Imaging for Percutaneous Left Atrial Appendage Closure: A Contemporary Review

A comparison of conventional and advanced 3D imaging techniques for percutaneous left atrial appendage closure

Background

Understanding complex cardiac anatomy is essential for percutaneous left atrial appendage (LAA) closure. Conventional multi-slice computed tomography (MSCT) and transesophageal echocardiography (TEE) are now supported by advanced 3D printing and virtual reality (VR) techniques for three-dimensional visualization of volumetric data sets. This study aimed to investigate their added value for LAA closure procedures.

Methods

Ten patients scheduled for interventional LAA closure were evaluated with MSCT and TEE. Patient-specific 3D printings and VR models were fabricated based on MSCT data. Ten cardiologists then comparatively assessed LAA anatomy and its procedure relevant surrounding structures with all four imaging modalities and rated their procedural utility on a 5-point Likert scale questionnaire (from 1 = strongly agree to 5 = strongly disagree).

Results

Device sizing was rated highest in MSCT (MSCT: 1.9 ± 0.8; TEE: 2.6 ± 0.9; 3D printing: 2.5 ± 1.0; VR: 2.5 ± 1.1; p < 0.01); TEE, VR, and 3D printing were superior in the visualization of the Fossa ovalis compared to MSCT (MSCT: 3.3 ± 1.4; TEE: 2.2 ± 1.3; 3D printing: 2.2 ± 1.4; VR: 1.9 ± 1.3; all p < 0.01). The major strength of VR and 3D printing techniques was a superior depth perception (VR: 1.6 ± 0.5; 3D printing: 1.8 ± 0.4; TEE: 2.9 ± 0.7; MSCT: 2.6 ± 0.8; p < 0.01). The visualization of extracardiac structures was rated less accurate in TEE than MSCT (TEE: 2.6 ± 0.9; MSCT: 1.9 ± 0.8, p < 0.01). However, 3D printing and VR insufficiently visualized extracardiac structures in the present study.

Conclusion

A true 3D visualization in VR or 3D printing provides an additional value in the evaluation of the LAA for the planning of percutaneous closure. In particular, the superior perception of depth was seen as a strength of a 3D visualization. This may contribute to a better overall understanding of the anatomy. Clinical studies are needed to evaluate whether a more comprehensive understanding through advanced multimodal imaging of patient-specific anatomy using VR may translate into improved procedural outcomes.

Periprocedural Echocardiographic Guidance of Transcatheter Mitral Valve Edge-to-Edge Repair Using the MitraClip

Transcatheter edge-to-edge mitral valve repair is a minimally invasive treatment option for selected patients with moderate to severe or severe mitral regurgitation. Although transcatheter edge-to-edge mitral valve repair offers a significant step forward in the management of mitral regurgitation, the rate of procedural-related complications is not trivial. High-quality periprocedural imaging is important for optimal patient selection and procedural success. In this review, we present a step-by-step approach of the recommended echocardiographic views for transcatheter edge-to-edge mitral valve repair.

The Emerging Role of Intracardiac Echocardiography (ICE) in Left Atrial Appendage Closure (LAAC)

PURPOSE OF REVIEW

Intracardiac echocardiography (ICE) has emerged as a powerful imaging tool to guide percutaneous left atrial appendage closure (LAAC). Herein, we review an imaging protocol for ICE-guided LAAC and discuss the evidence for its use.

RECENT FINDINGS

Standardized imaging protocols have been proposed but have not been fully validated. ICE imaging yields similar procedural and clinical outcomes when compared to transesophageal echocardiography (TEE) to guide LAAC. Despite benefits of avoiding general anesthesia, TEE, and multiple physicians for LAAC procedures, ICE imaging remains under-utilized. Novel ICE catheters with 3D imaging capabilities may improve accuracy and efficiency of LAAC device implantation. ICE guidance is feasible, safe, and effective for LAAC. As the field evolves, further studies will be necessary to assess this technological advancement in imaging guidance.

Role of Multimodality Imaging in Transcatheter Structural Interventions

Cardiac imaging is the backbone for safe and optimal transcatheter structural interventions. Transthoracic echocardiogram is the initial modality to assess valvular disorders, while transesophageal echocardiogram is best to delineate the mechanism of valvular regurgitation, preprocedural assessment for transcatheter edge-to-edge repair, and for intraprocedural guidance. Cardiac computed tomography is the modality of choice for assessing calcifications, maneuvering multiplaner reconstruction of different cardiac structures, preprocedural planning for various transcatheter valve replacement, and assessing for hypoattenuated leaflet thickening and reduced leaflet motion. Cardiac magnetic resonance imaging is best known for most accurate volumetric assessment of valvular regurgitation and chamber size quantification. Cardiac positron emission tomography is the only modality that could assess active infection through using fluorine 18 fluorodeoxyglucose radiotracer.

Intra- and Postprocedural Multimodality Imaging in Atrial Fibrillation

Multi-modality imaging plays critical roles during and after procedures associated with atrial fibrillation. Transesophageal echocardiography is an invaluable tool for left atrial appendage occlusion during the procedure and at follow-up. Both cardiac computed tomography and cardiac magnetic resonance contribute to postprocedural evaluation of pulmonary vein isolation ablation. The present review is the second of a 2-part series where we discuss the roles of cardiac imaging in the evaluation and management of patients with atrial fibrillation, focusing on intraprocedural and postprocedural assessment, including the clinical evidence and outcomes data supporting this future applications.

Periprocedural Echocardiographic Guidance of Transcatheter Mitral Valve Edge-to-Edge Repair Using the MitraClip

Transcatheter edge-to-edge mitral valve repair is a minimally invasive treatment option for selected patients with moderate to severe or severe mitral regurgitation. Although transcatheter edge-to-edge mitral valve repair offers a significant step forward in the management of mitral regurgitation, the rate of procedural-related complications is not trivial. High-quality periprocedural imaging is important for optimal patient selection and procedural success. In this review, we present a step-by-step approach of the recommended echocardiographic views for transcatheter edge-to-edge mitral valve repair.