Interventional treatments for stroke prevention in atrial fibrillation with emphasis upon the WATCHMAN device

Percutaneous left atrial appendage closure with SeaLA device in non-valvular atrial fibrillation

OBJECTIVES

The clinical efficacy and safety of a novel left atrial appendage (LAA) occluder of the SeaLA closure system in patients with nonvalvular atrial fibrillation (NVAF) were reported.

BACKGROUND

Patients with NVAF are at a higher risk of stroke compared to healthy individuals. Left atrial appendage closure (LAAC) has emerged as a prominent strategy for reducing the risk of thrombosis in individuals with NVAF.

METHODS

A prospective, multicenter study was conducted in NVAF patients with a high risk of stroke.

RESULTS

The LAAC was successfully performed in 163 patients. The mean age was 66.93 ± 7.92 years, with a mean preoperative CHA2DS2-VASc score of 4.17 ± 1.48. One patient with residual flow >3 mm was observed at the 6-month follow-up, confirmed by TEE. During the follow-up, 2 severe pericardiac effusions were noted, and 2 ischemic strokes were observed. Four device-related thromboses were resolved after anticoagulation treatment. There was no device embolism.

CONCLUSIONS

The LAAC with the SeaLA device demonstrates encouraging feasibility, safety, and efficacy outcomes.

Percutaneous Closure of the Left Atrial Appendage

This article reviews the published evidence on stroke prevention with percutaneous closure of the left atrial appendage and provides comparative insight into the various left atrial appendage closure devices currently in development.

Catheter-based left atrial appendage occlusion procedure: role of echocardiography

Atrial fibrillation is a common, clinically significant arrhythmic disorder that results in increased risk of morbidity and mortality in affected patients. Atrial fibrillation is more prevalent among men compared with women and the risk for developing atrial fibrillation increases with advancing age. Ischaemic stroke is the most common clinical manifestation of embolic events from atrial fibrillation. While anticoagulation treatment is the preferred treatment, unfortunately, many patients have contraindications for anticoagulation treatment making this option unavailable to them. Previous data have shown that most thrombi that form in association with non-valvular atrial fibrillation occur in the left atrial appendage (LAA). It has been suggested that isolating the LAA from the body of the left atrium might reduce the risk of embolic events and that LAA obliteration may be a treatment option for patients with atrial fibrillation who are not candidates for anticoagulation treatment. Several procedures have been developed for isolation of the LAA, including surgical procedures as well as catheter-based ones. In this paper, we will review the currently available techniques, emphasizing the catheter-based ones. We will examine the increasing role of real-time three-dimensional transoesophageal echocardiography for appropriate screening and patient selection for these procedures, intra-procedural guidance, and follow-up care.

Surgical treatment of atrial fibrillation: a review

Atrial fibrillation is the most commonly sustained arrhythmia in man. While it affects millions of patients worldwide, its incidence will markedly increase with an aging population. Primary goals of AF therapy are to (1) reduce embolic complications, particularly stroke, (2) alleviate symptoms, and (3) prevent long-term heart remodelling. These have been proven to be a challenge as there are major limitations in our knowledge of the pathological and electrophysiological mechanisms underlying AF. Although advances continue to be made in the medical management of this condition, pharmacotherapy is often unsuccessful. Because of the high recurrence rate of AF despite antiarrhythmic drug therapy for maintenance of sinus rhythm and the adverse effects of these drugs, there has been growing interest in nonpharmacological strategies. Surgery for treatment of AF has been around for some time. The Cox-Maze procedure is the gold standard for the surgical treatment of atrial fibrillation and has more than 90% success in eliminating atrial fibrillation. Although the cut and sew maze is very effective, it has been superseded by newer operations that rely on alternate energy sources to create lines of conduction block. In addition, the evolution of improved ablation technology and instrumentation has facilitated the development of minimally invasive approaches. In this paper, the rationale for surgical ablation for atrial fibrillation and the different surgical techniques that were developed will be explored. In addition, it will detail the new approaches to surgical ablation of atrial fibrillation that employ alternate energy sources.

[Techniques for occlusion of the left atrial appendage: chances and risks]

Atrial fibrillation causes 15-20% of ischemic strokes and the overall risk of stroke in patients with non-valvular atrial fibrillation is about 5% per year globally. Warfarin has long been the cornerstone for decreasing risks of stroke in patients with atrial fibrillation and its efficacy has been well established. However, 14-44% of patients with atrial fibrillation who are at risk of stroke are ineligible for anticoagulation therapy, mostly owing to the risks of major bleeding and falls. Occlusion of the left atrial appendage (LAA) appears to be an interesting new tool to prevent thromboembolic events in selected cases. In addition to surgical techniques, percutaneous transcatheter approaches have been introduced to occlude the LAA. Recent results indicate non-inferiority of mechanical occlusion of the LAA in comparison to warfarin therapy.

Use of real time three-dimensional transesophageal echocardiography in intracardiac catheter based interventions

BACKGROUND

Real-time three-dimensional (RT3D) echocardiography is a recently developed technique that is being increasingly used in echocardiography laboratories. Over the past several years, improvements in transducer technologies have allowed development of a full matrix-array transducer that allows acquisition of pyramidal-shaped data sets. These data sets can be processed online and offline to allow accurate evaluation of cardiac structures, volumes, and mass. More recently, a transesophageal transducer with RT3D capabilities has been developed. This allows acquisition of high-quality RT3D images on transesophageal echocardiography (TEE). Percutaneous catheter-based procedures have gained growing acceptance in the cardiac procedural armamentarium. Advances in technology and technical skills allow increasingly complex procedures to be performed using a catheter-based approach, thus obviating the need for open-heart surgery.

METHODS

The authors used RT3D TEE to guide 72 catheter-based cardiac interventions. The procedures included the occlusion of atrial septal defects or patent foramen ovales (n=25), percutaneous mitral valve repair (e-valve clipping; n=3), mitral balloon valvuloplasty for mitral stenosis (n=10), left atrial appendage obliteration (n=11), left atrial or pulmonary vein ablation for atrial fibrillation (n=5), percutaneous closures of prosthetic valve dehiscence (n=10), percutaneous aortic valve replacement (n=6), and percutaneous closures of ventricular septal defects (n=2). In this review, the authors describe their experience with this technique, the added value over multiplanar two-dimensional TEE, and the pitfalls that were encountered.

RESULTS

The main advantages found for the use RT3D TEE during catheter-based interventions were (1) the ability to visualize the entire lengths of intracardiac catheters, including the tips of all catheters and the balloons or devices they carry, along with a clear depiction of their positions in relation to other cardiac structures, and (2) the ability to ability to demonstrate certain structures in an "en face" view, which is not offered by any other currently available real-time imaging technique, enabling appreciation of the exact nature of the lesion that is undergoing intervention.

CONCLUSION

RT3D TEE is a powerful new imaging tool that may become the technique of choice and the standard of care for guidance of selected percutaneous catheter-based procedures.