Percutaneous left atrial appendage transcatheter occlusion to prevent stroke in high-risk patients with atrial fibrillation: early clinical experience

Reflections on the early invasive clinical cardiac electrophysiology era through fifty manuscripts: 1967-1992

In 1967, researchers in The Netherlands and France independently reported a new technique, later called programmed electrical stimulation. The ability to reproducibly initiate and terminate arrhythmias heralded the beginning of invasive clinical cardiac electrophysiology as a medical discipline. Over the next fifty years, insights into the pathophysiologic basis of arrhythmias would transform the field into an interventional specialty with a tremendous armamentarium of procedures. In 2015, the variety and complexity of these procedures were major reasons that led to the recommendation for an increase in the training period from one year to two years. The purpose of this manuscript is to present fifty manuscripts from the early invasive clinical cardiac electrophysiology era, between 1967 and 1992, to serve as an educational resource for current and future electrophysiologists. It is our hope that reflection on the transition from a predominantly noninvasive discipline to one where procedures are commonly utilized will lead to more thoughtful patient care today and to inspiration for innovation tomorrow. In the words of the late Dr. Mark E. Josephson, "It is only by getting back to the basics that the field of electrophysiology will continue to grow instead of stagnate."

Pathophysiological and therapeutic implications in patients with atrial fibrillation and heart failure

Heart failure and atrial fibrillation are common and responsible for significant mortality of patients. Both share the same risk factors like hypertension, ischemic heart disease, diabetes, obesity, arteriosclerosis, and age. A variety of microscopic and macroscopic changes favor the genesis of atrial fibrillation in patients with preexisting heart failure, altered subcellular Ca²⁺ homeostasis leading to increased cellular automaticity as well as concomitant fibrosis that are induced by pressure/volume overload and altered neurohumoral states. Atrial fibrillation itself promotes clinical deterioration of patients with preexisting heart failure as atrial contraction significantly contributes to ventricular filling. In addition, atrial fibrillation induced tachycardia can even further compromise ventricular function by inducing tachycardiomyopathy. Even though evidence has been provided that atrial functions significantly and independently of confounding ventricular pathologies, correlate with mortality of heart failure patients, rate and rhythm controls have been shown to be of equal effectiveness in improving mortality. Yet, it also has been shown that cohorts of patients with heart failure benefit from a rhythm control concept regarding symptom control and hospitalization. To date, amiodarone is the most feasible approach to restore sinus rhythm, yet its use is limited by its extensive side-effect profile. In addition, other therapies like catheter-based pulmonary vein isolation are of increasing importance. A wide range of heart failure-specific therapies are available with mixed impact on new onset or perpetuation of atrial fibrillation. This review highlights pathophysiological concepts and possible therapeutic approaches to treat patients with heart failure at risk for or with atrial fibrillation.

Peridevice Leak After Left Atrial Appendage Closure: Incidence, Risk Factors, and Clinical Impact

BACKGROUND

Limited studies reported the rate and clinical impact of peridevice leaks (PDL) after percutaneous left atrial appendage closure (LAAC).

METHODS

All consecutive patients with a nonvalvular atrial fibrillation admitted for LAAC between November 2011 and October 2016 were prospectively enrolled. The follow-up included clinical, transesophageal echocardiography, and/or cardiac computed tomography angiogram (CCTA). PDL was defined by the presence of contrast within the left atrial appendage on CCTA, and Major Adverse Cardiac Event (MACE) included stroke, device-related thrombosis, and cardiovascular death.

RESULTS

Overall, 77 patients (mean CHA₂DS₂-VASc score = 4.4 ± 1.5 and mean HAS-BLED = 3.4 ± 1.1) were implanted using Amplatzer Cardiac Plug (n = 24), Amulet (n = 37), or Watchman devices (n = 16). Indications were stroke recurrence despite adequate oral anticoagulation (OAC, n = 6) or contraindication to long-term OAC (n = 71). From 3-month to 12-month CCTA follow-up, the PDL rate decreased from 68.5% to 56.7% (P = 0.02), without any difference between the various devices. Patients with PDL were more often in permanent atrial fibrillation, and had a larger landing zone diameter, a lower ratio of device compression, and a more frequent off-axis position of the device. A device compression ratio < 10% was the only parameter associated with PDL occurrence. During follow-up (median 236 days) the MACE rate was 9.1%, with no statistically significant difference between patients with vs without PDL (12% vs 4.3%, P = 0.3).

CONCLUSIONS

The PDL rate detected by CCTA after LAAC was high, especially in cases with a low device compression ratio (< 10%), but decreased over time. The incidence of MACE was quantitatively greater with PDL, but the difference was not statistically significant. Larger studies are needed to determine the clinical importance of PDL.

Accuracy of Commonly-Used Imaging Modalities in Assessing Left Atrial Appendage for Interventional Closure: Review Article

Periprocedural imaging assessment for percutaneous Left Atrial Appendage (LAA) transcatheter occlusion can be obtained by utilizing different imaging modalities including fluoroscopy, magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound imaging. Given the complex and variable morphology of the left atrial appendage, it is crucial to obtain the most accurate LAA dimensions to prevent intra-procedural device changes, recapture maneuvers, and prolonged procedure time. We therefore sought to examine the accuracy of the most commonly utilized imaging modalities in LAA occlusion. Institutional Review Board (IRB) approval was waived as we only reviewed published data. By utilizing PUBMED which is an integrated online website to list the published literature based on its relevance, we retrieved thirty-two articles on the accuracy of most commonly used imaging modalities for pre-procedural assessment of the left atrial appendage morphology, namely, two-dimensional transesophageal echocardiography, three-dimensional transesophageal echocardiography, computed tomography, and three-dimensional printing. There is strong evidence that real-time three-dimensional transesophageal echocardiography is more accurate than two-dimensional transesophageal echocardiography. Three-dimensional computed tomography has recently emerged as an imaging modality and it showed exceptional accuracy when merged with three-dimensional printing technology. However, real time three-dimensional transesophageal echocardiography may be considered the preferred imaging modality as it can provide accurate measurements without requiring radiation exposure or contrast administration. We will present the most common imaging modality used for LAA assessment and will provide an algorithmic approach including preprocedural, periprocedural, intraprocedural, and postprocedural.

Day-case percutaneous left atrial appendage occlusion-Safety and efficacy

OBJECTIVES

We evaluated the safety and efficacy of percutaneous left atrial appendage (LAA) occlusion performed as a day case procedure.

BACKGROUND

LAA occlusion has been shown to be safe and effective for stroke prevention in patients with atrial fibrillation. It has not been shown if the procedure can safely be performed on a day-case basis.

METHODS

Retrospective analysis was made of 117 LAA occlusion procedures in a single large teaching hospital in the UK. Procedural success, procedural complications, length of stay, and readmission data were examined.

RESULTS

Successful deployment of a device was possible in all but one patient (whose appendage was too large). Major in-hospital complications occurred in 1.7% of patients (both femoral vascular). Same-day discharge was made in 66% of patients overall. Since January 2016, only 3 of 59 patients (5%) have remained in hospital overnight following LAAO. Echocardiography 2-4 hr postprocedure was undertaken prior to discharge. One patient was readmitted within 7 days but this readmission would not have been prevented by overnight stay.

CONCLUSIONS

LAA occlusion can be safely performed as a day case procedure with acceptable complication rates and no increment of complications related to the lack of routine overnight stay.

Cardiovascular Therapies Targeting Left Atrial Appendage

Left atrial appendage (LAA) closure has evolved as an effective strategy for stroke prevention in patients with atrial fibrillation who are considered suitable for oral anticoagulation. There is strong evidence based on randomized clinical trials with 1 percutaneous device, as well as a large registry experience with several devices, regarding the safety and efficacy of this strategy. In addition, there is encouraging data regarding the effect of epicardial LAA closure on decreasing arrhythmia burden and improvements in systemic homeostasis by neurohormonal modulation. However, there are several unresolved issues regarding optimal patient selection, device selection, management of periprocedural complications including device-related thrombus, residual leaks, and pericarditis. In this review, we summarize the rationale, evidence, optimal patient selection, and common challenges encountered with mechanical LAA exclusion.

Applications of low-cost 3D printing in left atrial appendage closure using epicardial approaches - initial clinical experience

Introduction

Left atrial appendage occlusion procedure (LAAO) became an alternative method for stroke prevention in atrial fibrillation (AF) patients with contraindication or intolerance for oral anticoagulation therapy. However, LAA anatomy is complex with several different types of LAA morphology. Therefore matching the correct size of a delivery device to LAA morphology is difficult. In such circumstances, the 3D-printed model of LAA closure may be useful for preoperative planning which increases the efficacy of LAAO procedure.

Material and methods

We report as a first 2 cases of LAA occlusion procedure using 2 different systems: thoracoscopic AtriClip and the LARIAT device in which a 3D printed LAA model was used in preoperative planning.

Results

In the first patient, preoperative measurements of 3D LAA model were performed using a dedicated selection guide for AtriClip device were comparable with the intraoperative examination. Left atrial appendage was closed epicardial using 40 mm size AtriClip. In second patients, LAA closure was performed completely percutaneously using LARIAT device. For better visualization of LAA shape on fluoroscopy and TEE examination, intraoperatively sterilized 3D LAA model was used during the procedure. In both cases, intraoperative TEE examination confirmed complete LAA closure with no leak.

Conclusions

Left atrial appendage 3D model is a useful tool in preoperative planning of a left atrial appendage occlusion using epicardial approaches with thoracoscopic or percutaneous access using LARIAT device. The quality of low-cost 3D printed LAA model is sufficient in planning minimally invasive procedure.

Left Atrial Appendage Occlusion: What Are the Options and Where is the Evidence?

Left atrial appendage occlusion (LAAO) has emerged as an effective site-directed therapy in patients with nonvalvular atrial fibrillation (AF) for stroke prevention, who are ineligible for long-term oral anticoagulation. The objective of this study was to assess the safety, efficacy, and availability of LAAO devices by reviewing the literature and to review the development and effectiveness of LAAO by the transcatheter approach with plugging devices such as WATCHMAN™ (Boston Scientific, Natick, MA, USA); AMPLATZER™ Cardiac Plug and AMPLATZER™ Amulet™ (Abbott Laboratories, Chicago, IL, USA); and the LARIAT® Suture Delivery Device (SentreHEART, Redwood City, CA, USA), which features an entirely unique hybrid (endocardial and epicardial) approach in closing the left atrial appendage (LAA). The conducted literature review ultimately revealed a substantial body of literature supporting the safety and efficacy of various LAAO strategies, including endocardial, epicardial, and hybrid approaches, in AF patients who are not eligible for long-term oral anticoagulant use. Specifically, the most attractive population suitable for LAA closure appears to be patients at high risk for ischemic stroke with a longer life expectancy but a moderate-to-high bleeding risk with long-term oral anticoagulation. The benefit of LAA closure in reducing the incidence of stroke in patients with nonvalvular AF has been evolving gradually, and we are confident that this new field of percutaneous LAA closure will continue to emerge as a game-changer in the treatment of AF.

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.

Surgical Closure of the Left Atrial Appendage: The Past, The Present, The Future

Occlusion of the left atrial appendage (LAA) may protect against stroke in patients with atrial fibrillation. While percutaneous LAA closure devices have demonstrated efficacy in stroke reduction, surgical LAA occlusion has been performed with mixed results to date. Although surgical exclusion via internal sutures or noncutting stapler is ineffective due to recanalization of the LAA, surgical excision and certain exclusion devices including the AtriClip device are effective methods to achieve complete closure of the LAA. No data currently exists to support routine, prophylactic LAA closure at the time of cardiac surgery, but this practice may benefit certain patients at high risk for stroke. The currently enrolling Left Atrial Appendage Occlusion Study (LAAOS) III is the largest study to date designed to assess the efficacy of LAA occlusion for stroke prevention. The results of this trial will inform future clinical practice regarding stroke prevention with surgical LAA occlusion for patients with atrial fibrillation. Meanwhile, the ATLAS trial is investigating the efficacy of LAA occlusion in surgical patients who do not have atrial fibrillation but are at increased risk for developing it post-operatively.

Update on the Non-Pharmacological Management of Stroke Prevention in Patients with Atrial Fibrillation

Non-surgical left atrial appendage occlusion has emerged as an alternative to anticoagulant therapy in the management of stroke risk in patients with atrial fibrillation. This review reports on some of the more common devices that are currently being used to manage patients in this challenging group.

Transcatheter left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation: results from the Belgian registry

AIMS

This study aimed to assess the safety and efficacy at midterm follow-up of left atrial appendage occlusion (LAAO) using different devices, in real life in Belgium.

METHODS AND RESULTS

Between June 2009 and November 2016, 457 consecutive patients (63% male, 75±12 yrs, CHA2DS2-VASc 4±0.6, HAS-BLED 3.5±0.7) undergoing LAAO were included. Technical success was 97.1%. There were 19 periprocedural major adverse events (4.1%) including three deaths (0.6%), nine tamponades (1.9%), four major bleedings (0.8%) and two device embolisations (0.4%). Among patients successfully implanted having a complete follow-up (672 patient-years, median follow-up 370 days), the actual annual stroke rate was 1.2%, lower than the expected stroke risk of 4% (70% reduction). The observed bleeding rate was 2%, while the calculated risk was 3.7% (46% reduction). Kaplan-Meier analysis showed a similar overall survival (93±2% and 87±3% versus 91±3% and 87±4%; p=0.35) and event-free survival (92±2% and 84±3% versus 88±3% and 80±5%; p=0.17) at one and two years, for the ACP/Amulet versus the WATCHMAN groups of patients, respectively.

CONCLUSIONS

The data from the Belgian left atrial appendage occlusion registry suggest that the procedure is effective and relatively safe in a real-world setting, using either the WATCHMAN or the ACP/Amulet device.

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 Closure Devices for Stroke Prevention in Patients with Non-Valvular AF

The left atrial appendage (LAA) may be involved in offloading atrial pressure during left ventricular systole. As ventricular rate increases, LAA emptying decreases during early diastole causing increased risk of thrombus formation particularly in patients with non-valvular AF (NVAF). The LAA is the site of thrombus formation in more than 90 % of patients with NVAF, so is an important target for thromboembolic prophylaxis in these patients. Anticoagulation therapy is used to treat NVAF, but it has long-term complications and may be contraindicated in some patients. Therefore, alternative strategies to reduce embolic risk in patients with AF have been developed. These include percutaneous, thoracoscopic, and open closure strategies. This study reviews the safety and efficacy of these strategies, comparing these approaches and devices with pharmacological strategies. There is little data to endorse one strategy over another. Given the minimal evidence available, recommendations in support of LAA occlusion remain weak and guidelines have called for more research and coding of endpoints for this emerging technology.

[Left atrial appendage clusure in nonvalvular atrial fibrillation : Clinical evidence 2017]

Nonvalvular atrial fibrillation (AF) is the most common arrhythmia with a prevalence of 1-2% and affects approximately 15-20% of all octogenarians. Patients are at increased risk of thromboembolic stroke, with an overall risk of 5% per year. Thrombi form almost exclusively in the left atrial appendage (LAA), a blind sac-like heterogeneous structure trabeculated by pectinate muscles. In the past five decades, life-long oral anticoagulation (OAC) with vitamin K antagonists (VKA) has been the state-of-the art treatment to prevent stroke and systemic embolism from thrombi in AF. In the last decade, nonvitamin K dependent oral anticoagulants (NOAC) have been shown to be superior to VKA. Given the safety issues of indefinite OAC with either VKA or NOAC, it is plausible to consider left atrial appendage closure (LAAC) as an alternative strategy to prevent death, stroke or other systemic embolization, and bleeding. In recent years, LAAC has been compared to VKA in prospective randomized trials, yielding superior results regarding efficacy and noninferiority regarding safety in the mid-term. This review provides an update on the current state of LAAC in the field of prevention of death, stroke, and bleedings in patients suffering from nonvalvular AF. We elucidate the evidence and limitations of anticoagulation as the classical treatment paradigm, and review devices and techniques for LAAC. Most importantly, the current clinical evidence on efficacy and safety is outlined.

Anatomy of the atria : A road map to the left atrial appendage

The left atrial appendage (LAA) has received increasing attention in recent years because of thrombi formation in patients with atrial fibrillation, which increases the risk of stroke. In patients who have contraindications for long-term oral anticoagulation therapy, percutaneous procedures are used to occlude the LAA and there are now several devices available for implantation, both endocardially and epicardially. Despite the high-resolution imaging techniques on hand today, limitations remain in providing information about wall thickness and neighboring structures; therefore, in-depth knowledge of the normal atrial anatomy is mandatory when considering such interventions. Here, the anatomy of the right and left atria is reviewed with relevance to interventional procedures required for LAA occlusion. The components of the atria, particularly the LAA as well as the atrial septum, are described with emphasis on their spatial relationships to neighboring cardiac and extracardiac structures. Sound knowledge of the atrial anatomy including endocardial and epicardial aspects is necessary. This will help interventionists take full advantage of imaging techniques when assessing the suitability of the LAA anatomy for closure, selecting the optimal device types and sizes, and guiding the LAA closure procedure, thereby reducing potential complications and increasing procedural success.

[Left atrial appendage closure and embolic events]

Atrial fibrillation (AF) is frequent and responsible for embolic events. Currently, the gold standard to prevent such embolic events is anticoagulant therapy with vitamin K antagonist (VKA) or direct oral anticoagulant in nonvalvular AF. Recently, left atrial appendage closure was proposed as an alternative to anticoagulant inpatient with high embolic risk and contraindication to anticoagulant therapy. Data from randomized trials were consistent with a non-inferiority of left atrial appendage closure in comparison to VKA in terms of stroke and cardiovascular death. However, despite improvements in procedure results and complications reduction, this invasive strategy has to be performed with optimal security as this strategy is a preventive treatment in high-risk patients. These improvements may allow an extension of indications of left atrial appendage closure to lower profile risk patients as an alternative to anticoagulant. Indeed, anticoagulant is a risky therapy with hemorrhagic events and observance is a real issue in an asymptomatic population. Finally, there is a lack of data in recent literature comparing left atrial appendage closure to direct oral anticoagulant, widely used in daily practice, as well as cost-effectiveness of this procedure in comparison to anticoagulant.

Pharmacological and Non-pharmacological Treatments for Stroke Prevention in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is associated with significant risk of stroke and other thromboembolic events, which can be effectively prevented using oral anticoagulation (OAC) with either vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, or edoxaban. Until recently, VKAs were the only available means for OAC treatment. NOACs had similar efficacy and were safer than or as safe as warfarin with respect to reduced rates of hemorrhagic stroke or other intracranial bleeding in the respective pivotal randomized clinical trials (RCTs) of stroke prevention in non-valvular AF patients. Increasing “real-world” evidence on NOACs broadly confirms the results of the RCTs. However, individual patient characteristics including renal function, age, or prior bleeding should be taken into account when choosing the OAC with best risk–benefit profile. In patients ineligible for OACs, surgical or interventional stroke prevention strategies should be considered. In patients undergoing cardiac surgery for other reasons, the left atrial appendage excision, ligation, or amputation may be the best option. Importantly, residual stumps or insufficient ligation may result in even higher stroke risk than without intervention. Percutaneous left atrial appendage occlusion, although requiring minimally invasive access, failed to demonstrate reduced ischemic stroke events compared to warfarin. In this review article, we summarize current treatment options and discuss the strengths and major limitations of the therapies for stroke risk reduction in patients with AF.

Managing the Left Atrial Appendage in Atrial Fibrillation: Current State of the Art

BACKGROUND

Patients with atrial fibrillation are at increased risk for thromboembolic stroke originating predominantly in the left atrial appendage. To reduce the risk, the standard of care is anticoagulation. In addition, several devices for exclusion of the left atrial appendage have been developed.

METHODS

PubMed was searched for articles relevant to left atrial appendage management. The resulting articles were reviewed as were relevant articles in their bibliographies. Relevant journals were manually searched for sources.

RESULTS

Devices are being used for left atrial appendage exclusion by percutaneous and surgical approaches. Their indications, limitations, and outcomes are reviewed.

CONCLUSIONS

Excision and exclusion of the left atrial appendage is safe and as effective as medical management of atrial fibrillation for stroke prevention. The choice of treatment should be made based on patients' anatomy, history, and preference informed by an appropriate left atrial appendage management team.

Approaches to Left Atrial Appendage Closure: Device Design, Performance, and Limitations

Up to 6.1 million people in the United States have atrial fibrillation (AF), which is associated with an increased risk of stroke. Oral anticoagulants are the mainstay of stroke prevention in AF. For decades, warfarin was the only available drug, fraught with compliance limitations, a narrow therapeutic window, and a high risk of hemorrhage. Pharmacologic developments have produced new anticoagulants that have improved the rates of stroke related to AF; however, they still confer a high risk of bleeding, making them unsuitable for some patients. Studies have shown that roughly 90% of strokes in patients with AF occur in the left atrial appendage (LAA). This understanding has prompted the development and testing of novel percutaneous strategies for LAA closure as an alternative to anticoagulation therapy. The following review examines the relative merits and shortcomings of these strategies and explores future prospects in the prevention of AF-related stroke.

Dealing With the Left Atrial Appendage for Stroke Prevention: Devices and Decision-Making

Left atrial appendage (LAA) device occlusion represents a major evolution in stroke prevention for atrial fibrillation (AF). Left atrial appendage device occlusion is now a proven strategy which provides long-term thromboembolic stroke prevention for patients with non-rheumatic AF. Evidence supports its benefit as an alternative to long-term anticoagulation while mitigating long-term bleeding risks and improving cardiovascular mortality. The therapy offers expanded options to physicians and patients negotiating stroke prevention (both primary and secondary prevention), but a good understanding of the risks and benefits is required for decision-making. This review aims to summarise the evolution of LAA device occlusion therapy, current knowledge in the field and a snapshot of current status of the therapy in clinical practice in Australia and around the world.

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.

Novel stroke risk reduction in atrial fibrillation: left atrial appendage occlusion with a focus on the Watchman closure device

Atrial fibrillation (AF) remains an important clinical problem with severe complications such as stroke, which especially harms those with risk factors as calculated by the CHADS2 or CHA2DS2-VASc. Until now, no therapy has proven 100% effective against AF. Since the left atrial appendage (LAA) is the most prominent nonvalvular AF-related thromboembolic source and (novel) oral anticoagulant [(N)OAC] carries the hazard of bleeding, LAA occlusion may be an alternative, especially in patients who are ineligible for (N)OAC therapy. In this review, we discuss several LAA occlusion techniques with a focus on the Watchman device since this device is the most thoroughly studied device of all.

Incidence and Clinical Impact of Device-Associated Thrombus and Peri-Device Leak Following Left Atrial Appendage Closure With the Amplatzer Cardiac Plug

OBJECTIVES

Routine device surveillance after successful left atrial appendage closure is recommended to evaluate for intermediate to late complications. The aim of this study was to assess the incidence and clinical impact of these complications on cardiovascular events.

METHODS

Centers participating in the Amplatzer Cardiac Plug multicenter study were requested to submit their post-procedural transesophageal echocardiograms for independent adjudication. Thirteen of 22 centers contributed all their post-procedural echocardiograms, which included 344 from 605 consecutive patients. These images were submitted to a core laboratory and reviewed by 2 independent experts for peri-device leak, device-associated thrombus, device embolization, device migration, left atrial appendage thrombus, and left atrial thrombus. Clinical events were prospectively collected by each center.

RESULTS

Of the 344 transesophageal echocardiograms, 339 were deemed analyzable. Patients' mean age was 74.4 ± 7.5 years, and 67.3% were men. The mean CHADS2 score was 2.7 ± 1.3, the mean CHA2DS2-VASc score was 4.3 ± 1.5, and the mean HAS-BLED score was 3.0 ± 1.2. Amplatzer Cardiac Plug implantation was successful in all patients. Periprocedural major adverse events occurred in 2.4%. Median clinical follow-up duration was 355 days (range 179 to 622 days). Follow-up transesophageal echocardiography was performed after a median of 134 days (range 88 to 227 days). Device-associated thrombus was observed in 3.2% and peri-device leak in 12.5% (5.5% minimal, 5.8% mild, 0.6% moderate, 0.6% severe). Neither device-associated thrombus nor peri-device leak was associated with an increased risk for cardiovascular events. Independent predictors of device-associated thrombus were smoking (odds ratio: 5.79; p = 0.017) and female sex (odds ratio: 4.22; p = 0.027).

CONCLUSIONS

Following successful left atrial appendage closure with the Amplatzer Cardiac Plug, the presence of peri-device leak was relatively low, and device-associated thrombus was infrequent. Neither was associated with increased risk for thromboembolism.

Non-Pharmacologic Approach to Prevent Embolization in Patients with Atrial Fibrillation in Whom Anticoagulation is Contraindicated

Ischemic stroke is the most common complication of atrial fibrillation (AF). Anticoagulation therapy reduces the risk of systemic embolization in almost all patients with AF irrespective of the type of AF (paroxysmal, persistent or permanent). But, all patients are not suitable candidates for systemic anticoagulation mainly due to the risk of bleeding. Left atrial appendage closure (LAAC) devices have been found to be very effective non-pharmacologic alternative therapy for such patients. There are various types of LAAC devices but United States Food and Drug Administration (US-FDA) have approved only Watchman device. Initially, bigger medical centers in the US had started the insertion of Watchman device but with improving procedural techniques and exciting outcomes, even the community-based hospitals have started to embrace this therapy. We have presented the first three cases of Watchman device placement performed in our hospital and discussed about the indications for placement of LAAC devices. We have also reviewed their efficacy individually.

Left atrial appendage closure: outcomes and challenges

Whereas the left atrial appendage plays a rather minor role under physiological circumstances, it gains an importance in patients with atrial fibrillation. Compelling evidence has revealed that the left atrial appendage is implicated as the source of thrombus in the vast majority of strokes in atrial fibrillation. Oral anticoagulation remains the standard of care for stroke prevention in atrial fibrillation; nevertheless, this treatment has several limitations and is often contraindicated, particularly in the elderly population in whom the risk of stroke is high. Therefore, occluding the left atrial appendage is a logical approach to prevent thrombus formation and subsequent cardioembolic events in these patients. We present a review of clinical outcomes of patients with atrial fibrillation undergoing left atrial appendage closure and the challenges faced in this field.

Pulmonary artery perforation and coronary air embolism-two fatal outcomes in percutaneous left atrial appendage occlusion

Percutaneous left atrial appendage (LAA) closure is a routinely performed method to reduce the risk of stroke in patients suffering from atrial fibrillation, when an oral anticoagulation is no longer indicated due to relevant bleeding complications. Currently, the Amplatzer Amulet and the Watchman system are two equally used systems. While there is an acute success rate of more than 95 per cent for this intervention, several minor and major complications such as pericardial effusions, air embolism, vascular lesions in proximity to the heart or even death can occur. Here, we report two cases of very rare fatal outcomes in percutaneous LAA occlusion. Eight hours after deployment of an Amplatzer Amulet a patient died, after the pulmonary trunk was perforated by a hook of the occluder device causing pericardial tamponade. In the second case during final radiological position control of the deployed Watchman occluder air was injected accidentally. The patient immediately died due to coronary air embolism. Forensic autopsies are necessary to solve the cause and manner of death, to evaluate and develop medical devices and to rule out medical malpractice. Thus, a close collaboration of legal medicine and the various cardiologic departments is proposed.

Percutaneous left atrial appendage closure devices: safety, efficacy, and clinical utility

Atrial fibrillation (AF) is the most common arrhythmia treated in the clinical practice. One of the major complications of AF is a thromboembolic cerebral ischemic event. Up to 20% of all strokes are caused by AF. Thromboembolic cerebral ischemic event in patients with AF occurs due to atrial thrombi, mainly from the left atrial appendage (LAA). Prevention of clot formation with antiplatelet agents and especially oral anticoagulants (vitamin K antagonists or newer oral anticoagulants) has been shown to be effective in reducing the stroke risk in patients with AF but has several drawbacks with (major) bleedings as the most important disadvantage. Therefore, physical elimination of the LAA, which excludes the site of clot formation by surgical or percutaneous techniques, might be a good alternative. In this review, we discuss the safety, efficacy, and clinical utility of the Watchman™ LAA closure device.

Initial experience with the WATCHMAN™ left atrial appendage system for stroke prevention in atrial fibrillation: A single-centre registry

BACKGROUND

Left atrial appendage (LAA) closure using the WATCHMAN™ device (WM) may be considered in patients with non-valvular atrial fibrillation (AF) and a high-risk of stroke who are ineligible for long-term oral anticoagulation (OAC).

AIM

To report our single-centre preliminary experience, focusing on feasibility, safety and short-term efficacy of this procedure.

METHODS

Patients implanted from December 2013 to February 2014 were included. The procedure, performed under general anaesthesia, was guided by fluoroscopy and transoesophageal echocardiography (TOE). Efficacy was defined as the ability to implant the WM with no peridevice leak; safety was defined as the occurrence of in-hospital and 45-day events, including stroke, pericardial effusion and device migration.

RESULTS

Twenty-three patients (mean age: 77.6 years; 16 men [69.6%]; mean CHA₂DS₂-VASc score: 5) underwent WM implantation. The indication was gastrointestinal bleeding in 14 (60.9%) patients, cerebral haemorrhage in eight (34.8%) and need for long-term ticagrelor after stent thrombosis on clopidgrel in one (4.3%). Procedural success was 95.7% (95% confidence interval: 77.3-100.0); efficacy was 90.9% (95% confidence interval: 71.0-98.7). The size of the implanted WATCHMAN™ device was in agreement with the prespecified size, based on measurement of the LAA, in 56.5% of cases. In five cases, the criteria were not met, but the device was successfully implanted in four of these, with a good result (80.0%). Treatment at discharge was a reduced dose of anticoagulant plus aspirin in three cases (13.0%) or antiplatelet therapy alone in 20 cases (90.9%). No adverse event occurred during the index hospitalization or at 45 days. At 45 days, the LAA was sealed in 18/19 patients (94.7%) on TOE, with no difference between those who did or did not have an implanted device of the prespecified size.

CONCLUSION

When performed by an operator trained in the procedure, WM implantation appears to be safe and effective. This procedure may be considered in patients at high-risk of stroke who are ineligible for long-term OAC.

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.

Interventional left atrial appendage occlusion: added value of 3D transesophageal echocardiography for device sizing

Aim of this study was the assessment of left atrial appendage (LAA) dimensions comparing 2D- to 3D-TEE measurements in patients with nonvalvular atrial fibrillation undergoing percutaneous LAA occlusion. Patients underwent transesophageal echocardiography (TEE) before, during and 45 days after intervention. The maximal LAA orifice diameters in 2D-TEE (LODmax 2D) were obtained from multiple views. Test-retest reliability (screening vs. implantation), inter- and intra-observer variability for echocardiographic parameters were assessed by two independent examiners. Overall, 74 patients underwent percutaneous LAA occlusion. 2D-TEE significantly underestimated the maximal LAA orifice diameter compared with 3D-TEE (screening LODmax 2D 21.11 ± 2.75 mm vs. 22.52 ± 3.45 mm for LODmax 3D, p < 0.001; during implantation LODmax 2D 21.56 ± 3.48 mm vs. 22.99 ± 3.24 mm for LODmax 3D, p < 0.001). The intraobserver and interobserver variability calculated as coefficient of variation (CV) were both lower for the 3D-TEE quantification of the maximal orifice diameter (intraobserver CV for 3D-TEE 6.07 % vs. 9.31 % for 2D-TEE; interobserver CV for 3D-TEE 6.73 % vs. 9.69 % for 2D-TEE). Compared to 3D-TEE the test-retest reliability of 2D-TEE showed a lower intraclass correlation coefficient calculated as average of raters (0.92 for 3D-TEE vs. for 2D-TEE 0.78). Firstly, 2D-TEE significantly underestimates the maximal LAA orifice diameter compared to 3D-TEE. Secondly, 3D-TEE measurements are associated with a lower observer variability and higher reliability than 2D-TEE.

Left Atrial Appendage Closure for Stroke Prevention: Devices, Techniques, and Efficacy

Left atrial appendage closure can be performed either surgically or percutaneously. Surgical approaches include direct suture, excision and suture, stapling, and clipping. Percutaneous approaches include endocardial, epicardial, and hybrid endocardial-epicardial techniques. Left atrial appendage anatomy is highly variable and complex; therefore, preprocedural imaging is crucial to determine device selection and sizing, which contribute to procedural success and reduction of complications. Currently, the WATCHMAN is the only device that is approved for left atrial appendage closure in the United States.

Left atrial appendage occlusion in atrial fibrillation for stroke prevention: A systemic review

BACKGROUND

Atrial fibrillation (AF) is an arrthymia characterized by increased risk of ventricle arrthymias and thromboembolism especially ischemic stroke. Most thrombus originated in the left atrial appendage, thus left atrial occlusion (LAAO) may be an effective alternative for stroke prevention in atrial fibrillation.

OBJECTIVE

To assess the effect and safety of left atrial occlusion for stroke prevention in atrial fibrillation.

METHODS AND RESULTS

We searched Pub Med, CENTRAL in The Cochrane Library, Embase, CBM-Disk, CNKI for published trials, ClinicalTrials.gov, ISI Proceedings for conference abstracts, and WHO International Clinical Trial registration Platform for ongoing studies. The search results were extracted, and then the quality of included studies was assessed. By RevMan 5.3, meta analysis was used if there was low heterogeneity. Three randomized controlled clinical trials involving 1165 participants were included (percutaneous 1114 in 2 trials, surgical 51 in 1 trial). The current data suggest that left atrial occlusion may be as efficacious as warfarin in stroke prevention (RR 0.78 [0.33, 1.84]) and mortality reduction (RR 0.68 [0.40, 1.16]) for AF.

CONCLUSION

In contrast to warfarin left atrial occlusion with Watchman device may have the same effectivity in stroke reduction. Surgical LAAO may also get positive outcomes compared with warfarin, but owing to the small sample size the evidence is less powerful. Total outcomes of percutaneous and surgical LAAO support this approach.

Percutaneous interventions for left atrial appendage exclusion: options, assessment, and imaging using 2D and 3D echocardiography

Percutaneous left atrial appendage (LAA) exclusion is an evolving treatment to prevent embolic events in patients with nonvalvular atrial fibrillation. In the past few years multiple percutaneous devices have been developed to exclude the LAA from the body of the left atrium and thus from the systemic circulation. Two- and 3-dimensional transesophageal echocardiography (TEE) is used to assess the LAA anatomy and its suitability for percutaneous closure to select the type and size of the closure device and to guide the device implantation procedure in conjunction with fluoroscopy. In addition, 2- and 3-dimensional TEE is also used to assess the effectiveness of device implantation acutely and on subsequent follow-up examination. Knowledge of the implantation options that are currently available along with their specific characteristics is essential for choosing the appropriate device for a given patient with a specific LAA anatomy. We present the currently available LAA exclusion devices and the echocardiographic imaging approaches for evaluation of the LAA before, during, and after LAA occlusion.