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

Intracardiac echocardiography is a promising strategy for guiding closure of the left atrial appendage

Background and Aims

Percutaneous transcatheter left atrial appendage (LAA) closure (LAAC) is an effective approach for preventing ischemic stroke in nonvalvular atrial fibrillation patients. Intracardiac echocardiography (ICE), a new imaging modality, is a promising strategy for guiding LAAC. This review highlights the various strategies for ICE-guided-LAAC as an option for clinical policy.

Methods

A comprehensive literature search was conducted of PubMed, ScienceDirect, Ovid Web of Science, SpringerLink, and other notable databases to identify recent peer-reviewed clinical trials, reviews, and research articles related to ICE and its application in the guidance of LAAC.

Results

Various methods are used to evaluate the spatial structure and dimensions of the LAA. The main techniques for guiding LAAC are transesophageal echocardiography (TEE), cardiac computed tomography (CTA), and ICE. Among these techniques, the advantages of ICE typically include (1) multiangle and real-time assessment of intracardiac structure, (2) a reduction in procedural fluoroscopy, (3) reduced operation time and improved workflow in the catheterization laboratory, and (4) the avoidance of general anesthesia and the early detection of complications.

Conclusion

ICE is a promising strategy for the guidance of LAAC. Among the most advanced and recent technological innovations in cardiovascular imaging in general and volume imaging in particular, ICE offers greater efficacy and safety.

Advances in TEE-Centric Intraprocedural Multimodal Image Guidance for Congenital and Structural Heart Disease

Percutaneous interventions are gaining rapid acceptance in cardiology and revolutionizing the treatment of structural heart disease (SHD). As new percutaneous procedures of SHD are being developed, their associated complexity and anatomical variability demand a high-resolution special understanding for intraprocedural image guidance. During the last decade, three-dimensional (3D) transesophageal echocardiography (TEE) has become one of the most accessed imaging methods for structural interventions. Although 3D-TEE can assess cardiac structures and functions in real-time, its limitations (e.g., limited field of view, image quality at a large depth, etc.) must be addressed for its universal adaptation, as well as to improve the quality of its imaging and interventions. This review aims to present the role of TEE in the intraprocedural guidance of percutaneous structural interventions. We also focus on the current and future developments required in a multimodal image integration process when using TEE to enhance the management of congenital and SHD treatments.

Echocardiographic Imaging in Transcatheter Structural Intervention: An AAE Review Paper

Transcatheter structural heart intervention (TSHI) has gained popularity over the past decade as a means of cardiac intervention in patients with prohibitive surgical risks. Following the exponential rise in cases and devices developed over the period, there has been increased focus on developing the role of "structural imagers" amongst cardiologists. This review, as part of a growing initiative to develop the field of interventional echocardiography, aims to highlight the role of echocardiography in myriad TSHIs available within Asia. We first discuss the various echocardiography-based imaging modalities, including 3-dimensional echocardiography, fusion imaging, and intracardiac echocardiography. We then highlight a selected list of structural interventions available in the region-a combination of established interventions alongside novel approaches-describing key anatomic and pathologic characteristics related to the relevant structural heart diseases, before delving into various aspects of echocardiography imaging for each TSHI.

Periprocedural Imaging for Left Atrial Appendage Closure: Computed Tomography, Transesophageal Echocardiography, and Intracardiac Echocardiography

Percutaneous left atrial appendage closure is increasingly performed for stroke prevention for patients with nonvalvular atrial fibrillation with contraindications to oral anticoagulation. The success and complication rates with left atrial appendage closure have dramatically improved with maturing experience, growing procedural familiarity, and preprocedural planning. Multimodality imaging involving cardiac computer tomography angiography, transesophageal echocardiography, or intracardiac echocardiography in conjunction with fluoroscopy has improved the efficacy, procedural success, and safety of left atrial appendage closure in recent years. Proceduralists need to familiarize themselves with the various modalities and understand their complimentary roles and their limitations.

Novel Echocardiographic Biomarkers in the Management of Atrial Fibrillation

Purpose of Review

Atrial fibrillation (AF) is the most common arrhythmia in adults. The number of patients with AF is anticipated to increase annually, mainly due to the aging population alongside improved arrhythmia detection. AF is associated with a significantly elevated risk of hospitalization, stroke, thromboembolism, heart failure, and all-cause mortality. Echocardiography is one of the key components of routine assessment and management of AF. Therefore, the aim of this review is to briefly summarize current knowledge on “novel” echocardiographic parameters that may be of value in the management of AF patients.

Recent Findings

Novel echocardiographic biomarkers and their clinical application related to the management of AF have been taken into consideration. Both standard parameters such as atrial size and volume but also novels like atrial strain and tissue Doppler techniques have been analyzed.

Summary

A number of novel echocardiographic parameters have been proven to enable early detection of left atrial dysfunction along with increased diagnosis accuracy. This concerns particularly experienced echocardiographers. Hence, these techniques might improve the prediction of stroke and thromboembolic events among AF patients and need to be further developed and disseminated. Nonetheless, even the standard imaging parameters could be of significant value and should not be discontinued in everyday clinical practice.

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.

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

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

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.

Hybrid Imaging in the Catheter Laboratory: Real-time Fusion of Echocardiography and Fluoroscopy During Percutaneous Structural Heart Disease Interventions

Percutaneous catheter-based techniques for the treatment of structural heart disease are becoming more complex, and current imaging techniques have limitations: while fluoroscopy gives poor visualisation of cardiac anatomical structures, echocardiography is limited in its ability to detect the position of catheters and devices. The EchoNavigator® (Philips) live image guidance tool is a novel system that integrates real-time echocardiography with fluoroscopic X-ray imaging, optimising the guidance and positioning of devices. Use of the EchoNavigator system facilitates improved understanding of anatomical structures while showing enhanced visualisation of catheter and device movements. Early clinical experience suggests that the technology is feasible and safe, and provides enhanced understanding of the relationship between soft tissue anatomy and catheter devices in structural heart disease. The use of the EchoNavigator system can improve the confidence of interventional cardiologists in the targeting and positioning of devices in percutaneous interventions in structural heart disease, and has the potential to reduce procedural time, reduce the dosage of contrast and radiation and increase safety in the performance of procedural steps.

Initial clinical experience using the EchoNavigator®-system during structural heart disease interventions

AIM: To present our initial clinical experience using this innovative software solution for guidance of percutaneous structural heart disease interventions.

METHODS: Left atrial appendage, atrial septal defect and paravalvular leak closure, transaortic valve repair and MitraClip^® procedures were performed in the catheter laboratory under fluoroscopic and echocardiographic guidance. The two-dimensional and three-dimensional images generated by the transesophageal echocardiography probe were interfaced with the fluoroscopic images in real-time using the EchoNavigator^®-system.

RESULTS: The application of the novel image fusion technology was safe and led to a better appreciation of multimodality imaging guidance due to improved visualization of the complex relationship between catheter devices and anatomical structures.

CONCLUSION: The EchoNavigator^®-system is a feasible and safe tool for guidance of interventional procedures in structural heart disease. This innovative technology may improve confidence of interventional cardiologists in targeting and positioning interventional devices in order to increase safety, accuracy, and efficacy of percutaneous interventions in the catheter laboratory.

The left atrial appendage: anatomy, function, and noninvasive evaluation

The left atrial appendage (LAA) is a finger-like extension originating from the main body of the left atrium. Atrial fibrillation (AF) is the most common clinically important cardiac arrhythmia, occurring in approximately 0.4% to 1% of the general population and increasing with age to >8% in those >80 years of age. In the presence of AF thrombus, formation often occurs within the LAA because of reduced contractility and stasis; thus, attention should be given to the LAA when evaluating and assessing patients with AF to determine the risk for cardioembolic complications. It is clinically important to understand LAA anatomy and function. It is also critical to choose the optimal imaging techniques to identify or exclude LAA thrombi in the setting of AF, before cardioversion, and with current and emerging transcatheter therapies, which include mitral balloon valvuloplasty, pulmonary vein isolation, MitraClip (Abbott Laboratories, Abbott Park, Illinois) valve repair, and the implantation of LAA occlusion and exclusion devices. In this review, we present the current data regarding LAA anatomy, LAA function, and LAA imaging using the currently available noninvasive imaging modalities.

Optimized viewing angles for cardiac electrophysiology ablation procedures

PURPOSE

Catheter ablation is a common treatment option for atrial fibrillation (AF). Interventional C-arm X-ray systems are used for guiding AF procedures, employing standard view positions. Since the projection angles are not adapted to the individual patient anatomy, standard projections do not necessarily offer the best views of important anatomical structures. Using a pre-procedural 3D data set acquired with MRI or CT, suitable ablation sites (lines) can be identified in advance so an ablation plan can be superimposed on fluoroscopic images to guide the procedure.

METHODS

A method was developed to estimate optimized projection views for biplane X-ray C-arm systems based on planning data for AF ablation procedures. The estimated viewing angles were compared to standard angulations using an objective quality metric, the length of the planned ablation line as seen under X-ray. This method was tested using 35 clinical datasets annotated with planned ablation lines for ipsilateral pulmonary vein isolation.

RESULTS

The optimized views computed using the new method yielded 28 % less foreshortening of pre-planned ablation lines on average. In one case, anatomy-based view calculation lead to a 69 % reduction in foreshortening.

CONCLUSION

The commonly used standard views provide reasonable a priori choices, and some improvement is possible by switching among common angulations depending on the treatment region. Further gains are possible by using anatomy-optimized biplane C-arm angulations.

Update on cardiac imaging techniques 2012

Cardiac imaging is one of the basic pillars of modern cardiology. The potential list of scenarios where cardiac imaging techniques can provide relevant information is simply endless so it is impossible to include all relevant new features of cardiac imaging published in the literature in 2012 in the limited format of a single article. We summarize the year's most relevant news on cardiac imaging, highlighting the ongoing development of myocardial deformation and 3-dimensional echocardiography techniques and the increasing use of magnetic resonance imaging and computed tomography in daily clinical practice.

[Echocardiography during transcatheter interventions. New developments]

Interventional techniques for percutaneous treatment of structural heart disease have become an important option for patients ineligible for conventional operating procedures in cardiovascular medicine. Echocardiography plays an essential role not only for patient selection but also for guiding transcatheter interventions in order to safely accomplish the procedure. Echocardiographic 2D and 3D techniques next to conventional fluoroscopy have therefore become an integral part for monitoring interventional procedures in the catheter laboratory. This review aims to describe new developments for the application of echocardiography during transcatheter interventions in the context of the current literature and current recommendations.