Left Atrial Appendage Ligation and Ablation for Persistent Atrial Fibrillation

Detection and identification of factors in the atrium responsible for blood pressure regulation in patients with hypertension

Resection of the left atrial appendage reportedly improves blood pressure in patients with hypertension. This study aimed to validate the transcriptional profiles of atrial genes responsible for blood pressure regulation in patients with hypertension as well as to identify the molecular mechanisms in rat biological systems. RNA sequencing data of left atrial appendages from patients with (n = 6) and without (n = 6) hypertension were subjected to unsupervised principal component analysis (PCA). Reduction of blood pressure was reflected by third and ninth principal components PC3 and PC9, and that eighteen transcripts, including endothelin-1, were revealed by PCA-based pathway analysis. Resection of the left atrial appendage in hypertensive rats improved their blood pressure accompanied by a decrease in serum endothelin-1 concentration. Expression of the endothelin-1 gene in the atrium and atrial appendectomy could play roles in blood pressure regulation in humans and rats.

Pulmonary Vein Isolation With or Without Left Atrial Appendage Ligation in Atrial Fibrillation: The aMAZE Randomized Clinical Trial

Importance

Left atrial appendage elimination may improve catheter ablation outcomes for atrial fibrillation.

Objective

To assess the safety and effectiveness of percutaneous left atrial appendage ligation adjunctive to catheter pulmonary vein isolation for nonparoxysmal atrial fibrillation.

Design, Setting, and Participants

This multicenter, prospective, open-label, randomized clinical trial evaluated the safety and effectiveness of percutaneous left atrial appendage ligation adjunctive to planned pulmonary vein isolation for nonparoxysmal atrial fibrillation present for less than 3 years. Eligible patients were randomized in a 2:1 ratio to undergo left atrial appendage ligation and pulmonary vein isolation or pulmonary vein isolation alone. Use of a 2:1 randomization ratio was intended to provide more device experience and safety data. Patients were enrolled from October 2015 to December 2019 at 53 US sites, with the final follow-up visit on April 21, 2021.

Interventions

Left atrial appendage ligation plus pulmonary vein isolation compared with pulmonary vein isolation alone.

Main Outcomes and Measures

A bayesian adaptive analysis was used for primary end points. Primary effectiveness was freedom from documented atrial arrythmias of greater than 30 seconds duration 12 months after undergoing pulmonary vein isolation. Rhythm was assessed by Holter monitoring at 6 and 12 months after pulmonary vein isolation, symptomatic event monitoring, or any electrocardiographic tracing obtained through 12 months after pulmonary vein isolation. Primary safety was a composite of predefined serious adverse events compared with a prespecified 10% performance goal 30 days after the procedure. Left atrial appendage closure was evaluated through 12 months after pulmonary vein isolation.

Results

Overall, 404 patients were randomized to undergo left atrial appendage ligation plus pulmonary vein isolation and 206 were randomized to undergo pulmonary vein isolation alone. Primary effectiveness was 64.3% with left atrial appendage ligation and pulmonary vein isolation and 59.9% with pulmonary vein isolation only (difference, 4.3% [bayesian 95% credible interval, -4.2% to 13.2%]; posterior superiority probability, 0.835), which did not meet the statistical criterion to establish superiority (0.977). Primary safety was met, with a 30-day serious adverse event rate of 3.4% (bayesian 95% credible interval, 2.0% to 5.0%; posterior probability, 1.0) which was less than the prespecified threshold of 10%. At 12 months after pulmonary vein isolation, complete left atrial appendage closure (0 mm residual communication) was observed in 84% of patients and less than or equal to 5 mm residual communication was observed in 99% of patients.

Conclusions and Relevance

Percutaneous left atrial appendage ligation adjunctive to pulmonary vein isolation did not meet prespecified efficacy criteria for freedom from atrial arrhythmias at 12 months compared with pulmonary vein isolation alone for patients with nonparoxysmal atrial fibrillation, but met prespecified safety criteria and demonstrated high rates of closure at 12 months.

Trial Registration

ClinicalTrials.gov Identifier: NCT02513797.

Repeat catheter ablation for atrial fibrillation

Catheter ablation of atrial fibrillation (AF) is an established therapy that reduces AF burden, improves quality of life, and reduces the risks of cardiovascular outcomes. Although there are clear guidelines for the application of de novo catheter ablation, there is less evidence to guide recommendations for repeat catheter ablation in patients who experience recurrent AF. In this review, we examine the rationale for repeat ablation, mechanisms of recurrence, patient selection, optimal timing, and procedural strategies. We discuss additional important considerations, including treatment of comorbidities and risk factors, risk of complications, and effectiveness. Mechanisms of recurrent AF are often due to non-pulmonary vein (non-PV) triggers; however, there is insufficient evidence supporting the routine use of empiric lesion sets during repeat ablation. The emergence of pulsed field ablation may alter the safety and effectiveness of de novo and repeat ablation. Extrapolation of data from randomized trials of de novo ablation does not optimally inform efficacy in cases of redo ablation. Additional large, randomized controlled trials are needed to address important clinical questions regarding procedural strategies and timing of repeat ablation.

Catheter ablation for non-paroxysmal atrial fibrillation. A review

Atrial fibrillation (AF), the most common cardiac arrhythmia is associated with increased morbidity and mortality. The higher mortality is due to the risk of heart failure and cardioembolic events. This in-depth review focuses on the strategies and efficacy of catheter ablation for non-paroxysmal atrial fibrillation. The main medical databases were searched for contemporary studies on catheter ablation for non-paroxysmal AF. Catheter ablation is currently proven to be the most effective treatment for AF and consists of pulmonary vein isolation as the cornerstone plus additional ablations. In terms of SR maintenance, it is less effective in non-paroxysmal AF than in paroxysmal patients. but the clinical benefit in non-paroxysmal patients is substantially higher. Since pulmonary vein isolation is ineffective, a variety of techniques have been developed, e.g. linear ablations, ablation of complex atrial fractionated electrograms, etc. Another paradox consists in the technique of catheter ablation. Despite promising results in early observation studies, further randomized studies have not confirmed the initial enthusiasm. Recently, a new approach, pulsed-field ablation, appears promising. This is an in-depth summary of current technologies and techniques for the ablation of non-paroxysmal AF. We discuss the benefits, risks and implications in the treatment of patients with non-paroxysmal AF.

Left Atrial Appendage Closure: A Narrative Review

Atrial fibrillation (AF) is the most common cardiac arrhythmia and the cause of thromboembolic events in elderly patients worldwide. AF is associated with a significantly increased risk of morbidity and mortality due to cardiac emboli, primarily from left atrial appendage (LAA) thrombus. Oral anticoagulation therapy is the standard treatment to effectively reduce the risk of thromboembolic events in patients with AF. However, anticoagulation treatment increases bleeding risk. LAA closure (LAAC) has recently been introduced as a feasible mechanical preventive intervention for thromboembolic events while minimizing the risk of bleeding. Transcatheter LAAC devices have evolved in the past decade, and several ongoing trials have demonstrated the improvements of safety and outcomes in newer generation devices. This review summarizes the current perspectives and outcomes regarding LAAC as an alternative to pharmacologic therapy.

Research progress on predicting atrial fibrillation recurrence after radiofrequency ablation based on electrocardiogram-related parameters

Atrial fibrillation (AF) is the most common arrhythmia. It is associated with increased stroke risks, thromboembolism, and other complications, which are great life and economic burdens for patients. In recent years, with the maturity of percutaneous catheter radiofrequency ablation (RFA) technology, it has become a first-line therapy for AF. However, some patients still experience AF recurrence (AFR) after RFA, which can cause serious consequences. Therefore, it is critical to identify appropriate parameters that are predictive of prognosis and to be able to translate the parameters easily into the clinical setting. Here, we reviewed possible predicting indicators for AFR, focusing on all the electrocardiogram indicators, such as P wave duration, PR interval and so on. It may provide valuable information for guiding clinical works.

Considerations for Left Atrial Appendage Occlusion During Cardiac Surgery

Atrial fibrillation is associated with an increased risk of stroke secondary to thrombus formation in the left atrial appendage. Left atrial appendage occlusion (LAAO) is an effective method of reducing the risk of stroke in patients with atrial fibrillation. Although LAAO does not remove the requirement for anticoagulation, it reduces the risk of stroke when compared to anticoagulation alone. We critically analyze the data on LAAO in cardiac surgery. We also discuss the methods of LAAO, the risks of LAAO, and patient populations that could benefit from LAAO. We discuss high-level evidence that LAAO at the time of cardiac surgery reduces the risk of stroke in patients with a history of atrial fibrillation. In patients without a history of atrial fibrillation undergoing cardiac surgery, we suggest that LAAO should be considered in select patients at high risk of atrial fibrillation and stroke, when technically feasible.

Antithrombotic Treatment in Patients With Hemophilia: an EHA-ISTH-EAHAD-ESO Clinical Practice Guidance

Cardiovascular disease is an emerging medical issue in patients with hemophilia (PWH) and its prevalence is increasing up to 15% in PWH in the United States. Atrial fibrillation, acute and chronic coronary syndromes, venous thromboembolism, and cerebral thrombosis are frequent thrombotic or prothrombotic situations, which require a careful approach to fine-tune the delicate balance between thrombosis and hemostasis in PWH when using both procoagulant and anticoagulant treatments. Generally, PWH could be considered as being naturally anticoagulated when clotting factors are <20 IU/dL, but specific recommendations in patients with very low levels according to the different clinical situations are lacking and mainly based on the anecdotal series. For PWH with baseline clotting factor levels >20 IU/dL in need for any form of antithrombotic therapy, usually treatment without additional clotting factor prophylaxis could be used, but careful monitoring for bleeding is recommended. For antiplatelet treatment, this threshold could be lower with single-antiplatelet agent, but again factor level should be at least 20 IU/dL for dual antiplatelet treatment. In this complex growing scenario, the European Hematology Association in collaboration with the International Society on Thrombosis and Haemostasis, the European Association for Hemophilia and Allied Disorders, the European Stroke Organization, and a representative of the European Society of Cardiology Working Group on Thrombosis has produced this current guidance document to provide clinical practice recommendations for health care providers who care for PWH.

Combined atrial fibrillation ablation and left atrial appendage occlusion procedure in the United States: a propensity score matched analysis from 2016-2019 national readmission database

AIMS

The safety and feasibility of combining percutaneous catheter ablation (CA) for atrial fibrillation with left atrial appendage occlusion (LAAO) as a single procedure in the USA have not been investigated. We analyzed the US National Readmission Database (NRD) to investigate the incidence of combined LAAO + CA and compare major adverse cardiovascular events (MACEs) with matched LAAO-only and CA-only patients.

METHODS AND RESULTS

In this retrospective study from NRD data, we identified patients undergoing combined LAAO and CA procedures on the same day in the USA from 2016 to 2019. A 1:1 propensity score match was performed to identify patients undergoing LAAO-only and CA-only procedures. The number of LAAO + CA procedures increased from 28 (2016) to 119 (2019). LAAO + CA patients (n = 375, mean age 74 ± 9.2 years, 53.4% were males) had non-significant higher MACE (8.1%) when compared with LAAO-only (n = 407, 5.3%) or CA-only patients (n = 406, 7.4%), which was primarily driven by higher rate of pericardial effusion (4.3%). All-cause 30-day readmission rates among LAAO + CA patients (10.7%) were similar when compared with LAAO-only (12.7%) or CA-only (17.5%) patients. The most frequent primary reason for readmissions among LAAO + CA and LAAO-only cohorts was heart failure (24.6 and 31.5%, respectively), while among the CA-only cohort, it was paroxysmal atrial fibrillation (25.7%).

CONCLUSION

We report an 63% annual growth (from 28 procedures) in combined LAAO and CA procedures in the USA. There were no significant difference in MACE and all-cause 30-day readmission rates among LAAO + CA patients compared with matched LAAO-only or CA-only patients.

Abnormal left atrial body stiffness is predicted by appendage size: impact of appendage occlusion on left atrial mechanics assessed by pressure-volume analysis

Atrial cardiomyopathy has been recognized as having important consequences for cardiac performance and clinical outcomes. The pathophysiological role of the left atrial (LA) appendage and the effect of percutaneous left atrial appendage occlusion (LAAO) upon LA mechanics is incompletely understood. We evaluated if changes in LA stiffness due to endocardial LAAO can be detected by LA pressure-volume (PV) analysis and whether stiffness parameters are associated with baseline characteristics. Patients undergoing percutaneous endocardial LAAO (n = 25) were studied using a novel PV analysis using near-simultaneous three-dimensional LA volume measurements by transesophageal echocardiography (TEE) and direct invasive LA pressure measurements. LA stiffness (dP/dV, change in pressure with change in volume) was calculated before and after LAAO. Overall LA stiffness significantly increased after LAAO compared with baseline (median, 0.41-0.64 mmHg/mL; P ≪ 0.001). LA body stiffness after LAAO correlated with baseline LA appendage size by indexed maximum depth (Spearman's rank correlation coefficient R_s = 0.61; P < 0.01). LA stiffness change showed an even stronger correlation with baseline LA appendage size by indexed maximum depth (R_s = 0.70; P < 0.001). We found that overall LA stiffness increases after endocardial LAAO. Baseline LA appendage size correlates with the magnitude of increase and LA body stiffness. These findings document alteration of LA mechanics after endocardial LAAO and suggest that the LA appendage modulates overall LA compliance.NEW & NOTEWORTHY Our study documents a correlation of LA appendage remodeling with the degree of chronically abnormal LA body stiffness. In addition, we found that LA appendage size was the baseline parameter that best correlated with the magnitude of a further increase in overall LA stiffness after appendage occlusion. These findings offer insights about the LA appendage and LA mechanics that are relevant to patients at risk for adverse atrial remodeling, especially candidates for LA appendage occlusion.

Metabolic Effects of the Left Atrial Appendage Exclusion (THE HEART HORMONE STUDY)

OBJECTIVE

The effect of epicardial LAA occlusion therapy on lipid and glucose metabolism in AF patients over the long term follow up is unclear.

METHODS

In a single-center prospective observational study, 60 patients with longstanding persistent AF with cardiovascular risk factors had undergone an epicardial exclusion procedure. Anthropometric parameters and glucose, glycated hemoglobin (HbA1c), insulin, leptin, adiponectin, free fatty acids, beta-hydroxybutyrate, and total cholesterol levels were evaluated on fasting at baseline before the procedure and compared with levels at 24 hours, 7 days, 1 month, 3 months, 6 months, and 24 months follow the procedure.

RESULTS

The mean age of the patients was 67.5 ± 8.1. Insulin levels significantly increased at 7 days, 1 month, 3 months, 6 months, 12 months, and 24 months follow-up. The leptin levels showed a significant increase in 6 months, 12 months, and 24 months when compared to baseline. Whereas the adiponectin levels showed a significant decrease at 3 months, 6 months, 12 months, and 24 months when compared to baseline levels. In patients with the epicardial procedure, when compared to baseline, glucose, glycated hemoglobin, total cholesterol, and beta-hydroxybutyrate levels did not show any significant changes at baseline and 24 months follow up.

CONCLUSION

The epicardial exclusion ligation in AF patients was associated with significant changes in insulin, leptin, and adiponectin over long follow up. This article is protected by copyright. All rights reserved.

Long-term Outcome of Patients with Long-standing Persistent Atrial Fibrillation undergoing Ablation Guided by a Novel High-Density Panoramic Mapping System - A Propensity Score Matching Study

Background

Catheter ablation is a current therapeutic approach for atrial fibrillation (AF). However, its efficacy for long-standing persistent AF remains suboptimal.

Objective

The purpose of this study was to test the hypothesis that a panoramic mapping system (CARTOFINDER, Biosense Webster) can guide pulmonary vein (PV) isolation and additional potential AF drivers.

Methods

A total of 76 patients with nonparoxysmal AF referred for ablation guided by a novel high-density panoramic mapping system with CARTOFINDER were prospectively enrolled. Of this cohort, 40 patients (52.6%) had long-standing persistent AF (CARTOFINDER group). We then retrospectively screened the patients with long-standing persistent AF undergoing conventional PV isolation and elimination of non-PV triggers during the contemporary period (conventional group). They were matched at a 1:2 ratio (40 patients in group 1 received ablation guided by CARTOFINDER; 80 patients in group 2 receiving conventional PV isolation and elimination of non-PV triggers).

Results

During follow-up, patients in group 1 had a lower recurrence AF rate than those in group 2 (P = .040). There was no difference in recurrence of atrial flutter (P = .996) and atrial tachycardia (P = .525). In Cox proportional hazards regression analysis, AF duration and PV isolation along with AF driver ablation using a panoramic mapping system with CARTOFINDER both were independent predictors of recurrent AF after catheter ablation of long-standing persistent AF.

Conclusion

Identification of the potential drivers in long-standing AF is crucial. Compared with conventional PV isolation and elimination of non-PV triggers, ablation guided by a high-density panoramic mapping system (CARTOFINDER) might have a better outcome in patients with long-standing persistent AF.

Efficacy and safety of left atrial appendage electrical isolation during catheter ablation of atrial fibrillation: an updated meta-analysis

AIMS

Left atrial appendage electrical isolation (LAAEI) has been shown to improve freedom from all-atrial arrhythmia recurrence in patients with non-paroxysmal atrial fibrillation (AF). The aim of this study is to investigate the long-term efficacy and safety outcomes of LAAEI in patients with non-paroxysmal AF undergoing catheter ablation.

METHODS AND RESULTS

A systematic review of Medline, Cochrane, and Embase was performed for clinical studies evaluating the benefit of LAAEI in non-paroxysmal AF. Nine studies with a total of 2336 patients were included (mean age: 65 ± 9 years, 63% male). All studies included patients with persistent AF, long-standing persistent AF, or both. At a mean follow-up of 40.5 months, patients who underwent LAAEI had significantly higher freedom from all-atrial arrhythmia recurrence than patients who underwent standard ablation alone [69.3% vs. 46.4%; risk ratio (RR) 0.54; 95% confidence interval (CI) 0.42-0.69; P < 0.0001]. A 46% relative risk reduction and 22.9% absolute risk reduction in atrial-arrhythmia recurrence was noted with LAAEI. Rates of cerebral thromboembolism were not significantly different between the two groups (LAAEI 3% vs. standard ablation 1.6%, respectively; RR 1.76; 95% CI 0.61-5.04; P = 0.29). Furthermore, there was no significant difference in the acute procedural complication rates between the two groups (LAAEI 4% vs. standard ablation 3%, respectively; RR 1.29; 95% CI 0.83-2.02; P = 0.26).

CONCLUSION

At long-term follow-up, LAAEI led to a significantly higher improvement in freedom from all-atrial arrhythmia recurrence in patients with non-paroxysmal AF, when compared to standard ablation alone. Importantly, this benefit was achieved without an increased risk of acute procedural complications or cerebral thromboembolic events.

Safety and efficacy of left atrial appendage closure using an epicardial suture snaring device: Systematic review and current status

INTRODUCTION

The LARIAT epicardial suture snaring device has been fraught with technical challenges and procedural complications. Over time, technique modification and improved operator experience have helped overcome many of these challenges. METHODS AND RESULTS: Studies reporting left atrial appendage epicardial closure over a 12-year period from 2009 to 2020 were evaluated. The primary efficacy outcome evaluated was left atrial appendage closure with residual flow ≤1 mm. Safety outcomes evaluated were periprocedural and long term complications after device placement. Nine studies consisting of 1430 patients were included in this analysis, of which 1386 (97%) underwent successful device placement. The mean age was 69.3 years, with a mean CHADS₂ -VASC score of 3.78. Primary efficacy end point was achieved in 95.8% patients immediately after device placement, and in 92.8% patients on long term follow-up. Early procedural complications consisted of pericardial effusion 5.6%, cardiac perforation 2.7%, pericarditis 2.6%, and need for open heart surgery 1.5%. Long term complications consisted of all-cause mortality 2.3%, stroke 1.5%, and left atrial appendage thrombus 2.3%. Reduced complications were noted using micropuncture needles (2.20% vs. 10.14%; p < .0001), a longer duration pericardial drainage, and use of anti-inflammatory medications (1.58% vs. 8.4%). Oral anticoagulation use decreased from 44.7% to 22.9% post device implantation, and to 8.5% on last clinical follow up.

CONCLUSIONS

The LARIAT device is effective in epicardial closure of the left atrial appendage. Improvement in device techniques such as use of micropuncture needle, prophylactic colchicine, and maintenance of a pericardial drain have helped improve safety over time.

Role of the Left Atrial Appendage in Systemic Homeostasis, Arrhythmogenesis, and Beyond

The left atrial appendage (LAA) affects body homeostasis via atrial natriuretic peptide and the renin-angiotensin-aldosterone system and plays an important role in atrial compliance. Approximately 90% of clots in nonvalvular atrial fibrillation (AF) are formed in the LAA. AF is the most common sustained cardiac arrhythmia and is frequently associated with stroke. Because anticoagulation for stroke prophylaxis carries a higher bleeding risk, LAA closure via epicardial and endocardial approaches has gained popularity and is being increasingly pursued for arrhythmogenic, homeostatic, and stroke-reduction benefits. This review discusses the homeostatic role of the LAA and its involvement in arrhythmogenesis and thrombus formation.

Current practice and future prospects in left atrial appendage occlusion

The thromboembolic complications of Atrial fibrillation (AF) remain a major problem in contemporary clinical practice. Despite advances and developments in anticoagulation strategies, therapy is complicated by the high risk of bleeding complications and need for meticulous medication compliance. Over the past few decades, the left atrial appendage has emerged as a promising therapeutic target to prevent thromboembolic events while mitigating bleeding complications and compliance issues. Emerging data indicates that it is a safe, effective and feasible alternative to systemic anticoagulation in patients with non-valvular AF. A number of devices have been developed for endocardial or epicardial based isolation of the left atrial appendage. Increasing experience has improved overall procedural safety and ease while simultaneously reducing device related complication rates. Furthermore, increasing recognition of the non-mechanical advantages of this procedure has led to further interest in its utility for further indications beyond the prevention of thromboembolic complications. In this review, we present a comprehensive overview of the evolution of left atrial appendage occlusion, commercially available devices and the role of this modality in the current management of AF. We also provide a brief outline of the landmark trials supporting this approach as well as the ongoing research and future prospects of left atrial appendage occlusion.

Managing Atrial Fibrillation in Patients With Heart Failure and Reduced Ejection Fraction: A Scientific Statement From the American Heart Association

Atrial fibrillation and heart failure with reduced ejection fraction are increasing in prevalence worldwide. Atrial fibrillation can precipitate and can be a consequence of heart failure with reduced ejection fraction and cardiomyopathy. Atrial fibrillation and heart failure, when present together, are associated with worse outcomes. Together, these 2 conditions increase the risk of stroke, requiring oral anticoagulation in many or left atrial appendage closure in some. Medical management for rate and rhythm control of atrial fibrillation in heart failure remain hampered by variable success, intolerance, and adverse effects. In multiple randomized clinical trials in recent years, catheter ablation for atrial fibrillation in patients with heart failure and reduced ejection fraction has shown superiority in improving survival, quality of life, and ventricular function and reducing heart failure hospitalizations compared with antiarrhythmic drugs and rate control therapies. This has resulted in a paradigm shift in management toward nonpharmacological rhythm control of atrial fibrillation in heart failure with reduced ejection fraction. The primary objective of this American Heart Association scientific statement is to review the available evidence on the epidemiology and pathophysiology of atrial fibrillation in relation to heart failure and to provide guidance on the latest advances in pharmacological and nonpharmacological management of atrial fibrillation in patients with heart failure and reduced ejection fraction. The writing committee's consensus on the implications for clinical practice, gaps in knowledge, and directions for future research are highlighted.

Atrial fibrillation evolution and rhythm control strategy following left appendage closure: new insights from the prospective FLAAC registry

BACKGROUND

Percutaneous left atrial appendage (LAA) closure is an alternative to oral anticoagulation (OAC) for atrial fibrillation (AF) patients with high thromboembolism risk, particularly with contraindications to OAC. The LAA itself could possess proarrhythmogenic properties. As patients undergoing LAA closure could be candidates for cardioversion or ablation, we aimed to evaluate AF disease progression following LAA closure and the outcome of patients undergoing a rhythm control strategy after the procedure.

METHODS

The prospective multicenter French Nationwide Observational LAA Closure Registry (FLAAC) comprises 33 French interventional cardiology departments. Patients were included if they fulfilled the following criteria: history of non-valvular AF, successful LAA closure and long-term ECG follow-up.

RESULTS

A total of 331 patients with successful LAA closure were enrolled in the study. Patients mean age was 75.4 ± 0.5 years. The study population was characterized by a high thromboembolic risk (CHA₂DS₂-VASc score: 4.5 ± 0.1) and frequent comorbidities. The median follow-up was 11.9 months. One hundred and nineteen (36.0%) patients were in sinus rhythm (SR) at baseline. Among SR patients, documented AF was observed in 16 (13.4%) patients whereas 15 (7.1%) patients in AF at baseline restored SR, at the end of follow up. Finally, only 13 patients (4%) underwent procedures to restore SR without complications during the follow-up.

CONCLUSIONS

The vast majority of patients undergoing LAA closure have the same AF status at baseline and one year after the index procedure. During the follow-up, a very small proportion (4%) of our population underwent procedures to restore SR without complications whatever the post-procedural antithrombotic strategy was.

Concomitant epicardial left atrial appendage ligation and left atrial ablation of atrial fibrillation: Safety, feasibility and outcome

Introduction

We present initial results of patients undergoing a combined procedure of epicardial LAA ligation in addition to left atrial ablation for AF.

Methods

9 patients were included for additional use of LARIAT as an individual treatment approach for AF. First an epicardial LAA ligation was performed, in the same procedure left atrial ablations consisting of PVI and additional substrate based modifying ablations were performed. Follow–up at 3 months and 12 months was performed.

Results

There was only 1 minor procedural complication (11%) involving epicardial bleeding and 2 late adverse events of pericardial tamponade and stroke. At the final follow-up (median 20 months) 7 patients were in stable sinus rhythm (78%) and 2 pts had reduced AF burden.

Conclusion

Concomitant epicardial LAA ligation and ablation is feasible in selected patients with a reasonable risk profile. More prospective data are required to validate the safety and efficacy.

Percutaneous epicardial approach for LAA ligation

PURPOSE

The left atrial appendage (LAA) is believed to be a source for thrombus formation and an ancillary structure involved in the initiation and maintenance of atrial fibrillation (AF). LAA ligation has been proposed as adjunctive therapy for the treatment of AF. This study will determine the feasibility of a percutaneous epicardial approach for LAA ligation.

METHODS

The pericardium of 5 dogs was accessed via percutaneous subxyphoid approach. A 20F epicardial cannula was inserted into the pericardial space and contrast-injected to visualize the LAA. Under fluoroscopic guidance, a suction cup catheter was inserted and attached to the LAA. A 12F snare device was inserted over the vacuum cup to ligate the LAA. The closure of the LAA was verified with LA angiography, in the first 2 dogs, and ICE in all 5 animals. All animals were sacrificed for post hoc assessment of LAA closure.

RESULTS

All 5 dogs underwent successful epicardial suture ligation of the LAA. In the first 2 dogs, LA angiography demonstrated complete closure of the LAA. All dogs underwent gross examination of the LAA. Post hoc assessment was notable for a small well-circumscribed hematoma on the LAA, consistent with point of suction cup attachment, as well as complete closure of the entire LAA. No laceration or perforation was noted on the LAA.

CONCLUSIONS

Exclusion of the LAA via a novel percutaneous epicardial-only approach was successful without complications. This demonstrates the feasibility of this technique in an animal model, and may provide an effective approach for epicardial-only LAA exclusion in humans.

Risks and Benefits of Removal of the Left Atrial Appendage

PURPOSE OF REVIEW

In patients with atrial fibrillation who are unable to take novel oral anticoagulants for stroke prophylaxis due to bleeding risk or other contraindications, left atrial appendage (LAA) occlusion and exclusion devices have shown benefit. In this review, we highlight the risks and benefits associated with LAA removal.

RECENT FINDINGS

LAA, once considered a vestigial organ, has been shown to have physiological, anatomical, and arrhythmogenic properties. Device-related complications such as pericardial effusion, device embolization, device-related thrombus, while uncommon, are still present. With increased operator experience related to appendage occlusion, overall procedural complications have declined. Further refinements in device technology will help decrease complications. While benefits of appendage removal are plenty, procedural complications need to be weighed into the equation when making decisions regarding LAA occlusion.

Surgical left atrial appendage occlusion in patients with atrial fibrillation undergoing mechanical heart valve replacement

BACKGROUND

Surgical left atrial appendage occlusion (SLAAO) may be associated with a lower risk of thromboembolism in patients with atrial fibrillation undergoing cardiac surgery. However, evidence regarding the effectiveness of SLAAO in patients undergoing mechanical heart valve replacement (MHVR) is lacking. Therefore, we aimed to evaluate the association between SLAAO and the cardiovascular outcomes in patients with atrial fibrillation undergoing MHVR.

METHODS

We retrospectively analyzed data for 497 patients with atrial fibrillation; 27.6% of the patients underwent SLAAO, and the remainder of the patients did not (No-SLAAO group). The primary outcome was a composite of ischemic stroke, systemic embolism, and all-cause mortality. Cumulative event-free survival rates were estimated using Kaplan-Meier curves, and we performed multivariate Cox analyses to evaluate the association between SLAAO and outcomes. We used one-to-one propensity score matching to balance patients' baseline characteristics, and analyzed 120 matching pairs.

RESULTS

Five patients died within 30 days postoperatively, and there were no significant differences between the two groups regarding in-hospital complications (all P > 0.05). After a median follow-up of 14 months, 14 primary events occurred. Kaplan-Meier curves showed no difference in the cumulative incidence of freedom from the primary outcome (log-rank P = 0.830), hemorrhagic events (log-rank P = 0.870), and the secondary outcome (log-rank P = 0.730), between the two groups. Multivariable Cox proportional hazards regression analysis showed no association between SLAAO and any outcome (all P > 0.05). After propensity score matching, cardiopulmonary bypass time and aortic cross-clamp time, and the postoperative length of stay were significantly longer in the SLAAO group (all P < 0.05); results were similar to the unadjusted analyses.

CONCLUSIONS

Concomitant SLAAO and MHVR was associated with longer length of stay, and cardiopulmonary bypass time and aortic cross-clamp time, but was not associated with additional protective effects against thromboembolic events and mortality during the 14-month follow-up.

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.

Morphological and functional parameters of left atrial appendage play a greater role in atrial fibrillation relapse after radiofrequency ablation

This study was to quantitatively investigate the role of morphological and functional parameters of the left atrium (LA) and left atrial appendage (LAA) with 256-slice spiral computed tomography (CT) in the recurrence of atrial fibrillation (AF) after radiofrequency ablation (RFA). Eighty-three patients with AF who underwent RFA for the first time were divided into the recurrence (n = 27) and non-recurrence (n = 56) groups. All patients underwent a 256-slice spiral CT examination before the operation. The clinical data and quantitative measurement of the morphology and functional parameters of the LA and LAA were analyzed, including the maximal and minimal volume, ejection fraction and volume, and volume strain of LAA and LA (LAAVmax, LAAVmin, LAAEF, LAAEV, and LAA-VS, LAVmax, LAVmin, LAEF, LAEV and LA-VS, respectively). The CHA2DS2-VASc score and the proportion of patients with heart failure were significantly (P < 0.05) higher in the recurrence than non-recurrence group. The LAAVmax, LAAVmin, LAVmax, LAVmin, LAAV and LAV were all significantly greater in the recurrence than non-recurrence group (P < 0.05), and the perimeter, major and minor axes of LAA orifice and LAA depth were also significantly greater in the recurrence than non-recurrence group. The LAAEF, LAEF and LAA-VS were significantly (P < 0.05) lower in the recurrence than non-recurrence group (P < 0.05). Heart failure, CHA2DS2-VASC score, LAEF, LAV, LAAEF and LAA-VS were univariately significant (P < 0.05) risk factors for AF recurrence after ablation. Multivariate analysis revealed LAAEF (HR: 0.790, 95% CI: 0.657–0.950, P = 0.012) and LAAV (HR: 1.160, 95% CI: 1.095–1.229, P <0.001) to be two significant independent predictors of recurrence. ROC curve analysis showed that LAAEF <44.68% had the highest predictive value for recurrence after radiofrequency ablation, with the sensitivity of 90% and specificity of 67.4%, whereas LAA volume >9.25 ml had the highest predictive value for AF recurrence after RFA, with the sensitivity of 85.2% and specificity of 67.9%. In conclusion, the volume of left atrium, volume and morphology of left atrial appendage have all significantly increased while the ejection fraction and volume strain of left atrium and left atrial appendage have both significantly decreased in recurrence than in non-recurrence after radiofrequency ablation. The ejection fraction and volume of left atrial appendage are significant independent predictors of atrial fibrillation recurrence after radiofrequency ablation.

Persistence and Distortion of Electrical Activity in the LAA 5 Years After Endovascular Occlusion

This is the first report demonstrating persistence and distortion of electrical activity in the left atrial appendage 5 years after endovascular occlusion with a Watchman device. Electrical conduction is impaired providing an arrhythmogenic substrate for atrial tachyarrhythmias. Localized inflammation may result in structural and electrical remodeling in these patients. (Level of Difficulty: Intermediate.)

Epicardial versus Endocardial Closure: Is One Better than the Other?

Left atrial appendage occlusion is an evolving technology with demonstrable benefits of stroke prophylaxis in patients with atrial fibrillation unsuitable for anticoagulation. This has resulted in the development of a plethora of transcatheter devices to achieve epicardial exclusion and endocardial occlusion. In this review, the authors summarize the differences in technique, target patient population, outcomes, and complication profiles of endocardial and epicardial techniques.

Current State of Surgical Left Atrial Appendage Exclusion: How and When

Left atrial appendage exclusion is efficacious for stroke prophylaxis in patients with atrial fibrillation. Surgical excision provides reliable left atrial appendage exclusion, whereas surgical occlusion does not. Specifically, 2-layer internal suture ligation has a high failure rate. Left atrial appendage exclusion concomitant to another cardiac surgical procedure is indicated in patients with atrial fibrillation but not in patients without baseline atrial fibrillation. Studies currently underway will further define the role of concomitant surgical left atrial appendage exclusion, especially for the population without baseline atrial fibrillation but at high risk of developing postoperative atrial fibrillation.

Region-specific parasympathetic nerve remodeling in the left atrium contributes to creation of a vulnerable substrate for atrial fibrillation

Atrial fibrillation (AF) is the most common heart rhythm disorder and a major cause of stroke. Unfortunately, current therapies for AF are suboptimal, largely because the molecular mechanisms underlying AF are poorly understood. Since the autonomic nervous system is thought to increase vulnerability to AF, we used a rapid atrial pacing (RAP) canine model to investigate the anatomic and electrophysiological characteristics of autonomic remodeling in different regions of the left atrium. RAP led to marked hypertrophy of parent nerve bundles in the posterior left atrium (PLA), resulting in a global increase in parasympathetic and sympathetic innervation throughout the left atrium. Parasympathetic fibers were more heterogeneously distributed in the PLA when compared with other left atrial regions; this led to greater fractionation and disorganization of AF electrograms in the PLA. Computational modeling revealed that heterogeneously distributed parasympathetic activity exacerbates sympathetic substrate for wave break and reentry. We further discovered that levels of nerve growth factor (NGF) were greatest in the left atrial appendage (LAA), where AF was most organized. Preferential NGF release by the LAA - likely a direct function of frequency and regularity of atrial stimulation - may have important implications for creation of a vulnerable AF substrate.

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.

Recent advances in cryoballoon ablation for atrial fibrillation

Introduction: Pulmonary vein isolation (PVI), by catheter ablation, represents the current treatment for drug-resistant atrial fibrillation (AF). Nowadays cryoballoon (CB) is a recognized ablation method in patients with atrial fibrillation, mainly due to its ease of use, leading to reproducible and fast procedures. This novel single shot technology literally revolutionized the approach to AF ablation. Areas covered: The historical development of the cryoballoon, ablation techniques and new approaches beyond the ordinary PVI and complications are summarized here. Expert opinion: Although cryoballoon ablation has greatly standardized the approach to PVI a few critical points still need to be clarified scientifically in order to further uniform this procedure in cath labs worldwide. Duration and dosage of the cryoapplication is undoubtedly a topic of great interest.

The Next 10 Years in Atrial Fibrillation

Predicting future advancements in arrhythmia management – specifically AF – with any certainty is impossible. The clinical approach to AF has changed markedly since the turn of the century in ways that could never have been foreseen, but the current methods of identification and treatment remain far from perfect. Over the next decade we expect significant continued progress in AF management. However, if asked to forecast the future, we consider it wise to predict advancements in the nearer term. We believe there will be widespread expansion in digital health and mobile devices, altering the way we detect and monitor the arrhythmia. We expect substantial growth in advanced MRI to aid in early detection, evaluation, and possibly non-invasive treatment of AF substrate. We imagine there will be increasing focus on individual populations to identify at-risk groups and personalize early management. We also anticipate improvement in anticoagulation employment and left atrial appendage modification. Finally, recognizing the benefit of improvement in modifiable risk factors such as mandatory tobacco cessation and weight loss in obese patients, we predict that reimbursement will be dependent on successfully addressing modifiable risk. For now, several questions remain unanswered, and while no one can predict the next 10 years in AF, there is, without doubt, an abundance of opportunity.

Atrial Fibrillation in Heart Failure: Left Atrial Appendage Management

Atrial fibrillation is common in patients with congestive heart failure (CHF). Due to reduced left atrial appendage (LAA) emptying velocities and increased sludge formation, a higher rate of stroke and embolism are seen with CHF. Up to 50% of CHF patients are inadequately covered for stroke protection with anticoagulation, and, even while on therapy, CHF patients are at risk for failure to clear LAA or left ventricular (LV) thrombus. Device-based LAA closure (LAAC) alternatives exist. Following intracardiac device closure, an increased rate of device-related thrombus is seen in heart failure patients, which warrants further study to optimize LAAC benefits.

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 isolation in atrial fibrillation catheter ablation: A meta-analysis

A significant proportion of patients' experience recurrence of atrial fibrillation (AF) despite pulmonary venous isolation (PVI), especially those with persistent AF. Isolation of the left atrial appendage (LAA) may reduce AF recurrence. The aim of this study was to assess the efficacy of LAA isolation in addition to PVI compared with PVI alone. We conducted a comprehensive search of electronic databases, up to April 21st, 2017, for all studies comparing the effect LAA electrical isolation or ligation in addition to PVI, as opposed to PVI alone, on the recurrence of atrial fibrillation after catheter ablation. We used random-effects meta-analysis models to summarize the studies. One RCT and four observational studies enrolling 781 patients were retained. Four studies assessed the added effect of LAA catheter ablation, and one study evaluated the effect of LAA ligation with the aim of LAA electrical isolation. Four studies exclusively enrolled patients with persistent atrial fibrillation and one study predominantly enrolled patients with persistent atrial fibrillation. Follow-up ranged from 12 to 15 months. The addition of LAA isolation to PVI reduced AF recurrence compared with the latter alone (odds ratio (OR) = 0.19; 95% confidence intervals (CI) = 0.10-0.37; P < 0.00001). Left atrial appendage isolation was also associated with a reduction in AF recurrence after repeat ablation (OR = 0.40; CI = 0.25-0.65; P = 0.0003). The addition of LAA isolation to PVI was associated with a decrease in AF recurrence in patients with persistent AF. Further studies are needed to assess the effect on long-term risk of stroke.

LARIAT Trial Updates

The thrombus formed within the LAA is responsible for the vast (about 90%) majority of strokes. Anticoagulation, although effective therapy for stroke prevention is not feasible in a significant minority of patients due to various reasons. Two percutaenous LAA exclusion techniques have been developed in an effort to decrease risk for stroke: endocardial closure/plugging of the LAA (Watchman, Amplatzer devices) and epicardial LAA ligation (LARIAT). The aim of this study is to review the trial data to date for the LARIAT device. The LARIAT suture has been used in more than 4500 patients with high success of LAA complete closure (92-100%), mostly in the patients unable to take anticoagulation and in a small minority as antiarrhythmic option. The LARIAT technique has evolved with a change in pericardial access method that resulted in dramatic improvement of safety. LAA closure performance with LARIAT system seems to be similar to Watchman device, with small leaks during follow-up in 6-24% of the cases, which do not to correlate with thrombo-embolic events. LAA has been proven to play an important triggering role in patients with persistent atrial fibrillation. Small studies had shown that LAA ligation with LARIAT could terminate persistent atrial fibrillation and possible improve ablation success. Ongoing aMAZE randomized trial is studying if LAA ligaiton using LARIAT suture leads to improved atrial fibrillation ablation success. Available data suggests that LAA closure using LARIAT epicardial suture is a good alternative for stroke risk reduction in patients who are unable to be on anticoagulation therapy. LARIAT system might improve success of AF ablation for patients with persistent and long persistent AF, pending the results of the ongoing aMAZE trial.

Mechanical function of the left atrium is improved with epicardial ligation of the left atrial appendage: Insights from the LAFIT-LARIAT Registry

BACKGROUND

Left atrial (LA) strain (ε) and ε rate (SR) analysis by 2-dimensional speckle tracking echocardiography is a novel method for functional assessment of the LA.

OBJECTIVE

The purpose of this study was to determine the impact of left atrial appendage (LAA) exclusion by Lariat epicardial ligation on mechanical function of the LA by performing ε and SR analysis before and after the procedure.

METHODS

A total of 66 patients who underwent successful LAA exclusion were included in the study. Of these 66 patients, 32 had adequate paired data for ε and SR analysis. SR during ventricular systole (LA-SRs) represents LA reservoir function, and SR during early ventricular diastole (LA-SRe) represents LA conduit function. ε and SR were determined from apical 4- and 2-chamber views using the electrocardiographic QRS as a reference point. LA volume index as surrogate for LA remodeling was measured from apical views.

RESULTS

Mean patient age was 70 ± 9.2 years. LAA ligation resulted in improved reservoir function (LA-SRs: pre 0.72, confidence interval [CI] 0.63-0.83 vs post 0.81, CI 0.73-0.98; P = .043) and conduit function (LA-SRe: pre 0.74, CI 0.67-0.99 vs post 0.89, CI 0.82-1.07; P = .025). LA volume index improved significantly with the Lariat (pre 35.4, CI 29.4-37.2 vs post 29.2, CI 28.2-35.9; P <.023).

CONCLUSION

LAA exclusion seems to improve mechanical function of the LA and results in reverse LA remodeling.

Left Atrial Appendage Closure Devices for Stroke Prevention in Patients with Non-Valvular AF

The left atrial appendage (LAA) may be involved in offloading atrial pressure during left ventricular systole. As ventricular rate increases, LAA emptying decreases during early diastole causing increased risk of thrombus formation particularly in patients with non-valvular AF (NVAF). The LAA is the site of thrombus formation in more than 90 % of patients with NVAF, so is an important target for thromboembolic prophylaxis in these patients. Anticoagulation therapy is used to treat NVAF, but it has long-term complications and may be contraindicated in some patients. Therefore, alternative strategies to reduce embolic risk in patients with AF have been developed. These include percutaneous, thoracoscopic, and open closure strategies. This study reviews the safety and efficacy of these strategies, comparing these approaches and devices with pharmacological strategies. There is little data to endorse one strategy over another. Given the minimal evidence available, recommendations in support of LAA occlusion remain weak and guidelines have called for more research and coding of endpoints for this emerging technology.

Ablation of long-standing persistent atrial fibrillation

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in the clinical setting affecting nearly 6 million people in United States and the numbers are only expected to rise as the population continues to age. Broadly it is classified into paroxysmal, persistent and longstanding persistent AF. Electrical, structural and autonomic remodeling are some of the diverse pathophysiological mechanisms that contribute to the persistence of AF. Our review article emphasizes particularly on long standing persistent atrial fibrillation (LSPAF) aspect of the disease which poses a great challenge for electrophysiologists. While pulmonary vein isolation (PVI) has been established as a successful ablation strategy for paroxysmal AF, same cannot be said for LSPAF owing to its long duration, complexity of mechanisms, multiple triggers and substrate sites that are responsible for its perpetuation. The article explains different approaches currently being adopted to achieve freedom from atrial arrhythmias. These mainly include ablation techniques chiefly targeting complex fractionated atrial electrograms (CFAE), rotors, linear lesions, scars and even considering hybrid approaches in a few cases while exploring the role of delayed enhancement magnetic resonance imaging (deMRI) in the pre-procedural planning to improve the overall short and long term outcomes of catheter ablation.

Left atrial appendage occlusion for stroke prevention in patients with atrial fibrillation

Atrial fibrillation (AF) is a commonly sustained atrial arrhythmia with associated morbidity and mortality. AF is associated with increased risk of thromboembolism and stroke, requiring use of anticoagulation. Anticoagulation decreases the risk of stroke but is associated with a higher risk of bleeding, necessitating discontinuation in some patients. The left atrial appendage is the likely source of thrombus in the majority of patients with AF. This has led to the development of left atrial appendage occlusion as a means to reduce stroke risk in patients who have a contraindication to long-term anticoagulation. Multiple implantable devices have surfaced in the last few years, with some promising prospects. The main purpose of this review is to highlight the indications and use of these devices for left atrial appendage occlusion.