Left atrial appendage occlusion for stroke prevention in atrial fibrillation: multicentre experience with the AMPLATZER Cardiac Plug

Indications and Outcome in Patients Undergoing Left Atrial Appendage Closure-The Austrian LAAC Registry

Background: Complete real-world data on the indications and outcomes of left atrial appendage closure (LAAC) outside of clinical trials are rare. In this study, we stratified patients undergoing LAAC by indication groups. Methods: This analysis of the national multicentre Austrian LAAC Registry comprised all patients that underwent LAAC up until 2018 at the currently active centres in Austria. The baseline characteristics, procedural details and outcomes between the following indication groups were compared: bleeding as an indication for LAAC (“bleeding” group) vs. thromboembolism despite oral anticoagulation (OAC; “thromboembolism” group) vs. an intolerance to OAC for reasons other than the above (“other” group). Results: The analysis included 186 patients, with 59.7% in the “bleeding” group, 8.1% in the “thromboembolism” group and 32.2% in the “other” group. The CHADS₂ score was the highest in the “thromboembolism” group and the HAS-BLED score was the highest in the “bleeding” group. The procedural outcomes were similar between groups (implantation success, 97.3%), with major complications occurring in 7.0% of patients. One-year survival free from stroke, bleeding or LAAC-associated hospitalisation was 83.9%, 90.0% and 81.4% in the “bleeding”, “thromboembolism” and “other” groups, respectively (p = 0.891). Conclusions: In routine clinical practice, LAAC was used in a heterogeneous patient population with atrial fibrillation (AF) and contraindication, inefficacy or intolerance to OAC. The long-term outcome was favourable in all groups.

Use of a Novel Septal Occluder Device for Left Atrial Appendage Closure in Patients With Postsurgical and Postlariat Leaks or Anatomies Unsuitable for Conventional Percutaneous Occlusion

Background:

Interventional therapies aiming at excluding the left atrial appendage (LAA) from systemic circulation have been established as a valid alternative to oral anticoagulation in patients at high thromboembolic risk. However, their efficacy on stroke prophylaxis may be compromised owing to incomplete LAA closure. Additionally, the need for an alternative thromboembolic prevention may remain unmet in patients with contraindications to oral anticoagulation whose appendage anatomy is unsuitable for some conventional devices commercially available. We aimed at evaluating the feasibility of LAA closure with the novel Gore Cardioform Septal Occluder in patients with incomplete appendage ligation or anatomic features which do not meet the manufacturer’s requirements for Watchman deployment.

Methods:

Twenty-one consecutive patients (mean age: 72±6 years; 85.7% males; CHA 2 DS 2 -VASc: 4.5±1.4; HAS-BLED: 3.6±1.0) were included. Transesophageal echocardiography was performed within 2 months to assess for residual LAA patency.

Results:

Fourteen patients had incomplete LAA closure following surgical (n=6) or Lariat ligation (n=8). In 7 patients with an appendage anatomy unsuitable for Watchman deployment, the mean maximal landing zone size and LAA depth were 14.4±1.3 and 18.6±2.8 mm. Successful Cardioform Septal Occluder deployment was achieved in all patients. No peri-procedural complications were documented. Procedure and fluoroscopy times were 46±13 and 14±5 minutes. Follow-up transesophageal echocardiography after 58±9 days revealed complete LAA closure in all patients.

Conclusions:

Transcatheter LAA closure via a Cardioform Septal Occluder device might be a valid alternative in patients with residual leaks following failed appendage ligation or whose LAA anatomy does not meet the minimal anatomic criteria to accommodate a Watchman device.

Graphic Abstract:

A graphic abstract is available for this article.

Rationale and design of a randomized clinical trial to compare two antithrombotic strategies after left atrial appendage occlusion: double antiplatelet therapy vs. apixaban (ADALA study)

BACKGROUND

Data on antithrombotic therapy after percutaneous left atrial appendage occlusion (LAAO) is scarce and no randomized evaluation has been performed to demonstrate what is the best antithrombotic strategy. Up to date, different antithrombotic regimens with variable durations are currently used. In fact, the use of oral anticoagulation (OAC) or dual antiplatelet therapy (DAPT) with aspirin and clopidogrel during the initial phase (∓ 3 months post-LAAO) has been proposed as valid strategies. However, antiplatelet and OAC therapies have never been compared in a randomized study after left atrial appendage closure (LAAC). The purpose of the present study is to ascertain an optimal antithrombotic strategy after LAAC in terms of safety and efficacy. The study will compare a novel OAC (NOAC) with a highly safety profile like apixaban 5 mg/12 h or 2.5 mg/12 h (after dose adjustment or in high-risk patients) with standard antiplatelet therapy with DAPT. The aim of the study was to compare a strategy of anticoagulation with apixaban 5 mg/2.5 mg bid to the current standard of care (DAPT with aspirin and clopidogrel) after LAAO in patients with non-valvular atrial fibrillation (AF).

METHODS

This is a phase IV multicenter randomized, open-label, controlled trial comparing the efficacy and safety of apixaban vs. DAPT after LAAO, both for 3 months. The primary endpoint is a combined endpoint of death, myocardial infarction, stroke, thromboembolic complications, and major or significant bleeding at 3 months of follow-up. Approximately 160 subjects will be enrolled and followed 12 months from randomization.

CONCLUSIONS

Considering the high risk of both thromboembolic and hemorrhagic events of patients undergoing LAAO, establishment of an appropriate antithrombotic therapy in terms of efficacy and safety after LAAO is of vital importance.

TRIAL REGISTRATION

EudraCT number: 2018-001013-32.

A simple method to detect leaks after left atrial appendage occlusion with Watchman

BACKGROUND

We evaluated the efficacy of a new method in identifying peri-device leak (PDL) using morphology of the thrombus formed inside the left atrial appendage (LAA) as seen on follow-up transesophageal echo (TEE).

METHOD

A total of 291 consecutive patients undergoing Watchman procedure were included in this analysis. TEE was performed at 45 days postprocedure. Based on the presence of the thrombus inside the LAA behind the device, patients were grouped as (1) white (W) group: LAA completely filled with thrombus (n = 101), 2) nonwhite (NW) group: LAA completely black or mixed (part black and part white; n = 190). Follow-up TEE was repeated at 6 and 12 months.

RESULTS

Baseline characteristics were comparable between groups except the device size, number of patients with chicken-wing morphology, and prevalence of left atrial "smoke" that were significantly higher in the NW group. Detection of black appearance was comparable between the pre-coil closure image and the NW population (26/36 [72.2%] vs 99/154 [64.3%], p = .37). After adjusting for clinically relevant covariates, NW appearance of the LAA was associated with the presence of significant leak (odds ratio: 47.96, 95% confidence interval: 2.91-790.2, p < .001). The 11 patients with mixed appearance at the 6-month TEE remained unchanged (part black and part white) at the 12-month TEE. LAA appearance was white in all 36 patients following coil closure.

CONCLUSION

Our findings demonstrated white and nonwhite appearance of the appendage on TEE to be reliable markers of complete closure and leak respectively, following LAA occlusion with the Watchman device.

Cerebral protection in left atrial appendage closure in the presence of appendage thrombosis

BACKGROUND

Presence of thrombus in the left atrial appendage (LAA) remains a severe contraindication to the percutaneous left atrial appendage closure procedure (LAAC), due to increased embolic risk. Recently, the experience developed in cerebral protection device in transcatheter aortic valve implantation (TAVI) procedure was translated in LAAC to address this issue.

AIM

To evaluate efficacy and safety of Sentinel cerebral protection system (CPS) in supporting LAAC in real-world patient with persistent LAA thrombus.

METHODS AND RESULTS

The study retrospectively enrolled consecutive patients with non-valvular atrial fibrillation (NVAF) and thrombus in LAA who underwent LAAC supported by Sentinel CPS in seven European high-volume centres. Twenty-seven patients were included with a median age of 69.1 ± 9.7 years old, with median CHA₂ DS₂ -VASc and HAS-BLEED scores 3 [2-5] and 3 [2.75-4], respectively. Technical and procedural success was achieved in all patients. No periprocedural TIA, stroke, or supra-aortic trunks dissection was recorded.

CONCLUSIONS

In this multicenter registry, LAAC supported by Sentinel CPS in patients with LAA persistent thrombus seems to be a safe and efficacious treatment.

Percutaneous Left Atrial Appendage Occlusion: A View From the UK

AF is associated with an increased risk of thromboembolic events, which is usually managed with oral anticoagulation therapy. However, despite a broad range of anticoagulant options and improved uptake in anticoagulation over the past decade, there are some limitations to this approach. Percutaneous left atrial appendage occlusion has been shown to be an effective alternative in this setting, and population data suggest a clear demand for this procedure. Over the past decade, several important changes to the commissioning and delivery of this service have occurred in the UK. In this article, the authors describe the use of percutaneous left atrial appendage occlusion in the UK and discuss the challenges that lie ahead.

Propensity-matched comparison of antiplatelet versus anticoagulant after left atrial appendage closure with the Watchman

BACKGROUND

Optimal antithrombotic therapy following left atrial appendage closure (LAAC) with the Watchman occluder remains uncertain. This study retrospectively compared clinical outcomes of a 3-month dual antiplatelet therapy (DAPT group) and a protocol of anticoagulation plus aspirin for 45 days followed by DAPT for 6 months (ACT group) after LAAC with the Watchman device.

METHODS

Of two Watchman registries (Coburg and Lichtenfels hospitals, Germany), 220 and 304 consecutive patients with successful LAAC were included. Patients in Coburg hospital received DAPT while they received ACT in Lichtenfels. After a 1:1 propensity score matching, 174 (DAPT) versus 174 (ACT) patients were compared by use of the primary efficacy endpoint of thromboembolic events and cardiovascular/unexplained death, the primary safety endpoint of nonprocedural related major bleeding events at follow-up, and the combined hazard endpoint, a composite of all above-mentioned hazards.

RESULTS

The mean age 77.5 ± 7.2 (DAPT) versus 77.3 ± 7.1 (ACT) years, CHA₂ DS₂ -VASc score 4.6 ± 1.5 versus 4.7 ± 1.6, and HAS-BLED score 3.3 ± 0.8 versus 3.3 ± 0.8 were similar. After 12 months, the clinical efficacy (13/174, 7.4% [DAPT] vs 11/174, 6.3% [ACT]; hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.38-1.86; P = .66) and safety (6/174, 3.4% vs 8/174, 4.5%; HR, 0.86; 95% CI, 0.29-2.56; P = .79) as well as the combined hazard endpoint (18/174, 10.3% vs 18/174, 10.3%; HR,1.01; 95% CI, 0.53-1.95; P = .97) were comparable.

CONCLUSIONS

This study suggests comparable efficacy and safety of 3-month DAPT versus 6 weeks ACT plus aspirin following LAAC with the Watchman.

Why Follow-up Examinations After Left Atrial Appendage Closure Are Important: Detection of Complications During Follow-up and How to Deal with Them

PURPOSE OF REVIEW

Device-related thrombus (DRT) formation and incomplete left atrial appendage closure (LAAC) are the two major complications that can occur after LAAC and can potentially limit the success of such a procedure. This review discusses the incidence, clinical and/or prognostic significance, detection methods, treatment options, and potential strategies to prevent these complications.

RECENT FINDINGS

It has recently been proven that the presence of a DRT represents an independent predictor for ischemic stroke after LAAC. Continued need for anticoagulation due to incomplete LAAC is clinically relevant to the patient. The appearances of a DRT or an incompletely closed LAA after a LAAC procedure are not rare complications. Due to the clinical and/or prognostic significance of these complications, it is important to detect them in a timely manner during follow-up by using the appropriate diagnostic imaging techniques. Since a DRT is associated with an increased risk of stroke, the therapy should be aggressive. In the case of incomplete LAA closure, an additional closure device may be used to complete occlusion and avoid lifelong anticoagulation therapy.

Kidney function stratified outcomes of percutaneous left atrial appendage occlusion in patients with atrial fibrillation and high bleeding risk

Background: Patients with chronic kidney disease (CKD) and atrial fibrillation have increased risks for stroke and bleeding under oral anticoagulation (OAC). We investigated an alternative therapy of percutaneous left atrial appendage occlusion (LAAO) in CKD patients in this study.Methods: Consecutive patients undergoing LAAO were included in a retrospective analysis and stratified for kidney function into CKD/Non-CKD groups (cutoff eGFR 60 ml/min). Procedural characteristics, in-hospital and follow-up events were analysed and compared between groups.Results: LAAO was performed in 146 patients (81 CKD; 65 Non-CKD), mean follow-up was 391 days. Groups differed in eGFR (40.1 (CKD) vs. 75.1 (Non-CKD) ml/min) and CHA₂DS₂VASc scores (4.65 ± 1.3 (CKD) vs. 4.06 ± 1.4 (Non-CKD)). Procedural success was 98.6%, contrast-induced acute kidney injury was significantly more frequent in CKD patients (11.1% vs. 0%; p = .004). Follow-up mortality was higher in CKD (10.5/100 PY vs. 4.2/100 PY; p = .156). Follow-up stroke rates were 2.3/100 (CKD) patient-years (PY) and 1.4/100 PY (Non-CKD) (p = 1.000), corresponding to a relative risk reduction (RRR) of 60% (all), 68% (CKD) and 71% (Non-CKD) compared to expected stroke rates. Follow-up major bleeding rates were 3.5/100 PY (CKD) and 4.2/100 PY (Non-CKD), corresponding to RRR of 57% (all), 61% (CKD) and 53% (Non-CKD) compared to OAC.Conclusions: Left atrial appendage occlusion shows comparable efficacy for stroke and bleeding prevention in CKD and Non-CKD patients. CKD patients experience more adverse events during follow-up and a significantly increased risk for periprocedural contrast-induced acute kidney injury.

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.

Left Atrial Appendage Occlusion: Past, Present and Future

There are several situations whereby oral anticoagulation may be unsuitable for stroke prevention in patients with atrial fibrillation (AF). Percutaneous left atrial appendage (LAA) occlusion has received much attention in this area. Various devices have already been developed and tested for this purpose. Data from registries and cohort studies have indicated favourable short- and long-term outcomes with LAA occlusion, and several international guidelines recommend its use in AF patients with contraindications to oral anticoagulation. However, prospective controlled trials in this very population are lacking. Furthermore, while modelling studies on cost analyses have suggested that LAA occlusion may be a cost-effective strategy compared with standard medical therapy, these have not been performed in high-risk patients who may have limited survival in the medium to long term. Thus, while LAA occlusion offers promise, there is a strong need for additional research to investigate its exact role, its long-term outcomes and cost efficacy.

5-Year Experience of In-Hospital Outcomes After Percutaneous Left Atrial Appendage Closure in Germany

OBJECTIVES

The aim of this study was to evaluate 5-year in-hospital trends and safety outcomes of left atrial appendage (LAA) closure in the German nationwide inpatient sample.

BACKGROUND

The safety and efficacy of percutaneous LAA closure have been demonstrated in randomized trials and prospective cohort studies, but results from large samples are missing.

METHODS

Data on patient characteristics and in-hospital safety outcomes for all percutaneous LAA closures performed in Germany between 2011 and 2015 were analyzed. Overall, 15,895 inpatients were included.

RESULTS

The annual number of LAA occlusions increased from 1,347 in 2011 to 4,932 in 2015 (β = 1.00; 95% confidence interval [CI]: 0.95 to 1.01; p < 0.001), with a nonsignificant uptrend of in-hospital mortality (from 0.5% in 2011 to 0.9% in 2015; β = 0.01; 95% CI: -0.09 to 0.32; p = 0.271). Patient characteristics shifted toward older age and higher prevalence of comorbidities such as heart failure, chronic obstructive pulmonary disease, and chronic renal insufficiency over time. Important independent predictors of in-hospital mortality were cancer (odds ratio [OR]: 2.49; 95% CI: 1.00 to 6.12; p = 0.050), heart failure (OR: 2.42; 95% CI: 1.72 to 3.41; p < 0.001), stroke (OR: 5.39; 95% CI: 2.76 to 10.53; p < 0.001), acute renal failure (OR: 13.28; 95% CI: 9.08 to 19.42; p < 0.001), pericardial effusion (OR: 5.65; 95% CI: 3.76 to 8.48; p < 0.001), and shock (OR: 45.11; 95% CI: 31.01 to 65.58; p < 0.001).

CONCLUSIONS

The use of percutaneous LAA closure increased 3.6-fold from 2011 to 2015, with a nonsignificant uptrend of in-hospital mortality rate in this real-world setting. Important predictors of in-hospital death were acute renal failure, pericardial effusion, and ischemic stroke during hospitalization.

Major Bleeding Predictors in Patients with Left Atrial Appendage Closure: The Iberian Registry II

Introduction and objective: Major bleeding events in patients undergoing left atrial appendage closure (LAAC) range from 2.2 to 10.3 per 100 patient-years in different series. This study aimed to clarify the bleeding predictive factors that could influence these differences. Methods: LAAC was performed in 598 patients from the Iberian Registry II (1093 patient-years; median, 75.4 years). We conducted a multivariate analysis to identify predictive risk factors for major bleeding events. The occurrence of thromboembolic and bleeding events was compared to rates expected from CHA2DS2-VASc (congestive heart failure, hypertension, age, diabetes, stroke history, vascular disease, sex) and HAS-BLED (hypertension, abnormal renal and liver function, stroke, bleeding, labile INR, elderly, drugs or alcohol) scores. Results: Cox regression analysis revealed that age ≥75 years (HR: 2.5; 95% CI: 1.3 to 4.8; p = 0.004) and a history of gastrointestinal bleeding (GIB) (HR: 2.1; 95% CI: 1.1 to 3.9; p = 0.020) were two factors independently associated with major bleeding during follow-up. Patients aged <75 or ≥75 years had median CHA2DS2-VASc scores of 4 (IQR: 2) and 5 (IQR: 2), respectively (p < 0.001) and HAS-BLED scores were 3 (IQR: 1) and 3 (IQR: 1) for each group (p = 0.007). Events presented as follow-up adjusted rates according to age groups were stroke (1.2% vs. 2.9%; HR: 2.4, p = 0.12) and major bleeding (3.7 vs. 9.0 per 100 patient-years; HR: 2.4, p = 0.002). Expected major bleedings according to HAS-BLED scores were 6.2% vs. 6.6%, respectively. In patients with GIB history, major bleeding events were 6.1% patient-years (HAS-BLED score was 3.8 ± 1.1) compared to 2.7% patients-year in patients with no previous GIB history (HAS-BLED score was 3.4 ± 1.2; p = 0.029). Conclusions: In this high-risk population, GIB history and age ≥75 years are the main predictors of major bleeding events after LAAC, especially during the first year. Age seems to have a greater influence on major bleeding events than on thromboembolic risk in these patients.

Transseptal puncture versus patent foramen ovale or atrial septal defect access for left atrial appendage closure

AIMS

The aim of this study was to compare the periprocedural and late clinical outcomes of left atrial appendage closure (LAAC) with AMPLATZER devices by access through transseptal puncture (TSP) versus a patent foramen ovale (PFO) or an atrial septal defect (ASD).

METHODS AND RESULTS

Between 2009 and 2018, 578 consecutive patients underwent LAAC via TSP or PFO/ASD access in three centres. After a 3:1 propensity score matching, 246 (TSP) versus 91 (PFO/ASD) patients were compared using the primary efficacy endpoint of all-cause stroke, systemic embolism and cardiovascular/unexplained death and the primary safety endpoint of major periprocedural complications and major bleedings at follow-up. Mean age was 75.2±8.7 (TSP) vs 74.4±10.9 (PFO/ASD) years, CHA2DS2-VASc score 4.5±1.6 vs 4.3±1.4 and HAS-BLED score 3.3±1.0 vs 3.3±0.9. Device success (97.6% vs 97.8%, p=0.90) was similar. After 2.5±1.4 vs 2.6±1.6 years, clinical efficacy (46/603, 7.6% [TSP] vs 21/233, 9.0% [PFO/ASD], hazard ratio [HR] 1.2; 95% confidence interval [CI]: 0.69-0.85, p=0.54) and safety (24/603, 4.0% vs 11/233, 4.7%; HR 1.4; 95% CI: 0.52-3.6, p=0.49) did not differ.

CONCLUSIONS

Use of a PFO/ASD access for LAAC with AMPLATZER devices offers similar periprocedural and late clinical outcomes to TSP. Simultaneous PFO/ASD closure for an additional protective benefit does not increase risk.

Left atrial appendage occlusion in patients with atrial fibrillation and large prevalence of prior intracranial bleeding

BACKGROUND

Left atrial appendage occlusion (LAAO) represents an alternative approach for the prevention of cardioembolic stroke in patients with nonvalvular atrial fibrillation (NVAF) and contraindication for oral anticoagulation (OAC). The aim of our study was to analyse the outcomes in patients treated with LAAO, with a focus on cases with previous intracranial bleeding.

METHODS

Sixty patients with NVAF underwent LAAO (75.4 ± 9 years); mean CHA2DS2-VASc was 4.4 ± 1.7, mean HAS-BLED 3.2 ± 0.9. Thirty-two patients (53.3%) reported previous intracranial bleeding. Ischaemic and bleeding events recorded during follow-up were compared with expected event rates according to CHA2DS2-VASc and HAS-BLED scores.

RESULTS

Device implantation was successful in 58 patients (96.7%). The antiplatelet therapy was tailored according to patients' bleeding risk. During follow-up (2.32 ± 1.5 years) 3 ischaemic strokes and 1 transient ischaemic attack occurred, versus 13 total expected thromboembolic events (P = 0.033); 5 major bleedings were observed, versus 7 expected ones, if the patients were under OAC. Considering the combined endpoint (thromboembolic and major bleeding events) 9 events were observed versus 20 expected major events (P = 0.031). In the prespecified subgroup of patients with previous intracranial bleeding, two ischaemic strokes and one transient ischaemic attack were observed during follow-up versus six total expected thromboembolic events; no intracranial bleeding recurrence was recorded. Regarding the combined endpoint four major events were recorded versus nine expected ones.

CONCLUSION

LAAO is an efficient and safe option for the prevention of cardioembolic stroke in patients with NVAF, high thromboembolic risk and contraindication to OAC, particularly in patients with previous intracranial bleeding.

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.

Late Presentation of Pulmonary Artery-Left Atrial Appendage Fistula Formation After Left Atrial Appendage Device Closure

Atrial fibrillation is the most common arrhythmia in clinical practice with indication for anticoagulation in those patients whose annual risk for thromboembolism is >2%. Left atrial appendage closure is growing as an alternative to anticoagulation. We present a case of pulmonary artery-left atrial appendage fistula seen after left atrial appendage closure. (Level of Difficulty: Intermediate.)

Left atrial appendage closure in patients with a reduced left ventricular ejection fraction: results from the multicenter German LAARGE registry

Background

Interventional left atrial appendage closure (LAAC) effectively prevents thromboembolic events in atrial fibrillation patients. Impaired left ventricular ejection fraction (LVEF) increases not only the thromboembolic risk but also the complication rates of cardiac interventions. The LAAC procedure’s benefit in patients with an impaired LVEF, therefore, has yet to be investigated.

Methods

LAARGE is a prospective, non-randomized registry depicting the clinical reality of LAAC in Germany. Procedure was conducted with different standard commercial devices, and follow-up period was one year. In the sense of an as-treated analysis, patients with started procedure and documented LVEF were selected from the whole database.

Results

619 patients from 37 centers were categorized into one of three groups: LVEF > 55% (56%), 36–55% (36%), and ≤ 35% (8%). Prevalence of cardiovascular comorbidity increased with LVEF reduction (p < 0.001 for trend). CHA₂DS₂-VASc score was 4.3, 4.8, and 5.1 (p < 0.001), and HAS-BLED score was 3.7, 4.1, and 4.2 (p < 0.001). Implantation success was consistently high (97.9%), rates of intra-hospital MACCE (0.5%), and other major complications (4.2%) were low (each p = NS). Kaplan–Meier estimation showed a decrease in survival free of stroke with LVEF reduction during one-year follow-up (89.3 vs. 87.0 vs. 79.8%; p = 0.067), a trend which was no longer evident after adjustment for relevant confounding factors. Rates of non-fatal strokes (0.4 vs. 1.1 vs. 0%) and severe bleedings (0.7 vs. 0.0 vs. 3.1%) were consistently low across all groups (each p = NS).

Conclusions

LVEF reduction neither influenced the procedural success nor the effectiveness and safety of stroke prevention by LAAC.

Trial Registration

ClinicalTrials.gov Identifier: NCT02230748

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01627-8) contains supplementary material, which is available to authorized users.

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.

Clinical Implications and Management Strategies for Left Atrial Appendage Leaks

Left atrial appendage (LAA) is the dominant source of systemic thromboembolic (TE) events in patients with nonvalvular atrial fibrillation (AF). In patients with significant bleeding risk, various LAA exclusion strategies have been developed as an alternative to pharmacologic TE prophylaxis. Nevertheless, in a relatively small percentage of patients, incomplete LAA closure can be documented, either at the time of procedure or during follow-up. This persistent patency can potentially jeopardize an effective stroke prophylaxis. Hereby, we report an update on the current clinical implications of LAA leaks and how to manage them.

Postprocedural Management: Anticoagulation and Beyond

Excluding the left atrial appendage in patients with nonvalvular atrial fibrillation is a mechanical way to decrease stroke risk. During endothelialization, the closure device is exposed to circulating blood, which might activate the coagulation cascade. In excessive proportions, possibly resulting in the development of device-related thrombus, requiring a bridging period with optimal antithrombotic treatment. Initial protocol treatment is less suitable for patients with contraindications to anticoagulation. Less intensive antithrombotic regimens investigated suggest safety and efficacy, however further research is required. A tailored treatment, considering bleeding and thromboembolic risk based on patient/procedural characteristics in every patient, is probably the best approach.

[Left atrial appendage occlusion in patients with nonvalvular atrial fibrillation : Present evidence, ongoing studies, open questions]

About every fifth ischemic stroke is caused by atrial fibrillation. Oral anticoagulation is highly effective in secondary stroke prevention, but a relevant portion of patients with atrial fibrillation is not (permanently) anticoagulated for a variety of reasons. Based on present evidence, no general recommendation can be given for left atrial appendage occlusion in patients with nonvalvular atrial fibrillation. However, left atrial appendage occlusion is a treatment option after severe anticoagulation-related bleeding, if the cause of bleeding is not treatable. Left atrial appendage occlusion is critical in patients with a relative contraindication for oral anticoagulation or lack of adherence to given medication. It seems to be important that further randomized studies confirm a benefit of left atrial appendage occlusion in selected patients with nonvalvular atrial fibrillation. In addition, it is vital to clarify whether discontinuation of antiplatelets is feasible after catheter-based left atrial appendage occlusion, as antiplatelets are associated with a risk of bleeding. Within this review article, we discuss present evidence, gaps of knowledge and provide an overview on ongoing clinical studies. In addition, we summarize the design of the CLOSURE-AF study. This randomized multicenter study will start recruitment soon and is funded by the German Center for Cardiovascular Research e. V.

The History of the Left Atrial Appendage Occlusion

Atrial fibrillation (AF) has been a source of fascination for more than 100 years. Most early investigations centered on the mechanisms of the arrhythmia (reentry versus automaticity; site of origin; approaches to treatment or prevention; and the clinical consequences), specifically tachycardia-induced cardiomyopathy and the potential for lethal events in special circumstances (eg, preexcitation syndromes). The current increased interest in AF has been heightened by increasing information on the clinical volume and number of patients affected. Recent data identify a current prevalence rate of 6 million patients in the United States, which is predicted to become 12 million by 2030.

Systematic Review of Contiguous Vessel and Valve Injury Associated with Endocardial Left Atrial Appendage Occlusion Devices

Endocardial LAAO has been increasingly utilized in atrial fibrillation (AF) patients who are not suitable for long term oral anticoagulation. While overall procedural complications have decreased, rare complications like contiguous vessel and valve injury may be more frequently seen in the future with increase in the procedure volume. We performed a systematic search using predefined terms which reviewed all cases published in literature of contiguous vessel (pulmonary artery, pulmonary vein and left circumflex artery) and mitral valve injury caused by LAAO devices. Our results showed that Amplatzer Cardiac Plug (ACP) and Amplatzer Amulet devices were the most commonly used devices. Pulmonary artery perforation was the most commonly seen collateral vessel injury associated with LAAO. Close proximity of left atrial appendage to pulmonary artery was noted in all cases of pulmonary artery injury. Pulmonary artery injury commonly manifests as pericardial tamponade with hemodynamic collapse and is often fatal. Most common denominator of all the reviewed cases was the presence of an oversized LAAO device. In conclusion, collateral vessels and valve injury can be seen after LAAO mostly with double lobe devices such as ACP or Amulet. Increased awareness by the operators along with proper imaging and investigations could potentially mitigate such rare complications associated with LAAO.

Clinical outcomes of Watchman vs. Amplatzer occluders for left atrial appendage closure (WATCH at LAAC)

Aims

This study compares clinical outcomes of Watchman vs. Amplatzer devices for left atrial appendage closure (LAAC).

Methods and results

Of two real-world registries, the Watchman registry Lichtenfels, Germany, and the Amplatzer registry Bern-Zurich, Switzerland, 303 and 333 consecutive patients, respectively, were included. After a 1:1 propensity score matching, 266 vs. 266 patients were compared by use of the predefined primary efficacy endpoint of stroke, systemic embolism and cardiovascular/unexplained death, the primary safety endpoint of major peri-procedural complications and major bleeding events at follow-up, and the combined hazard endpoint, a composite of all above-mentioned hazards. Mean age was 75.3 ± 7.8 (Watchman) vs. 75.1 ± 9.9 (Amplatzer) years, CHA2DS2-VASc score 4.5 ± 1.7 vs. 4.5 ± 1.5, and HAS-BLED score 3.2 ± 1.0 vs. 3.2 ± 1.0. At a mean follow-up of 2.4 ± 1.3 vs. 2.5 ± 1.5 years and 1.322 patient-years, the primary endpoints of efficacy [40/646, 6.2% [Watchman] vs. 43/676, 6.4% [Amplatzer]; hazard ratio (HR), 1.02; 95% confidence interval (CI), 0.66–1.58; P = 0.92] and safety (33/646, 5.1% vs. 30/676, 4.4%; HR, 0.57; 95% CI, 0.29–1.11; P = 0.10), as well as the combined hazard endpoint (69/646, 10.7% vs. 66/676, 9.8%; HR, 0.80; 95% CI, 0.55–1.12; P = 0.26) were similar for both groups.

Conclusion

This study suggests comparable efficacy and safety of the Watchman and Amplatzer devices.

Risk stratification in patients undergoing interventional left atrial appendage occlusion-Prognostic impact of EuroSCORE II

Background

Interventional closure of the left atrial appendage (LAA) is an alternative option to stroke prophylaxis, particularly in multimorbid patients with a high risk of bleeding under oral anticoagulation. Due to the multiple comorbidities, the prognosis of patients is reduced, and the clinical benefit of the procedure is therefore questionable in the individual patient.

Hypothesis

The present study aims to identify independent preprocedural risk factors to improve risk stratification in these highly selected patients.

Methods

This study consecutively included 128 patients who received an interventional LAA occlusion with Amplatzer device (St Jude Medical, St Paul, Minnesota). The preinterventional risk assessment was performed with the logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) II. The primary endpoint was all‐cause mortality. Secondary endpoints were thromboembolic events and severe bleeding.

Results

During a follow‐up of 781 ± 498 days the primary endpoint (all‐cause mortality) was reached in 35 patients (27%). The only independent predictor of mid‐term mortality was a logistic EuroSCORE II > 2% (Hazard risk [HR] 4.55, confidence interval [CI] 1.599‐12.966, P = .005). In our study, 33 patients (26%) suffered from end‐stage renal disease which was not associated with increased mortality (P = .371), increased thromboembolic events (P = .475), or severe bleeding (P = .613).

Conclusions

In patients undergoing interventional LAA occlusion, preprocedural assessment of logistic EuroSCORE II provide independent prognostic information. This parameter might help to improve risk stratification in these highly selected patients. In contrast, terminal renal failure was not associated with a significantly worse outcome.

Percutaneous retrieval of a dislocated LAmbre left atrial appendage occluder in a canine model

BACKGROUND

Dislocated left atrial appendage (LAA) occluders can be retrieved by percutaneous intervention when performing device embolization into the left atrium (LA), aorta (AO), or left ventricle (LV). However, few reports exist regarding LAmbre LAA occluder dislocation.

OBJECTIVE

The study was aimed to explore the outcome of retrieving dislocated LAmbre LAA occluder.

METHODS

Sixteen healthy dogs received LAmbre implants. After implantation of an occlusion device (not released), the occlusion device was completely retrieved. Subsequently, the device was released in the LA, resulting in the dislocation of the device. Angiography and transesophageal echocardiography (TEE) were performed to check the occluders position. Disposable grasping rat-tooth forceps were used to percutaneously retrieve the LAA occluder.

RESULTS

All the 16 dogs were successfully implanted with the LAmbre LAA occluder and the success rate was 100%. After the occluder was released, TEE and angiography confirmed that the device was located in the LA in eight cases (50%), in the AO in five cases (31%), and in the LV in three cases (19%). One subject died due to cardiogenic shock before the retrieval procedure was complete as the device fell into the LV. Two cases of device-related aortic valve injury occurred during the retrieval procedure when the device was located in the LV. No complications were observed when the device was located in the LA or AO.

CONCLUSIONS

Device retrieval is feasible in most cases. However, potentially lethal complications may occur once the device is dislocated into the LV/AO.

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.

Left Atrial Appendage Closure: Prevention and Management of Periprocedural and Postprocedural Complications

Left atrial appendage closure (LAAC) is noninferior to oral vitamin K antagonist therapy for the reduction of nonvalvular atrial fibrillation-related stroke risk. Currently, the procedure is most widely accepted in patients who cannot tolerate oral anticoagulants. This patient population is generally comorbid, making any reduction in procedural complications paramount. LAAC has important complications described in the periprocedural and postprocedural periods. The prevention and management of complications regarding vascular access, transseptal puncture, pericardial effusion, device embolization, stroke, air embolusperidevice leak, device-related thrombus and device erosion/ late pericardial effusion are discussed.

Percutaneous left atrial appendage closure, a safe alternative to anticoagulation for patients with nonvalvular atrial fibrillation and end-stage renal disease on hemodialysis: A single center experience

The evidence about the effectiveness and safety of oral anticoagulation in patients on hemodialysis is conflicting and scarce. Percutaneous left atrial appendage occlusion (LAAO) has demonstrated to be a valid alternative therapeutic option for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). The aim of this study is to present the outcomes of percutaneous LAAO in patients with end-stage renal disease (ESRD) on hemodialysis and NVAF in our center. We conducted a retrospective review of clinical records, demographics, LAAO procedure, complications, and outcomes of patients with NVAF and ESRD on hemodialysis who underwent a percutaneous LAAO in our center between January 2017 and January 2019. In the period of the study, eight patients with ESRD on hemodialysis underwent a percutaneous LAAO in our center. The overall mean age was 67.5 years (range 56-81; SD ± 7.2). All patients had permanent NVAF. The total mean dialysis duration was 8.49 years (range 0.83-14.8; SD ± 6.2). The mean CHA2DS2-VASc and HAS-BLED scores were high (4.75 [SD ± 1.16] and 4.62 [SD ± 0.91], respectively). All patients had history of a major hemorrhagic event (BARC Score ≥3). Most patients (n = 6) showed left ventricular hypertrophy, and the average LVEF was 54% (SD ± 6.5). All devices were implanted successfully. Postprocedural antithrombotic regimen prescribed was based on antiplatelet therapy. No deaths, cardioembolic events, or major bleeding (according to the BARC scale) were reported during a mean follow-up of 14.24 months (SD ± 9.44). Percutaneous LAAO could be of particular interest in patients with NVAF and CKD in hemodialysis. Further studies will be necessary to confirm this hypothesis.

Effectiveness of Only Aspirin or Clopidogrel Following Percutaneous Left Atrial Appendage Closure

Percutaneous left atrial appendage closure (LAAC) offers a feasible option for stroke prevention in patients with atrial fibrillation (AF), but the optimal antithrombotic treatment strategy for patients with strict contraindications to oral anticoagulation (OAC) remains uncertain. We sought to evaluate short- and long-term outcome after percutaneous LAAC in these very patients discharged on single antiplatelet therapy (SAPT) alone. All consenting AF patients who underwent LAAC from February 2009 to August 2018 in Turku University Hospital, Finland, were enrolled into a prospectively maintained registry. Only patients discharged on SAPT alone were considered for the present analysis. Patients were prospectively followed up to 5 years. The primary end points were thromboembolic event (stroke, transient ischemic attack, or systemic embolism) and intracranial bleeding. Of the 165 LAAC patients, 81 patients (mean age 75 ± 7 years; 44% women; CHA₂DS₂-VASc 4.8 ± 1.4; HAS-BLED 3.2 ± 0.8) were discharged on SAPT only (77 with aspirin 100 mg) after successful LAAC using Amplatzer devices. The duration of SAPT was ≤6 months in 61 (75%) patients. The most common contraindication to OAC was previous intracranial bleeding in 48 (59%) patients. During a mean follow-up of 2.9 years, there were 6 thromboembolic events (2.7 of 100 patient-years; 73% lower-than-predicted rate of thromboembolism). Eight patients (3.6 of 100 patient-years) had a major bleeding event after discharge, and 4 patients had intracerebral bleeding (1.7 of 100 patient-years). At 6-month landmark analysis, freedom from thromboembolism and intracranial bleeding at 3-year follow-up was similar in those with discontinued and life-long SAPT (95.1% vs 88.9% and 97.6% vs 91.7%, respectively). In conclusion, long-term outcome is satisfactory after LAAC in selected AF patients with strict contraindications to OAC receiving short-term SAPT. However, adverse events are not infrequent during early postoperative months.

Incidence, Predictors, and Prognostic Value of Acute Kidney Injury Among Patients Undergoing Left Atrial Appendage Closure

OBJECTIVES

The aims of this registry were to determine the incidence, predictors, and prognostic value of periprocedural acute kidney injury (AKI) after left atrial appendage closure (LAAC).

BACKGROUND

No data exist on the occurrence of AKI after LAAC.

METHODS

A total of 355 patients undergoing LAAC were included in the study. AKI was defined as an absolute or a relative increase in serum creatinine of >0.3 mg/dl or ≥50%, respectively, after the procedure or the need for hemodialysis during index hospitalization.

RESULTS

The incidence of AKI was 9%, and patients with worse baseline renal function were at higher risk for developing AKI (odds ratio: 1.32; 95% confidence interval [CI]: 1.09 to 1.61; p = 0.004 for each 10 ml/min decrease in glomerular filtration rate). In-hospital bleeding events occurred more frequently in the AKI group (5.3% vs. 15.6%; p = 0.037). After a median follow-up period of 18 months, patients in the AKI group had higher mortality (hazard ratio [HR]: 2.59; 95% CI: 1.36 to 4.92; p = 0.004), more embolic events (HR: 6.14; 95% CI: 2.23 to 16.92; p = 0.001) and major bleeding events (HR: 2.36; 95% CI: 0.89 to 6.24; p = 0.083). The occurrence of AKI was an independent predictor of midterm mortality (HR: 2.00; 95% CI: 1.02 to 3.91; p = 0.044).

CONCLUSIONS

The occurrence of AKI was relatively frequent following LAAC, and patients with lower renal glomerular filtration rates were at high risk for developing this complication. AKI identified a group of patients with worse midterm outcomes, highlighting the importance of further preventive strategies in this population.

Intracardiac Versus Transesophageal Echocardiographic Guidance for Left Atrial Appendage Occlusion: The LAAO Italian Multicenter Registry

OBJECTIVES

This study sought to evaluate the feasibility, safety, and efficacy of intracardiac echocardiography (ICE)-guided versus transesophageal echocardiography (TEE)-guided left atrial appendage occlusion (LAAO) by the use of Amplatzer Cardiac Plug or Amulet devices included in a large Italian registry.

BACKGROUND

TEE is widely used for LAAO procedure guidance. ICE may be a potential alternative imaging modality in LAAO.

METHODS

Data from 604 LAAO procedures performed in 16 Italian centers were reviewed. ICE-guided LAAO was performed in 187 patients, whereas TEE was used in 417 patients. Procedural success was defined as LAAO without occurrence of pericardial tamponade, stroke, systemic embolism with end organ damage, major bleeding, and device embolization. Stroke, transient ischemic attack, major bleeding, overall and cardiovascular death were analyzed.

RESULTS

CHA₂DS₂-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65 to 74 years, sex category) and HAS-BLED (hypertension, abnormal renal and liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol) scores were similar between the ICE and TEE groups. TEE implied lower procedural (delta 12 min) and fluoroscopy time (delta 5 min) when compared with ICE. Procedural success was similarly high (≥94%) between the TEE and ICE groups with a complication rate of 6.5% for TEE versus 4.2% for ICE (odds ratio: 1.468; 95% confidence interval: 0.681 to 3.166; p = 0.327). At median follow-up of 451 days (interquartile range: 162 to 899 days), the rate of cerebral ischemic events was similar between TEE-guided and ICE-guided procedures.

CONCLUSIONS

ICE-guided LAAO by means of Amplatzer devices may represent a second alternative imaging modality after an appropriate learning curve and bearing in mind that pre-procedural computed tomography imaging is mandatory. When comparing ICE with TEE, TEE remains the gold standard.

Lifetech LAmbre: a new promising and novel device in the interventional stroke prevention

The advances in the left atrial appendage closure as a stroke prevention method in patients with atrial fibrillation and contraindications to oral anticoagulants made a huge revolution offering a great alternative for patients with a high risk of bleeding. The nitinol-based, self-expanding LAmbre closure system shows promising initial results in terms of efficacy and safety in worldwide different clinical trials offering an alternative to the known Amulet and Watchman closure systems. Lifetech received CE Mark approval for the LAmbre closure system on 15 June 2016. Different studies have shown encouraging results in terms of feasibility and efficacy of the novel occluder. The favorable device design gives a big advantage in the occlusion of difficult left atrial appendage anatomy.

Interventional occlusion of left atrial appendage in patients with atrial fibrillation. Acute and long-term outcome of occluder implantation in the LAARGE Registry

BACKGROUND

Left atrial appendage occluder (LAAO) implantation is an alternative method for stroke prevention in atrial fibrillation (AF) patients who are not eligible for long-term oral anticoagulation. The present paper describes the acute and 1-year follow-up outcome data of the prospective, multicenter German left atrial appendage occlusion registry (LAARGE).

METHODS

LAARGE enrolled 641 patients who were scheduled for LAAO implantation. The data collected included demographics, clinical characteristics, procedure indication, details of implantation, and outcome; patients were followed at 1-year post-implant. Efficacy and safety during follow-up are assessed by the occurrence of thrombembolic and bleeding events, respectively.

RESULTS

A total of 641 consecutive patients (mean age: 75.9 ± 8.0) were enrolled from July 2014 to January 2016 in 38 hospitals in Germany. Patient demographics represent a critically-ill population with a calculated mean CHA2DS2-VASc score and HASBLED score of 4.5 and 3.9, respectively, with bleeding events as the main indication for LAAO implantation (79.4%). One-year all-cause mortality post-procedure was 11.5% with a non-fatal stroke/TIA rate of 1.3% (8 patients) and a rate of major bleeding of 1.6% (10 patients). The anticoagulation regimen after 1 year consisted of oral anticoagulation in 5.5% of patients and an antiplatelet therapy (APT) rate of 84.1% (majority single APT with ASS (74.5%), dual APT in 6.7%).

CONCLUSIONS

LAARGE, a prospective multicenter real-world and all-comer registry, is unique in its concept, as it is non-manufacturer sponsored and includes all commercially available devices. LAAO implantation is mainly performed in elderly, critically-ill patients with a history of bleeding. LAARGE demonstrates a favorable outcome at 1-year follow-up in terms of stroke/TIA (1.3%) and major bleeding (1.6%) while using a single APT in the vast majority of patients.

[Left atrial appendage closure in non-valvular atrial fibrillation]

Atrial fibrillation is the most frequent cardiac arrhythmia worldwide, causing approximately 20% of all ischemic strokes. Therefore, oral anticoagulation is recommended in patients with atrial fibrillation with at least a moderate risk of stroke; however, there is a significant proportion of patients who cannot undergo long-term oral anticoagulation. As the left atrial appendage is of major relevance for atrial fibrillation-induced thrombus formation, catheter-based or surgical closure of the left atrial appendage appears to be a promising therapeutic option. Large registry studies including patients with catheter-based left atrial appendage closure have proven its effectiveness and a decreasing procedure-related complication rate. This review article summarizes the current knowledge and introduces major ongoing randomized studies, which will investigate the impact of left atrial appendage closure on stroke prevention. The authors hope that the results of the randomized CLOSURE AF trial, which is funded by the German Center for Cardiovascular Research e. V. and is now recruiting patients in Germany, will help to solve many of the currently prevalent clinical questions.

The left atrial appendage in humans: structure, physiology, and pathogenesis

For many years, the left atrial appendage (LAA) was considered a dormant embryological remnant; however, it is a structurally complex and functional organ that contributes to cardiac haemodynamic changes and volume homeostasis through both its contractile properties and neurohormonal peptide secretion. When dysfunctional, the LAA contributes to thrombogenesis and subsequent increased predisposition to cardioembolic events. Consequently, the LAA has gained much attention as a therapeutic target to lower this risk. In addition, attention has focused on the LAA in its role as an electrical trigger for atrial tachycardia and atrial fibrillation with ablation of the LAA to achieve electrical isolation showing promising results in the maintenance of sinus rhythm. This in-depth review explores the structure, physiology and pathophysiology of the LAA, as well as LAA intervention and their sequelae.

Stroke and thromboembolism prevention in atrial fibrillation

Prevention of stroke and systemic thromboembolism remains the cornerstone for management of atrial fibrillation (AF) and flutter. Multiple risk assessment models for stroke and systemic thromboembolism are currently available. The score, with its known limitations, remains as the recommended risk stratification tool in most major guidelines. Once at-risk patients are identified, vitamin K antagonists (VKAs) and, more recently, direct oral anticoagulants (DOACs) are the primary medical therapy for stroke prevention. In those with contraindication for long-term anticoagulation, left atrial appendage occluding devices are developing as a possible alternative therapy. Some controversy exists regarding anticoagulation management for cardioversion of acute AF (<48 hours); however, systemic anticoagulation precardioversion and postcardioversion is recommended for those with longer duration of AF. Anticoagulation management peri-AF ablation is also evolving. Uninterrupted VKA and DOAC therapy has been shown to reduce perioperative thromboembolic risk with no significant escalation in major bleeding. Currently, under investigation is a minimally interrupted approach to anticoagulation with DOACs periablation. Questions remain, especially regarding the delivery of anticoagulation care and integration of wearable rhythm monitors in AF management.