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

Hypertrophic Cardiomyopathy Predicts Thromboembolism and Heart Failure in Patients With Nonvalvular Atrial Fibrillation - A Prospective Analysis From the Hokuriku-Plus AF Registry

BACKGROUND

The prognostic effect of concomitant hypertrophic cardiomyopathy (HCM) on adverse events in patients with atrial fibrillation (AF) has not been evaluated in a multicenter prospective cohort study in Japan.Methods and Results: Using the Hokuriku-Plus AF Registry, 1,396 patients with nonvalvular AF (1,018 men, 72.3±9.7 years old) were assessed prospectively; 72 (5.2%) had concomitant HCM. During a median follow-up of 5.0 years (interquartile range 3.5-5.3 years), 79 cases of thromboembolism (1.3 per 100 person-years) and 192 of heart failure (HF) (3.2 per 100 person-years) occurred. Kaplan-Meier analysis revealed that the HCM group had a significantly greater incidence of thromboembolism (P=0.002 by log-rank test) and HF (P<0.0001 by a log-rank test) than the non-HCM group. The Cox proportional hazards model demonstrated that persistent AF (adjusted hazard ratio 2.98, 95% confidence interval 1.56-6.21), the CHA2DS2-VASc score (1.35, 1.18-1.54), and concomitant HCM (2.48, 1.16-4.79) were significantly associated with thromboembolism. Conversely, concomitant HCM (2.81, 1.72-4.43), older age (1.07, 1.05-1.10), lower body mass index (0.95, 0.91-0.99), a history of HF (2.49, 1.77-3.52), and lower left ventricular ejection fraction (0.98, 0.97-0.99) were significantly associated with the development of HF.

CONCLUSIONS

Concomitant HCM predicts the incidence of thromboembolism and HF in AF patients.

Safety of left atrial appendage closure in heart failure patients

INTRODUCTION

Left atrial appendage closure (LAAC) is an intervention aimed at stroke prevention in nonvalvular atrial fibrillation (AF). There is a three-fold increased risk of stroke in patients with concomitant presence of AF and heart failure (HF). While anticoagulation is effective, only 60% receive it. We aimed at studying the safety of LAAC in HF patients using a national all-payer database.

METHODS

We queried the National Inpatient Sample for the year 2016-2018 for WATCHMAN device insertion using ICD 10 procedure codes. We divided the study population into HF and non-HF groups. Outcomes were compared using appropriate statistical tests, p< .05 was considered significant.

RESULTS

34 385 LAAC procedures were identified of which 8530 (24.8%) were done in patients with HF. The mean (SD) age of the study population was 76 (7.9) years and 42% were female. There was no difference in mean age between HF and non-HF groups. Our findings indicate that there is no difference in inpatient mortality and cardiac complications between the HF and non-HF groups. However, noncardiac complications including acute kidney injury and respiratory failure were higher in the HF group.

CONCLUSION

LAAC appears to be a safe procedure in patients with HF. The study is limited by a short follow up period and long-term follow-up is required before definitive conclusions can be made.

Large Device-Related Thrombus Detected following Symptoms of Transient Ischemic Attack

As an independent risk factor for stroke, atrial fibrillation has been shown to be associated with a fivefold increase in the cause of embolic stroke in comparison to healthy individuals without atrial fibrillation. This risk may be compounded by other factors; however, the main probable cause of stroke leading from atrial fibrillation is thrombus formation in the left atrial appendage. In patients for whom anticoagulation is contraindicated, left atrial appendage occlusion has become a leading alternative option for therapeutic prevention of thromboembolism and stroke in patients with this condition. Unfortunately, these devices (particularly the WATCHMAN) have been associated with a 3-6% incidence of intracardiac thrombus development postimplantation. Some risk factors for the development of device-related thrombus are high platelet count, permanent atrial fibrillation, resistance to clopidogrel, and prior transient ischemic attack or stroke. Despite following an anticoagulant regimen, thrombus formation was reported in 5.6% of participants of a randomized clinical trial, and further analysis showed that some of these patients continued to develop either ischemic stroke or thromboembolism five years later as compared to patients without initial thrombus development. We present a case of an elderly male with prior history of stroke and transient ischemic attack who developed a large device-related thrombus five months following WATCHMAN FLX™ implantation. Currently, there are no specific recommendations on the management of this rare complication; however, we discuss possible consideration of initially prolonging anticoagulation therapy following implantation for high-risk individuals, as there is an increased possibility for thrombus formation in this population. Management options should continue to be studied for therapeutic benefit in streamlining postprocedural therapy and improve future outcomes in the use of left atrial appendage occlusion devices, as well as continual thrombus prevention.

State-of-the-art preclinical testing of the OMEGATM left atrial appendage occluder

OBJECTIVES

This study aimed to present a new approach of thorough preclinical testing of a novel left atrial appendage (LAA) occluder device.

BACKGROUND

The development of a safe and effective LAA occluder has been shown to be challenging.

METHODS

The novel OMEGATM LAA occluder (Eclipse Medical, Ireland) was tested in a porcine model and three-dimensional (3D) human LAA models - this as a prelude to its first-in-human use.

RESULTS

In a first series of in-vivo experiments, the OMEGATM LAA occluder was shown to have a satisfactory device biocompatibility in a porcine model. The design of the OMEGATM device was further refined and optimized following three more series of in-vivo experiments. The second generation OMEGATM device was designed with thinner wires, leading to a profile reduction. Based on in-vitro testing of different OMEGATM device sizes implanted at different depths in human three-dimensional (3D) LAA models, it could be determined that (1) the landing zone should be measured at a median depth of 12 mm from the LAA ostium; (2) the distal self-retaining inverted cup should have 10%-25% compression to minimize device embolization risk; and (3) the disc should be slightly inverted, i.e. pulled into the LAA, to promote complete LAA occlusion. The combined in-vivo and in-vitro testing resulted in an optimized pre-procedural planning of the first-in-human case treated with the OMEGATM device.

CONCLUSIONS

This series of carefully planned in-vivo and in-vitro experiments allowed demonstration of the safety and efficacy of the OMEGATM LAA occluder. This approach of thorough preclinical testing of medical devices may reduce the risk of complications in first-in-human cases and may become the standard approach for device development and preclinical testing in the future.

Value of FEops HEARTguide patient-specific computational simulations in the planning of left atrial appendage closure with the Amplatzer Amulet closure device: rationale and design of the PREDICT-LAA study

BACKGROUND

Optimal preprocedural planning is essential to ensure successful device closure of the left atrial appendage (LAA).

DESIGN

The PREDICT-LAA study is a prospective, international, multicentre, randomised controlled trial (ClinicalTrials.gov NCT04180605). Two hundred patients eligible for LAA closure with an Amplatzer Amulet device (Abbott, USA) will be enrolled in the study. Patients will be allocated to a computational simulation arm (experimental) or standard treatment arm (control) using a 1:1 randomisation. For patients randomised to the computational simulation arm, preprocedural planning will be based on the analysis of cardiac computed tomography (CCT)-based patient-specific computational simulations (FEops HEARTguide, Ghent, Belgium) in order to predict optimal device size and position. For patients in the control arm, preprocedural planning will be based on local practice including CCT analysis. The LAA closure procedure and postprocedural antithrombotic therapy will follow local practice in both arms. The primary endpoint of the study is incomplete LAA closure and device-related thrombus as assessed at 3 months postprocedural CCT. Secondary endpoints encompass procedural efficiency (number of devices used, number of repositioning, procedural time, radiation exposure, contrast dye), procedure-related complications within 7 days postprocedure and a composite of all-cause death and thromboembolic events at 12 months.

CONCLUSION

The objective of the PREDICT-LAA study is to test the hypothesis that a preprocedural planning for LAA closure with the Amplatzer Amulet device based on patient-specific computational simulations can result in a more efficient procedure, optimised procedural outcomes and better clinical outcomes as compared with a standard preprocedural planning.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04180605).

Advances in the management of atrial fibrillation with a special focus on non-pharmacological approaches to prevent thromboembolism: a review of current recommendations

Atrial fibrillation (AFIB) is the most common heart rhythm abnormality and is associated with significant morbidity and mortality. While the treatment of AFIB involves strategies of rate with or without rhythm control, it is also essential to strategize appropriate therapies to prevent thromboembolic complications arising from AFIB. Previously, anticoagulation was the main treatment option which exposed patients to higher than usual risk of bleeding. However, with the advent of new technology, novel therapeutic options aimed at surgical or percutaneous exclusion or occlusion of the left atrial appendage in preventing thromboembolic complications from AFIB have evolved. This review evaluates recent advances and therapeutic options in treating AFIB with a special focus on both surgical and percutaneous interventions which can reduce and/or eliminate thromboembolic complications of AFIB.

Impact of Left Atrial Appendage Exclusion on Short-Term Outcomes in Isolated Coronary Artery Bypass Graft Surgery

BACKGROUND

The objective of this study was to evaluate the impact of left atrial appendage (LAA) exclusion on short-term outcomes in patients with atrial fibrillation undergoing isolated coronary artery bypass graft surgery.

METHODS

We queried the 2010 to 2014 National Readmissions Database for patients who underwent coronary artery bypass graft repair with and without LAA ligation by using International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes (International Classification of Diseases, Ninth Revision, Clinical Modification: 36.1xx). Only patients with a history of atrial fibrillation were included in our analysis. The primary outcome of our study was 30-day readmissions following discharge. Secondary outcomes were in-hospital mortality and stroke. To assess the postoperative outcomes, we used multivariate logistic regression models to adjust for clinical and demographic covariates.

RESULTS

In total, we analyzed 253 287 patients undergoing coronary artery bypass graft surgery, 7.0% of whom received LAA closure. LAA exclusion was associated with a greater risk of postoperative respiratory failure (8.2% versus 6.2%, P<0.0001) and acute kidney injury (21.8% versus 18.5%, P<0.0001), but it did not significantly change the rate of blood transfusions or occurrence of cardiac tamponade. LAA exclusion was associated with a nonsignificant reduction in stroke (7.9% versus 8.6%, P=0.12), no difference in in-hospital mortality (2.2% versus 2.2% P=0.99), and a greater risk of 30-day readmission (16.0% versus 9.6%, P<0.0001). After covariate adjustment, LAA ligation remained a significant predictor of 30-day readmission (odds ratio, 1.640 [95% CI, 1.603-1.677], P<0.0001).

CONCLUSIONS

LAA exclusion during isolated coronary artery bypass graft surgery in patients with atrial fibrillation is associated with a higher rate of 30-day readmission. Postoperative measures to mitigate the loss of the hormonal and hemodynamic effects of the LAA may increase the therapeutic benefit of this procedure.

Efficacy and safety of catheter ablation combined with left atrial appendage occlusion for nonvalvular atrial fibrillation: A systematic review and meta-analysis

Atrial fibrillation (AF) is currently the most prevalent arrhythmia in clinical practice, with stroke being one of its major complications. Combining catheter ablation and percutaneous left atrial appendage occlusion (LAAO) into a "one-stop" intervention could reduce stroke incidence in selected high-risk patients and, at the same time, relieve AF symptoms in a single procedure. This meta-analysis analyzed the efficacy and safety of catheter ablation combined with LAAO for nonvalvular AF. PubMed, EMBASE, and the Cochrane Library were searched from inception to April 2019 to identify relevant citations. Efficacy indexes were procedural success, AF recurrence, stroke/transient ischemic attacks (TIA), and device-related thrombus (DRT). Safety indexes were all-cause death, major hemorrhagic complications, and pericardial effusion/cardiac tamponade. The incidence rate of events (ratio of events to patients) and 95% confidence interval (CI) were calculated as summary results. A forest plot was constructed to present pooled rates. Eighteen studies (two randomized controlled trials and 16 observational studies) were included. The results showed that one-stop intervention has significant efficacy and safety, with procedural success of .98 (95% CI, .97-1.00), AF recurrence of .24 (95% CI, .15-.35), stroke/TIA of .01 (95% CI, .00-.01), DRT of .00 (95% CI, .00-.01), all-cause mortality of .00 (95% CI, .00-.00), cardiac/neurological mortality of .00 (95% CI, .00-.00), major hemorrhagic complications of .01 (95% CI, .00-.02), and pericardial effusion/cardiac tamponade of .01 (95% CI, .00-.01). A single procedure with catheter ablation and LAAO in AF is a feasible strategy with significant efficacy and safety.

Comparison of echocardiographic and fluoroscopic sizing of the left atrial appendage prior to percutaneous closure

PURPOSE

Sizing of the left atrial appendage (LAA) ostium prior to occlusion (LAAO) is routinely performed with transesophageal echocardiography (TEE). We sought to compare the utility of sizing via fluoroscopy to TEE for percutaneous LAAO.

METHODS

We retrospectively evaluated all patients undergoing percutaneous LAAO at our institution from April 2015 through January 2018 (n = 195). We evaluated baseline characteristics, maximum measured ostium size (for both TEE and fluoroscopy), and differences in measured size to device size for both techniques.

RESULTS

Of the total cohort, 185 (95%) had both intraoperative TEE and fluoroscopic images available for analysis and were included in the final analysis. The mean age was 74 years and 64% were male. Hypertension was present in 89%, diabetes in 30%, and stroke in 32% of patients. The mean ejection fraction was 51%. The most common LAA morphology was "wind sock" (52%). Measured ostial diameter on fluoroscopy was larger compared with TEE (2.04 ± 3.43 mm larger on fluoroscopy, p < 0.001). Ostium diameter on TEE was more closely correlated to the size of the device implanted compared with fluoroscopy (0.76 vs. 0.61, p = 0.001).

CONCLUSIONS

Fluoroscopy results in larger estimated LAA ostium diameter compared with TEE. Despite this, TEE was more strongly correlated to operator choice in device sizing, which may reflect practice patterns. Because compression of the ostium on the device is necessary for long-term procedural success, under-sizing may lead to a higher rate of leaks. Prospective evaluation of the utility of routine fluoroscopic sizing compared with TEE is warranted.

The value of the left atrial appendage orifice perimeter of 3D model based on 3D TEE data in the choice of device size of LAmbre™ occluder

Preoperative optimal selection of the occluder size is crucial in percutaneous left atrial appendage (LAA) occlusion, and the maximal width of the LAA orifice is the main reference index, however it can not fully meet the practical operation requirements. We retrospectively analyzed three-dimensional (3D) transesophageal echocardiography (TEE) and computed tomography (CT) imaging dataset of the 41 patients who underwent LAA occlusion with LAmbre™ system. The LAA orifice parameters were overall evaluated to determine their role in device size selection. Eight LAA 3D models of the four cases who had been replaced their device during the procedure based on TEE and CT were printed out to verify the optimal parameter decision strategy. There was a significant concordance of the results between 3D TEE and CT in the LAA orifice evaluation. The correlations between the perimeter and maximal width measurements by 3D TEE and the closure disk of the device were stronger than that between the area measurements and the closure disk (r = 0.93, 0.95, 0.86, respectively and p < 0.001 all), and the result was similar to that by CT (r = 0.92, 0.93, 0.84, respectively and p < 0.001 all). The ratios of the maximal width to the minimal width of the four cases were all > 1.4, however the rest 37 cases were all ≤ 1.4. Based on the comprehensive assessment of the LAA orifice perimeter and maximal width of the 3D printed models, the experiments were all succeed just for one try. The LAA orifice perimeter of 3D printed model based on 3D TEE may help in choosing the optimal device size of LAmbre™, especially for the LAA with flater ostial shape.

Left Atrial Appendage Occlusion in the Management of Stroke in Patients With Atrial Fibrillation

Atrial fibrillation (AF) is associated with a substantially higher risk of thromboembolism, particularly stroke events, resulting in significant morbidity and mortality. Oral anticoagulation (OAC), while effective in reducing embolic events in AF patients, is associated with an increased bleeding risk. Thus, not all patients with AF are candidates for OAC and some are only candidates for OAC in the short term. Of the available nonpharmacologic strategies for the management of AF, left atrial appendage occlusion (LAAO) has emerged as a potential approach for reducing the risk of systemic thromboembolism in AF patients eligible for OAC. LAAO can be achieved either surgically or percutaneously using an epicardial, endocardial, or a combined approach. Although available data are limited, currently available LAAO devices, and those being developed, have shown promise in reducing bleeding risk in AF patients because of the reduced overall need for anticoagulation, while maintaining efficacy in preventing thromboembolism. The optimal device will reduce both embolic and hemorrhagic strokes, and other bleeds, with a high implant success rate and a low complication rate. Until that time, anticoagulation remains the gold standard that these devices strive to surpass, and thus LAAO devices are currently indicated in patients with relative contraindication to OAC therapy.

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.

Catheterization Laboratory: Structural Heart Disease, Devices, and Transcatheter Aortic Valve Replacement

The cardiac catheterization laboratory is advancing medicine by performing procedures on patients who would usually require sternotomy and cardiopulmonary bypass. These procedures are done percutaneously, allowing them to be performed on patients considered inoperable. Patients have compromised cardiovascular function or advanced age. An anesthesiologist is essential for these procedures in case of hemodynamic compromise. Interventionalists are becoming more familiar with transcatheter aortic valve replacement and the device has become smaller, both contributing to less complications. Left atrial occlusion and the endovascular edge-to-edge mitral valve repair devices were approved. Although these devices require general anesthesia, an invasive surgery and cardiopulmonary bypass machine are not necessary for deployment.

Left atrial appendage occlusion: rationale, evidence, devices, and patient selection

Atrial fibrillation (AF) is a worldwide epidemic associated with significant morbidity and mortality, often due to disabling or fatal thromboembolic stroke. Oral anticoagulation is highly effective at preventing ischaemic stroke and improving all-cause survival in patients with non-valvular AF. Despite the efficacy of oral anticoagulation, many patients are not treated due to either absolute or perceived contraindications to therapy, including bleeding. Left atrial appendage (LAA) closure has emerged as a mechanical alternative to pharmacologic stroke prevention. Initial and mid-term clinical trial data suggest that LAA closure is safe, with less intracranial bleeding, and a net clinical benefit that appears to be non-inferior to oral anticoagulation. However, concern remains over the possible increased risk of ischaemic stroke in long-term follow-up. Careful patient selection for LAA closure is paramount. Patients with prior intracranial bleeding or recurrent serious bleeding who are not eligible for long-term oral anticoagulation are typical candidates for LAA closure; however, other populations may benefit as well, such as patients with end-stage renal disease. Clinical investigation and randomized trials are needed to clarify the best methods of LAA occlusion, optimal pharmacologic strategies in the short-term after LAA closure, and to identify patient populations who will derive the most benefit from LAA occlusion. In this article, we review the rationale for LAA closure, the currently available devices and their evidence base, patient selection, challenges in management, and future directions for LAA closure science.

Current State of Left Atrial Appendage Closure

PURPOSE OF REVIEW

Atrial fibrillation (AF), the most common sustained arrhythmia, is a major cause of stroke and systemic embolism, and is increasing in prevalence. Device closure of the left atrial appendage (LAA) represents a non-pharmacologic approach to stroke prevention in AF patients. This review presents the rationale for LAA closure (LAAC), describes current transcatheter approaches to LAAC, and summarizes the current evidence for LAAC for stroke prevention, highlighting the main randomized trials and the most recent data available.

RECENT FINDINGS

Meta-analysis of randomized clinical trials demonstrates similar rates of all-cause stroke with transcatheter LAAC compared with vitamin K antagonist therapy and significantly less bleeding with LAAC after cessation of mandated post-procedure pharmacology. Recent prospective observational studies, including those evaluating outcomes after commercial approval in the USA, show significantly improved procedure safety compared with earlier experiences. LAAC appears to be an attractive alternative strategy for stroke prevention in AF patients, particularly in those who can take short-term oral anticoagulation (OAC), but are not optimal candidates for long-term OAC. Recent data suggests the procedure can be safely performed in patients with contraindications to OAC. Further, robust studies are needed to evaluate safety and efficacy in OAC-contraindicated patients, to compare outcomes with non-vitamin K antagonist OACs, and to explore the relative safety and efficacy of different LAAC devices.

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.

[Left atrial appendage closure and embolic events]

Atrial fibrillation (AF) is frequent and responsible for embolic events. Currently, the gold standard to prevent such embolic events is anticoagulant therapy with vitamin K antagonist (VKA) or direct oral anticoagulant in nonvalvular AF. Recently, left atrial appendage closure was proposed as an alternative to anticoagulant inpatient with high embolic risk and contraindication to anticoagulant therapy. Data from randomized trials were consistent with a non-inferiority of left atrial appendage closure in comparison to VKA in terms of stroke and cardiovascular death. However, despite improvements in procedure results and complications reduction, this invasive strategy has to be performed with optimal security as this strategy is a preventive treatment in high-risk patients. These improvements may allow an extension of indications of left atrial appendage closure to lower profile risk patients as an alternative to anticoagulant. Indeed, anticoagulant is a risky therapy with hemorrhagic events and observance is a real issue in an asymptomatic population. Finally, there is a lack of data in recent literature comparing left atrial appendage closure to direct oral anticoagulant, widely used in daily practice, as well as cost-effectiveness of this procedure in comparison to anticoagulant.

Evaluating the morphology of the left atrial appendage by a transesophageal echocardiographic 3-dimensional printed model

The novel 3-dimensional printing (3DP) technique has shown its ability to assist personalized cardiac intervention therapy. This study aimed to determine the feasibility of 3D-printed left atrial appendage (LAA) models based on 3D transesophageal echocardiography (3D TEE) data and their application value in treating LAA occlusions.Eighteen patients with transcatheter LAA occlusion, and preprocedure 3D TEE and cardiac computed tomography were enrolled. 3D TEE volumetric data of the LAA were acquired and postprocessed for 3DP. Two types of 3D models of the LAA (ie, hard chamber model and flexible wall model) were printed by a 3D printer. The morphological classification and lobe identification of the LAA were assessed by the 3D chamber model, and LAA dimensions were measured via the 3D wall model. Additionally, a simulation operative rehearsal was performed on the 3D models in cases of challenging LAA morphology for the purpose of understanding the interactions between the device and the model.Three-dimensional TEE volumetric data of the LAA were successfully reprocessed and printed as 3D LAA chamber models and 3D LAA wall models in all patients. The consistency of the morphological classifications of the LAA based on 3D models and cardiac computed tomography was 0.92 (P < .01). The differences between the LAA ostium dimensions and depth measured using the 3D models were not significant from those measured on 3D TEE (P > .05). A simulation occlusion was successfully performed on the 3D model of the 2 challenging cases and compared with the real procedure.The echocardiographic 3DP technique is feasible and accurate in reflecting the spatial morphology of the LAA, which may be promising for the personalized planning of transcatheter LAA occlusion.

A comparative study of different imaging modalities for successful percutaneous left atrial appendage closure

Objectives

Accurate sizing of the left atrial appendage (LAA) is essential when performing percutaneous LAA closure. This study aimed to compare different LAA imaging modalities and sizing methods in order to obtain successful LAA closure.

Background

Percutaneous LAA closure is an increasingly used treatment strategy to prevent stroke in patients with atrial fibrillation. LAA sizing has typically been done by 2D-transoesophageal echocardiography (TEE).

Methods

Patients who had a preprocedural TEE and preprocedural and postprocedural multislice CT (MSCT) were identified. Preprocedural measurements of LAA ostia and landing zones by 2D-TEE, MSCT and angiography were collected and analysed for those patients with successful LAA closure - i.e. with no contrast leakage at 3-month follow-up MSCT.

Results

The study population (n=67) had a mean CHA₂DS₂-VASc score of 3.0 and HAS-BLED score of 2.7. Fifty-eight patients (87%) were identified to have successful LAA closure. Based on MSCT, 48 LAA sizings (83%) resulted in a correct LAA closure device size selection, whereas with 2D-TEE sizing, only 33 measurements (57%) would have resulted in a correct device size selection (p<0.01). Using adapted Bland-Altman method, MSCT-based perimeter-derived mean diameter was shown to be the best parameter to guide LAA device size selection for ‘closed-end’ devices (Amulet, WatchmanFLX), whereas the maximal diameter was the best parameter for the ‘open-end’ Watchman device.

Conclusions

Preprocedural MSCT-based LAA closure device size selection proves to be a more accurate method than conventional 2D-TEE-based sizing. Depending on the LAA closure device design, perimeter-derived mean diameter or maximal diameter could be the better sizing method.

Novel stroke risk reduction in atrial fibrillation: left atrial appendage occlusion with a focus on the Watchman closure device

Atrial fibrillation (AF) remains an important clinical problem with severe complications such as stroke, which especially harms those with risk factors as calculated by the CHADS2 or CHA2DS2-VASc. Until now, no therapy has proven 100% effective against AF. Since the left atrial appendage (LAA) is the most prominent nonvalvular AF-related thromboembolic source and (novel) oral anticoagulant [(N)OAC] carries the hazard of bleeding, LAA occlusion may be an alternative, especially in patients who are ineligible for (N)OAC therapy. In this review, we discuss several LAA occlusion techniques with a focus on the Watchman device since this device is the most thoroughly studied device of all.

Left atrial appendage occlusion: A better alternative to anticoagulation?

Non-valvular atrial fibrillation is associated with a significantly increased risk of embolic stroke due to blood clot forming predominantly in the left atrial appendage (LAA). Preventive measures to avoid embolic events are permanent administration of anticoagulants or surgical closure of the LAA. Various clinical trials provide evidence about safety, effectiveness and therapeutic success of LAA occlusion using various cardiac occluder devices. The use of such implants for interventional closure of the LAA is likely to become a valuable alternative for stroke prevention, especially in patients with contraindication for oral anticoagulation as safety, clinical benefit and cost-effectiveness of LAA occlusion has recently been demonstrated.

Percutaneous closure of the left atrial appendage for stroke prevention in atrial fibrillation: an alternative to lifelong anticoagulation?

Atrial fibrillation is an important risk factor for thromboembolic stroke and it significantly increases the risk of stroke. The left atrial appendage (LAA) is the most common site of thrombus formation in nonvalvular atrial fibrillation, and the recent applications of percutaneous LAA closure devices offer a promising alternative for patients who are unable to tolerate lifelong anticoagulation. Critical care nurses who understand the procedures and are familiar with the various devices used for LAA closure will be well prepared to provide optimum care and appropriate education for these patients.

Heart within a Heart

Device based closure of the left atrial appendage (LAA) has emerged as a viable approach for stroke prevention in atrial fibrillation (AF) patients with contraindications to chronic oral anticoagulation. One of the most feared complications is device related thrombus formation. We present a 66-year-old male with chronic AF who developed a life-threatening intracranial bleed on oral anti-coagulation. He subsequently underwent LAA closure using an Amplatzer muscular ventricular septal defect closure device for stroke prevention. However, he was found to have a large thrombus attached to the device a year later. We present a review of the various LAA closure devices, importance of periodic surveillance via echocardiography and management options to prevent this complication. Also, the case highlights the importance of contrast-enhance echocardiography in diagnosis of LAA closure device thrombus.

Atrial fibrillation ablation and left appendage closure in heart failure patients

PURPOSE OF REVIEW

Patients with atrial fibrillation and heart failure experience an increased morbidity and mortality from the hemodynamic consequences of atrial fibrillation and an increased stroke risk. Consequently, there has been increased attention to procedural alternatives to pharmacologic rhythm control and anticoagulation for stroke prevention. This review aims to evaluate the evidence for atrial fibrillation ablation and left atrial appendage closure in heart failure patients.

RECENT FINDINGS

Several randomized control trials and systematic reviews demonstrate the safety and efficacy of atrial fibrillation ablation in patients with heart failure and left ventricular systolic dysfunction. In multiple trials, these patients have shown clinical benefit from atrial fibrillation ablation including improved left ventricular systolic function, quality of life, and clinical heart failure symptoms. The evidence of clinical benefit of atrial fibrillation ablation in heart failure patients with preserved ejection fraction remains limited. Only a handful of randomized controlled trials have been performed evaluating left atrial appendage closure, and there is insufficient data regarding the safety and efficacy of these procedures in heart failure patients.

SUMMARY

Atrial fibrillation ablation in heart failure patients remains well tolerated with an overall efficacy comparable to atrial fibrillation ablation in patients without heart failure. There is consistent evidence for the clinical benefit of atrial fibrillation ablation in heart failure patients with left ventricular systolic dysfunction and limited evidence for atrial fibrillation ablation in heart failure patients with preserved ejection fraction. Currently, there is insufficient data regarding the safety and efficacy of left atrial appendage closure devices in heart failure patients.

Predicting Peri-Device Leakage of Left Atrial Appendage Device Closure Using Novel Three-Dimensional Geometric CT Analysis

Background

After left atrial appendage (LAA) device closure, peri-device leakage into the LAA persists due to incomplete occlusion. We hypothesized that pre-procedural three-dimensional (3D) geometric analysis of the interatrial septum (IAS) and LAA orifice can predict this leakage. We investigated the predictive parameters of LAA device closure obtained from baseline cardiac computerized tomography (CT) using a novel 3D analysis system.

Methods

We conducted a retrospective study of 22 patients who underwent LAA device closure. We defined peri-device leakage as the presence of a Doppler signal inside the LAA after device deployment (group 2, n = 5) compared with patients without peri-device leakage (group 1, n = 17). Conventional parameters were measured by cardiac CT. Angles θ and φ were defined between the IAS plane and the line, linking the LAA orifice center and foramen ovale.

Results

Group 2 exhibited significantly better left atrial (LA) function than group 1 (p = 0.031). Pre-procedural θ was also larger in this group (41.9° vs. 52.3°, p = 0.019). The LAA cauliflower-type morphology was more common in group 2. Overall, the patients' LA reserve significantly decreased after the procedure (21.7 mm³ vs. 17.8 mm³, p = 0.035). However, we observed no significant interval changes in pre- and post-procedural values of θ and φ in either group (all p > 0.05).

Conclusion

Angles between the IAS and LAA orifice might be a novel anatomical parameter for predicting peri-device leakage after LAA device closure. In addition, 3D CT analysis of the LA and LAA orifice could be used to identify clinically favorable candidates for LAA device closure.

Early results of first versus second generation Amplatzer occluders for left atrial appendage closure in patients with atrial fibrillation

BACKGROUND

Transcatheter left atrial appendage (LAA) occlusion has been proven to be an effective treatment for stroke prophylaxis in patients with atrial fibrillation. For this purpose, the Amplatzer cardiac plug (ACP) was introduced. Its second generation, the Amulet, was developed for easier delivery, better coverage, and reduction of complications.

AIM

To investigate the safety and efficacy of first generation versus second generation Amplatzer occluders for LAA occlusion.

METHODS

Retrospective analysis of prospectively collected data from the LAA occlusion registries of the Bern and Zurich university hospitals. Comparison of the last consecutive 50 ACP cases versus the first consecutive 50 Amulet cases in patients with non-valvular atrial fibrillation. For safety, a periprocedural combined endpoint, which is composed of death, stroke, cardiac tamponade, and bailout by surgery was predefined. For efficacy, the endpoint was procedural success.

RESULTS

There were no differences between the two groups in baseline characteristics. The percentage of associated interventions during LAA occlusion was high in (78% with ACP vs. 70% with Amulet p = ns). Procedural success was similar in both groups (98 vs. 94%, p = 0.61). The combined safety endpoint for severe adverse events was reached by a similar rate of patients in both groups (6 vs. 8%, p = 0.7). Overall complication rate was insignificantly higher in the ACP group, which was mainly driven by clinically irrelevant pericardial effusions (24 vs. 14%, p = 0.31). Death, stroke, or tamponade were similar between the groups (0 vs. 2%, 0 vs. 0%, or 6 vs. 6%, p = ns).

CONCLUSION

Transcatheter LAA occlusion for stroke prophylaxis in patients with atrial fibrillation can be performed with similarly high success rates with first and second generations of Amplatzer occluders. According to this early experience, the Amulet has failed to improve results of LAA occlusion. The risk for major procedural adverse events is acceptable but has to be taken into account when selecting patients for LAA occlusion, a preventive procedure.