Initial worldwide experience with the WATCHMAN left atrial appendage system for stroke prevention in atrial fibrillation.

OBJECTIVES: This study assessed the feasibility of implanting a device in the left atrial appendage (LAA) in patients with atrial fibrillation (AF) to prevent thromboembolic stroke. BACKGROUND: Meta-analyses confirmed that in cases of left atrial thrombus in nonrheumatic AF patients approximately 90% of them are in the LAA. METHODS: The WATCHMAN Left Atrial Appendage System (Atritech Inc., Plymouth, Minnesota) is a nitinol device implanted percutaneously to seal the LAA. Patients were followed by clinical and transesophageal echocardiography at 45 days and 6 months with annual clinical follow-up thereafter. RESULTS: Sixty-six patients underwent device implantation. Mean follow-up was 740 +/- 341 days. At 45 days, 93% (54 of 58) devices showed successful sealing of LAA according to protocol. Two patients experienced device embolization, both successfully retrieved percutaneously. No embolizations occurred in 53 patients enrolled after modification of fixation barbs. There were 2 cardiac tamponades, 1 air embolism, and 1 delivery wire fracture (first generation) with surgical explantation but no long-term sequelae for the patient. Four patients developed a flat thrombus layer on the device at 6 months that resolved with additional anticoagulation. Two patients experienced transient ischemic attack, 1 without visible thrombus. There were 2 deaths, neither device related. Autopsy documented a stable, fully endothelialized device 9 months after implantation. No strokes occurred during follow-up despite >90% of patients with discontinuation of anticoagulation. CONCLUSIONS: Preliminary data suggest LAA occlusion with the WATCHMAN System to be safe and feasible. A randomized study is ongoing comparing oral anticoagulation with percutaneous closure.     

Self-Expandable Device for Percutaneous Closing of Left Atrial Appendage With Organized Thrombus in a Patient With Permanent Atrial Fibrillation

While a left atrial appendage (LAA) occlusion device may reduce the risk of cardioembolic stroke in patients with nonvalvular atrial fibrillation, an antithromboembolic strategy for patients with an organized thrombus in the LAA is still unclear. The present case is the first report of percutaneous closing of an LAA and organized thrombus with a self-expandable LAA occlusion device without complication. This minimally invasive intervention is a potential treatment option in a patient with significant risk of recurrent thromboembolism.     

Transcatheter cerebral embolic protection during WATCHMAN procedure in two patients with persistent left atrial appendage thrombus: Case report with review of the literature

Percutaneous left atrial appendage closure (LAAC) has been increasingly used in patients with atrial fibrillation who are poor candidates for long-term oral anticoagulation. The presence of a left atrial appendage (LAA) thrombus is a contraindication for percutaneous LAAC. Despite oral anticoagulation, persistent thrombus is not uncommon. We describe the use of transcatheter cerebral embolic protection with the Sentinel cerebral protection system during LAAC using WATCHMAN in two atrial fibrillation patients who had persistent LAA thrombus despite oral anticoagulation.     

Left atrial thrombus after complete left atrial appendage exclusion with LARIAT device

A 74‐year‐old woman with paroxysmal atrial fibrillation underwent left atrial appendage (LAA) exclusion with a LARIAT snare device. Transesophageal echocardiogram one month later demonstrated a left atrial thrombus at orifice of the completely occluded LAA that subsequently resolved with two months of anticoagulation. This case highlights that LAA ligation with LARIAT device continues to pose a risk for left atrial thrombosis in the immediate post‐operative period. It also emphasizes the need for further evidence regarding antiplatelet and anticoagulation therapy in these patients. © 2014 Wiley Periodicals, Inc.     

Watchman FLX Implantation for Challenging Left Atrial Appendage Anatomy: Case-Based Discussion

Left atrial appendage (LAA) occlusion devices provided an acceptable and valid alternative to anticoagulation among patients with atrial fibrillation who carry high bleeding risk. Watchman device is non-inferior to oral anticoagulation to prevent cerebrovascular accidents. The presence of a longer distal portion of the older generation Watchman led to exclusion of patients with prohibitive anatomy of the LAA such as chicken-wing morphology or shallow LAA. Watchman FLX provides a wider range of sizes and can be implanted with complex anatomy or shallow LAA. In the case series, we discuss 3 patients with challenging LAA anatomy that underwent successful Watchman FLX implantation.     

Intraprocedural and long-term incomplete occlusion of the left atrial appendage following placement of the WATCHMAN device: a single center experience

Incomplete LAA Occlusion by WATCHMAN Device . Introduction: Transcatheter left atrial appendage (LAA) closure with the WATCHMAN device has become one of the therapeutic options in atrial fibrillation (AF) patients who are at high risk for ischemic stroke. However, the incidence and evolution of incomplete occlusion of the LAA during and after placement of the WATCHMAN device has not been reported. Methods and Results: Fifty‐eight consecutive patients who had undergone WATCHMAN device implant were included in the study. Intraprocedural, 45‐day and 12‐month transesophageal echocardiogram images were reviewed and analyzed. Peridevice gap was noted in 16 (27.6%), 17 (29.3%), and 20 (34.5%) patients across the 3 time points. Intraprocedural gaps are more likely to be persistent until 12 months and become larger in size over time. New gap also occurs during follow‐up even if the LAA was completely sealed at implantation. One patient had an ischemic stroke 4.7 months after implant; another patient developed a left atrial thrombus over the device 21.6 months after implant. Both patients had intraprocedural gap and discontinued warfarin therapy after the 45‐day evaluation. Conclusion: Incomplete LAA occlusion with a gap between the WATCHMAN device surface and the LAA wall is relatively common. Intraprocedural gaps are more likely to become bigger over time and persist, while new gaps also occur during follow‐up. Further studies are warranted to verify whether the presence and persistence of a peridevice gap is associated with increased risk of thromboembolic event in AF patients implanted with a WATCHMAN device. (J Cardiovasc Electrophysiol, Vol. 23, pp. 455‐461, May 2012)     

Left atrial appendage closure with amplatzer cardiac plug in atrial fibrillation: Initial european experience

Background: In most patients with atrial fibrillation (AF) and stroke, there is thrombotic embolization from the left atrial appendage (LAA). Percutaneous closure of the LAA is a novel alternative for the treatment of patients with AF at a high risk of stroke, in whom long‐term anticoagulation therapy is not possible or not desired. This study details the initial experience with the Amplatzer Cardiac Plug (ACP) in humans. Methods: Investigator‐initiated retrospective preregistry data collection to evaluate procedural feasibility and safety up to 24 hr after implantation of the ACP, a nitinol device designed for percutaneous trans‐septal implantation in LAA of patients with paroxysmal, permanent, or persistent AF. Results: In 137 of 143 patients, LAA occlusion was attempted, and successfully performed in 132 (96%). There were serious complications in 10 (7.0%) patients (three patients with ischemic stroke; two patients experienced device embolization, both percutaneously recaptured; and five patients with clinically significant pericardial effusions). Minor complications were insignificant pericardial effusions in four, transient myocardial ischemia in two, and loss of the implant in the venous system in one patient. Conclusion: The implantation of the ACP device is a feasible method for percutaneous occlusion of the LAA. © 2011 Wiley‐Liss, Inc.     

Use of intracardiac echocardiography to guide implantation of a left atrial appendage occlusion device (PLAATO).

BACKGROUND: Over 90% of thrombi in atrial fibrillation (AF) originate from the left atrial appendage (LAA). Patients with contraindications to anticoagulation are potential candidates for LAA occlusion using the Percutaneous Left Atrial Appendage Transcatheter Occlusion system (PLAATO, ev3 Inc., Plymouth, MN). Transesophageal echocardiography (TEE) is typically used to guide implantation. OBJECTIVE: This study sought to examine the utility of intracardiac echocardiography (ICE) in providing adequate imaging guidance as an alternative to TEE during PLAATO implantation. METHODS: The study group consisted of 10 patients who underwent PLAATO implantation with simultaneous TEE and ICE imaging guidance. ICE was used to perform the following tasks typically fulfilled by TEE: (1) verification of the absence of LAA thrombus, (2) identification of the LAA ostial dimension for device sizing, (3) guidance of transseptal puncture, (4) verification of the delivery sheath position, and (5) confirmation of location and stability of device before its irrecoverable release. The ability of ICE to perform these tasks was assessed from three separate positions: the standard right atrial (RA) position, within the coronary sinus (CS), and the right ventricular outflow tract. RESULTS: ICE imaging of the LAA was optimal from within the CS, although imaging from the proximal pulmonary artery provided better visualization of the distal LAA in cross-section. The LAA dimensions, confirmation of the absence of LAA thrombus, proper positioning of the delivery sheath, verification of location and stability of the device obtained by ICE were consistent with findings from TEE. CONCLUSION: Using nonconventional imaging planes, ICE imaging was able to perform the intraprocedural functions provided by TEE during implantation of the PLAATO left atrial appendage occlusion device.     

Stroke Prevention in Atrial Fibrillation: Atrial Appendage Closure

The left atrial appendage (LAA) is the primary nonvalvular cause of cardioembolic stroke in patients with atrial fibrillation (AF). Warfarin and direct thrombin inhibitors such as dabigatran are presumed to prevent formation of LAA thrombus, and are first-line treatments to prevent ischemic stroke in AF. However, these medications carry many contraindications such as hemorrhage, and can interact with many drugs and supplements. Epicardial and endovascular techniques for occlusion of LAA are being explored, whether to mitigate the need for anticoagulation in patients at risk of bleeding or as a first-line therapy to reduce the risk of thromboembolic stroke. The purposes of this article are to 1) review the LAA structure and its potential contribution to ischemic stroke; 2) discuss the results of surgical and endovascular trials of LAA occlusion on risk of stroke and adverse events in AF patients; and 3) present early data on devices in development.     

Percutaneous left atrial appendage transcatheter occlusion (PLAATO system) to prevent stroke in high-risk patients with non-rheumatic atrial fibrillation: results from the international multi-center feasibility trials

OBJECTIVES: These studies were conducted to evaluate the feasibility of percutaneous left atrial appendage (LAA) occlusion using the PLAATO system (ev3 Inc., Plymouth, Minnesota). BACKGROUND: Patients with atrial fibrillation (AF) have a five-fold increased risk for stroke. Other studies have shown that more than 90% of atrial thrombi in patients with non-rheumatic AF originate in the LAA. Transvenous closure of the LAA is a new approach in preventing embolism in these patients. METHODS: Within two prospective, multi-center trials, LAA occlusion was attempted in 111 patients (age 71 +/- 9 years). All patients had a contraindication for anticoagulation therapy and at least one additional risk factor for stroke. The primary end point was incidence of major adverse events (MAEs), a composite of stroke, cardiac or neurological death, myocardial infarction, and requirement for procedure-related cardiovascular surgery within the first month. RESULTS: Implantation was successful in 108 of 111 patients (97.3%, 95% confidence interval [CI] 92.3% to 99.4%) who underwent 113 procedures. One patient (0.9%, 95% CI 0.02% to 4.9%) experienced two MAEs within the first 30 days: need for cardiovascular surgery and in-hospital neurological death. Three other patients underwent in-hospital pericardiocentesis due to a hemopericardium. Average follow-up was 9.8 months. Two patients experienced stroke. No migration or mobile thrombus was noted on transesophageal echocardiogram at one and six months after device implantation. CONCLUSIONS: Closing the LAA using the PLAATO system is feasible and can be performed at acceptable risk. It may become an alternative in patients with AF and a contraindication for lifelong anticoagulation treatment.     

Interventioneller Vorhofohrverschluss zur Schlaganfallprophylaxe bei Vorhofflimmern

Ischemic stroke is a major risk factor for morbidity and mortality in western societies. Besides oral anticoagulation (OAC), interventional left atrial appendage (LAA) occlusion has been recently introduced for stroke prophylaxis in patients with atrial fibrillation. This procedure has proven its non-inferiority to OAC in terms of safety and efficacy in randomized trials. So far mainly patients with contraindications to OAC or with an elevated risk for both embolic and bleeding events have been treated with LAA occlusion devices. Various devices are currently in use in the clinical routine, mainly using a transseptal access to the LAA. It has been shown that in experienced centers the procedure can be performed with a minimum risk for serious complications. After successful LAA occlusion dual anti-platelet therapy or OAC is necessary until the device is fully endothelialized after approximately 3 months. In the clinical practice a dual platelet inhibition is often used; however, data from large registries imply that OAC can most likely be safely discontinued directly after implantation. Interventional LAA occlusion is therefore a viable option for stroke prevention in atrial fibrillation.     

Cardiac embolism after implantable cardiac defibrillator shock in non-anticoagulated atrial fibrillation:The role of left atrial appendage occlusion

Cardioembolic events are one of the most feared complications in patients with non-valvular atrial fibrillation(NVAF) and a formal contraindication to oral anticoagulation(OAC).The present case report describes a case of massive peripheral embolism after an implantable cardiac defibrillator(ICD) shock in a patient with NVAF and a formal contraindication to OAC due to previous intracranial hemorrhage.In order to reduce the risk of future cardioembolic events,the patient underwent percutaneous left atrial appendage(LAA) occlusion.A 25 mm AmplatzerTM Amulet was implanted and the patient was discharged the following day without complications.The potential risk of thrombus dislodgement after an electrical shock in patients with NVAF and no anticoagulation constitutes a particular scenario that might be associated with an additional cardioembolicrisk.Although LAA occlusion is a relatively new technique,its usage is rapidly expanding worldwide and constitutes a very valid alternative for patients with NVAF and a formal contraindication to OAC.     

Perkutaner Vorhofohrverschluss

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia affecting up to 10–15?% of the population aged over 80 years. Oral anticoagulation (OAC) is necessary in the majority of AF patients for prevention of left atrial thrombus formation and thromboembolism of cardiac origin which are responsible for approximately 20–30?% of strokes. Thus, a considerable risk reduction can be achieved; however, OAC is associated with an increased bleeding risk. Many AF patients are not treated by OAC due to a history of bleeding complications or an increased bleeding risk. As over 90?% of thrombi in non-valvular AF develop in the left atrial appendage (LAA) percutaneous occlusion of the LAA is an alternative concept for the prevention of cardiovascular thromboembolism in AF patients. Currently, the most widely used occlusion devices are the WATCHMAN device and the Amplatzer Cardiac Plug. Available data records indicate that closure of the LAA is as equally effective as OAC. Moreover, with increasing experience percutaneous occlusion of the LAA can be performed with low complication rates. Therefore, according to the current guidelines of the European Society of Cardiology (ESC) this intervention is recommended as an alternative therapy, especially in patients with a high stroke risk and contraindications for OAC.     

Thrombus‐in‐Transit Following Watchman Device Implantation

Thrombus‐in‐transit crossing an interatrial communication is a rare but potentially serious clinical condition, which has so far not been described after implantation of left atrial appendage (LAA) closure devices. Here, we describe the case of a 76‐year‐old woman with permanent atrial fibrillation and contraindication for oral anticoagulation therapy, who developed pericardial tamponade and acute pulmonary embolism with visible thrombus‐in‐transit formation following LAA closure. Most likely manipulation of the Watchman device in the LAA during two failed attempts in device positioning led to pericardial tamponade and venous puncture, manual compression after completion of the procedure and further immobilization resulted in deep vein thrombosis with consecutive pulmonary embolism and thrombus‐in‐transit formation. This case highlights the value of echocardiography after LAA closure.     

The role of echocardiography in percutaneous left atrial appendage occlusion

Percutaneous device closure of the left atrial appendage (LAA) has been introduced in the last decade as a minimally invasive alternative treatment to long-term anticoagulation to reduce the risk of thrombo-embolism in patients with atrial fibrillation. Echocardiography is an essential tool at all stages of the procedure. Pre-procedural echocardiography is used to screen suitable candidates and to define LAA morphology and dimension; peri-procedural transoesophageal or intracardiac echocardiography has a major role in guiding, delivery, and deployment of the device, for screening of procedural complications and for assessing procedural success; and post-procedural echocardiography is important in the surveillance and monitoring of long-term outcome. This article aims to outline the role of echocardiography at each stage of LAA occlusion.     

左心耳封堵策略选择

心房颤动是临床上最常见的心律失常之一,血栓栓塞并发症是其致残、致死的主要原因。经食管超声检查发现,非瓣膜性房颤患者心房内血栓90%位于左心耳。因此,预防左心耳血栓形成可能会减少血栓栓塞事件的发生。口服抗凝药是预防房颤血栓栓塞并发症的有效方法,但是很多患者不能耐受口服抗凝药药物治疗。随着心血管介入治疗和器械研发的进展,经皮左心耳封堵预防卒中越来越受到关注,已经成为一种替代华法林预防房颤并发卒中的有效方法。     

Incomplete occlusion of the left atrial appendage with the percutaneous left atrial appendage transcatheter occlusion device is not associated with increased risk of stroke

Background  

Percutaneous approaches to left atrial appendage (LAA) closure are being developed for stroke prophylaxis in atrial fibrillation patients as an alternative to warfarin. Non-randomized clinical trials suggested that the first of these devices, the percutaneous left atrial appendage transcatheter occlusion (PLAATO) device, is safe and reduces stroke risk. Percutaneous closure has the potential limitation of incomplete exclusion of LAA from the systemic circulation, which could potentially lead to thrombus formation and stroke. This study investigated the interaction between residual blood flow in the LAA after percutaneous closure with PLAATO and risk of stroke.     

Future epidemic impact of atrial fibrillation and a new interventional strategy for stroke prophylaxis

The rising incidence of atrial fibrillation (AF) and its most fatal consequences, cerebral ischemic attacks, will be of increasing relevance in the future. One third to one half of AF patients are ineligible for oral anticoagulation and even after stroke, only approximately every second patient receives oral anticoagulation. Apart from that, the risk of bleeding is indefinite and escalates with age, arterial hypertension, cerebrovascular disease and renal insufficiency. Anticoagulation with new oral compounds may be easier to handle but a significant risk of major bleeding remains. Since over 90% of all thrombi in AF are located in the left atrial appendage (LAA), the idea of excluding this source of emboli, thereby reducing the risk of stroke by approximately 90% without anticoagulation, has arisen. Since 2001, devices for transcatheter occlusion of the LAA have been available, offering a minimally invasive intervention. Currently, two dedicated occluders are approved in Europe, the Amplatzer Cardiac Plug and the WATCHMAN device. Percutaneous occlusion of the LAA is technically feasible and safe and should be considered as an alternative for patients with AF and contraindications or disfavor against oral anticoagulation.     

Percutaneous transcatheter left atrial appendage exclusion in atrial fibrillation

Stroke is one of the leading causes of mortality, morbidity and serious disability in the developed world. Atrial fibrillation (AF), one of the most common cardiac arrhythmias, is a well-known predisposing factor for stroke, raising the risk significantly. Oral anticoagulation with warfarin is currently the most effective therapy for stroke risk reduction; however, this therapy increases the risk of bleeding and is often underutilized, contraindicated, or when administered, often subtherapeutic. It has been documented that the left atrial appendage (LAA) is the main source of left atrial thrombus, especially in non-rheumatic AF. Therefore, LAA exclusion may reduce the risk of stroke in AF, and retrospective surgical data have demonstrated a reduced risk of embolic events if surgical LAA exclusion was also performed during mitral valve replacement. Recently, several less invasive percutaneous transcatheter techniques of LAA exclusion - the PLAATO device, the Watchman device, and the Amplatzer Septal Occluder - have been employed with initially encouraging results. There is currently an ongoing randomized trial comparing percutaneous LAA exclusion to long-term oral anticoagulation therapy. Until such data are available, however, oral anticoagulation should remain the standard of care for stroke prevention in patients with AF.     

Prevalence and Clinical Characteristics Associated With Left Atrial Appendage Thrombus in Fully Anticoagulated Patients Undergoing Catheter‐Directed Atrial Fibrillation Ablation

LAA Thrombus Among Anticoagulated AF Patients. Introduction: Catheter‐directed atrial fibrillation (AF) ablation is contraindicated among patients with left atrial appendage (LAA) thrombus. The prevalence of LAA thrombus among fully anticoagulated patients undergoing AF ablation is unknown. Methods and Results: We retrospectively evaluated the prevalence of LAA thrombus among 192 consecutive patients undergoing AF ablation between July 2006 and January 2009. Seven of 192 patients (3.6%) had evidence of thrombus on transesophageal echocardiogram (TEE) despite being fully anticoagulated on warfarin (international normalized ratio [INR] 2–3) for 4 consecutive weeks prior to echocardiogram. Univariate analysis demonstrated that structural heart disease, large left atrial dimension, and number of AF ablations were associated with thrombus. Three patients with thrombus had paroxysmal AF with normal LV function. Conclusion: Despite full anticoagulation, 3.6% of patients undergoing AF ablation had LAA thrombus. We recommend that all patients, regardless of LV function or left atrial size, should undergo preprocedural TEE to exclude the presence of LAA thrombus. (J Cardiovasc Electrophysiol, Vol. 21, pp. 849‐852, August 2010)