Moderate conscious sedation for transesophageal echocardiography guidance of percutaneous left atrial appendage closure: The MID-DEX protocol

OBJECTIVES

The aim of this study was to assess the feasibility, effectiveness, and safety of a novel moderate conscious sedation protocol of Dexmedetomidine plus Midazolam (MID-DEX MCS) in patients undergoing transcatheter left atrial appendage closure (LAAC).

DESIGN

This is a retrospective and single-arm study.

SETTING

Single-center, hospital.

PARTICIPANTS

All consecutive patients referred for LAAC.

INTERVENTIONS

LAAC procedures were TEE-guided under MCS using Midazolam and Dexmedetomidine.

MEASUREMENTS AND MAIN RESULTS

100 patients underwent LAAC under MID-DEX MCS protocol with an acute procedural success rate of 100 %. Ninety-four patients (94 %) successfully underwent TEE guidance under MCS for LAAC. In 6 patients (6 %), ICE guidance was required. Of these, only 2 cases (2 %) were due to insufficient sedation and psychomotor agitation, while the other 4 patients (4 %) had absolute contraindications to TEE. No MCS-related complications were observed. Conversion from MCS to general anesthesia was not required in any patient.

CONCLUSIONS

LAAC was safe and effective when performed under MCS. The application of the proposed MCS protocol may simplify the LAAC procedure, as well as reduce procedural time and procedural costs, while increasing overall patient and physician satisfaction.

Use of Computed Tomography for Left Atrial Appendage Occlusion Procedure Planning and Post-Procedure Assessment

Transcatheter left atrial appendage occlusion (LAAO) is an alternative to systemic anticoagulation in patients with non-valvular atrial fibrillation with increased risk for thromboembolic events. Pre- and post-procedural imaging is essential for technical success, allowing practitioners to identify contraindications, select appropriate devices, and recognize procedural complications. Although transesophageal echocardiography has traditionally served as the preeminent imaging modality in LAAO, cardiac computed tomography imaging has emerged as a noninvasive surrogate given its excellent isotropic spatial resolution, multiplanar reconstruction capability, rapid temporal resolution, and large field of view.

Cardiac magnetic resonance imaging for preprocedural planning of percutaneous left atrial appendage closure

Introduction

Percutaneous closure of the left atrial appendage (LAA) facilitates stroke prevention in patients with atrial fibrillation. Optimal device selection and positioning are often challenging due to highly variable LAA shape and dimension and thus require accurate assessment of the respective anatomy. Transesophageal echocardiography (TEE) and x-ray fluoroscopy (XR) represent the gold standard imaging techniques. However, device underestimation has frequently been observed. Assessment based on 3-dimensional computer tomography (CTA) has been reported as more accurate but increases radiation and contrast agent burden. In this study, the use of non-contrast-enhanced cardiac magnetic resonance imaging (CMR) to support preprocedural planning for LAA closure (LAAc) was investigated.

Methods

CMR was performed in thirteen patients prior to LAAc. Based on the 3-dimensional CMR image data, the dimensions of the LAA were quantified and optimal C-arm angulations were determined and compared to periprocedural data. Quantitative figures used for evaluation of the technique comprised the maximum diameter, the diameter derived from perimeter and the area of the landing zone of the LAA.

Results

Perimeter- and area-based diameters derived from preprocedural CMR showed excellent congruency compared to those measured periprocedurally by XR, whereas the respective maximum diameter resulted in significant overestimation (p < 0.05). Compared to TEE assessment, CMR-derived diameters resulted in significantly larger dimensions (p < 0.05). The deviation of the maximum diameter to the diameters measured by XR and TEE correlated well with the ovality of the LAA. C-arm angulations used during the procedures were in agreement with those determined by CMR in case of circular LAA.

Discussion

This small pilot study demonstrates the potential of non-contrast-enhanced CMR to support preprocedural planning of LAAc. Diameter measurements based on LAA area and perimeter correlated well with the actual device selection parameters. CMR-derived determination of landing zones facilitated accurate C-arm angulation for optimal device positioning.

Feasibility of concomitant left atrial appendage closure and percutaneous coronary intervention in patients with acute coronary syndrome and atrial fibrillation: a randomized pilot study

The optimal approach for prevention of cardiovascular events and reduction of bleeding in patients with acute coronary syndrome (ACS) and atrial fibrillation (AF) is still controversial. The aim of our study is to asses our single-center experience with concomitant left atrial appendage occlusion (LAAO) and percutaneous coronary intervention (PCI). 50 patients with ACS without ST elevation and history of AF were randomized after successful PCI to LAAO or conventional medical therapy. The primary endpoints were safety and length of hospitalization. The follow-up period was 30 days. The mean procedural times were 113 ± 23 min PCI + LAAO implantation and 39 ± 19 min of PCI only (p < 0.001), while mean fluoroscopy times were 18 ± 8 min and 12 ± 8 min (p < 0.001), respectively. No procedure-related complications were observed. There was no difference observed for length of hospitalization between two groups. LAAO in patients with ACS and AF undergoing PCI appears safe.

Left Atrial Appendage Occlusion Device Buckling: An Avoidable Deployment Complication Identified and Corrected Using Intraprocedural Transesophageal Echocardiography

•

Watchman device buckling is a previously undescribed deployment complication.

•

Both 2D and 3D TEE assist in detection of buckling during and after the procedure.

•

Challenging LAA anatomy may play a significant role in buckling risk.

•

An acute angle between the deployment catheter and the LAA ostium may confer risk.

•

With diligent TEE guidance, buckling may be corrected during the procedure.

Clinical application of percutaneous left atrial appendage occlusion guided only by transesophageal echocardiography without fluoroscopy and angiography in the patients with nonvalvular atrial fibrillation

BACKGROUND AND AIM

The objective of this study was to understand the clinical efficacy and application of the percutaneous left atrial appendage occlusion (PLAAO) guided only by the transesophageal echocardiography (TEE) in patients with nonvalvular atrial fibrillation (NVAF), without using the fluoroscopy and angiography.

METHODS

During the time period of this study from June 2020 to June 2021, 32 patients underwent PLAAO and all underwent a TEE guided approach. The anatomical features of the left atrial appendage (LAA) were evaluated and observed by TEE before and during the procedure. LAA occluder device was selected for the appropriate size. Intraoperative TEE guided and monitored the process of PLAAO in real-time, and also evaluated the stability and tightness of the occluder device, following monitored postoperative complications.

RESULTS

The PLAAO procedure was successful in all the patients. No serious complications like dislocation of the occluder and embolism were seen. Postoperative TEE demonstrated that the PLAAO occluder devices were in a good position without residual shunting.

CONCLUSIONS

PLAAO only guided by TEE may become a safe and reliable surgical procedure, which can protect surgeons and patients from radiation, and can gradually become a novel surgical method of PLAAO with the practical application value.

Pre- and Postprocedural CT of Transcatheter Left Atrial Appendage Closure Devices

Transcatheter left atrial appendage (LAA) closure is an alternative to long-term anticoagulation therapy in selected patients with nonvalvular atrial fibrillation who have an increased risk for stroke. LAA closure devices can be implanted by means of either an endocardial or a combined endocardial and epicardial approach. Preprocedural imaging is key to identifying contraindications, accurately sizing the device, and minimizing complications. Transesophageal echocardiography (TEE) has been the reference standard imaging modality to assess the anatomy for LAA closure and to provide intraprocedural guidance. However, CT has emerged as a less-invasive alternative to TEE for pre- and postprocedural imaging. CT is comparable to TEE for exclusion of thrombus but is superior to TEE for the delineation of complex LAA anatomy, measurement for device sizing, and evaluation of pulmonary venous and extracardiac structures. CT provides accurate measurements of the LAA ostial diameter, landing zone diameter, and LAA length, which are vital for accurate sizing of the device. CT allows evaluation of the relationship with the pulmonary veins and other adjacent structures that can be injured during the procedure. CT also simulates procedural fluoroscopic angles and provides evaluation of the interatrial septum, which is punctured during LAA closure. CT also provides a more convenient method for the evaluation of postprocedural complications such as incomplete closure, peridevice leaking, device-related thrombus, and device dislodgement. Online supplemental material is available for this article. ^©RSNA, 2021.

Left atrial appendage size in patients with atrial fibrillation in Japan and the United States

Left atrial appendage (LAA) evaluation is important to select the optimal LAA closure device for patients with atrial fibrillation (AF). The LAA characteristics of Japanese patients remain uninvestigated. We compared the LAA size and morphology between 212 Japanese AF patients before catheter ablation and 119 AF patients undergoing LAA closure in the United States (US). We measured the LAA ostial dimension and depth by transesophageal echocardiography in all patients and determined the LAA morphology types of Japanese patients by multidetector cardiac computed tomography and those of US patients by LAA angiography. The maximum LAA ostial dimension was significantly larger in Japanese patients than in US patients (22.6 ± 4.1 mm vs. 21.5 ± 3.5 mm, P = 0.02). Also, Japanese patients had larger maximum dimension and depth corrected by body surface area than US patients in both paroxysmal and nonparoxysmal AF groups. The angle showing the maximum dimension was 0° or 135° in approximately 75% of patients in both groups. The common LAA morphology types were "cauliflower" and "chicken wing" in Japanese patients and "cactus" and "windsock" in US patients. In this study, Japanese patients had a larger LAA size than US patients. Because the maximum LAA dimension was obtained at the same angles, the LAA measurement method for US patients can be applicable to Japanese patients.

Morphologic and functional features of left atrial appendage in Iranian population: an echocardiographic study

Introduction: Cardioembolic events are accompanied by left atrial appendage (LAA) in patients suffering from atrial fibrillation (AF); therefore, the LAA closure is implemented as a preventive strategy. The detection of LAA morphologies and function is a paramount step before establishing the LAA closure. Herein, we sought to determine the morphologic features of the LAA in an Iranian population using echocardiographic evaluation.

Methods: Seventy-two near-normal heart patients were investigated by conducting a cross-sectional study. All patients were examined using the 2-dimensional and 3-dimensional transesophageal echocardiography (2D- and 3D-TEE) method. The anatomical features and functions of LAA were examined. All images were stored and analyzed offline.

Results: The patients’ mean age was 39 ± 15.5 year and 33 (45.8%) were female. The most frequent shape of LAA was wind sock . More LAA lobes was observed in patients with AF compared to those with NSR. In comparison with AF group, the NSR had higher LAA flow velocity (P < 0.01). The paroxysmal AF had greater LAA flow velocity and LAA ejection fraction in comparison with the chronic AF (39 ± 19 vs. 75 ± 22, P < 0.01; and 49±4 vs. 72±14, P < 0.003; respectively). The paroxysmal AF had smaller systolic LAA orifice area in comparison with the chronic AF (P < 0.02).

Conclusion: The morphologic features of LAA in Iranian population were within the range of other studies and LAA length and orifice diameters in 2D- and 3D-TEE were consistent. In addition, AF influenced the morphologies and functions of LAA compared to sinus rhythm.

Left Atrial Appendage Occlusion Guided Only by Transesophageal Echocardiography

Aims

To investigate a new method of left atrial appendage occlusion without fluoroscopy.

Methods and Results

We performed left atrial appendage occlusion for 14 patients with atrial fibrillation in our hospital. All of the surgeries were completed in a general surgery setting, avoiding fluoroscopy, and in each case, the entire procedure was guided by transesophageal echocardiography (TEE). All of the surgeries were performed through the femoral vein pathway. All operations went smoothly with no serious complications. Postoperative TEE indicated that each device was in a good position, and there was no residual shunt around any of the devices.

Conclusions

TEE-guided left atrial appendage occlusion is safe and reliable, simplifies the procedure, protects doctors and patients from radiation, and is gradually becoming the mainstream operation for left atrial appendage occlusion. This trial is registered with ChiCTR1800018387.

Safety and feasibility of interventional left atrial appendage closure without contrast agent

AIMS

Interventional left atrial appendage closure (LAAC) is routinely performed under both echocardiographic and angiographic guiding. However, adverse outcomes, e.g., kidney injury and cerebral embolism, might be associated with injections of contrast agent into the LAA. Therefore, this prospective registry investigated the safety and feasibility of LAAC without the support of angiographic images as the default approach.

METHODS AND RESULTS

This single-centre registry included a total of 46 non-selected, consecutive patients. In the first 25 patients (54%), LAAC with the Amulet device was performed routinely with LAA angiography prior to implantation and after release of the device. The following 21 patients (46%) were treated without the use of contrast agent. The combination of successful implantation and lack of procedural complications was regarded as the primary endpoint. Procedure time, number of recapture manoeuvres, change of device size, compression, leakage, dose area product and late thrombosis on the device were investigated as secondary endpoints. Besides the longer fluoroscopy time and duration of the procedure in the group using angiography, no significant differences could be found. Major complications occurred equally often in both cohorts.

CONCLUSIONS

Interventional LAAC with the Amulet device can be performed safely without the use of contrast agent. This approach might help to enhance the use of LAAC in patients at high risk of contrast-induced nephropathy and procedural stroke.

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.

Evaluation of the left atrial appendage by real time three-dimensional transesophageal echocardiography online

OBJECTIVE

The objective of this study was to evaluate the feasibility of online real time three-dimensional transesophageal echocardiography (RT3DTEE) in the measurement of left atrial appendage (LAA) orifice size. We also analyzed the correlation between LAA ejection fraction (EF) and its peak empty velocity (PEV).

METHODS

There were 91 subjects enrolled in this study, with 46 patients with AF and 45 individuals with sinus rhythm (SR). RT3DTEE was performed by four methods including iSlice and iCrop online and QLAB software 3DQ and GI-3DQ off-line which were used to measure LAA orifice area, long diameter, short diameter, depth in the largest LAA, and number of LAA lobes. These LAA parameters achieved by the four methods were compared, respectively. GI-3DQ off-line was used to measure LAA end-diastolic and end-systolic volumes to calculate EF of LAA. Two-dimensional (2D) TEE was applied to measure PEV of LAA. The correlation between EF and PEV was analyzed.

RESULTS

There were no significant differences in all LAA parameters between any two RT3DTEE methods (All P > .05). There was a significant and positive correlation between PEV and EF (r = .423, P = .000). There were statistical differences in LAA EF and PEV between patients with AF and SR individuals (0.38 ± 0.12 vs 0.61 ± 0.07, 35.7 ± 12.1 vs 49.5 ± 10.0 cm/s, P = .000).

CONCLUSION

Using online RT3DTEE for measuring LAA orifice size is feasible, and online RT3DTEE is more convenient than offline RT3DTEE. EF is positively correlated with PEV. LAA function is significantly decreased in patients with AF.

The growing role of echocardiography in interventional cardiology: The present and the future

As structural heart disease interventions continue to evolve to a sophisticated level, accurate and reliable imaging is required for pre-procedural selection of cases, intra-procedural guidance, post-procedural evaluation, and long-term follow-up of patients. Traditionally, cardiovascular procedures in the catheterization laboratory are guided by fluoroscopy and angiography. Advances in echocardiography can overcome most limitations of conventional imaging modalities and provide successful completion of each step of any catheter-based treatment. Echocardiography's unique characteristics rendered it the ideal technique for percutaneous catheter-based procedures. The purpose of this review is to demonstrate the use of the most common and up-to-date echocardiographic techniques in recent non-coronary percutaneous interventional procedures, underlining its inevitable and growing role, as well as illustrating areas of weakness and limitations, and to provide future perspectives.

Cardiac CT Angiography (CCTA) predicts left atrial appendage occluder device size and procedure outcome

AIM

To investigate the role of cardiac CT angiography (CCTA) in predicting optimal left atrial appendage (LAA) occluder size and procedure outcome.

METHODS AND RESULTS

Thirty-six patients underwent pre-procedural CCTA. CCTA and TEE LAA orifice diameters and perimeters were compared with the implanted device size. CCTA 3D configuration was correlated with procedure outcome. Watchman™ device (N = 18): diameters were 21 ± 4, 26 ± 5 and 25 ± 3 mm for TEE, CCTA and inserted device, respectively. Average perimeters were 61 ± 10, 74 ± 8 and 78 ± 11 mm for TEE, CCTA and inserted device, respectively. Better agreement with the device size was found for CCTA compared to TEE (Bland-Altman). ACP™ device (N = 15): diameters were 20 ± 5, 25 ± 4 and 23 ± 4 for TEE, CCTA and inserted device, respectively. Average perimeters were 58 ± 11, 72 ± 15 and 72 ± 13 mm for TEE, CCTA and inserted device, respectively. Excellent correlation and agreement with the device size was found for CCTA compared to TEE. CCTA perimeter >100 mm and "cactus" 3D configuration had a specificity of 96 and 81% respectively for procedure failure.

CONCLUSIONS

CCTA LAA ostial perimeter predicted better the optimal occluder size as compared with the currently used LAA TEE diameter. Moreover, CCTA 3D data may help in predicting potential complications.

Left Atrial Appendage Closure Under Intracardiac Echocardiographic Guidance: Feasibility and Comparison With Transesophageal Echocardiography

Background

Transcatheter left atrial appendage closure is an alternative therapy for stroke prevention in atrial fibrillation patients. These procedures are currently guided with transesophageal echocardiography and fluoroscopy in most centers. As intracardiac echocardiography (ICE) is commonly used in other catheter‐based procedures, we sought to determine the safety and effectiveness of intracardiac echocardiography–guided left atrial appendage closure with the Watchman device.

Methods and Results

A total of 27 patients (11 males, 77.0±8.5 years) with atrial fibrillation receiving Watchman left atrial appendage closure under intracardiac echocardiography guidance at a single center were investigated. All patients were implanted successfully. There were no major procedural complications. The overall procedure‐related complication rate was 14.8%, mainly due to access site hematoma. Transesophageal echocardiography demonstrated successful closure of the left atrial appendage in all patients at 45 days after device implant.

Conclusions

Transcatheter left atrial appendage closure with intracardiac echocardiography guidance is safe and feasible.

Rotational method simplifies 3-dimensional measurement of left atrial appendage dimensions during transesophageal echocardiography

Background

Not all echo laboratories have the capability of measuring direct online 3D images, but do have the capability of turning 3D images into 2D ones “online” for bedside measurements. Thus, we hypothesized that a simple and rapid rotation of the sagittal view (green box, x-plane) that shows all needed left atrial appendage (LAA) number of lobes, orifice area, maximal and minimal diameters and depth parameters on the 3D transesophageal echocardiography (3DTEE) image and LAA measurements after turning the images into 2D (Rotational 3DTEE/“Yosefy Rotation”) is as accurate as the direct measurement on real-time-3D image (RT3DTEE).

Methods

We prospectively studied 41 consecutive patients who underwent a routine TEE exam, using QLAB 10 Application on EPIQ7 and IE33 3D-Echo machine (BORTHEL Phillips) between 01/2013 and 12/2015. All patients underwent 64-slice CT before pulmonary vein isolation or for workup of pulmonary embolism. LAA measurements were compared between RT3DTEE and Rotational 3DTEE versus CT.

Results

Rotational 3DTEE measurements of LAA were not statistically different from RT3DTEE and from CT regarding: number of lobes (1.6 ± 0.7, 1.6 ± 0.6, and 1.4 ± 0.6, respectively, p = NS for all); internal area of orifice (3.1 ± 0.6, 3.0 ± 0.7, and 3.3 ± 1.5 cm², respectively, p = NS for all); maximal LAA diameter (24.8 ± 4.5, 24.6 ± 5.0, and 24.9 ± 5.8 mm, respectively, p = NS for all); minimal LAA diameter (16.4 ± 3.4, 16.7 ± 3.3, and 17.0 ± 4.4 mm, respectively, p = NS for all), and LAA depth (20.0 ± 2.1, 19.8 ± 2.2, and 21.7 ± 6.9 mm, respectively, p = NS for all).

Conclusion

Rotational 3DTEE method for assessing LAA is a simple, rapid and feasible method that has accuracy similar to that of RT3DTEE and CT. Thus, rotational 3DTEE (“Yosefy rotation”) may facilitate LAA closure procedure by choosing the appropriate device size.

Transesophageal Echocardiography in Atrial Fibrillation

Transesophageal echocardiography (TEE) plays an important role in atrial fibrillation (AF), mainly to detect the presence of left atrial appendage (LAA) thrombus. It is useful in direct current cardioversion (DCC) guidance and for AF ablation and LAA occlusion. With the increasing number of patients affected by AF, the use of TEE will grow and become an important screening modality for LAA thrombus. Future direction includes broader multi-institutional use; further tools to risk stratify patients; and the use of a new spectrum of oral anticoagulants and their cost-effectiveness in patients with AF undergoing DCC, AF ablation, and LAA occlusion.

Interventional imaging: the role of echocardiography

Interventional echocardiography is a rapidly evolving field requiring imaging expertise. An increasing number of structural heart interventions now require real-time imaging guidance for device placement and immediate functional evaluation. Continuous 2- and 3-dimensional transesophageal echocardiography are now required by many heart teams during complex structural interventions, including percutaneous closure of atrial septal defects, left atrial appendage occlusion, transcatheter aortic valve replacement (TAVR), transcatheter repair of paravalvular regurgitation, and percutaneous mitral valve repair. In this review, we describe the role of echocardiography during the initial structural evaluation, throughout the device placement procedure, and for the assessment of acute device function and complications.

Optical coherence tomography assessment of a PLGA-polymer with electro-grafting base layer versus a PLA-polymer sirolimus-eluting stent at three-month follow-up: the BuMA-OCT randomised trial

AIMS

To compare stent strut coverage using optical coherence tomography (OCT) at three-month follow-up between a PLGA-polymer with electro-grafting base layer sirolimus-eluting stent (SES) (BuMA) and a PLA-polymer SES (EXCEL).

METHODS AND RESULTS

This prospective, single-centre, non-inferiority randomised BuMA-OCT trial enrolled patients with de novo coronary artery lesions, treated with either the BuMA or the EXCEL stent. The study primary endpoint was OCT-evaluated stent strut coverage at three months. Secondary endpoints were neointimal thickness of stent struts, and incomplete stent apposition evaluated with OCT. A total of 80 patients were randomly assigned to receive the BuMA (n=40) or the EXCEL (n=40) stent. In OCT follow-up (achieved in 86.3% of cases: BuMA, n=33; EXCEL, n=36), the percentage of stent strut coverage was significantly higher in the BuMA vs. the EXCEL group (strut level: 94.2% vs. 90.0%, p<0.01; p(non-inferiority)<0.0001; p(superiority) <0.0001), while the proportion of malapposed struts (strut level: 1.28% vs. 1.80%, p=0.51) and the mean neointimal thickness (strut level: 0.07±0.03 mm vs. 0.06±0.02 mm, p=0.31) were similar. Rates of myocardial infarction (periprocedural non-Q-wave, 7.5% vs. 7.5%, p=1.00) and target lesion failure (7.5% vs. 7.5%, p=1.00) were similar between groups, with no cardiac death or stent thrombosis.

CONCLUSIONS

In the BuMA-OCT randomised trial, the novel BuMA PLGA-polymer with electro-grafting base layer SES was superior to the EXCEL PLA-polymer SES in the primary endpoint of stent strut coverage at three-month follow-up.

A New Method for Direct Three-Dimensional Measurement of Left Atrial Appendage Dimensions during Transesophageal Echocardiography

AIMS

Currently, two-dimensional transesophageal echocardiography (2DTEE) at a cut-plane angulation of 135° is the recommended method to size maximal left atrial appendage (LAA) orifice diameter before introducing a percutaneous LAA closure device. We compared real time three-dimensional TEE (RT3DTEE) and 2DTEE for measuring LAA dimensions versus computed tomography (CT) as gold standard.

METHODS AND RESULTS

We prospectively studied 30 consecutive patients who underwent a routine TEE examination, using QLAB 10.0 Application on EPIQ7 iE33 3D echo machine between December 2012 and December 2013. All patients underwent 64-slice CT before pulmonary vein isolation or for workup of pulmonary embolism. LAA measurements were compared between 135 2DTEE and RT3DTEE. Results were compared with CT measurements. Using RT3DTEE, larger LAA diameters were measured versus 2DTEE (23.5 ± 3.9 vs. 24.5 ± 4.7 mm). In seven patients (23.3%), the measurements in 135° 2DTEE were smaller than the cut-plane angulation with maximal orifice diameter. RT3DTEE measurements of LAA were not different from CT regarding number of lobes, area of orifice, and maximal diameter. LAA volume could not be measured directly using RT3DTEE. No difference was found between LAA depth using RT3DTEE (19.5 ± 2.3 mm) vs. CT (19.6 ± 2.3, P = NS) and 2DTEE (19.4 ± 2.2 mm) vs. CT (P = NS). However, RT3DTEE (24.5 ± 4.7 mm) vs. CT (24.6 ± 5, P = NS) was more accurate in measuring maximal LAA diameter compared to 2DTEE (23.5 ± 3.9 mm) vs. CT (P < 0.01).

CONCLUSION

RT3DTEE method is more accurate than 2DTEE for assessment of maximal LAA orifice diameter. Bedsides, RT3DTEE LAA measurements are not statistically different from CT. Thus, RT3DTEE may facilitate LAA closure procedure by choosing the appropriate device size.

First in vivo evaluation of a flexible self-apposing left atrial appendage closure device in the canine model

OBJECTIVES

Aimed to evaluate the feasibility of deployment and healing response of a novel transcatheter left atrial appendage (LAA) occlusion device in the canine model

BACKGROUND

LAA occlusion is proposed to reduce the risk of stroke in atrial fibrillation patients

METHODS

Transseptal puncture and device deployment was guided under fluoroscopy and transesophageal echocardiography (TEE) in five dogs. First, a distal cylindrical bulb occluder was released and secured to the appendage wall with hooks. Subsequently, a proximal sail was unfolded, covering the LAA ostium. Rotational angiography, TEE, and histology outcomes were assessed 30 days following implantation

RESULTS

Pre-operative TEE revealed the mean diameter of the LAA ostium to be 17.2 ± 1.6 mm with a depth of 18.5 ± 1.7 mm. The landing zone for the distal bulb was measured to be 12.8 ± 1.3 mm. The mean bulb diameter at implant was 16.8 ± 1.8 mm. Post-operative TEE showed adequate positioning and successful LAA occlusion with all implanted devices. Pericardial effusion requiring pericardiocentesis was seen in one animal following device implantation. At 30 days, TEE revealed full occlusion of all LAA ostia with the exception of a minimal peri-device leak (<3 mm) observed in one animal. No pericardial effusion or device-related thrombus formation was found at termination. Histological analysis confirmed circumferential occlusion of all appendages and complete neointimal coverage on the luminal aspect of the occluder

CONCLUSION

The percutaneous delivery of a novel self-positioning LAA occlusion device is feasible and safe in a canine model. At 30 days, all devices displayed complete healing and occlusion of the LAA without any device related adverse events.

Interventional Echocardiography: Current Role and Progress

Advances in cardiovascular interventional techniques have enabled percutaneous treatment for a wide spectrum of non-coronary cardiovascular diseases, also known as ‘structural heart diseases (SHD)’. As these therapies are performed without an open-heart surgery, the use of echocardiography is crucial for detailed visualisation of cardiac anatomy, and to provide guidance for optimal success of these catheter-based interventions. This review will describe the key role of the echocardiographic techniques and imaging protocols that are currently used in different catheter-based SHD interventions.

Left atrial appendage exclusion for atrial fibrillation

Percutaneous left atrial appendage (LAA) closure is being increasingly used as a treatment strategy to prevent stroke in patients with atrial fibrillation (AF) who have contraindications to anticoagulants. Several approaches and devices have been developed in the last few years, each with their own unique set of advantages and disadvantages. In this article, the published studies on surgical and percutaneous approaches to LAA closure are reviewed, focusing on stroke mechanisms in AF, LAA structure and function relevant to stroke prevention, practical differences in procedural approach, and clinical considerations surrounding management.

The figure-of-eight artifact in the echocardiographic assessment of percutaneous disc occluders: impact of imaging depth and device type

PURPOSE

Echocardiography is increasingly important in the guidance and follow-up of percutaneous transcatheter device closures. It was recently shown that the Amplatzer left atrial appendage occluder frequently presents as a figure-of-eight artifact due to interaction of device mesh and ultrasound waves. It remains unknown whether this can be translated to other types of disc occluders. Furthermore, the morphology of this figure-of-eight artifact appears to be different in the transesophageal and transthoracic image of the same device. The aim of this study was to evaluate the echocardiographic appearance of different types of disc occluders, and to clarify differences in morphology of the figure-of-eight artifact.

METHODS

A mathematical model of an epitrochoid curve was used for numerical simulation of disc occluder appearance at various imaging depths. In addition, an in vitro setup was used for echocardiographic analysis of different types of disc occluders at adjustable imaging depth and position.

RESULTS

Mathematically, decreasing the imaging depth resulted in a more asymmetric figure-of-eight, i.e. with small upper part and wide lower part. In vitro results were in close agreement with the mathematical results. In addition, in vitro a figure-of-eight artifact was obtained in all different types of disc occluder devices.

CONCLUSIONS

Different types of percutaneous disc occluders all present as a figure-of-eight artifact on echocardiography when imaged from a coronal imaging position. The morphology of the artifact depends on the imaging depth, with a more asymmetric figure-of-eight morphology at smaller probe-to-device distance. This clarifies the differences observed between transesophageal and transthoracic imaging.

Percutaneous left atrial appendage occlusion for stroke prevention in atrial fibrillation: an update

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. One of its most devastating complications is the development of thromboembolism leading to fatal or disabling stroke. Oral anticoagulation (OAC, warfarin) is the standard treatment for stroke prevention in patients with AF with an increased stroke risk. However, there are several obstacles to long-term OAC therapy, including the risk of serious bleeding, several drug–drug interactions and the need for frequent blood testing. Although newer oral anticoagulants have been developed, these drugs also face issues of major bleeding and non-compliance. Therefore, alternative treatment options for stroke prevention in patients with AF with a high stroke risk are needed. Percutaneous left atrial appendage (LAA) occlusion is an evolving therapy, which should be taken into consideration in those patients with non-valvular AF with a high stroke risk and contraindications for OAC. This article aims to discuss the rationale for LAA closure, the available LAA occlusion devices and their clinical evidence until now. Moreover, we discuss the importance of proper patient selection, the role of various imaging techniques and the need for a more tailored postprocedural antithrombotic therapy.

The Role of Cardiac Imaging in Stroke Prevention

This article reviews the role of cardiac imaging in stroke prevention, defining how imaging tools can be useful in this field. Cardioembolic sources during atrial fibrillation are discussed. New closure devices can be implanted in the left atrial appendage and routinely monitored with imaging modalities. Acute and chronic left ventricular dysfunction is reviewed, identifying the possible mechanism of thrombus formation and its early detection. Valvular evaluation of native heart disease and possible implications for stroke risk are defined.

Left Atrial Appendage Closure for Stroke Prevention: Emerging Technologies

Current anticoagulant therapies aimed at stroke prevention in atrial fibrillation (AF) are increasingly challenged by a complex patient population at significant risk of bleeding. Mounting evidence shows that left atrial appendage (LAA) closure is an effective strategy for reducing stroke risk in patients with nonvalvular AF, without the need for anticoagulation. Several approaches and devices have been developed in recent years, each with their own set of advantages and disadvantages. This article reviews these approaches, identifies pertinent aspects, and outlines necessary or ongoing research in establishing LAA closure as a safe and effective approach to stroke risk reduction.

Thromboembolism Prevention via Transcatheter Left Atrial Appendage Closure with Transeosophageal Echocardiography Guidance

Atrial fibrillation (AF) is an independent risk factor for stroke. Anticoagulation therapy has a risk of intracerebral hemorrhage. The use of percutaneous left atrial appendage (LAA) closure devices is an alternative to anticoagulation therapy. Echocardiography has a leading role in LAA closure procedure in patient selection, during the procedure and during followup. A comprehensive echocardiography study is necessary preprocedural in order to identify all the lobes of the LAA, evaluate the size of the LAA ostium, look for thrombus or spontaneous echo contrast, and evaluate atrial anatomy, including atrial septal defect and patent foramen ovale. Echocardiography is used to identify potential cardiac sources of embolism, such as atrial septal aneurysm, mitral valve disease, and aortic debris. During the LAA occlusion procedure transeosophageal echocardiography provides guidance for the transeptal puncture and monitoring during the release of the closure device. Procedure-related complications can be evaluated and acceptable device release criteria such as proper position and seating of the occluder in the LAA, compression, and stability can be assessed. Postprocedural echocardiography is used for followup to assess the closure of the LAA ostium. This overview paper describes the emerging role of LAA occlusion procedure with transeosophageal echocardiography guidance as an alternative to anticoagulation therapy in patients with AF.

Etiology and relevance of the figure-of-eight artifact on echocardiography after percutaneous left atrial appendage closure with the Amplatzer Cardiac Plug

BACKGROUND

The Amplatzer Cardiac Plug (ACP) device, used for percutaneous left atrial appendage closure, frequently presents as an unexplained figure-of-eight on echocardiography. The aim of this study was to clarify the figure-of-eight display of the ACP device during echocardiography and to relate this finding to device position and function.

METHODS

A mathematical model was developed to resemble device geometry and predict the echocardiographic appearance of the ACP device. In addition, an in vitro setup was used to validate the model. Finally, echocardiographic images of consecutive patients referred for percutaneous left atrial appendage closure (n = 24) were analyzed for the presence of a figure-of-eight display.

RESULTS

Because the ACP device resembles an epitrochoid curve, those points with tangent vector perpendicular to the ultrasound waves are emphasized, resulting in a figure-of-eight display, which can be replicated in vitro in the coronal imaging position. We found the figure-of-eight display in 100% (11 of 11) of three-dimensional periprocedural transesophageal images and in 87% (34 of 39) of postprocedural transthoracic echocardiographic images.

CONCLUSIONS

The figure-of-eight display of the ACP device during echocardiography is the result of the specific epitrochoid geometry of the device mesh and its interaction with ultrasound waves. It is important to recognize the figure-of-eight as being a normal imaging artifact of a correctly deployed device in the coronal imaging position on both transesophageal and transthoracic echocardiography. In the future, this could be used during follow-up to aid clinical practitioners in assessing device position and function.