The left atrial appendage: our most lethal human attachment! Surgical implications

A Comparative Study of Thoracoscopic Left Atrial Appendage Clipping vs Stapled Resection

BACKGROUND

The left atrial appendage (LAA) is the predominant site of thrombus formation in atrial fibrillation (AF), which is associated with ischemic stroke. This study comparatively evaluated the complete LAA closure rates between LAA clipping and stapled resections.

METHODS

The study included 333 patients who underwent thoracoscopic operation with both preoperative and postoperative computed tomographic scans. Propensity score matching (4:1 ratio) was applied, matching 90 LAA clipping patients with 206 stapled resection patients. The primary end point was complete LAA closure, defined as a residual LAA depth of <1 cm on computed tomographic images obtained 1 year postoperatively.

RESULTS

No 30-day death was observed. Complete LAA closure was achieved in 85.9% (286 of 333) of patients. After propensity score matching, the clipping group demonstrated a significantly higher complete LAA closure rate than the stapled resection group (95.6% vs 83.0%, P = .003). The residual LAA stump depth was also shorter in the clipping group compared with the stapled resection group (2.9 vs 5.3 mm, P = .001). Two patients with a residual LAA stump exhibited an association with ischemic stroke during follow-up.

CONCLUSIONS

The clipping group demonstrated a higher rate of complete LAA closure compared with the stapled resection group. Close monitoring of patients with residual LAA stumps is essential. Further research with larger cohorts is needed to elucidate impact of the residual LAA stump on thromboembolic events.

Left atrial appendage occlusion in an older population cohort

BACKGROUND

Atrial fibrillation is the most common cardiac arrhythmia and is a major risk factor for stroke, with an incidence rate of 4-5% per year. The use of DOACs is recommended for specific patient populations however the risk of bleeding commonly precludes their use. Left atrial appendage occlusion is a relatively novel procedure recommended for such patients. We set out to analyse the initial success and safety of this procedure in a single site.

RESULTS

Twenty patients were included in the study with an average age of 81 years. Seventy percent (n = 14) were male. Ninety percent (n = 18) had a history of major bleeding, an absolute contraindication to anticoagulation. The mean CHADS2VaSc and HASBLED scores were 4.75 and 3.7, respectively. The technical success rate was 95% comparable with existing data. The procedural success rate in our study was 80%. The most frequent complication was cardiac tamponade, occurring in 10% of cases.

CONCLUSION

We report lower technical success and procedural success rates in an older population cohort than historically studied, 90% of whom had an absolute contraindication to oral anticoagulation, with higher CHADS2VaSc and HASBLED scores than commonly studied.

Age-Based Trends in the Outcomes of Percutaneous Left Atrial Appendage Occlusion: Insights from a Real-World Database

The age-based trends in-hospital outcomes in patients with percutaneous left atrial appendage occlusion (LAAO) are unknown. Using the National Readmission Database from 2016 to 2019, patients who underwent LAAO were divided into 2 age groups: 60 to 79 and ≥80 years. The primary objective was to evaluate the age-based trends in the outcomes related to LAAO. The secondary objectives were to evaluate the mean cost and total cumulative cost of readmissions in both age groups in 2019. We identified 58,818 patients who underwent LAAO, of whom 36,964 (63%) were aged 60 to 79 years, and 21,854 (37%) were ≥80 years. The hospital mortality, pericardial complications, acute kidney injury, and in-hospital cardiac arrest did not change over time. The risk-adjusted postoperative stroke and bleeding requiring blood transfusion decreased in patients aged ≥80 years (p trend 0.03 for both outcomes). The length of stay decreased, and early discharge rates increased over time in both the unadjusted and risk-adjusted models in both age groups. The risk-adjusted 90-day readmission rates also decreased in patients aged ≥80 years. The inflation-adjusted cost did not change over time on the unadjusted and adjusted analyses. The total cumulative all-cause 90-readmission cost for both groups in 2019 was $31.7 million. Most outcomes after LAAO either improved or did not change from 2016 to 2019. Hospital mortality has remained <0.5% consistently since 2016. The risk-adjusted postoperative stroke, bleeding, and 90-day readmission rates improved in elderly vulnerable patients aged ≥80 years. The inflation-adjusted cost did not improve despite the decreasing length of stay and improving early discharge rates.

SCAI/HRS Expert Consensus Statement on Transcatheter Left Atrial Appendage Closure

Exclusion of the left atrial appendage to reduce thromboembolic risk related to atrial fibrillation was first performed surgically in 1949. Over the past 2 decades, the field of transcatheter endovascular left atrial appendage closure (LAAC) has rapidly expanded, with a myriad of devices approved or in clinical development. The number of LAAC procedures performed in the United States and worldwide has increased exponentially since the Food and Drug Administration approval of the WATCHMAN (Boston Scientific) device in 2015. The Society for Cardiovascular Angiography & Interventions (SCAI) has previously published statements in 2015 and 2016 providing societal overview of the technology and institutional and operator requirements for LAAC. Since then, results from several important clinical trials and registries have been published, technical expertise and clinical practice have matured over time, and the device and imaging technologies have evolved. Therefore, SCAI prioritized the development of an updated consensus statement to provide recommendations on contemporary, evidence-based best practices for transcatheter LAAC focusing on endovascular devices.

Left Atrial Thrombus-Are All Atria and Appendages Equal?

Although the left atrial appendage (LAA) seems useless, it has several critical functions that are not fully known yet, such as the causes for being the main origin of cardioembolic stroke. Difficulties arise due to the extreme range of LAA morphologic variability, making the definition of normality challenging and hampering the stratification of thrombotic risk. Furthermore, obtaining quantitative metrics of its anatomy and function from patient data is not straightforward. A multimodality imaging approach, using advanced computational tools for their analysis, allows a complete characterization of the LAA to individualize medical decisions related to left atrial thrombosis patients.

The Strengths and Weaknesses of Left Atrial Appendage Ligation or Exclusion (LARIAT, AtriaClip, Surgical Suture)

Left atrial appendage (LAA) epicardial exclusion has been associated with addressing 2 potential deleterious consequences attributed to the LAA, namely, thrombus formation and an arrhythmogenic contributor in advanced forms of atrial fibrillation. With more than 60 years of history, the surgical exclusion of the LAA has been firmly established. Numerous approaches have been used for surgical LAA exclusion including surgical resections, suture ligation, cutting and non-cutting staples, and surgical clips. Additionally, a percutaneous epicardial LAA ligation approach has been developed. A discussion of the various epicardial LAA exclusion approaches and their efficacy will be discussed, along with the salient beneficial affects on LAA thrombus formation, LAA electrical isolation and neuroendocrine homeostasis.

SCAI/HRS Expert Consensus Statement on Transcatheter Left Atrial Appendage Closure

Exclusion of the left atrial appendage to reduce thromboembolic risk related to atrial fibrillation was first performed surgically in 1949. Over the past 2 decades, the field of transcatheter endovascular left atrial appendage closure (LAAC) has rapidly expanded, with a myriad of devices approved or in clinical development. The number of LAAC procedures performed in the United States and worldwide has increased exponentially since the Food and Drug Administration approval of the WATCHMAN (Boston Scientific) device in 2015. The Society for Cardiovascular Angiography & Interventions (SCAI) has previously published statements in 2015 and 2016 providing societal overview of the technology and institutional and operator requirements for LAAC. Since then, results from several important clinical trials and registries have been published, technical expertise and clinical practice have matured over time, and the device and imaging technologies have evolved. Therefore, SCAI prioritized the development of an updated consensus statement to provide recommendations on contemporary, evidence-based best practices for transcatheter LAAC focusing on endovascular devices.

SCAI/HRS expert consensus statement on transcatheter left atrial appendage closure

Exclusion of the left atrial appendage to reduce thromboembolic risk related to atrial fibrillation was first performed surgically in 1949. Over the past 2 decades, the field of transcatheter endovascular left atrial appendage closure (LAAC) has rapidly expanded, with a myriad of devices approved or in clinical development. The number of LAAC procedures performed in the United States and worldwide has increased exponentially since the Food and Drug Administration approval of the WATCHMAN (Boston Scientific) device in 2015. The Society for Cardiovascular Angiography & Interventions (SCAI) has previously published statements in 2015 and 2016 providing societal overview of the technology and institutional and operator requirements for LAAC. Since then, results from several important clinical trials and registries have been published, technical expertise and clinical practice have matured over time, and the device and imaging technologies have evolved. Therefore, SCAI prioritized the development of an updated consensus statement to provide recommendations on contemporary, evidence-based best practices for transcatheter LAAC focusing on endovascular devices.

Nonthrombogenic Roles of the Left Atrial Appendage: JACC Review Topic of the Week

The atrial appendage (LAA) is a well-established source of cardioembolism in patients with atrial fibrillation. Therefore, research involving the LAA has largely focused on its thrombogenic attribute and the utility of its exclusion in stroke prevention. However, recent studies have highlighted several novel functions of the LAA that may have important therapeutic implications. In this paper, we provide a concise overview of the LAA anatomy and summarize the emerging data on its nonthrombogenic roles.

Impact of left atrial appendage morphology on thrombus formation in TAVI patients with atrial fibrillation

PURPOSE

We aimed to correlate left atrial appendage (LAA) morphology with thrombus formation in patients with severe aortic valve stenosis and atrial fibrillation.

METHODS

We analyzed LAA morphology and the prevalence of a thrombus in 231 patients with atrial fibrillation and severe aortic valve stenosis that were referred for pre-interventional CT scan before trans-catheter aortic valve implantation (TAVI) between 2016 and 2018. In addition, we documented neuro-embolic events depending on the presence of LAA thrombus within a follow-up of 18 months.

RESULTS

The overall distribution of different LAA morphologies was chicken-wing 25.5%, windsock 51.5%, cactus 15.6% and cauliflower 7.4%. Compared to chicken-wing morphology, patients with non-chicken-wing morphology showed a significantly higher thrombus rate (OR: 2.48, 95%; CI 1.05 to 5.86, p = 0.043). Within the 50 patients with a LAA thrombus, we observed chicken-wing (14.0%), windsock (62.0%), cactus (16.0%) and cauliflower (8.0%) configuration. In patients with LAA thrombus those with chicken-wing configuration have a higher risk (42.9%) to develop neuro-embolic events compared to non-chicken-wing configuration (20.9%).

CONCLUSION

We found a lower LAA thrombus rate in patients with chicken-wing morphology compared to patients with non-chicken-wing configuration. However, in the presence of thrombus, those patients with chicken-wing morphology showed a doubled risk for neuro-embolic events compared to patients with non-chicken-wing morphology. These results must be confirmed in larger trials but underline the importance of LAA evaluation in thoracic CT scans and could have an impact on the anticoagulation management.

Use of left atrial appendage as an autologous tissue source for epicardial micrograft transplantation during LVAD implantation

We report here the first clinical use of the left atrial appendage (LAA) for epicardial micrograft transplantation during left ventricular assist device (LVAD) implantation. Previously, a sample from the right atrial appendage (RAA) has been available for processing and administering micrograft therapy in cardiac surgery. Both LAA and RAA are rich sources of various types of myocardial cells and are capable of providing both paracrine and cellular support to the failing myocardium. The surgical approach of LAA micrografting facilitates epicardial micrograft therapy dose escalation and treatment of larger myocardial areas than done previously. Moreover, as collection of treated vs. untreated tissues from the recipient heart is possible following LVAD implantation at the time of heart transplantation, the evaluation of the therapy's mechanism of action can be further deciphered at cellular and molecular levels. This LAA modification of the epicardial micrografting technique has the overall potential to facilitate the adoption of cardiac cell therapy during heart surgery.

Left atrial appendage exclusion in atrial fibrillation

Although oral anticoagulants (OACs) are first-line therapy for stroke prevention in patients with atrial fibrillation (AF), some patients cannot be treated with OACs due to absolute or relative contraindications. Left atrial appendage (LAA) exclusion techniques have been developed over the years as a therapeutic alternative for stroke prevention. In this paper, we review the evolution of surgical techniques, employed as an adjunct to cardiac surgery or as a stand-alone procedure, as well as the recently introduced and widely utilized percutaneous LAA occlusion techniques. Until recently, data on surgical LAAO were limited and based on non-randomized studies. We focus on recently published randomized data which strongly support an add-on surgical LAAO in eligible patients during cardiac surgery and could potentially change current practice guidelines. In recent years, the trans-catheter techniques for LAA occlusion have emerged as another, less invasive alternative for patients who cannot tolerate oral anticoagulation. We review the growing body of evidence from prospective studies and registries, focusing on the two systems which are in widespread clinical use nowadays: the Watchman and Amulet type devices. These data show favorable results for both Watchman and Amulet devices, setting them as an important tool in our arsenal for stroke reduction in AF patients, especially in those who have contraindications for OACs. A better understanding of the different therapeutic alternatives, their specific benefits, and downfalls in different patient populations can guide us in tailoring the optimal therapeutic approach for stroke reduction in our AF patients.

A systematic review and meta-analysis of the impact of the left atrial appendage closure on left atrial function

Background

Left atrial (LA) appendage closure (LAAC) is effective in patients with atrial fibrillation who are not candidates for long‐term anticoagulation. However, the impact of LAAC on LA function is unknown. The aim of this study is to evaluate the impact of LAAC on atrial function.

Methods

This meta‐analysis was conducted according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. A search strategy was designed to utilize PubMed/Medline, EMBASE, and Google scholar for studies showing the effect of LAAC on the LA function from inception to November 20, 2021. The standardized mean difference (SMD) was calculated from the means and standard deviations.

Results

Of 247 studies initially identified, 8 studies comprising 260 patients were included in the final analysis. There was a significant increase in LA emptying fraction following LAAC compared with preoperative function (SMD: 0.53; 95% confidence interval [CI]: 0.04–1.01; p = .03; I² = 75%). In contrast, there were no significant differences in LA volume (SMD: −0.07; 95% CI: −0.82–0.69; p = .86; I² = 92%) peak atrial longitudinal strain (SMD: 0.50; 95% CI: −0.08–1.08; p = .09; I² = 89%), peak atrial contraction strain (SMD: 0.38; 95% CI: −0.22–0.99; p = .21; I² = 81%), strain during atrial contraction (SMD: −0.24; 95% CI: −0.61–0.13; p = .20; I² = 0%), strain during ventricular systole (SMD: 0.47; 95% CI: −0.32–1.27; p = .24; I² = 89%), strain during ventricular diastole (SMD: 0.09; 95% CI: −0.32–0.51; p = .66; I² = 65%).

Conclusion

LAAC is associated with improvement in the left atrial emptying fraction, but did not significantly influence other parameters.

The Strengths and Weaknesses of Left Atrial Appendage Ligation or Exclusion (LARIAT, AtriaClip, Surgical Suture)

Left atrial appendage (LAA) epicardial exclusion has been associated with addressing 2 potential deleterious consequences attributed to the LAA, namely, thrombus formation and an arrhythmogenic contributor in advanced forms of atrial fibrillation. With more than 60 years of history, the surgical exclusion of the LAA has been firmly established. Numerous approaches have been used for surgical LAA exclusion including surgical resections, suture ligation, cutting and non-cutting staples, and surgical clips. Additionally, a percutaneous epicardial LAA ligation approach has been developed. A discussion of the various epicardial LAA exclusion approaches and their efficacy will be discussed, along with the salient beneficial affects on LAA thrombus formation, LAA electrical isolation and neuroendocrine homeostasis.

Left Atrial Thrombus-Are All Atria and Appendages Equal?

Although the left atrial appendage (LAA) seems useless, it has several critical functions that are not fully known yet, such as the causes for being the main origin of cardioembolic stroke. Difficulties arise due to the extreme range of LAA morphologic variability, making the definition of normality challenging and hampering the stratification of thrombotic risk. Furthermore, obtaining quantitative metrics of its anatomy and function from patient data is not straightforward. A multimodality imaging approach, using advanced computational tools for their analysis, allows a complete characterization of the LAA to individualize medical decisions related to left atrial thrombosis patients.

Association Between Left Atrial Appendage Morphology and Function and the Risk of Ischaemic Stroke in Patients with Atrial Fibrillation

AF is the most common cardiac arrhythmia and has been identified as an independent risk factor for stroke. The European Society of Cardiology guidelines recommend a thromboembolic event risk assessment based on the CHA₂DS₂-VASc score. However, stroke also occurs in some patients with a low CHA₂DS₂-VASc score. Therefore, it is necessary to find new factors to improve thromboembolic risk stratification in AF patients. Over 90% of embolic strokes are caused by thrombi originating from the left atrial appendage (LAA). Thus, certain anatomical or functional parameters of the LAA could potentially be used to predict cardioembolic stroke. Studies have suggested that some of these factors, such as LAA morphology, number of LAA lobes, LAA dimensions, LAA volume, distance from the LAA ostium to the first bend of LAA, LAA orifice diameter, extent of LAA trabeculations, LAA takeoff, LAA flow velocity and LAA strain rate, are independently associated with a higher risk of stroke in a population of patients with AF and improve the performance of the CHA₂DS₂-VASc score. However, the results are conflicting and, so far, no new parameter has been added to the CHA₂DS₂-VASc score.

Routine left atrial appendage occlusion in patients undergoing cardiac surgery: a narrative review

PURPOSE OF REVIEW

New evidence suggests a greater prevalence of protracted postoperative atrial fibrillation (POAF) than previously recognized. The left atrial appendage (LAA) is the most common source of embolism in patients with nonvalvular atrial fibrillation. In this review, we ask whether there is evidence to support routine LAA occlusion (LAAO) in patients without preexisting atrial fibrillation undergoing cardiac surgery.

RECENT FINDINGS

Overall, available studies are small, inconsistent and have varying proportions of patients with and without preexisting atrial fibrillation. There is considerable discrepancy with respect to the efficacy of LAAO in reducing the risk of POAF-related stroke. Only one study reported a lower rate of stroke in the LAAO group compared with no LAAO. Two studies included a subgroup analysis of patients that developed POAF and report a significantly higher rate of stroke in patients that developed POAF and did not undergo LAAO. There are three clinical trials ongoing that are investigating prophylactic LAAO in patients undergoing cardiac surgery: ATLAS, LAA-CLOSURE and LAACS-2.

SUMMARY

There is currently insufficient evidence to recommend routine addition of LAAO to lower the risk of postoperative stroke. Ongoing clinical trials will provide important insight into the role of routine LAAO in all patients undergoing cardiac surgery.

Left atrial appendage (LAA) flow profile of its different waves and its correlation with direct left atrial pressure measurement: Can LAA flow profile be a surrogate to estimate left atrial pressure

Background:

Left Atril Appendage(LAA) is one of the most contractile structure of the heart. Elevated Left atrial pressure (LAP) can change the flow profile in and out of LAA. There is little data on the effect of LAP on LAA flow velocities for patients in sinus rhythm, and it's not properly known that by evaluation of LAA flow spectra and its velocities, the LAP can be predicted. We tried to find the relationship between LAA flow velocities and LAP, with the premise that LAA flow velocities can be used as a surrogate for measuring LAP, by obtaining a regression equation in this prospective observational study.

Methods:

In forty patients with normal systolic and diastolic heart function undergoing elective off pump coronary artery bypass (OPCAB) under general anaesthesia, TEE based LAA flow velocities were measured and simultaneous direct measurements of LAP was done by the surgeon. We also studied the relation between the ratio of early mitral inflow velocity (E) and mitral lateral annular early diastolic velocity (E'), that is, (E/E') in all patients.

Results:

We found significant correlation between E/E' and LAP (r = 0.424, p = 0.024) however there was no significant correlation between LAA flow velocities and LAP.

Conclusion:

LAA flow profile can not be used under anaesthesia to evaluate LAP however E/E' shows a strong correlation with directly measured LAP.

Surgery and Catheter Ablation for Atrial Fibrillation: History, Current Practice, and Future Directions

Atrial fibrillation (AF) is the most common of all cardiac arrhythmias, affecting roughly 1% of the general population in the Western world. The incidence of AF is predicted to double by 2050. Most patients with AF are treated with oral medications and only approximately 4% of AF patients are treated with interventional techniques, including catheter ablation and surgical ablation. The increasing prevalence and the morbidity/mortality associated with AF warrants a more aggressive approach to its treatment. It is the purpose of this invited editorial to describe the past, present, and anticipated future directions of the interventional therapy of AF, and to crystallize the problems that remain.

Left Atrial Appendage Occlusion for Stroke Prevention in Nonvalvular Atrial Fibrillation

The majority of embolic strokes in patients with nonvalvular atrial fibrillation are caused by thrombi in the left atrial appendage. It is projected that strokes related to atrial fibrillation will markedly increase in the future unless effective mitigation strategies are implemented. Systemic anticoagulation has been known to be highly effective in reducing stroke risk in patients with atrial fibrillation. However, bleeding complications and nonadherence are barriers to effective anticoagulation therapy. Surgical and percutaneous left atrial appendage occlusion devices are nonpharmacologic strategies to mitigate the challenges of drug therapy. We present a contemporary review of left atrial appendage occlusion for stroke prevention in nonvalvular atrial fibrillation. A thorough review of the history of surgical and percutaneous left atrial appendage occlusion devices, recent trials, and US Food and Drug Administration milestones of current left atrial appendage occlusion devices are discussed.

Role of left atrial appendage occlusion in patients with HeartMate 3

OBJECTIVES

Left atrial appendage occlusion (LAAO) at the time of implantation may reduce thromboembolic events (TEs) during continuous-flow left ventricular assist device support. The HeartMate 3 (HM3) reduces TEs overall, but the efficacy of LAAO in HM3 is unknown.

METHODS

Adults receiving first HM3 implantation from November 2014 through December 2019 at a single, large medical centre were retrospectively reviewed. TEs included device thrombosis and ischaemic stroke. Patients were classified by whether they received LAAO or not. Incidence of TEs was compared between groups using cumulative incidence curves with competing risks (death and heart transplant) and risk factors for TEs were assessed with Fine and Gray competing risk regression.

RESULTS

A total of 182 patients received HM3, of whom 99 (54%) received LAAO versus 83 (46%) who did not. There were 14 TEs, including 13 strokes (7%) and 1 pump thrombosis (0.5%). No significant difference in the incidence of TEs in each group was found (Gray's test: P = 0.35). LAAO was not associated with TEs in multivariable Fine-Gray analysis (P = 0.10) and no significant risk factors for TEs were found. There were zero disabling strokes in those who received LAAO compared to 6 (7%) in those who did not receive LAAO (P = 0.008).

CONCLUSIONS

A low number of TEs was observed in HM3 recipients. LAAO did not further reduce the overall rate of TEs in this patient population, though its use may be beneficial in preventing disabling ischaemic strokes after HM3 implantation.

Surgical clip closure of the left atrial appendage

Atrial fibrillation (AF) is the most common atrial arrhythmia, but it is not a benign disease. AF is an important risk factor for thromboembolic events, causing significant morbidity and mortality. The left atrial appendage (LAA) plays an important role in thrombus formation, but the ideal management of the LAA remains a topic of debate. The increasing popularity of surgical epicardial ablation and hybrid endoepicardial ablation approaches, especially in patients with a more advanced diseased substrate, has increased interest in epicardial LAA management. Minimally invasive treatment options for the LAA offer a unique opportunity to close the LAA with a clip device. This review highlights morphologic, electrophysiologic, and surgical aspects of the LAA with regard to AF surgery, and aims to illustrate the importance of surgical clip closure of the LAA.

Ischemic Stroke Risk Factors in Patients with Atrial Fibrillation Treated with New Oral Anticoagulants

The most commonly used therapeutic option for the prevention of ischemic stroke in patients with atrial fibrillation is new- or old-generation oral anticoagulants. New oral anticoagulants are at least as effective as old-generation oral anticoagulants in the prevention of ischemic stroke, with a reduced risk of life-threatening hemorrhage. Moreover, the constant monitoring of these drugs in the patient’s blood is not required during routine use. However, ischemic stroke can still occur in these patients. Therefore, the aim of this study was to investigate the pattern of risk factors for ischemic stroke in patients with atrial fibrillation treated with new oral anticoagulants. Our multicenter retrospective study involved 2032 patients with acute ischemic stroke. The experimental group consisted of 256 patients with acute ischemic stroke and nonvalvular atrial fibrillation, who were treated with new oral anticoagulants. The control group consisted of 1776 ischemic stroke patients without coexisting atrial fibrillation. The results of our study show that patients with atrial fibrillation treated with new oral anticoagulants are more likely to display thrombotic, proatherogenic, and proinflammatory factors in addition to the embolic factors associated with atrial fibrillation. Therefore, solely taking new oral anticoagulants is insufficient in protecting this group of patients from ischemic stroke.

Interventional Treatment for Stroke Prevention

Closure of the left atrial appendage using percutaneous transcatheter occlusion devices is used for stroke prevention as an alternative for patients with a high risk or contraindications for long-term oral anticoagulation use. Herein, we will discuss the practical aspects of five among the available devices used for interventional left atrial appendage occlusion: Watchman, Amulet, WaveCrest, LAmbre, and Lariat.

Effects of left atrial appendage surgical treatment on the incidence of ischemic cerebrovascular accidents in patients with atrial fibrillation undergoing cardiac surgery

BACKGROUND

We sought to assess different surgical methods for left atrial appendage treatment to determine whether any could reduce the incidence of atrial fibrillation-related long-term ischemic cerebrovascular accidents.

METHODS

A total of 1243 patients were treated with left atrial appendage removal, and 107 patients (8.6%) were lost to follow-up and excluded. The primary outcome was the long-term incidence of ischemic cerebrovascular events (ie, ischemic stroke, excluding transient ischemic attack) and all-cause mortality.

RESULTS

Of the 1136 patients, 37 (3.3%) had ischemic cerebrovascular events. The 1-year, 5-year, and 10-year freedoms from long-term ischemic cerebrovascular events of the left atrial appendage extracardiac ligation group were 99.7%, 94.0%, and 90.8%, respectively. The 1-year, 5-year, and 10-year survivals of the left atrial appendage intracardiac suture group were 99.7%, 94.6%, and 93.6%, respectively. There was a significant difference between the left atrial appendage extracardiac ligation group and the left atrial appendage excision group (P = .041). Seventeen patients (4.6%) had long-term ischemic cerebrovascular events in the left atrial appendage extracardiac ligation group (1.1% per year), 14 patients (3.5%) in the left atrial appendage intracardiac suture group (0.9% per year), and 6 patients (1.7%) in the left atrial appendage excision group (0.44% per year). Left atrial appendage excision can reduce the occurrence of long-term thrombotic stroke compared with left atrial appendage extracardiac ligation (95% confidence interval, 1.09-9.26; P = .035).

CONCLUSIONS

For patients with atrial fibrillation, the removal of the left atrial appendage can effectively prevent stroke caused by atrial fibrillation.

Considerations for Reduction of Risk of Perioperative Stroke in Adult Patients Undergoing Cardiac and Thoracic Aortic Operations: A Scientific Statement From the American Heart Association

Perioperative stroke is one of the most severe and feared complications of cardiac surgery. Based on the timing of onset and detection, perioperative stroke can be classified as intraoperative or postoperative. The pathogenesis of perioperative stroke is multifactorial, which makes prediction and prevention challenging. However, information on its incidence, mechanisms, diagnosis, and treatment can be helpful in minimizing the perioperative neurological risk for individual patients. We herein provide suggestions on preoperative, intraoperative, and postoperative strategies aimed at reducing the risk of perioperative stroke and at improving the outcomes of patients who experience a perioperative stroke.

A novel surgical technique of left atrial appendage closure

BACKGROUND AND AIMS

Surgical left atrial appendage occlusion or exclusion has been performed with various techniques, however, during the following years the left atrial appendage elimination often fails. We propose a novel, rapid surgery process of safely closing and obliterating the left atrial appendage by an intra-atrial sutureless closure.

METHODS

The left atrial appendage elimination is performed by invaginating the appendage into the left atrium and tying it on the interluminal base to permanently prevent its evagination back into the normal position.

RESULTS

In the current study we present two cases where this technique was performed with a satisfactory result. In both cases the postoperative course was uneventful, and at follow-up echocardiography the left atrial appendage was not visualized.

CONCLUSIONS

While we have shown that this technique is feasible, a longer follow-up and a larger series of patients is necessary before this method can be accepted in routine clinical practice.

Path to precision: prevention of post-operative atrial fibrillation

Development of post-operative atrial fibrillation (POAF) following open-heart surgery is a significant clinical and economic burden. Despite advancements in medical therapies, the incidence of POAF remains elevated at 25-40%. Early work focused on detecting arrhythmias from electrocardiograms as well as identifying pre-operative risk factors from medical records. However, further progress has been stagnant, and a deeper understanding of pathogenesis and significant influences is warranted. With the advent of more complex machine learning (ML) algorithms and high-throughput sequencing, we have an unprecedented ability to capture and predict POAF in real-time. Integration of multimodal heterogeneous data and application of ML can generate a paradigm shift for diagnosis and treatment. This will require a concerted effort to consolidate and streamline real-time data. Herein, we will review the current literature and emerging opportunities aimed at predictive targets and new insights into the mechanisms underlying long-term sequelae of POAF.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Structural heart intervention for prevention of embolic and hemorrhagic stroke: The new field of neurocardiology

Cardiogenic stroke (CS), characteristic causes of which include atrial fibrillation (AF) and right-to-left shunting due to a patent foramen ovale (PFO), has a well-known tendency to be associated with a more extensive ischemic area. This may result in severe neurological damage, and require strict life-long antithrombotic therapy. However, the fact that some patients have problems complying with the requirement for extended oral antithrombotic treatment has motivated the development of alternative approaches for stroke prevention. Heart structures such as the left atrial appendage (LAA) and PFO are potential targets for stroke prevention by way of device implantation. Several large prospective randomized clinical trials have demonstrated efficacy and safety of devices dedicated to this purpose. Percutaneous LAA occlusion for patients with non-valvular AF resulted in similar embolic event rates but significantly reduced bleeding events than did therapy with warfarin. Furthermore, PFO closure significantly reduced the frequency of recurrent embolic stroke relative to oral antithrombotic treatment. Current unsolved problems remaining in the application of these two strategies can be identified as the lack of standardized regimens for post-procedural antithrombotic therapy, ambiguity of determining the indications therefore, and the problem of device-related thrombus, which need to be investigated in depth in future. Cost-benefit analysis in comparison with standard medication is also required for each instance. A heart-brain multidisciplinary team approach, mandated to start such structural heart interventions, will become the future standard unit of personnel for stroke management, which promises to usher in the new field of neurocardiology.

[Left atrial appendage closure for stroke prevention in atrial fibrillation : An update]

Atrial fibrillation (AF) is one of the most frequent causes of ischemic stroke. Without treatment the annual risk of ischemic stroke is on average approximately 5-6%/year in patients with atrial fibrillation, depending on the overall cardiovascular risk profile. Oral anticoagulation with new oral anticoagulants (NOAC) or vitamin K antagonists (VKA) is recommended for patients with AF and an elevated risk for stroke (CHA₂DS₂-VASc score ≥1); however, severe bleeding complications are potential reasons for discontinuation of this treatment. Overall, up to 30 % of the patients with AF remain without effective thromboembolism prophylaxis. Left atrial appendage (LAA) closure represents an alternative to pharmaceutical stroke prevention. Catheter-based and surgical LAA closure techniques are available. For catheter-based procedures with closure systems, high implantation success rates and relatively low periprocedural complication rates have been observed in recent registry studies. The reason for the restrained recommendation in the European guidelines is the as yet limited experience from large randomized studies.

Closure of the left atrial appendage using percutaneous transcatheter occlusion devices

Closure of the left atrial appendage (LAA) using percutaneous transcatheter occlusion devices is used for stroke prevention as an alternative for patients with a high risk and contraindications for long-term oral anticoagulation use. In this manuscript, we will discuss the practical aspects of four among the available devices that provide percutaneous intravascular closure of the LAA: Watchman, Amulet, WaveCrest, and LAmbre.

Pericardial patch closure of left atrial appendage orifice

Seven patients underwent pericardial patch closure of the left atrial appendage orifice in our clinic. Usually 5-to-7 U-sutures with 4-0 prolene were placed to the left atrial appendage orifice. These sutures were stretched out to measure exact sizes of the left atrial appendage orifice. Then, U-sutures were passed through the pericardial patch which was treated with glutaraldehyde. Pericardium was placed over the left atrial appendage orifice through the left atrium and stay sutures were tied. The upper suture was continuously sutured along the border of the orifice clockwise and tied to the lower suture. The lower suture was continuously sutured in a counter-clockwise direction and tied to the upper suture. Then, mitral valve surgery (repair or replacement) was performed.

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.

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.

Concomitant Left Atrial Appendage Closure Outcomes and Cost: A Multi-institutional Cohort Analysis

BACKGROUND

Left atrial appendage closure (LAAC) is frequently performed during cardiac operations, but the impact of LAAC on patient outcomes is not fully known. We hypothesized that the addition of LAAC would increase morbidity and resource utilization.

METHODS

All patients undergoing cardiac surgery from a multi-institutional Society of Thoracic Surgeons database from 2011 to 2016 were stratified by LAAC. The effect of LAAC on risk-adjusted outcomes was assessed by hierarchical regression modeling accounting for preoperative risk factors, planned surgical procedure, hospital, and year.

RESULTS

Concomitant LAAC was performed on 2384 of 28,311 patients (9.3%), who were older, with a greater burden of preoperative atrial fibrillation and heart failure. Although the addition of LAAC increased the risk of new-onset postoperative atrial fibrillation (OR 1.69, P < 0.01), it did not increase rates of major morbidity (OR 1.00, P = 0.970), stroke (OR 0.92, P = 0.787), or mortality (OR 0.93, P = 0.684). Although cardiopulmonary bypass time was not significantly increased by LAAC, patients' total hospitalization costs were $3035 higher (P = 0.018).

CONCLUSIONS

Although concomitant LAAC was not associated with major complications, there were higher risk-adjusted rates of new-onset postoperative atrial fibrillation. Furthermore, LAAC added approximately $3000 to a patient's total hospital cost. These short-term risks and costs should be weighed against potential long-term benefits of left atrial appendage closure.

Useful indices of thrombogenesis in the exclusion of intra-cardiac thrombus

Background

Cardioversion in patients with atrial fibrillation (AF) can cause cardioembolic stroke, and effective clinical management is necessary to reduce morbidity and mortality. Currently, transesophageal echocardiography (TEE) is the accepted standard to diagnose cardiogenic thromboemboli; however, a negative TEE does not eliminate the possibility of left atrial thrombus. The objective of this study was to evaluate the diagnostic value of supplementing the TEE with additional noninvasive markers to ensure thrombus absence.

Methods

A prospective study was conducted on 59 patients who underwent TEE for suspected intra‐cardiac thrombi. The TEE indications included acute ischemic stroke (45.7%) and AF or flutter (59.3%). D‐dimer level and white blood cell counts were assessed.

Results

A negative D‐dimer level (<200 ng/mL) excluded the presence of intra‐cardiac thrombi. Groups with either negative (n = 14) or positive (n = 45) D‐dimer levels had comparable clinical characteristics. Comparing positive D‐dimer–level patients with thrombus (n = 7) and without thrombus (n = 33), patients with thrombus had reduced left atrial appendage (LAA) velocity (P = .0024), reduced left ventricular ejection fraction (LVEF) (P = .0263), increased neutrophil percent (P = .0261), decreased lymphocyte percent (P = .0216), and increased monocyte counts (P = .0220). The area under the receiver operating characteristic (ROC) curve for thrombus diagnostics was larger for combinations of clinical and biochemical data than for each parameter individually.

Conclusions

Supplementing the gold standard TEE with the analysis of LAA velocity, noninvasive LVEF, D‐dimer, and hemostatic markers provided additional useful diagnostic information. Larger studies are needed to further validate the efficacy of supplementing the TEE to better assess patients for intra‐cardiac thrombi.

Left Atrial Occlusion Device Implantation: the Role of the Echocardiographer

PURPOSE OF REVIEW

Atrial fibrillation is the most common arrhythmia worldwide and is a major risk factor for embolic stroke. For patients with atrial fibrillation who are unable to tolerate systemic anticoagulation, left atrial appendage (LAA) occlusion has been shown to mitigate stroke risk. In this article, we describe the vital role of the echocardiographer in intraprocedural guidance of percutaneous LAA occlusion procedures as well as in the pre- and post-procedure assessment of these patients.

RECENT FINDINGS

A few percutaneously delivered devices for LAA exclusion from the systemic circulation are available in contemporary practice. These devices employ an either exclusive endocardial LAA occlusion approach, such as the Watchman (Boston Scientific, Maple Grove, MN) and Amulet (St. Jude Medical, Minneapolis, MN), or both an endocardial and pericardial (epicardial) approach such as the Lariat procedure (SentreHEART, Palo Alto, CA). Two- and three-dimension transesophageal echocardiography is critical for patient selection, procedure planning, procedural guidance, and ensuring satisfactory immediate as well as long-term LAA occlusion/exclusion efficacy. This review will provide an overview of the role of the echocardiographer in all aspects of LAA occlusion/exclusion procedures for the most commonly used commercially available devices in current practice.

Left Atrial Appendage Epicardial Clip (AtriClip): Essentials and Post-Procedure Management

Left atrial appendage exclusion is a viable alternative to anticoagulation for stroke risk reduction in atrial fibrillation patients. In this article we address the essentials and post-procedural management of left atrial appendage exclusion using the AtriClip.