Is left atrial appendage occlusion useful for prevention of stroke or embolism in atrial fibrillation?

Summary Since in atrial fibrillation more than 90% of the thrombi are located in the left atrial appendage, an “elimination” of the left atrial appendage, either by resection or occlusion, seems an attractive alternative to oral anticoagulation. Although frequently regarded as an useless appendage, data from animal and human investigations show that the left atrial appendage may play an important role in the maintenance and regulation of the cardiac function, especially in arterial hypertension, atrial fibrillation, coronary heart disease, valvular heart disease and heart failure. Elimination of the left atrial appendage may impede thirst in hypovolemia, deteriorate hemodynamic responses to volume or pressure overload, decrease cardiac output and promote heart failure. Instead of preventing stroke, the consequences of left atrial appendage elimination may create new risk factors for stroke and thus might induce more harm than benefit to patients with atrial fibrillation. As long as the physiologic and pathophysiologic role of the left atrial appendage is not fully understood, left atrial appendage elimination should not be an alternative to oral anticoagulation. Received: 25 January 2002 Accepted: 29 January 2002     

An Endovascular Approach to Cardioembolic Stroke Prevention in Atrial Fibrillation Patients

This report is of a 62-year-old woman presenting with a 3-year history of chronic atrial fibrillation (AF) and unable to tolerate chronic warfarin therapy due to bleeding episodes and unstable INR values. Additional high risk factors for stroke are a history of congestive heart failure and previous embolic stroke. Percutaneous left atrial appendage transcatheter occlusion (PLAATO™) was performed to seal the LAA. A transesophageal echocardiography (TEE) at the 1- and 6-month follow-up showed no device migration and no new thrombus related to the implant. The patient has been doing well on postprocedure aspirin with no embolic events. (PACE 2003; 26[Pt. II]:1604–1606)     

Percutaneous Retrieval of Dislodged Left Atrial Appendage Occlusion Devices through the Transseptal Approach

Percutaneous left atrial appendage (LAA) occlusion is a promising treatment option in patients with atrial fibrillation who have a high risk of embolic stroke and are not eligible for chronic oral anticoagulation therapy. This procedure, however, can induce several complications. Device embolization can result in a serious situation, requiring immediate and safe device removal. We report two cases in which dislodged LAA occlusion devices were flitting in the left atrium or entrapped in the mitral valve leaflets and were successfully retrieved through a transseptal approach without complications.     

Stroke in atrial fibrillation: Update on pathophysiology,new antithrombotic therapies,and evolution of procedures and devices

Atrial fibrillation (AF) is said to be an epidemic, affecting 1%–1.5% of the population in the developed world. The clinical significance of AF lies predominantly in a 5‐fold increased risk of stroke. Strokes associated with AF are usually more severe and confer increased risk of morbidity, mortality, and poor functional outcome. Despite the advent of promising experimental therapies for selected patients with acute stroke, pharmacological primary prevention remains the best approach to reducing the burden of stroke.

New antithrombotic drugs include both parenteral agents (e.g. a long‐acting factor Xa inhibitor idraparinux) and oral anticoagulants, such as oral factor Xa inhibitors and direct oral thrombin inhibitors (ximelagatran, dabigatran). Ximelagatran had shown significant potential as a possible replacement to warfarin therapy, but has been withdrawn because of potential liver toxicity. Its congener dabigatran appears to have a better safety profile and has recently entered a phase III randomized clinical trial in AF. Oral factor Xa inhibitors (rivaroxaban, apixaban, YM150) inhibit factor Xa directly, without antithrombin III mediation, and may prove to be more potent and safe.

Selective inhibitors of specific coagulation factors involved in the initiation and propagation of the coagulation cascade (factor IXa, factor VIIa, circulating tissue factor) are at an early stage of development. Additional new agents with hypothetical, although not yet proven, anticoagulation benefits include nematode anticoagulant peptide (NAPc2), protein C derivatives, and soluble thrombomodulin.

A battery of novel mechanical approaches for the prevention of cardioembolic stroke has recently been evaluated, including various models of percutaneous left atrial appendage occluders which block the connection between the left atrium and the left atrial appendage, minimally invasive surgical isolation of the left atrial appendage, and implantation of the carotid filtering devices which divert large emboli from the internal to the external carotid artery, preventing the embolic material from reaching intracranial circulation.

Despite recent advances and promising new approaches, prevention of recurrent AF may be one of the best protections against AF‐related stroke and may reduce the prevalence of stroke by almost 25%. Improved pharmacological and nonpharmacological rhythm control strategies for AF as well as primary prevention of AF with ‘upstream’ therapy and risk factor modification are likely to produce a larger effect on the reduction of stroke rates in the general population than will specific interventions.     

Left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation

The most severe consequence of atrial fibrillation (AF) is a cardioembolic stroke. The incidence of cardioembolic stroke increases significantly in patients with AF. Although warfarin has been the mainstay of the prevention of cardioembolic stroke, there are several limitations to the use of warfarin that hinder its effectiveness. This article provides the historical development of devices that exclude the left atrial appendage, their effectiveness and potential patient selection, as an alternative to warfarin and the novel oral anticoagulation therapy for the prevention of cardioembolic stroke in patients with AF.     

Usefulness of an isoproterenol infusion to differentiate a left atrial appendage thrombus in a patient with nonvalvular atrial fibrillation

A 78‐year‐old male with a history of a cardiac embolic stroke due to persistent AF and cerebral bleeding (CHADS2 score 4, HAS‐BLED score 4) was referred to our hospital to implant a left atrial appendage (LAA) closure (LAAC) device. A trans esophageal echocardiography was performed and a high echoic lesion that was difficult to differentiate the spontaneous echo contrast or thrombus was found in the LAA cavity. After isoproterenol infusion, a high echoic lesion disappeared and we confirmed that it was not an LAA thrombus. Successful LAAC device implantation was performed without any thromboembolic events.     

超声心动图在非瓣膜性心房颤动患者经皮左心耳封堵术中的应用进展

目前,经皮左心耳封堵术被推荐用于高卒中风险、不能耐受长期抗凝治疗的非瓣膜性心房颤动患者的卒中预防。经胸超声心动图和经食管超声心动图不仅在经皮左心耳封堵术前患者的筛选、左心耳形态和大小的观测,以及术中封堵器选择和置入过程的实时监控中发挥重要作用,同时还有利于术后封堵器位置和心功能的评估,其中经食管超声心动图已经成为经皮左心耳封堵术必不可少的术中影像学监控手段。本文就超声心动图在非瓣膜性心房颤动患者经皮左心耳封堵术中的应用进展进行综述。     

Safety and efficacy analysis of one‐stop intervention for treating nonvalvular atrial fibrillation

1 Background

Nonvalvular atrial fibrillation (AF) is a common arrhythmia. The treatment strategy for AF mainly includes controlling symptoms and decreasing the rate of complications. Our study aimed to evaluate the safety and efficacy of combination treatment of catheter ablation and left atrial appendage (LAA) closure (one‐stop intervention) in patients with nonvalvular AF.

2 Methods and results

Thirty‐four patients with symptomatic AF (mean CHA₂DS₂‐VASc score 4.1 ± 1.3, mean HAS‐BLED score 3.8 ± 1.2) were included. Patients first received radiofrequency‐based left atrial ablation, and then the Watchman device (Boston Scientific, Natick, MA, USA) or AMPLATZER Cardiac Plug (ACP) (St. Jude Medical, Inc., St. Paul, MN, USA) was implanted for LAA closure. Follow‐up was performed at 45 days and 3 months after LAA closure to assess for recurrence of AF and prevent stroke. Radiofrequency ablation and LAA closure were successful in 100% of patients without evidence of residual flow at the final transesophageal echocardiography evaluation. A Watchman device was implanted in 29 (85.3%) patients, and an ACP was implanted in five (14.7%) patients. No device‐related thrombus formation or embolization was identified at the 45‐day or 3‐month follow‐up. Serious complications, including death, transient ischemic attack, ischemic or hemorrhagic stroke, or major bleeding, were also not identified during the follow‐ups.

3 Conclusion

For symptomatic patients with nonvalvular AF and a high risk of stroke, the one‐stop intervention is feasible, safe, and efficacious.     

经食管超声心动图在经皮WATCHMAN 左心耳封堵术中的应用体会

目的 通过对经食管超声心动图（transesophageal echocardiography ,TEE）获取的一组真实的临床数据的分析,认识TEE在心房颤动患者左心耳封堵术中及随访中的应用价值。方法 选取2015年3月至2017年4月于我院确诊房颤且行WATCHMAN左心耳经皮介入封堵术的患者为对象,通过TEE观察记录术中、随访45天、6个月封堵器效果,包括残余分流、有无血栓及封堵器压缩径。结果 共收集243例行左心耳经皮介入封堵术的房颤病例,成功植入WATCHMAN封堵器的病例为241例（99.2%）,围术期发现心脏压塞2例（0.83%）,发现器械血栓1例（0.41%）;随访45天时,发现器械血栓3例（1.36%）;随访6个月时,未发生器械相关血栓事件、死亡等重大不良事件。结论 TEE在WATCHMAN左心耳封堵术中及术后起到了重要的作用,其对手术效果及术后并发症的评估准确、客观、及时,值得推荐临床应用。     

心房颤动抗凝治疗进展

心房颤动是临床上最常见的心律失常,增加卒中风险。华法林抗凝效果虽已受到广泛的肯定,但同时存在出血风险、治疗窗狭窄、需要长期监测国际标准化比率以调整药量等缺点。新型口服抗凝药的应用如达比加群、利伐沙班、阿哌沙班可有效预防卒中及血栓栓塞。经皮左心耳封堵术亦可成为预防心房颤动血栓事件的有效替代治疗方式。     

Nonpharmacologic stroke prevention in atrial fibrillation

Atrial fibrillation is associated with significant mortality and morbidity. The burden of morbidity in atrial fibrillation is mostly due to stroke, one of the major causes of death and the leading cause of long-term disability. Although highly effective in prevention of thromboembolic stroke, several factors limit utilization of chronic oral anticoagulation therapy. Eradication of atrial fibrillation and restoration of effective atrial contraction by surgical methods, or recently, by percutaneous catheter ablation methods, are two attractive approaches for stroke prophylaxis. Surgical exclusion of the left atrial appendage has generated considerable interest in the past decades and it is now performed routinely during mitral valve surgery in many centers. Recently, minimally invasive and percutaneous methods for the exclusion of left atrial appendage have been introduced. Currently, these approaches are being evaluated in ongoing trials. This review will discuss the current status of nonpharmacologic methods in the prevention of stroke in atrial fibrillation.     

Transcatheter occlusion of the left atrial appendage for stroke prevention

Patients with atrial fibrillation are at an increased risk of having a cardioembolic stroke. Most of the thrombi responsible for these ischemic events originate in the left atrial appendage. Percutaneous occlusion of the left atrial appendange is a new approach to stroke prevention in patients with atrial fibrillation and contraindication for long-term warfarin treatment. Three different devices have been used so far: the PLAATO? system, the WATCHMAN® filter system and the Amplatzer® septal occluder. Left atrial appendage occlusion using these devices is feasible and safe and has shown promising results. The risk of stroke in atrial fibrillation patients appears to be reduced.     

左心耳封堵在非瓣膜性心房颤动卒中的预防作用

血栓栓塞事件是心房颤动(房颤)最严重的并发症,及早识别并预防其栓塞风险至关重要。传统的抗凝治疗在预防非瓣膜性房颤患者的血栓栓塞事件方面存在一定局限性。左心耳部被证实为房颤患者血栓形成的主要部位,这一发现促使了经皮左心耳封堵技术的迅速发展。与抗凝药物相比,经皮左心耳封堵术可有效降低房颤患者血栓栓塞事件的发生率,且适用于抗凝禁忌的房颤患者。目前,WATCHMAN与ACP封堵装置已被授权进入欧盟市场,LARIAT左心耳结扎装置也因其有效性及安全性被美国FDA批准应用。经皮左心耳封堵及结扎术的适应证广,安全性高,有望成为多数房颤患者预防血栓栓塞事件的选择。     

Left atrial appendage aneurysm presenting with recurrent embolic strokes

A case of left atrial appendage aneurysm is described in a 40-year-old man, who presented with recurrent embolic strokes and was asymptomatic until the last 6 months. Chest X-ray revealed a slightly prominent upper left heart border. The diagnosis was made by transthoracic two-dimensional echocardiography and confirmed by transesophageal echocardiography, magnetic resonance imaging and also by surgery.     

经食管超声心动图对心房颤动患者右心耳自发显影回声和血栓发生的研究

目的探讨经食管超声心动图(TEE)观察慢性心房颤动(房颤)时右心房、右心耳自发显影(SEC)和血栓发生情况。方法选取26例房颤患者和13例窦性心律患者，常规经胸超声心动图资料留取后，采用TEE充分清楚显示左、右心耳图像并采集血流流速曲线和其他相应指标。结果26例房颤患者左心耳内均可测及SEC，共测及血栓形成者10例；房颤患者右心耳内有SEC者共17例，共测及右心耳血栓形成者1例。结论房颤时右心耳内可有血栓发生，TEE检查在房颤抗凝治疗中和复律前后具有重要意义。     

经食管超声心动图对房颤时左右心耳血流频谱的对比研究

目的　探讨房颤时左、右心耳血流频谱的形态特点能否反映左、右心房的激动模式。方法　选取2 6例房颤患者,常规经胸超声资料的留取后,采用经食管超声心动图技术,充分清楚显示左、右心耳图像并采集血流频谱和其它相应指标。结果　房颤时,左右心耳血流频谱类型表现不一致。结论　经食管超声心动图对左右心耳血流频谱的研究为房颤时左右心房激动模式提供信息     

Transesophageal Echocardiography in Patients with Atrial Fibrillation

Over the past decade transesophageal echocardiography (TEE) has become an integral tool in the management of patients with AF. Thrombi can be readily detected and the function of the left atrium and left atrial appendage (LAA) can be easily assessed by this modality. With this knowledge, informed decisions regarding anticoagulation, cardioversion, and the likelihood of restoring and maintaining sinus rhythm can be made. An alternative TEE-guided strategy for achieving sinus rhythm in patients with AF is now available with efficacy and safety similar to the conventional approach. Refinements of this strategy may include the use of low molecular weight heparin to avoid hospitalization in patients planned for cardioversion. Further uses of TEE in patients with AF are in their early stages including evaluation of patients following pulmonary vein radiofrequency ablation and those undergoing percutaneous or surgical closure of the LAA. (PACE 2003; 26[Pt. II]:1597–1603)     

经皮左心耳封堵的研究进展

心房颤动（房颤）在人群中的发病率逐年升高,成为临床中最常见的心律失常之一。脑栓塞是房颤最主要的并发症。抗凝治疗仍然是预防房颤脑卒中的主要手段,但无论是华法林还是新型抗凝药都有一定的局限性,存在相关的风险及禁忌,且依从性差。鉴于非瓣膜病性房颤患者90%以上的血栓来源于左心耳（LAA),故对于一些栓塞风险高的房颤患者,经皮左心耳封堵术已成为长期华法林替代治疗以降低新发脑卒中风险的另一选择。     

Amulet IDE临床试验对左心耳封堵领域的启示

左心耳封堵术为预防心房颤动患者发生卒中事件的重要手段。目前,临床上已有多种形态结构的左心耳封堵器械。然而,左心耳结构复杂多样,单一类型封堵器无法满足临床需要,因此业界一直在不断改进左心耳封堵器,相关临床研究也成为了热点。Amulet IDE临床试验作为首个把2种常用的左心耳封堵器进行比较的RCT研究,其研究结果对经导管左心耳封堵技术的发展有很强的指导意义。     

斑点追踪成像技术评估非瓣膜性房颤左心耳血栓形成的研究进展

非瓣膜性心房颤动是临床上常见的心律失常类型之一,容易形成心房血栓,导致脑卒中、血栓栓塞、心力衰竭等疾病的风险增加。大部分非瓣膜性房颤患者血栓形成于左心耳。因此,早期发现和预测左心耳血栓形成对全身栓塞的诊治和预防有重要临床意义。斑点追踪成像在评价左心耳血栓形成方面的价值尚不清楚,本文旨在对斑点追踪成像技术评估非瓣膜性房颤患者左心耳血栓形成的价值进行综述。