Percutaneous Left Atrial Appendage Closure: Supporting Evidence, Limitations and Future Directions

Percutaneous Left Atrial Appendage Occlusion (LAAO) has emerged as a promising intervention for stroke prevention in patients with atrial fibrillation who are contraindicated for long-term anticoagulation therapy. Despite its growing adoption, a comprehensive review of the LAAO procedure is essential to consolidate the supporting evidence, identify limitations, and outline future directions. This review aims to evaluate the efficacy and safety of LAAO, drawing on clinical trials and real-world studies to provide a balanced perspective. Additionally, we address the limitations of current research, including variability in patient selection, procedural techniques, and follow-up protocols. By highlighting gaps in the knowledge and areas for improvement, this review aims to guide future research efforts to optimize and expand the therapeutic potential of LAAO.

The efficiency of endocardial suture occlusion of the left atrial appendage at a single institution: MICs vs. sternotomy

BACKGROUND

Most thrombi originate from the left atrial appendage (LAA), preventing thromboembolic stroke is an important aspect of stroke prevention. Previous studies have found that LAA closure is beneficial for preventing thrombosis. Currently, surgical procedures can achieve LAA closure by closing the endocardium or epicardium. LAA endocardial suture technique is performed concomitantly during sternotomy cardiac surgery but can also be performed during right minimally invasive cardiac surgery (MICS).

AIMS

This study aims to evaluate the efficacy of left atrial appendage closure (LAAC) with MICS.

METHODS

A total number of 74 patients who underwent LAAC during valve operation between 2017 and 2021 were retrospectively analyzed in this study. LAA was closed by continuous suture through the endocardium of the left atrium during cardiac surgery. 42 patients performed LAA endocardial suture during MICS, while 32 patients performed with the same LAAC technique during sternotomy. Patients underwent cardiac computed tomography (CT) follow-up after surgery to verify the completeness of the LAAC. The heart structure and function were recorded by echocardiography Transthoracic echocardiography (TTE), and the heart rhythm was recorded by electrocardiogram.

RESULTS

The LAA closure procedure was successful in 26 cases (81%) in the sternotomy group and 20 cases (48%) in the right minimally invasive group. Residual shunting (failed LAA closure) was more common in the right minimally invasive group (p = 0.003), and no correlation was found between residual shunting and left atrial (LA), left ventricular end-diastolic diameter (LVDD), and left ventricular ejection fraction (LVEF). The incidence of leaks was not associated with mitral valve replacement or valvuloplasty.

CONCLUSIONS

Compared to sternotomy, residual shunting after MICS was more common. CT imaging analysis of 22 patients with failed closure in the MICS group showed that residual shunting was mainly concentrated on margins of the suture (anterior superior and posterior inferior) (86%), with a middle area accounting for 3 (14%). Based on this finding, reinforcing the suture margins may significantly reduce the incidence of incomplete closure.

THE CLINICAL TRIAL NUMBER

KY-2023-001.

Preprocedural cardiac computed tomography versus transesophageal echocardiography for planning left atrial appendage occlusion procedures

The heterogeneous anatomy of the left atrial appendage (LAA) necessitates preprocedural imaging essential for planning of percutaneous LAA occlusion (LAAO) procedures. While transoesophageal echocardiography (TOE) remains the gold standard, cardiac computed tomography (CT) is becoming increasingly popular. To address the lack of consensus on the optimal imaging modality, we compared the outcomes of preprocedural TOE versus CT for LAAO procedure planning. A retrospective single-center cohort study of all LAAO procedures was performed to compare the outcomes of patients receiving preprocedural TOE versus those receiving CT. The primary outcome was procedural success and rate of major adverse events. The secondary outcomes were total procedure time, rate of device size change, and maximum landing zone diameter. A total of 64 patients was included. Of these, 25 (39.1%) underwent TOE and 39 (60.9%) underwent CT. There was no significant difference in the procedural success rate (96.0% vs. 100%, P = 0.39) or major adverse event rate (4.0% vs. 5.1%, P > 0.99) between TOE and CT patients. Compared with TOE, CT was associated with significantly shorter median procedure time (103 min vs. 124 min, P = 0.02) and a lower rate of device size change (7.7% vs. 28.0%, P = 0.04). Compared to CT, TOE was associated with a significantly smaller mean maximum landing zone diameter (20.8 mm vs. 25.8 mm, P < 0.01) and a higher rate of device upsizing (24.0% vs. 2.6%, P = 0.01). No significant difference in detected residual leak rates was found between TOE and CT (50.0% vs. 52.2%, P > 0.99). Planning of LAAO procedures with CT is associated with a shorter total procedure time and a lower rate of device size change and is less likely to underestimate the maximum landing zone diameter.

State-of-the-Art of Transcatheter Left Atrial Appendage Occlusion

Left atrial appendage occlusion (LAAO) is an increasingly used alternative to oral anticoagulation in patients with atrial fibrillation, especially in patients with absolute/relative contraindications to these therapies. This review will cover three main aspects of the procedure. In the fist part of the manuscript, we focus on patient selection. We describe three main categories of patients with primary indication to LAAO, namely patients with previous or at a high risk of intracerebral bleeding, patients with a history of major gastrointestinal bleeding and patients with end-stage renal disease and absolute contraindication to novel oral anticoagulants. Some other potential indications are also described. In the second part of the manuscript, we review available devices, trying to highlight different aspects and potential specific advantages. The last section overviews different ways for pre-, intra- and postprocedural imaging, in order to improve procedural safety and efficacy and ameliorate patient outcome. The characteristics of available contemporary devices and the role of imaging in procedural planning, intraprocedural guidance and follow-up are described.

Left atrial appendage occlusion

Prevention of stroke represents a goal of primary importance in health systems due to its associated morbidity and mortality. As several patient groups with increased stroke rates have been identified, multiple approaches have been developed and implemented: oral anticoagulation (OAC) for patients with atrial fibrillation, surgical and percutaneous revascularisation in patients with carotid disease, device closure for patients with patent foramen ovale, and now, left atrial appendage occlusion (LAAO) for selected patients with non-valvular atrial fibrillation (NVAF). The latter group of patients are the focus of this review which evaluates the pathophysiology, selection of patients, procedural performance, outcomes of treatment both during and post-procedure, adjunctive therapy, complications, and longer-term outcomes.

Percutaneous Treatment Approaches in Atrial Fibrillation: Current Landscape and Future Perspectives

Atrial fibrillation (AF), the most common sustained arrhythmia in clinical practice, represents a major cause of morbidity and mortality, with an increasing prevalence. Pharmacologic treatment remains the cornerstone of its management through rhythm and rate control, as well as the prevention of thromboembolism with the use of oral anticoagulants. Recent progress in percutaneous interventional approaches have provided additional options in the therapeutic arsenal, however. The use of the different catheter ablation techniques can now lead to long arrhythmia-free intervals and significantly lower AF burden, thus reducing the rate of its complications. Particularly encouraging evidence is now available for patients with persistent AF or concomitant heart failure, situations in which catheter ablation could even be a first-line option. In the field of stroke prevention, targeting the left atrial appendage with percutaneous device implantation may reduce the risk of thromboembolism to lower rates than that predicted with conventional ischemic risk scores. Left atrial appendage occlusion through the approved Watchman or Amplatzer devices is a well-established, efficacious, and safe method, especially in high-ischemic and bleeding risk patients with contraindications for oral anticoagulation.

Improving Left Atrial Appendage Occlusion Device Size Determination by Three-Dimensional Printing-Based Preprocedural Simulation

Background

The two-dimensional (2D)-based left atrial appendage (LAA) occluder (LAAO) size determination by using transesophageal echocardiography (TEE) is limited by the structural complexity and wide anatomical variation of the LAA.

Objective

This study aimed to assess the accuracy of the LAAO size determination by implantation simulation by using a three-dimensional (3D)-printed model compared with the conventional method based on TEE.

Methods

We retrospectively reviewed patients with anatomically and physiologically properly implanted the Amplatzer Cardiac Plug and Amulet LAAO devices between January 2014 and December 2018 by using the final size of the implanted devices as a standard for size prediction accuracy. The use of 3D-printed model simulations in device sizing was compared with the conventional TEE-based method.

Results

A total of 28 cases with the percutaneous LAA occlusion were reviewed. There was a minimal difference [−0.11 mm; 95% CI (−0.93, 0.72 mm); P = 0.359] between CT-based reconstructed 3D images and 3D-printed left atrium (LA) models. Device size prediction based on TEE measurements showed poor agreement (32.1%), with a mean difference of 2.3 ± 3.2 mm [95% CI (−4.4, 9.0)]. The LAAO sizing by implantation simulation with 3D-printed models showed excellent correlation with the actually implanted LAAO size (r = 0.927; bias = 0.7 ± 2.5). The agreement between the 3D-printed and the implanted size was 67.9%, with a mean difference of 0.6 mm [95% CI (−1.9, 3.2)].

Conclusion

The use of 3D-printed LA models in the LAAO size determination showed improvement in comparison with conventional 2D TEE method.

A Comparison of Cardiac Computed Tomography, Transesophageal and Intracardiac Echocardiography, and Fluoroscopy for Planning Left Atrial Appendage Closure

Background

Left atrial appendage (LAA) closure (LAAC) is accompanied by a high risk of complications. Due to the complex anatomy of the LAA and the oval-shaped ostium, the proper sizing of the device is often difficult.

Purpose

To assess individualized fluoroscopy viewing angles using pre-procedural CT analysis and to compare the results of landing zone measurements obtained from CT, transesophageal echocardiography (TEE), intracardiac echocardiography (ICE), and fluoroscopy.

Methods

Patients with indications for LAAC were enrolled. Cardiac CT and TEE were done before the procedure; ICE and fluoroscopy measurements were done peri-procedurally. Multiplanar reconstruction of CT images, using FluoroCT software, was done, and optimal "personalized" viewing angles for fluoroscopy were determined. Moreover, a mean (using multiplanar CT reconstruction, derived from the LAA perimetr) amd maximum (using all four imaging modalitities) landing zone (LZ) of the LAA were masured.

Results

Twenty-five patients were analyzed. Despite significant correlation between LZs obtained from different imaging modalities, the values of LZs differed significantly; the mean LZ diameter on CT was 20.60 ± 3.42 mm, the maximum diameters were 21.99 ± 4.03 mm (CT), 18.72 ± 2.44 mm (TEE), 18.20 ± 2.68 mm (ICE), and 17.76 ± 3.24 mm (fluoroscopy). The mean CT diameter matched with the final device selection in 92% patients, while fluoroscopy or TEE maximum diameters in only 72% patients. Optimal viewing angles differed significantly from the fluoroscopy projections usually recommended by the manufacturer in 3 patients.

Conclusions

CT provides the best measurement of the LZ and the best prediction of the optimum fluoroscopy projections for the implantation procedure.

Pre-procedural determination of device size in left atrial appendage occlusion using three-dimensional cardiac computed tomography

The complex structure of the left atrial appendage (LAA) brings limitations to the two-dimensional-based LAA occlusion (LAAO) size prediction system using transesophageal echocardiography. The LAA anatomy can be evaluated more precisely using three-dimensional images from cardiac computed tomography (CT); however, there is lack of data regarding which parameter to choose from CT-based images during pre-procedural planning of LAAO. We aimed to assess the accuracy of measurements derived from cardiac CT images for selecting LAAO devices. We retrospectively reviewed 62 patients with Amplatzer Cardiac Plug and Amulet LAAO devices who underwent implantation from 2017 to 2020. The minimal, maximal, average, area-derived, and perimeter-derived diameters of the LAA landing zone were measured using CT-based images. Predicted device sizes using sizing charts were compared with actual successfully implanted device sizes. The mean size of implanted devices was 27.1 ± 3.7 mm. The perimeter-derived diameter predicted device size most accurately (mean error = − 0.8 ± 2.4 mm). All other parameters showed significantly larger error (mean error; minimal diameter = − 4.9 ± 3.3 mm, maximal diameter = 1.0 ± 2.9 mm, average diameter = − 1.6 ± 2.6 mm, area-derived diameter = − 2.0 ± 2.6 mm) than the perimeter-derived diameter (all p for difference < 0.05). The error for other parameters were larger in cases with more eccentrically-shaped landing zones, while the perimeter-derived diameter had minor error regardless of eccentricity. When oversizing was used, all parameters showed significant disagreement. The perimeter-derived diameter on cardiac CT images provided the most accurate estimation of LAAO device size regardless of landing zone eccentricity. Oversizing was unnecessary when using cardiac CT to predict an accurate LAAO size.

Value of detecting peri-device leak and incomplete endothelialization by cardiac CT angiography in atrial fibrillation patients post Watchman LAAC combined with radiofrequency ablation

Objectives

To explore the value of detecting the peri‐device leak (PDL) and device endothelialization after left atrial appendage closure (LAAC) by cardiac computed tomography (CT) in patients with atrial fibrillation (AF), who underwent Watchman LAAC combined with radiofrequency ablation of atrial fibrillation (AFCA).

Methods

Patients with symptomatic drug‐refractory atrial fibrillation at high risk of stroke (CHA₂DS₂‐VASc Score ≥ 2), who underwent Watchman LAAC combined with AFCA in our center from March 2017 to December 2018 were enrolled. Maximum diameter of LAA orifice was determined by preoperative CCTA. A standardized view of Watchman device was obtained by postoperative CCTA multiplannar reconstruction to evaluate the PDL and device endothelialization.

Results

Approximately 84 patients post successful LAAC and AFCA were enrolled in this study. The satisfactory LAA occlusion rate was 100%. There was no death, bleeding, stroke, and device‐related thrombus (DRT) events. At 6‐month postprocedure, CCTA images evidenced complete endothelialization in 44 patients (no contrast enhancement in LAA); contrast enhancement in LAA and visible PDL in 33 patients; contrast enhancement in LAA but without PDL in seven patients (incomplete device endothelialization). Maximum diameter of LAA orifice could independently predict the occurrence of PDL (odds ratio, 1.31; 95% confidence interval, 1.11–1.55; p = .002), sensitivity was 69.7% and specificity was 80.4% with the cutoff value of maximum diameter of LAA orifice more than 28.2 mm on predicting PDL.

Conclusions

CCTA is feasible to evaluate PDL and device endothelialization after LAAC. The maximum diameter of LAA orifice derived from CT can independently predict the occurrence of post‐LAAC PDL.

CT assessment of the left atrial appendage post-transcatheter occlusion - A systematic review and meta analysis

BACKGROUND

Transesophageal echocardiography (TEE) is the standard imaging modality used to assess the left atrial appendage (LAA) after transcatheter device occlusion. Cardiac computed tomography angiography (CCTA) offers an alternative non-invasive modality in these patients. We aimed to conduct a comparison of the two modalities.

METHODS

We performed a comprehensive systematic review of the current literature pertaining to CCTA to establish its usefulness during follow-up for patients undergoing LAA device closure. Studies that reported the prevalence of inadequate LAA closure on both CCTA and TEE were further evaluated in a meta-analysis. 19 studies were used in the systematic review, and six studies were used in the meta-analysis.

RESULTS

The use of CCTA was associated with a higher likelihood of detecting LAA patency than the use of TEE (OR, 2.79, 95% CI 1.34-5.80, p ​= ​0.006, I2 ​= ​70.4%). There was no significant difference in the prevalence of peridevice gap ≥5 ​mm (OR, 3.04, 95% CI 0.70-13.17, p ​= ​0.13, I2 ​= ​0%) between the two modalities. Studies that reported LAA assessment in early and delayed phase techniques detected a 25%-50% higher prevalence of LAA patency on the delayed imaging.

CONCLUSION

CCTA can be used as an alternative to TEE for LAA assessment post occlusion. Standardized CCTA acquisition and interpretation protocols should be developed for clinical practice.

The use of cardiac computed tomography angiography in the assessment of percutaneous left atrial appendage closure - Review and experts recommendations endorsed by the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle

Atrial fibrillation is the most common cause of arrhythmia which is responsible for over 15% of ischemic strokes, most of these being secondary to migration of a left atrial appendage (LAA) thrombus. In patient with contraindication to anticoagulant therapy, percutaneous closure system placement may be indicated. Cardiac computed tomography (CT) angiography plays a central role in the initial assessment as well as in the follow-up. The purpose of the pre-implantation cardiac CT angiography is to evaluate the anatomy of the LAA in order to select the most suitable prosthesis and check for any contraindication to device implantation. Image analysis is divided into four steps that include analysis of the approach; search for a thrombus in the LAA; investigation of the anatomy of the LAA (morphology of the LAA, dimensions of the LAA and choice of device) and cardiac and thoracic assessments. Follow-up involves CT examination to check for correct placement of the device and to detect any complications. On the basis of the results of currently available published research, a panel of experts has issued recommendations regarding cardiac CT angiography prior to percutaneous LAA closure device placement, which were further endorsed by the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV).

Left atrial appendage occlusion in chicken-wing anatomies: Imaging assessment, procedural, and clinical outcomes of the "sandwich technique"

OBJECTIVES

To describe imaging assessment, procedural and follow-up outcome of patients undergoing left atrial appendage (LAA) occlusion (LAAO) using a "sandwich" technique.

BACKGROUND

The presence of a LAA with chicken wing morphology constitutes a challenge that sometimes requires specific occlusion strategies like the "sandwich" technique. However, procedural and follow-up data focusing on this implanting strategy is scarce.

METHODS

This multicenter study collected individual data from eight centers between 2012 and 2019. Consecutive patients with chicken-wing LAAs defined as an early (<20 mm from the ostium) and severe bend (>90°) who underwent LAAO with Amplatzer devices and using the "sandwich" technique were included in the analysis.

RESULTS

Overall, 190 subjects were enrolled in the study. Procedures were done with the Amulet device (85%) and the Amplatzer Cardiac Plug (15%). Successful implantation was achieved in 99.5% with ≤1 partial recapture in 80% of cases. Single (46.2%) and dual antiplatelet therapy (39.4%) were the most used antithrombotic therapies after LAAO. In-hospital major adverse events rate was 1.5% with no deaths. One patient (0.5%) had cardiac tamponade requiring percutaneous drainage. With a mean follow-up of 19.6 ± 14.8 months, the mortality and stroke rates were 7.7%/year and 2.5%/year, respectively. Follow-up transesophageal echocardiography (TEE) at 2-3 months showed device-related thrombosis in 2.8% and peri-device leak ≥3 mm in 1.2% of patients.

CONCLUSIONS

In a large series of patients with chicken wing LAA anatomies undergoing LAAO, the use of the "sandwich" technique was feasible and safe. Preprocedural imaging was a key-factor to determine specific measurements.

Multimodality Approach for Endovascular Left Atrial Appendage Closure: Head-To-Head Comparison among 2D and 3D Echocardiography, Angiography, and Computer Tomography

Background: Percutaneous left atrial appendage closure (LAAC) requires accurate pre- and intraprocedural measurements, and multimodality imaging is an essential tool for guiding the procedure. Two-dimensional (2D TOE) and three-dimensional (3D TOE) transoesophageal echocardiography, cardiac computed tomography (CCT), and conventional cardiac angiography (CCA) are commonly used to evaluate left atrial appendage (LAA) size. However, standardized approaches in measurement methods by different imaging modalities are lacking. The aims of the study were to evaluate the LAA dimension and morphology in patients undergoing LAAC and to compare data obtained by different imaging modalities: 2D and 3D TOE, CCT, and CCA. Methods: A total of 200 patients (mean age 70 ± 8 years, 128 males) were examined by different imaging techniques (161 2D TOE, 103 3D TOE, 98 CCT, and 200 CCA). Patients underwent preoperative CCT and intraoperative 2D and 3D TOE and CCA. Results: A significant correlation was found among all measurements obtained by different modalities. In particular, 3D TOE and CCT measurements were highly correlated with an excellent agreement for the landing zone (LZ) dimensions (LZ diameter: r = 0.87; LAA depth: r = 0.91, p < 0.001). Conclusions: Head-to-head comparison among imaging techniques (2D and 3D TOE, CCT, and CCA) showed a good correlation among LZ diameter measurements obtained by different imaging modalities, which is a parameter of paramount importance for the choice of the LAAC device size. LZ diameters and area by 3D TOE had the best correlation with CCT.

Cardiac CT angiography: normal and pathological anatomical features-a narrative review

The normal and pathological anatomy of the heart and coronary arteries are nowadays widely developed topics and constitute a fundamental part of the cultural background of the radiologist. The introduction of cardiac ECG-gated synchronized CT scanners with an ever-increasing number of detectors and with increasingly high structural characteristics (increase in temporal resolution, increase in contrast resolution with dual-source, dual energy scanners) allows the virtual measurement of anatomical in vivo structures complying with heart rate with submillimetric precision permitting to clearly depict the normal anatomy and follow the pathologic temporal evolution. Accordingly to these considerations, cardiac computed tomography angiography (CCTA) asserts itself as a gold standard method for the anatomical evaluation of the heart and permits to evaluate, verify, measure and characterize structural pathological alterations of both congenital and acquired degenerative diseases. Accordingly, CCTA is increasingly used as a prognostic model capable of modifying the outcome of diseased patients in planning interventions and in the post-surgical/interventional follow-up. The profound knowledge of cardiac anatomy and function through highly detailed CCTA analysis is required to perform an efficient and optimal use in real-world clinical practice.

The WATCHMAN left atrial appendage closure device for patients with atrial fibrillation: current status and future perspectives

INTRODUCTION

Atrial fibrillation (AF) is associated with an increased risk of stroke. Stroke prevention with oral anticoagulation (OAC) is recommended in AF patients at increased risk of stroke. The left atrial appendage (LAA) is the main source of thrombus formation in AF patients. The WATCHMAN percutaneous LAA closure (LAAC) device may serve as an alternative to OAC overcoming disadvantages including the risk of (major) bleeding.

AREAS COVERED

This review will focus on LAAC with the Watchman device for stroke prevention in AF patients. Current status, available literature, clinical safety and efficacy will be summarized. Furthermore, the future perspectives of Watchman will be discussed.

EXPERT OPINION

LAAC with Watchman appears a promising, safe, and effective alternative to OAC. Ongoing and future studies to consolidate the position of Watchman should focus on comparative safety and efficacy of different LAAC devices, patient selection, various post-procedural antithrombotic regimens, head-to-head comparisons with NOAC, better understanding of device-related thrombus, and the role of the LAA in the propagation of non-valvular AF. This research may attribute to a paradigm shift in which LAAC no longer serves as a 'last resort' treatment for AF patients ineligible for OAC but may serve as a second-line or even first-line treatment option for AF patients.

Preoperative Planning for Structural Heart Disease

Preoperative assessment with computed tomography (CT) is critical before transcatheter interventions for structural heart disease. CT provides information for device selection, device sizing, and vascular access approach. The interpreting radiologist must have knowledge of appropriate CT protocols, how and where to obtain the important measurements, and know additional imaging characteristics that are important to describe for optimal support of the interventionalist. CT is the modality of choice for pre-operative evaluation in patients undergoing transcatheter aortic valve replacement and left atrial appendage occlusion, and is also useful before transcatheter mitral valve replacement, which is an ongoing area of research.

Left atrial appendage occlusion with the Amplatzer Amulet: update on device sizing

PURPOSE

The present paper analyzes the role of different imaging modalities for left atrial appendage (LAA) assessment and the recommended specific measurements to improve device selection with regard to the Amulet device.

BACKGROUND

Morphological LAA assessment is one of the pivotal factors to achieve proper LAA sealing and potentially reduce the risk of complications by minimizing manipulation inside the appendage.

METHODS

Eight experienced physicians in LAAO were asked to contribute in the preparation of a device sizing consensus manuscript after comprehensive assessment of previous published data on LAA imaging/measurement.

RESULTS

LAA morphology is often complex and requires more detailed spatial resolution and 3-dimensional assessments to reduce the risk of mis-sizing. Traditionally, upsizing of devices based upon the largest measured LAA diameters have been used. However, this may lead to oversizing in markedly elliptical appendages. Thus, when 3D imaging modalities are available, utilizing the LAA mean diameters might be a better alternative. Operators should also note the systematic biases in differences in measurements obtained with different imaging modalities, with CT giving the largest measurements, followed by 3D-TEE, and then 2D-TEE and angiography. In fact, for 2D imaging techniques (2D-TEE and angiography), LAA diameters tend to be underestimated, and therefore, LAA largest diameters seem to be still the best option for device sizing. Some specific anatomies such as proximal chicken-wing or conic LAAs may require different measurements and implantations to achieve implant success.

CONCLUSIONS

In conclusion, LAA mean diameters might be a better alternative to largest diameters when 3D imaging modalities are available.

4D Volume Intracardiac Echocardiography for Intraprocedural Guidance of Transcatheter Left Atrial Appendage Closure

Background

Fluoroscopy and transesophageal echocardiography (TEE) are used to guide transcatheter left atrial appendage (LAA) closure in patients with atrial fibrillation to prevent thromboembolic events. This study examines whether real-time three-dimensional volume ICE guidance (4D volume ICE) can be used as an alternative to TEE during LAA closure (LAAC).

Methods and Results

Fifteen patients with atrial fibrillation (AF), who had high risk for stroke and contraindication for long-term warfarin therapy, were enrolled in the study. The WATCHMAN device was used for transcatheter LAAC under fluoroscopy. LAA and device sizing was performed using TEE and volume ICE guidance from the right heart. Intraprocedural ICE measurements were consistent with TEE; LAA maximal width and depth, and maximal diameter of the implanted device were moderately correlated (Pearson's coefficient: 0.63, 0.65, and 0.71 respectively; p<0.05) with good agreement (bias: -0.03 cm, -0.07 cm, and 0.003 cm respectively). The average imaging success rate, defined by the number of patients with all the required intraprocedural measurements, was 67% for ICE and 100% for TEE. The WATCHMAN device was successfully implanted in all patients with a device to patient ratio of 1.33.

Conclusions

4D volume ICE can be used as an intraprocedural sizing and guidance tool for transcatheter LAAC with measurements comparable to TEE. Challenging patient characteristics significantly degrade the diagnostic image quality when imaging from the right heart. Standardized workflow with proper patient selection and optimal preprocedural planning may improve the diagnostic quality of volume ICE guidance for transcatheter LAAC procedure.

Left atrial appendage patency and device-related thrombus after percutaneous left atrial appendage occlusion: a computed tomography study

Aims

Transoesophageal echocardiography studies have reported frequent peri-device leaks and device-related thrombi (DRT) after percutaneous left atrial appendage (LAA) occlusion. We assessed the prevalence, characteristics and correlates of leaks and DRT on cardiac computed tomography (CT) after LAA occlusion.

Methods and results

Consecutive patients underwent cardiac CT before LAA occlusion to assess left atrial (LA) volume, LAA shape, and landing zone diameter. Follow-up CT was performed after >3 months to assess device implantation criteria, device leaks and DRT. CT findings were related to patient and device characteristics, as well as to outcome during follow-up. One-hundred and seventeen patients (age 74 ± 9, 37% women, CHA2DS2VASc 4.4 ± 1.3, and HASBLED 3.5 ± 1.0) were implanted with Amplatzer cardiac plug (ACP)/Amulet (71%) or Watchman (29%). LAA patency was detected in 44% on arterial phase CT images and 69% on venous phase images. The most common leak location was postero-inferior. LAA patency related to LA dilatation, left ventricular ejection fraction impairment, non-chicken wing LAA shape, large landing zone diameter, incomplete device lobe thrombosis, and disc/lobe misalignment in patients with ACP/Amulet. DRT were detected in 19 (16%), most being laminated and of antero-superior location. DRT did not relate to clinical or imaging characteristics nor to implantation criteria, but to total thrombosis of device lobe. Over a mean 13 months follow-up, stroke/transient ischaemic attack occurred in eight patients, unrelated to DRT or LAA patency.

Conclusion

LAA patency on CT is common after LAA occlusion, particularly on venous phase images. Leaks relate to LA/LAA size at baseline, and device malposition and incomplete thrombosis at follow-up. DRT is also quite common but poorly predicted by patient and device-related factors.

Multimodality imaging of left atrium in patients with atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide associated with significant morbidity and mortality and represents a significant health care burden. Goals of AF treatment include prevention of cardioembolic stroke using anticoagulation and device therapy and restoration of sinus rhythm using antiarrhythmic drugs or catheter ablation techniques. A comprehensive assessment of cardiac chamber size and function is often started with echocardiography as a first line diagnostic imaging strategy. Recently, innovations in advanced imaging using cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) provide a detailed characterization of atrial anatomy and have been shown to accurately exclude thrombus and guide left atrial appendage (LAA) closure or catheter ablation (CA) of atrial fibrillation. Compared to echocardiography, CCT offers an uncompromised spatial resolution and a fast dataset acquisition, with the disadvantages of the need of iodine contrast agent and radiation exposure. CMR, conversely, can rely on very high temporal resolution, the unique feature of tissue characterization and the absence of radiation exposure. However, the main drawbacks of this diagnostic tool are long scan times and low availability. This review will illustrate the vital role of multimodality cardiac imaging in the accurate identification of left atrial, pulmonary vein and LAA size and function, discuss advanced imaging techniques to rule out thrombus and highlight novel CMR and CCT techniques to guide catheter ablation of AF and LAA occlusion.

CT support of cardiac structural interventions

Due to its high temporal and isotropic spatial resolution, CT has become firmly established for pre-procedural imaging in the context of structural heart disease interventions. CT allows to very exactly measure dimensions of the target structure, CT can provide information regarding the access route and, as a very valuable addition, volumetric CT data sets can be used to identify fluoroscopic projection angulations to optimally visualize the target structure and place devices. This review provides an overview of current methods and applications of pre-interventional CT to support adult cardiac interventions including transcatheter aortic valve implantation, percutaneous mitral valve intervention, left atrial appendage occlusion and paravalvular leak closure.

CT sizing for left atrial appendage closure is associated with favourable outcomes for procedural safety

Aims

We evaluated the utility of computerized tomography (CT) with respect to sizing work-up for percutaneous left atrial appendage (LAA) closure, and implications for procedural safety and outcomes.

Methods and results

Contrast-enhanced multi-detector CT was routinely conducted to guide sizing for LAA closure in addition to transoesophageal echocardiography (TOE). Procedural safety and efficacy were prospectively assessed. Across 73 consecutive cases there were no device-related procedural complications, and no severe leaks. Systematic bias in orifice sizing by TOE vs. CT was significant on retrospective analysis (bias -3.0 mm vs. maximum diameter on CT; bias -1.1 mm vs. mean diameter on CT). Importantly, this translated to an altered device size selection in more than half of all cases, and median size predicted by CT was one interval greater than that predicted by TOE (27 mm vs. 24 mm). Of particular note, gross sizing error by TOE vs. CT was observed in at least 3.4% of cases. Degree of discrepancy between TOE and CT was correlated with LAA orifice eccentricity, orifice size, and left atrial volume. Mean orifice size by CT had the greatest utility for final Watchman device-size selection.

Conclusions

In this single-centre registry of LAA closure, routine incorporation of CT was associated with excellent outcomes for procedural safety and absence of major residual leak. Mean orifice size may be preferable to maximum orifice size. A particular value of CT may be the detection and subsequent avoidance of gross sizing error by 2D TOE that occurs in a small but important proportion of cases.

Cardiac Computed Tomography for Left Atrial Appendage Occlusion: Acquisition, Analysis, Advantages, and Limitations

Transcatheter left atrial appendage occlusion is increasingly used for stroke prevention in atrial fibrillation. The technique has proven effective and safe in randomized trials and multiple observational studies. The procedure is challenging due to the complex anatomy of the left atrial appendage; accurate cardiac imaging is essential for procedural guidance. Transesophageal echocardiography is the gold standard, but cardiac computed tomography (CT) has gained increasing interest within recent years. Cardiac CT offers high-resolution imaging allowing for preprocedural anatomic evaluation and device sizing, but may also be useful for exclusion of left atrial appendage thrombus, and follow-up assessment of residual peri-device leaks.

Two-dimensional versus three-dimensional transesophageal echocardiography in percutaneous left atrial appendage occlusion

BACKGROUND

Real-time three-dimensional transesophageal echocardiography (RT3D TEE) enables better visualization of the left atrial appendage (LAA) and may be superior to real-time two-dimensional transesophageal echocardiography (RT2D TEE) for LAA occlusion (LAAO). The aim of this study was to assess inter- and intra-observer variability of RT2D TEE and RT3D TEE measurements of LAA, and to assess the accordance of RT2D TEE and RT3D TEE with appropriate occluder selection.

METHODS

Transesophageal echocardiography was performed in 40 patients during LAAO. RT2D TEE and RT3D TEE measurements of the ostium and landing zone were performed independently by two echocardiographers. The appropriate choice of occluder was confirmed with fluoroscopic criteria. After the procedures, RT2D TEE and RT3D TEE evaluation were repeated separately by the same echocardiographers.

RESULTS

The mean ostium diameters by RT2D TEE obtained by the two observers were 23.6 ± 4.2 vs. 24.8 ± 5.2 (p = 0.04), and the mean landing zone diameters were 17.7 ± 4.4 vs. 19.4 ± 3.9 (p < 0.01). In the case of RT3D TEE, the ostium diameters were 29.6 ± 5.3 vs. 29.4 ± 6.4 (p = not significant [NS]) and the landing zone diameters were 21.4 ± 3.8 vs. 21.6 ± 3.9 (p = NS). Intra-observer differences were absent in the case of RT3D TEE. The comparison of RT2D TEE vs. RT3D TEE analyses performed by the same echocardiographer revealed significant differences in the ostium and landing zone measurements (both p < 0.01). Agreement between the suggested device size was better for RT3D TEE (weighted kappa was 0.62 vs. 0.28, respectively).

CONCLUSIONS

The results obtained with RT3D TEE showed significantly larger dimensions of the ostium and the landing zone. RT3D TEE showed lesser inter- and intra-observer variability and better agreement with the implanted device.

Echocardiographic Guidance of AMPLATZER Amulet Left Atrial Appendage Occlusion Device Placement

In this report, we provided details of periprocedural echocardiographic guidance for patients undergoing Amplatzer-Amulet device left atrial closure. Familiarity with left atrial appendage (LAA) occlusion devices and the required left atrial examination and measurements are key before device placement. Device placement is assisted by transesophageal echocardiography (TEE) and fluoroscopy, but TEE will be the main guide for patients with renal insufficiency in whom contrast dye use needs to be minimal. TEE is also used to confirm LAA occlusion with the device and finally detect complications throughout the procedure and into the postoperative period.

Left atrial appendage closure: A single center experience and comparison of two contemporary devices

OBJECTIVES

To compare indications and clinical outcomes of two contemporary left atrial appendage (LAA) percutaneous closure systems in a "real-world" population.

BACKGROUND

Percutaneous LAA occlusion is an emerging therapeutic option for stroke prevention in atrial fibrillation. Some questions however remain unanswered, such as the applicability of results of randomized trials to current clinical practice. Moreover, currently available devices have never been directly compared.

METHODS

We retrospectively analyzed consecutive patients who underwent LAA closure at San Raffaele Hospital, Milan, Italy between 2009 and 2015. Clinical indications and device selection were left to operators' decision; routine clinical and transesophageal echocardiography (TEE) follow-up was performed.

RESULTS

One-hundred and sixty-five patients were included in the study, of which 99 were treated with the Amplatzer Cardiac Plug (ACP) and 66 with the Watchman system. During the follow-up period (median 15 months, interquartile range 6-26 months) five patients died. The incidence of ischemic events was low, with one patient suffering a transient ischemic attack and no episodes recorded of definitive strokes. Twenty-six leaks ≥1 mm were detected (23%); leaks were less common with the ACP and with periprocedural three-dimensional TEE evaluation, but were not found to correlate with clinical events. Clinical outcomes were comparable between the two devices.

CONCLUSIONS

Our data show excellent safety and efficacy of LAA closure, irrespectively of the device utilized, in a population at high ischemic and hemorrhagic risk. The use of ACP and 3D-TEE minimized the incidence of residual leaks; however, the clinical relevance of small peri-device flow warrants further investigation. © 2016 Wiley Periodicals, Inc.

Left atrial appendage closure: patient, device and post-procedure drug selection

Left atrial appendage closure (LAAC), a device-based therapy for stroke prevention in patients with atrial fibrillation, is considered an alternative to oral anticoagulation therapy, particularly for patients at high risk of bleeding. Proof of concept has been demonstrated by the PROTECT AF and PREVAIL trials which evaluated the WATCHMAN device (Boston Scientific, Marlborough, MA, USA) versus warfarin, showing favourable outcome for the device group. The most commonly used devices for LAAC are the WATCHMAN and its successor, the WATCHMAN FLX (Boston Scientific) and the AMPLATZER Cardiac Plug and more recently the AMPLATZER Amulet device (both St. Jude Medical, St. Paul, MN, USA). The procedure is typically performed via a transseptal puncture under fluoroscopic and echocardiographic guidance. Technically, it is considered quite demanding due to the anatomic variability and fragility of the appendage. Careful material manipulation, adequate operator training, and good cardiac imaging and device sizing allow a safe, uneventful procedure. Post-procedure antithrombotic drug selection is based on the patient's history, indication and quality of LAAC.