage Occlusion: Data Update

Resection of the left atrial appendage (LAA) to prevent recurrent arterial emboli in patients with atrial fibrillation was first suggested more than 60 years ago. Longer-term follow-up from randomized studies of the safety and efficacy of transcatheter LAA occlusion has recently been completed; data from large, observational cohorts are being reported. These recent data provide further insights into procedural safety with current techniques and the ability of LAA closure to reduce thromboembolic stroke compared with warfarin anticoagulation. This review summarizes the latest data regarding transcatheter LAA occlusion, focusing on larger prospective studies and further analyses of seminal clinical trials.

Safety and Efficacy of Transcatheter Left Atrial Appendage Closure for Stroke Prevention in Patients with Atrial Fibrillation

Atrial Fibrillation (AF) is associated with a substantial risk of thromboembolic stroke. Although long-term treatment with warfarin or the non-vitamin K oral anticoagulants can reduce this risk, such therapy is underutilized, and safe and consistent long-term treatment can be challenging. Transcatheter left atrial appendage (LAA) closure is an emerging alternative to long-term oral anticoagulation. Long-term follow-up of randomized clinical trials demonstrate that Watchman LAA closure provides significant reductions in hemorrhagic stroke, cardiovascular death, and all-cause mortality compared with continued warfarin therapy. Major bleeding is also reduced compared with continued warfarin therapy once the post-implant pharmacologic regimen is completed. This review summarizes the current dataset for the safety and efficacy of transcatheter LAA closure, and highlights the gaps in evidence and future directions for clinical research.

Left atrial appendage occlusion with the AMPLATZER Amulet device: an expert consensus step-by-step approach

AIMS

This document aims to describe a standardised methodology for performing left atrial appendage occlusion (LAAO) using the AMPLATZER Amulet device, and to provide useful tips and tricks for operators with different levels of experience.

METHODS AND RESULTS

Physicians who are experts in LAAO and had personal clinical experience with the AMPLATZER Amulet device were asked to contribute in the preparation of this consensus document. Twenty-seven physicians (20 interventional cardiologists and 7 electrophysiologists) from 14 different countries reviewed the manuscript. A step-by-step approach, simulating a real case, was followed. Starting with patient selection and planning, related cardiac imaging is discussed, followed by vascular access - transseptal puncture optimisation. Then, angiographic calibration/sizing and the required fluoroscopy views are explained and a device sizing strategy is proposed. Device preparation and de-airing is briefly described, followed by sheath exchange, device deployment steps, evaluation of device stability and decision for final release. The way to recapture and change a device is then shown, together with some additional tips on how to deal with challenging anatomies like "chicken wing" left atrial appendage. Finally, for operators who are switching from AMPLATZER Cardiac Plug to Amulet, the main differences between the two devices with respect to implantation technique are presented.

CONCLUSIONS

In conclusion, this document reflects a consensus approach by expert implanters on the steps of LAAO technique and best practices for implantation of the AMPLATZER Amulet device, along with some practical tips to minimise the complication rate.

Successful Left Atrial Appendage Occlusion with the New Generation Amulet® Device after Late-Occurring Embolization of an Amplatzer® Cardiac Plug in a Patient with Repetitive Strokes

The Amplatzer Cardiac Plug (ACP) is one of the most commonly used devices for percutaneous left atrial appendage (LAA) closure in order to prevent a stroke in patients with atrial fibrillation and contraindication for long-term oral anticoagulation therapy. We have previously described a patient who had experienced an embolization of the ACP device about 12 months after implantation and the device could be percutaneously retrieved. A few years later, he suffered from a posterior stroke and a stroke located in the brainstem as well as a transischemic attack (TIA). In order to protect him from further cardioembolic events a reocclusion of the LAA with the new generation of ACP device, the Amplatzer Amulet, was performed. A stable position of the device within follow-up period could be confirmed and the patient was free of additional strokes/TIA or bleeding events. This case stresses the importance of proper LAA sizing in order to prevent device embolization and notes that LAA size is not static. Moreover, it demonstrates that repeated implantation of an LAA occlusion device was still possible; one should be aware of undersizing the LAA dimensions and that the modifications of new generation LAA occlusion devices may overcome limitations of first-generation devices in order to prevent a cardioembolic stroke.

A meta-analysis for efficacy and safety evaluation of transcatheter left atrial appendage occlusion in patients with nonvalvular atrial fibrillation

OBJECTIVES

This meta-analysis was conducted to evaluate the efficacy and safety of transcatheter left atrial appendage (LAA) occlusion in patients with nonvalvular atrial fibrillation.

METHODS

The randomized controlled trials (RCT) or observational studies with any transcatheter LAA occlusion devices were searched in PubMed, Embase, and Cochrane library from inception to November 2015. The incidence rates from individual studies were combined to evaluate the procedural efficacy and safety, including all-cause death, cardiac/neurological death, stroke, transient ischemic attack (TIA), thrombosis, hemorrhagic complications, and pericardial effusion/tamponade.

RESULTS

Thirty-eight studies involving 3585 patients and 6 different occlusion devices were eligible for our inclusion criteria. The procedural failure rate for LAA closure was 0.02 (95% CI: 0.02-0.03). The all-cause mortality was 0.03 (95% CI: 0.02-0.03) and cardiac/neurological mortality was 0 (95% CI: 0.00-0.01). The stroke/TIA rate was estimated only 0.01 (95% CI: 0.01-0.01). The incidence of thrombus on devices was 0.01 (95% CI: 0.01-0.02). The major hemorrhagic complication rate was estimated 0.01 (95% CI: 0.00-0.01). Pericardial effusion/tamponade was estimated 0.02 (95% CI: 0.02-0.03). No heterogeneity was observed for above pooled estimates (I = 0). In devices subgroups analysis, the all-cause mortality and cardiac/neurological mortality of PLAATO group were the highest (P = 0.01 and P < 0.01 respectively), whereas the incidence of thrombus on devices in the ACP group was the highest (P < 0.01). In follow-up period subgroups analysis, there were significant differences in all-cause death, stroke/TIA, major hemorrhage, and pericardial effusion/tamponade events between the shorter and longer follow-up period subgroups (P < 0.05). However, the differences among the subgroups were numerically small.

CONCLUSIONS

the pooled data demonstrated that transcatheter LAA occlusion was effective and safe in the patients with nonvalvular atrial fibrillation who were not suitable for lifelong antithrombotic therapy.

Imaging Techniques in Percutaneous Cardiac Structural Interventions: Atrial Septal Defect Closure and Left Atrial Appendage Occlusion

Because of advances in cardiac structural interventional procedures, imaging techniques are playing an increasingly important role. Imaging studies show sufficient anatomic detail of the heart structure to achieve an excellent outcome in interventional procedures. Up to 98% of atrial septal defects at the ostium secundum can be closed successfully with a percutaneous procedure. Candidates for this type of procedure can be identified through a systematic assessment of atrial septum anatomy, locating and measuring the size and shape of all defects, their rims, and the degree and direction of shunting. Three dimensional echocardiography has significantly improved anatomic assessments and the end result itself. In the future, when combined with other imaging techniques such as cardiac computed tomography and fluoroscopy, 3-dimensional echocardiography will be particularly useful for procedure guidance. Percutaneous closure of the left atrial appendage offers an alternative for treating patients with atrial fibrillation and contraindication for oral anticoagulants. In the future, the clinical focus may well turn to stroke prevention in selected patients. Percutaneous closure is effective and safe; device implantation is successful in 94% to 99% of procedures. However, the procedure requires an experienced cardiac structural interventional team. At present, 3-dimensional echocardiography is the most appropriate imaging technique to assess anatomy suitability, select device type and size, guide the procedure alongside fluoroscopy, and to follow-up the patient afterwards.

Left Atrial Appendage: Physiology, Pathology, and Role as a Therapeutic Target

Atrial fibrillation (AF) is the most common clinically relevant cardiac arrhythmia. AF poses patients at increased risk of thromboembolism, in particular ischemic stroke. The CHADS2 and CHA2DS2-VASc scores are useful in the assessment of thromboembolic risk in nonvalvular AF and are utilized in decision-making about treatment with oral anticoagulation (OAC). However, OAC is underutilized due to poor patient compliance and contraindications, especially major bleedings. The Virchow triad synthesizes the pathogenesis of thrombogenesis in AF: endocardial dysfunction, abnormal blood stasis, and altered hemostasis. This is especially prominent in the left atrial appendage (LAA), where the low flow reaches its minimum. The LAA is the remnant of the embryonic left atrium, with a complex and variable morphology predisposing to stasis, especially during AF. In patients with nonvalvular AF, 90% of thrombi are located in the LAA. So, left atrial appendage occlusion could be an interesting and effective procedure in thromboembolism prevention in AF. After exclusion of LAA as an embolic source, the remaining risk of thromboembolism does not longer justify the use of oral anticoagulants. Various surgical and catheter-based methods have been developed to exclude the LAA. This paper reviews the physiological and pathophysiological role of the LAA and catheter-based methods of LAA exclusion.

Cardiac Plug I and Amulet Devices: Left Atrial Appendage Closure for Stroke Prophylaxis in Atrial Fibrillation

Percutaneous left atrial appendage (LAA) occlusion has emerged as an exciting and effective modality for stroke prophylaxis in patients with non-valvular atrial fibrillation who are deemed too high risk for anticoagulation with warfarin or newer anticoagulants. The Amplatzer devices have been used in LAA occlusion for more than a decade, starting with off label use of an atrial septal occluder device for LAA occlusion. This was followed by introduction of a dedicated Amplatzer cardiac plug (ACP) 1 for LAA occlusion, and more recently, the second generation Amulet device, with reported better stability enhancing features, has been introduced. Both these devices are widely used outside the United States, however in the US only the WATCHMAN device has been FDA approved. Unlike the WATCHMAN device, where the evidence is continuously building as the data from two pivotal randomized controlled trials are emerging, most of the evidence for ACP devices is from pooled multicenter registry data. In this article, we review the device design, implantation techniques and the most recently published evidence for both the Amplatzer cardiac plug 1 and the newer Amulet device. Our goal is to summarize the most recent literature and discuss the current role of the Amplatzer devices in the exciting and rapidly growing field of percutaneous LAA occlusion.

An overview of left atrial appendage occlusion devices

Atrial fibrillation (AF) places patients at increased risk of thromboembolic events that can be devastating. The left atrial appendage (LAA) has been identified as the source of thrombus formation in nonvalvular AF. Traditionally, systemic anticoagulation has been used to reduce the risk of stroke and systemic embolism. However, anticoagulation is not well tolerated in all patients and is underutilized. As a potential alternative to anticoagulation, novel therapies have been developed to remove the LAA. Three main techniques are being utilized to accomplish LAA exclusion: percutaneous intracardiac, percutaneous epicardial, and surgical approaches. Emerging evidence suggests that LAA exclusion may be an effective means of reducing the risk of stroke in patients with nonvalvular AF.

The WATCHMAN device for stroke prophylaxis in atrial fibrillation: an evolving niche

Atrial fibrillation is associated with a markedly increased risk of thromboembolic stroke. At present, lifelong antithrombotic therapy with warfarin or a novel oral anticoagulant is indicated for prophylaxis in the majority of patients. Left atrial appendage occlusion devices have been developed as an alternative to these agents, aiming to avoid issues around consistency of anticoagulation, bleeding risk, and drug-related side effects. The best evidence is available for Boston Scientific's WATCHMAN device. The safety and efficacy of WATCHMAN and other similar devices have been questioned, although the increasing body of evidence supports a role in selected settings. A recently updated randomized controlled trial of WATCHMAN (WATCHMAN Left Atrial Appendage System for Embolic PROTECTion in Patients with Atrial Fibrillation [PROTECT-AF]) demonstrates its noninferiority to warfarin and suggests an advantage in terms of functional outcome for patients, with superior net clinical benefit 6 to 9 months after starting treatment. The procedural risk associated with device implantation remains substantial, although improving device design and increasing operator experience means that this should decrease in the future. As the body of data and overall experience around WATCHMAN grow, it may come to be recognized as the best option in selected patients.