Anatomy of the normal left atrial appendage: a quantitative study of age-related changes in 500 autopsy hearts: implications for echocardiographic examination

Left Atrial Appendage Closure: Therapy Overview and Future Perspective

The left atrial appendage (LAA) has gained increasing attention in the field of cardiology as a potential site for intervention in patients with atrial fibrillation (AF) and an elevated risk of thromboembolic events. Left atrial appendage occlusion (LAAO) has emerged as a promising therapeutic strategy to mitigate the risk of stroke and systemic embolism, especially in individuals who are unsuitable candidates for long-term anticoagulation therapy. This review aims to provide a comprehensive analysis of the current state of LAAO, encompassing its anatomic considerations, procedural techniques, clinical outcomes, and future directions.

Morphological and functional assessment of the left atrial appendage in daily practice: a comprehensive approach using basic and advanced echocardiography with practical tips

Cardioembolic stroke is the most serious and life-threatening complication of atrial fibrillation (AF), with an associated mortality up to 30% at 12 months. Approximately 47% of thrombi in valvular AF and 91% of thrombi in nonvalvular AF are localized in the left atrial appendage (LAA). Therefore, identification or exclusion of LAA thrombi is critical in many clinical situations. It is essential to assess LAA morphology and function using imaging modalities (particularly echocardiography) before, during, and after interventional procedures such as AF ablation and LAA occlusion. This review article describes the anatomical, physiological, and pathological background of the LAA, followed by an assessment of different echocardiographic modalities. Many practical points are included to improve the diagnostic accuracy and to minimize errors during image acquisition and interpretation. In each clinical scenario where LAA is the crucial target, specific and essential information and parameters are collected.

Association of Left Atrial Appendage Morphology and Function With Stroke and Transient Ischemic Attack in Atrial Fibrillation Patients

We aimed to correlate left atrial appendage (LAA) structure and function with the history of stroke/transient ischemic attack (TIA) in patients with atrial fibrillation (AF). We analyzed the data of 649 patients with AF who were scheduled for catheter ablation. Patients underwent cardiac computed tomography and transesophageal echocardiography before ablation. The LAA morphologies depicted by cardiac computed tomography were categorized into 4 groups: cauliflower, chicken wing, swan, and windsock shapes. The mean age was 61.3 ± 10.5 years, 33.9% were women. The prevalence of stroke/TIA was 7.1%. After adjustment for the main risk factors, the LAA flow velocity ≤35.3 cm/s (odds ratio [OR] 2.18, 95% confidence interval [CI] 1.09 to 4.61, p = 0.033) and the swan LAA shape (OR 2.69, 95% CI 0.96 to 6.86, p = 0.047) independently associated with a higher risk of stroke/TIA, whereas the windsock LAA morphology proved to be protective (OR 0.32, 95% CI 0.12 to 0.77, p = 0.017) compared with the cauliflower LAA shape. Comparing the differences between the LAA morphology groups, we measured a significantly smaller LAA orifice area (389.3 ± 137.7 mm2 in windsock vs 428.3 ± 158.9 ml in cauliflower, p = 0.021) and LAA volume (7.4 ± 3.0 mm2 in windsock vs 8.5 ± 4.8 mm2 in cauliflower, p = 0.012) in patients with windsock LAA morphology, whereas the LAA flow velocity did not differ significantly. Reduced LAA function and swan LAA morphology were independently associated with a higher prevalence of stroke/TIA, whereas the windsock LAA shape proved to be protective. Comparing the differences between the various LAA morphology types, significantly lower LAA volume and LAA orifice area were measured in the windsock LAA shape than in the cauliflower LAA shape.

Feasibility of Amulet occluder implantation after failed left atrial appendage occlusion attempt: Insights from the EMERGE LAA postapproval study

BACKGROUND

Although expertise in left atrial appendage occlusion (LAAO) has grown, certain intricate anatomies may pose challenges, rendering them unsuitable for LAAO with the selected device.

OBJECTIVE

This analysis aimed to characterize outcomes of patients with prior failed percutaneous LAAO procedures who underwent a subsequent attempt with an Amulet occluder in the EMERGE LAA postapproval study.

METHODS

Patients enrolled in the National Cardiovascular Data Registry LAAO Registry who had an Amulet occluder implantation attempt between Food and Drug Administration approval (August 14, 2021) and June 30, 2023, were evaluated. A safety end point through 7 days or hospital discharge (whichever was later) and major adverse events through 45 days were reported.

RESULTS

A total of 8591 patients underwent attempted Amulet occluder implantation, of whom 244 patients had prior failed LAAO. Implantation success was 88.9% and 96.2% in patients with prior failed LAAO and index LAAO, respectively (P < .001). The safety composite end point was low, occurring in 1.6% and 0.8% of patients with prior failed LAAO and index LAAO, respectively (P = .148). Any major adverse event through 45 days occurred in 7.4% and 6.3% of prior failed LAAO and index LAAO patient cohorts, respectively (P = .497); most adverse events were similar between the groups (P > .05). At 45 days, peridevice leak ≤3 mm was achieved in >90% of patients in either group.

CONCLUSION

A high degree of implantation success with a low rate of adverse events can be achieved with the Amulet occluder. The findings imply that the dual occlusive mechanism Amulet occluder facilitates successful closure, even in challenging anatomic scenarios.

Personalized pulmonary vein isolation with very high-power short-duration lesions guided by left atrial wall thickness: the QDOT-by-LAWT randomized trial

AIMS

Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) using very high-power short-duration (vHPSD) radiofrequency (RF) ablation proved to be safe and effective. However, vHPSD applications result in shallower lesions that might not be always transmural. Multidetector computed tomography-derived left atrial wall thickness (LAWT) maps could enable a thickness-guided switching from vHPSD to the standard-power ablation mode. The aim of this randomized trial was to compare the safety, the efficacy, and the efficiency of a LAWT-guided vHPSD PVI approach with those of the CLOSE protocol for PAF ablation (NCT04298177).

METHODS AND RESULTS

Consecutive patients referred for first-time PAF ablation were randomized on a 1:1 basis. In the QDOT-by-LAWT arm, for LAWT ≤2.5 mm, vHPSD ablation was performed; for points with LAWT > 2.5 mm, standard-power RF ablation titrating ablation index (AI) according to the local LAWT was performed. In the CLOSE arm, LAWT information was not available to the operator; ablation was performed according to the CLOSE study settings: AI ≥400 at the posterior wall and ≥550 at the anterior wall. A total of 162 patients were included. In the QDOT-by-LAWT group, a significant reduction in procedure time (40 vs. 70 min; P < 0.001) and RF time (6.6 vs. 25.7 min; P < 0.001) was observed. No difference was observed between the groups regarding complication rate (P = 0.99) and first-pass isolation (P = 0.99). At 12-month follow-up, no significant differences occurred in atrial arrhythmia-free survival between groups (P = 0.88).

CONCLUSION

LAWT-guided PVI combining vHPSD and standard-power ablation is not inferior to the CLOSE protocol in terms of 1-year atrial arrhythmia-free survival and demonstrated a reduction in procedural and RF times.

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

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

Postoperative Coagulation Changes in Patients after Epicardial Left Atrial Appendage Occlusion Varies Based on the Left Atrial Appendage Size

Left atrial appendage occlusion affects systemic coagulation parameters, leading to additional patient-related benefits. The aim of this study was to investigate the differences in coagulation factor changes 6 months after epicardial left atrial appendage occlusion in patients with different LAA morphometries. This is the first study to analyze these relationships in detail. A prospective study of 22 consecutive patients was performed. Plasminogen, fibrinogen, tPA concentration, PAI-1, TAFI and computed tomography angiograms were performed. Patients were divided into subgroups based on left atrial appendage body and orifice diameter enlargement. The results of blood tests at baseline and six-month follow-up were compared. In a population with normal LAA body size and normal orifice diameter size, a significant decrease in analyzed clotting factors was observed between baseline and follow-up for all parameters except plasminogen. A significant decrease between baseline and follow-up was observed with enlarged LAA body size in all parameters except TAFI, in which it was insignificant and plasminogen, in which a significant increase was observed. Occlusion of the left atrial appendage is beneficial for systemic coagulation. Patients with a small LAA may benefit more from LAA closure in terms of stabilizing their coagulation factors associated with potential thromboembolic events in the future.

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.

The Left Atrial Appendage and Atrial Fibrillation-A Contemporary Review

In patients with atrial fibrillation, the left atrial appendage may serve as the site of thrombus formation due to stasis that occurs within the appendage because of its shape and trabeculations. Although thrombus formation can be reduced by using anticoagulants, this may be contraindicated in some patients. The need for a better alternative treatment prompted the study of left atrial appendage occlusion for thromboembolism prophylaxis. Due to this, procedures that excise or occlude the left atrial appendage have gained attention because of their ability to prevent thromboembolic events. This article provides a comprehensive review of the left atrial appendage and its associated procedures' clinical utility.

How the trabeculae protrude within the left atrial appendage is the key factor affecting thrombosis in patients with atrial fibrillation

The left atrial appendage (LAA) is a major site of thrombosis in patients with non-valvular atrial fibrillation. The myocardial trabeculae within the LAA have a peculiar tendency to protrude but its relationship to thrombosis remains unknown. This study aimed to investigate the relationship between the condition of trabeculae protrusion and LAA thrombosis. This retrospective study consecutively selected patients diagnosed with non-valvular atrial fibrillation and prepared for radiofrequency ablation from January 2011 to May 2020. Patients were divided into the thrombus group (n = 43), the sludge group (n = 35), and the normal group (n = 407) according to whether the thrombus or sludge was present. The trabeculae protruding angle (TPA), which was measured by the CT scans, was used to quantify the trabeculae protrusion condition. Patients' clinical data, TPA, LAA emptying velocity, and other factors were collected and compared among the three groups. A total of 485 patients were enrolled. The range of TPA was between 0 and 158 degrees, with an average of 89.3 ± 35.6 degrees. The TPA was significantly greater in the thrombus (109.3 ± 14.8 degrees) and sludge groups (110.8 ± 12.8 degrees) than in the normal group (85.3 ± 37.1). The incidence of LAA thrombus and sludge increased with increasing TPA. Multivariate regression analysis showed that the TPA was an independent risk factor for LAA thrombus (OR = 1.046, 95%CI: 1.020-1.073, p < 0.001) and sludge (OR = 1.035, 95%CI: 1.017-1.053, p < 0.001). Further analysis revealed that the TPA was negatively correlated with LAA emptying velocity but its effect on promoting thrombosis was not only mediated by slowing down the flow velocity. The TPA can well reflect the condition of trabeculae protrusion. This study revealed that the TPA was an independent risk factor for LAA thrombus or sludge, providing a potential indicator for future thrombosis risk assessment.

Efficacy of 3D-multidetector computed tomography and fluoroscopy fusion for percutaneous left atrial appendage occlusion procedures

INTRODUCTION

We studied the impact of the use of three-dimensional multidetector computed tomography (3D-MDCT) and fluoroscopy fusion on percutaneous left atrial appendage occlusion (LAAO) procedures in relation to procedure time, contrast volume, fluoroscopy time, and total radiation.

METHODS

This was a single-center, prospective, single-blinded, randomized control trial. Patients meeting criteria for LAAO were randomized to undergo LAAO with the WATCHMAN FLXTM device with and without 3D-MDCT-fluoroscopy fusion guidance using a prespecified protocol using computed tomography angiography for WATCHMAN FLXTM sizing, moderate sedation, and intracardiac echocardiography for procedural guidance.

RESULTS

Overall, 59 participants were randomly assigned to the fusion (n = 33) or no fusion (n = 26) groups. The median (interquartile range) age was 79 (75-83) years, 24 (41%) were female, and 55 (93%) were Caucasian. The median CHA2 DS2 VASc and HASBLED scores were 5 (4-6) and 3 (3-4), respectively. At the time of the study, 51 (53%) patients were on a direct acting oral anticoagulant. There were no significant differences between the fusion and no fusion groups in procedure time (52.4 ± 15.4 vs. 56.8 ± 19.5 min, p = .36), mean contrast volume used (33.8 ± 12.0 vs. 29.6 ± 11.5 mls, p = .19), mean fluoroscopy time (31.3 ± 9.9 vs. 28.9 ± 8.7 min, p = .32), mean radiation dose (1177 ± 969 vs. 1091 ± 692 mGy, p = .70), and radiation dose product curve (23.9 ± 20.5 vs. 35.0 ± 49.1 Gy cm2 , p = .29). There was no periprosthetic leak in the two groups in the immediate 1-month postprocedure follow-up periods.

CONCLUSIONS

There was no significant difference with and without 3D-MDCT-fluoroscopy fusion in procedure time, contrast volume use, radiation dose, and radiation dose product.

A highly-detailed anatomical study of left atrial auricle as revealed by in-vivo computed tomography

The left atrial auricle (LAA) is the main source of intracardiac thrombi, which contribute significantly to the total number of stroke cases. It is also considered a major site of origin for atrial fibrillation in patients undergoing ablation procedures. The LAA is known to have a high degree of morphological variability, with shape and structure identified as important contributors to thrombus formation. A detailed understanding of LAA form, dimension, and function is crucial for radiologists, cardiologists, and cardiac surgeons. This review describes the normal anatomy of the LAA as visualized through multiple imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and echocardiography. Special emphasis is devoted to a discussion on how the morphological characteristics of the LAA are closely related to the likelihood of developing LAA thrombi, including insights into LAA embryology.

Percutaneous Left Atrial Appendage Occlusion: What the Practising Physician Should Know

Non-valvular AF is a common clinical condition associated with an increased risk of thromboembolic complications. As a consequence, oral anticoagulant therapy (OAT) is the cornerstone of non-valvular AF management. Despite the well-established efficacy of OAT, many patients cannot receive this preventive therapy due to bleeding or a high risk of bleeding. The fact that more than 90% of thrombi are formed in the left atrial appendage has led to the development of alternative methods to reduce the embolic risk. Left atrial appendage occlusion (LAAO) is a non-pharmacological option for preventing cardioembolic events in patients with non-valvular AF with a contraindication to OAT. The demand for LAAO procedures is growing exponentially and clinicians should consider this alternative option when managing patients with a contraindication to OAT. This review summarises the current thinking about LAAO.

Double left atrial appendage: A diagnostic dilemma

We report a unique intraoperative finding of an additional double left atrial appendage (LAA) during an arterial switch operation with ventricular septal defect closure in a 4-month-old girl. Immediately after the procedure, a prolapsing mass within the left atrium (LA) on the transesophageal echocardiogram raised concerns of a possible thrombus. The LAA was clearly visible with a pressure monitoring line which was put intraoperatively. To investigate further, cardiopulmonary bypass was resumed, and the heart was arrested and explored. There was an appendage-like structure, separate from the one that had the pressure monitoring line, which was inverted inside. It was pulled out from outside clearly establishing a double LAA. This report illustrates an example of a diagnostic dilemma caused by a double atrial appendage which was invaginated into LA masquerading as a mass or thrombus.

Sex-related differences in outcome after left atrial appendage occlusion: Insights from Europe and the EWOLUTION registry

BACKGROUND

Women with atrial fibrillation (AF) generally experience worse symptoms, poorer quality of life, and have a higher risk of stroke and death. There is limited availability of sex-related differences regarding left atrial appendage occlusion (LAAO).

AIMS

The aim of this study was to evaluate the sex-related differences in patients undergoing LAAO in EWOLUTION.

METHODS

A total of 1025 patients scheduled for elective LAAO therapy employing the WATCHMAN Gen 2.5 prospectively consented for participation; 1005 patients received a successful implant and were followed for 2 years. As we detected sex-related differences in baseline data we performed a propensity score matching. The primary endpoint is a combined endpoint of survival free from mortality, major bleeding, ischemic stroke, transitory ischemic attack (TIA) and systemic embolization (SE) up to 2-year clinical follow-up. Secondary Endpoints were periprocedural data and overall 2-year survival.

RESULTS

Women were older but had less often vascular disease and hemorrhagic stroke. There was no sex-related significant difference after LAAO at 2 years in the combined endpoint of survival free from mortality, major bleeding, ischemic stroke, TIA, and SE (female vs. male: 79% vs.76%, p = 0.24) or in overall survival (female vs. male: 85% vs. 82%, p = 0.16). Procedural data showed a higher sealing rate after the implantation in women (complete sealing female 94% vs. male 90%, p = 0.033), significantly more pericardial effusions (female 1.2% vs. male 0.2%, p = 0.031) and a similar periprocedural risk profile.

CONCLUSIONS

Females undergoing LAAO differ in various baseline variables, but after adjustment, we observed similar safety and efficacy of LAAO with no significant difference in long-term outcomes between women and men.

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.

Evaluation of causal heart diseases in cardioembolic stroke by cardiac computed tomography

Cardioembolic stroke is a potentially devastating condition and tends to have a poor prognosis compared with other ischemic stroke subtypes. Therefore, it is important for proper therapeutic management to identify a cardiac source of embolism in stroke patients. Cardiac computed tomography (CCT) can detect the detailed visualization of various cardiac pathologies in the cardiac chambers, interatrial and interventricular septum, valves, and myocardium with few motion artifacts and few dead angles. Multiphase reconstruction images of the entire cardiac cycle make it possible to demonstrate cardiac structures in a dynamic manner. Consequently, CCT has the ability to provide high-quality information about causal heart disease in cardioembolic stroke. In addition, CCT can simultaneously evaluate obstructive coronary artery disease, which may be helpful in surgical planning in patients who need urgent surgery, such as cardiac tumors or infective endocarditis. This review will introduce the potential clinical applications of CCT in an ischemic stroke population, with a focus on diagnosing cardioembolic sources using CCT.

Left atrial appendage occlusion

Prevention of stroke represents a goal of primary importance in health systems due to its associated morbidity and mortality. As several patient groups with increased stroke rates have been identified, multiple approaches have been developed and implemented: oral anticoagulation (OAC) for patients with atrial fibrillation, surgical and percutaneous revascularisation in patients with carotid disease, device closure for patients with patent foramen ovale, and now, left atrial appendage occlusion (LAAO) for selected patients with non-valvular atrial fibrillation (NVAF). The latter group of patients are the focus of this review which evaluates the pathophysiology, selection of patients, procedural performance, outcomes of treatment both during and post-procedure, adjunctive therapy, complications, and longer-term outcomes.

Preprocedural Multimodality Imaging in Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide and is associated with increased risk of heart failure, stroke, and death. In current medical practice, multimodality imaging is routinely used in the management of AF. Twenty-one years ago, the ACUTE trial (Assessment of Cardioversion Using Transesophageal Echocardiography) results were published, and the management of AF changed forever by incorporating transesophageal echocardiography guided cardioversion of patients in AF for the first time. Current applications of multimodality imaging in AF in 2022 include the use of transesophageal echocardiography and computed tomography before cardioversion to exclude left atrial thrombus and in left atrial appendage occlusion device implantation. Transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance are clinically used for AF ablation planning. The decision to use a particular imaging modality in AF is based on patient's characteristics, guideline recommendation, institutional preferences, expertise, and cost. In this first of 2-part review series, we discuss the preprocedural role of echocardiography, computed tomography, and cardiac magnetic resonance in the AF, with regard to their clinical applications, relevant outcomes data and unmet needs, and highlights future directions in this rapidly evolving field.

Left Atrial Appendage Occlusion: Current Stroke Prevention Strategies and a Shift Toward Data-Driven, Patient-Specific Approaches

The left atrial appendage (LAA) is a complex structure with unknown physiologic function protruding from the main body of the left atrium. In patients with atrial fibrillation, the left atrium does not contract effectively. Insufficient atrial and LAA contractility predisposes the LAA morphology to hemostasis and thrombus formation, leading to an increased risk of cardioembolic events. Oral anticoagulation therapies are the mainstay of stroke prevention options for patients; however, not all patients are candidates for long-term oral anticoagulation. Percutaneous occlusion devices are an attractive alternative to long-term anticoagulation therapy, although they are not without limitations, such as peri-implant leakage and device-related thrombosis. Although efforts have been made to reduce these risks, significant interpatient heterogeneity inevitably yields some degree of device-anatomy mismatch that is difficult to resolve using current devices and can ultimately lead to insufficient occlusion and poor patient outcomes. In this state-of-the-art review, we evaluated the anatomy of the LAA as well as the current pathophysiologic understanding and stroke prevention strategies used in the management of the risk of stroke associated with atrial fibrillation. We highlighted recent advances in computed tomography imaging, preprocedural planning, computational modeling, and novel additive manufacturing techniques, which represent the tools needed for a paradigm shift toward patient-centric LAA occlusion. Together, we envisage that these techniques will facilitate a pipeline from the imaging of patient anatomy to patient-specific computational and bench-top models that enable customized, data-driven approaches for LAA occlusion that are engineered specifically to meet each patient's unique needs.

Occluding morphologically complicated left atrial appendage using the small-umbrella LAmbre device

BACKGROUND

Percutaneous left atrial appendage (LAA) occlusion is effective for stroke prevention in patients with atrial fibrillation. LAA can have a complex anatomy, such as multiple lobes or a large orifice, which may render it unsuitable for occlusion using regular devices. We aimed to investigate the feasibility, safety, and short-term efficacy of the small-umbrella LAmbre device for morphologically complicated LAA.

METHODS

We retrospectively enrolled 129 consecutive patients who underwent LAA occlusion using the LAmbre device; the small-umbrella LAmbre device was used in 30 of these patients. We analyzed patients' characteristics, procedural details, and outcomes.

RESULTS

Twenty-two patients (73.3%) had multilobed (≥ 2) LAA. The umbrella of the occluder was anchored in the branch in 9 patients and in the common trunks of branches in 13 patients. The landing zone and orifice diameters were 19.0 ± 4.39 mm and 27.4 ± 3.95 mm, respectively. The sizes of the umbrella and occluder cover were 22.0 ± 3.42 mm and 34.3 ± 2.75 mm, respectively. At 3-month follow-up transesophageal echocardiography in 24 patients, no peri-device residual flow was reported. Device thrombosis was detected in one patient at 3 months and disappeared after 3 months of anticoagulation. Ischemic stroke occurred in one patient; no other adverse events were reported.

CONCLUSIONS

Occlusion of morphologically complicated LAA using the small-umbrella LAmbre device was feasible, safe, and effective in patients with atrial fibrillation in this study. This occluder provides an alternative for patients who cannot be treated with regular-sized LAA occlusion devices.

Sex differences on outcomes following left atrial appendage occlusion in atrial fibrillation: A systematic review and meta-analysis

There is a lack of sufficient data on sex-related differences in outcomes of nonvalvular atrial fibrillation (AF) patients following left atrial appendage occlusion (LAAO). We conducted a meta-analysis to investigate the procedural complications and long-term outcomes after LAAO in women versus men. We screened Medline, EMBASE, Cochrane Center Register of Controlled Trials, and Clinical Trials.gov. The inclusion criteria were studies targeting the sex-related differences in outcomes in nonvalvular AF patients treated by LAAO. Procedural endpoints of interest included success rate, pericardial complications, major bleeding, and vascular complications during hospitalization. Long-term outcomes included all-cause mortality and ischemic stroke during follow-up. Studies that merely considered sex in the subgroup analysis were not included. Six observational studies with a total of 64,035 patients were identified. The procedural success rates did not differ between sexes (odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.89-1.09, p = 0.77), while women experienced more pericardial complications (OR: 1.78, 95% CI: 1.58-2.01, p < 0.00001), major bleedings (OR: 2.04, 95% CI: 1.75-2.39, p < 0.00001), and vascular complications (OR: 1.75, 95% CI: 1.41-2.17, p < 0.00001) than men. The sensitivity analysis performed by removing the largest study showed good stability. The long-term mortality and stroke rates did not differ between women and men in either the 1-year subgroup or the 2-year subgroup. In conclusion, despite comparable procedural success rates, women have a significantly higher incidence of pericardial complications, major bleeding, and vascular complications following LAAO. The long-term mortality and stroke rates do not differ between the sexes.

Anatomy of the left atrial appendage for the interventional cardiologist

Exact knowledge of the anatomy of the left atrial appendage (LAA) is crucial for LAA isolation by catheter ablation and for interventional LAA occlusion in patients with atrial fibrillation. This review outlines the current anatomical understanding of LAA morphology from ostium to distal lobes, myocardial fiber orientation and wall structure, and adjacent structures such as the left upper pulmonary vein with the Coumadin ridge, the circumflex artery with its side branches, the aortic root, pulmonary artery, and the pericardial space. Insight into these details will facilitate these interventions and reduce the risk of complications.

Changes in left atrial appendage orifice following percutaneous left atrial appendage closure using three-dimensional echocardiography

Percutaneous left atrial appendage (LAA) occlusion is increasingly performed in patients with atrial fibrillation and long-term contraindications for anticoagulation. Our aim was to evaluate the effects of LAA occlusion with the Watchman device on the geometry of the LAA orifice and assess its impact on the adjacent left upper pulmonary vein (LUPV) hemodynamics. We included 50 patients who underwent percutaneous LAA occlusion with the Watchman device and had acceptable three-dimensional transesophageal echocardiography images of LAA pre- and post-device placement. We measured offline the LAA orifice diameters in the long axis, and the minimum and maximum diameters, circumference, and area in the short axis view. Eccentricity index was calculated as maximum/minimum diameter ratio. The LUPV peak S and D velocities pre- and post-procedure were also measured. Patients were elderly (mean age 76 ± 8 years), 30 (60%) were men. There was a significant increase of all LAA orifice dimensions following LAA occlusion: diameter 1 (pre-device 18.1 ± 3.2 vs. post-device 21.5 ± 3.4 mm, p < 0.001), diameter 2 (20.6 ± 3.9 vs. 22.1 ± 3.6 mm, p < 0.001), minimum diameter (17.6 ± 3.1 vs. 21.3 ± 3.4 mm, p < 0.001), maximum diameter (21.5 ± 3.9 vs. 22.4 ± 3.6 mm, p = 0.022), circumference (63.6 ± 10.7 vs. 69.6 ± 10.5 mm, p < 0.001), and area (3.1 ± 1.1 vs. 3.9 ± 1.2 cm2, p < 0.001). Eccentricity index decreased after procedure (1.23 ± 0.16 vs. 1.06 ± 0.06, p < 0.001). LUPV peak S and D velocities did not show a significant difference (0.29 ± 0.15 vs. 0.30 ± 0.14 cm/s, p = 0.637; and 0.47 ± 0.19 vs. 0.48 ± 0.20 cm/s, p = 0.549; respectively). LAA orifice stretches significantly and it becomes more circular following LAA occlusion without causing a significant impact on the LUPV hemodynamics.

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.

Gender-Specific Outcomes after Percutaneous Left Atrial Appendage Closure - A Nationwide Readmission Database Analysis

BACKGROUND

Thromboembolism-associated stroke is the most feared complication of Atrial fibrillation (AF). Percutaneous left atrial appendage closure (pLAAC) is indicated for stroke prevention in patients with AF who can't tolerate long-term anticoagulation. We aim to study gender differences in peri-procedural and readmissions outcomes in pLAAC patients.

METHODS

Using the national readmission database from January 2016 to December 2018, AF patients undergoing the pLAAC procedure were identified. We used multivariate logistic regression analyses and time-to-event Cox regression analyses to conduct the study. Propensity matching with the Greedy method was done for the accuracy of results.

RESULT

28,819 patients were included in our study. Among them 11,946 (41.5%) were women and 16,873 (58.6%) were men. The mean age of overall population was 76.1 ± 8.5 years, with women ~ 1 year older than men. The overall rate of complications was higher in women (8.6% vs 6.6%, P<0.001), primarily driven by bleeding-related complications i.e., Major bleed (OR: 1.32 95% CI: 1.03-1.69, p=0.029), blood transfusion (OR: 1.45, 95% CI: 1.06-1.97, p=0.019) and cardiac tamponade (OR: 1.80, 95% CI: 1.13-2.89, p=0.014). Women had two times higher peri-procedural ischemic stroke. There was no difference in peri-procedural mortality. Women remained at 20% and 13% higher risk for readmission at 30 days and 6 months of discharge.

CONCLUSION

Women had higher peri-procedural complications and were at higher risk of readmissions at 30 days and six months. However, there was no difference in mortality during the index hospitalization. Further studies are necessary to determine causality. This article is protected by copyright. All rights reserved.

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.

Thirty-Day Readmissions After Percutaneous Left Atrial Appendage Occlusion: Insights from the Nationwide Readmissions Database

Percutaneous left atrial appendage occlusion (LAAO) provides a nonpharmacological alternative of preventing stroke in patients with non-valvular atrial fibrillation who are poor candidates for oral anticoagulation. Data on 30 day readmission measures following LAAO is limited. Index LAAO procedures and 30 day readmissions were identified using the Nationwide Readmissions Database (NRD) from 2016 to 2018. The rates and causes of 30 day readmissions were studied. Complex samples multivariable logistic regression models were used to identify predictors of 30 day readmission. Among 29,367 patients undergoing LAAO, the rates of 30 day readmissions were 9.2%. The most common overall cause of 30 day readmission was gastrointestinal bleeding (18.5%), followed by heart failure (13.1%), and infection (7.3%). Female gender (OR1.22; 95% CI 1.08-1.38), HF (OR 1.30; 95% CI 1.15-1.47), anemia (OR 1.37; 95% CI 1.11-1.68), chronic lung disease (OR 1.42; 95% CI 1.25-1.62), End stage renal disease (OR 2.75; 95% CI 2.13-3.55), Acute kidney injury (OR 1.66; 95% CI 1.25-2.20), bleeding/transfusion (OR 1.63; 95% CI 1.28-2.09) were found to be independent predictors of 30 days Readmission. The overall rate of 30 day readmission after LAAO was 9.2% with non-cardiac causes (gastrointestinal bleeding) being the most common. Reducing in-hospital complications and identifying optimal post procedural anticoagulation/antithrombotic regimen may help decrease readmissions following LAAO.

A Case of a Left Atrial Appendage Disguised as a Coronary Artery Aneurysm

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LAA is a complex, variable anatomic structure that can be mistaken for other cardiac structures.

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Color and spectral Doppler may help to discern the LAA from surrounding structures.

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Cross-sectional imaging such as CTA can aid in defining the morphology of the LAA.

Non coronary applications of cardiac computed tomography: A review

Acquired heart diseases including valvular pathologies and conduction abnormalities, along with coronary artery disease make cardiovascular disease one of the major causes of mortality and morbidity worldwide. Advances in cardiac computed tomography (CCT) have led to markedly improved image quality for assessment of several coronary and noncoronary cardiac abnormalities. With the latest versions of CT scanners, image acquisition can be completed within a few seconds, in a single breath hold and with much less radiation exposure, thus making CT an even more attractive diagnostic tool with its high temporal and excellent spatial resolution. Additional advantages are its noninvasive nature, wide availability, fast image acquisition and ability to provide additional data about the cardiac structure, function, valvular motion, and presence or absence of valvular vegetation, mass or intracardiac thrombus. These factors can result in change in management in many valvular pathologies pre- and post-intervention, and in electrophysiological procedures. The goal of this article is to review applications of cardiac CT in non-coronary indications including valvular assessment, pulmonary vein isolation procedure, and left atrial appendage evaluation for its transcatheter occlusion.

The Association of Left Atrial Appendage Morphology to Atrial Fibrillation Recurrence After Radiofrequency Ablation

Objective: The probability of late recurrent atrial fibrillation (AF) after radiofrequency ablation (RFA) has not yet been fully clarified. This study aims to study the association of left atrial appendage (LAA) morphology with AF recurrence after RFA.

Methods: We retrospectively enrolled 84 patients (24 patients had persistent AF, 60 patients had paroxysmal AF) who underwent RFA in Shanghai East Hospital from June 2014 to May 2018. The mean follow-up of these patients was 618.6 days. According to preoperative transesophageal echocardiography (TEE), the morphology feature of LAA was classified and evaluated by two classification methods. The first method was divided into chicken-wing, windsock, cactus, and cauliflower, and the second method was divided into one lobe, two lobes, and multiple lobes. The correlation between morphological feature of LAA and the recurrence rate of AF after RFA was analyzed.

Results: During follow-up, 12 patients (50%) and 10 patients (16.7%) had AF recurrence in persistent and paroxysmal AF, respectively. The LAA morphology was associated with the recurrence of AF after RFA with the chicken-wing highest recurrence risk (68.2%). The structure type of LAA was also related to the AF recurrence rate (p < 0.01). Compared with one lobe and multiple lobes, two lobes (recurrence, 47.6%) were more likely associated with the recurrence of AF (p < 0.02). Logistic regression analysis showed that the chicken-wing group had a higher risk of recurrence after RFA (OR = 8.13, p = 0.004), and the windsock group had a lower risk of recurrence (OR = 0.17, p = 0.002).

Conclusion: The morphological feature of LAA is related to the recurrence risk of AF after RFA. LAA morphology assessment can predict the risk of AF recurrence.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

Interventional occlusion of left atrial appendage in patients with atrial fibrillation. Gender-related outcomes in the German LAARGE Registry

INTRODUCTION

Gender-based differences in atrial fibrillation have been identified, but limited data exist for patients undergoing left atrial appendage occluder (LAAO) implantation. This study reports gender-related periprocedural and 1-year outcomes of the prospective, multicenter German left atrial appendage occlusion registry (LAARGE).

METHODS

LAARGE enrolled 641 patients who were scheduled for LAAO implantation from July 2014 to January 2016 in 38 hospitals in Germany. The data collected included demographics, clinical characteristics, details of implantation, and outcome. Efficacy and safety at 1-year follow-up were assessed by the occurrence of thrombembolic and bleeding events, as well as mortality.

RESULTS

Of 638 patients undergoing LAAO implantation 38.9% were female and 61.1% male. Females were older (76.4 ± 8.2 [females] vs. 75.6 ± 7.7 [males], p = .042) and had a higher stroke risk (CHA₂ DS₂ -VASc score: 4.9 ± 1.5 vs. 4.3 ± 1.5, p < .001). In contrast, males suffered more often from coronary artery (33.1% vs. 53.8%, p < .001) and vascular disease (18.5% vs. 31.0%, p < .001). Technical success was high and similar for both genders (98.4% vs. 97.2%, p = .33). Severe periprocedural complications (6.9% vs. 3.1%, p = .032) occurred more often in females. At 1-year follow-up the rates of all-cause stroke (0.5% vs. 1.3%, p = .65) and severe bleeding (0.0% and 1.0%, p = .29) were low and comparable between the genders. Also, one-year all-cause mortality (9.2% vs. 13.1%, p = .14) did not differ significantly.

CONCLUSION

LAARGE documented in this elderly patient population undergoing LAAO implantation a higher rate of severe periprocedural complications in females. At 1-year follow-up similar efficacy and safety outcomes were observed for both genders.

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.

The use of cardiac computed tomography angiography in the assessment of percutaneous left atrial appendage closure - Review and experts recommendations endorsed by the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle

Atrial fibrillation is the most common cause of arrhythmia which is responsible for over 15% of ischemic strokes, most of these being secondary to migration of a left atrial appendage (LAA) thrombus. In patient with contraindication to anticoagulant therapy, percutaneous closure system placement may be indicated. Cardiac computed tomography (CT) angiography plays a central role in the initial assessment as well as in the follow-up. The purpose of the pre-implantation cardiac CT angiography is to evaluate the anatomy of the LAA in order to select the most suitable prosthesis and check for any contraindication to device implantation. Image analysis is divided into four steps that include analysis of the approach; search for a thrombus in the LAA; investigation of the anatomy of the LAA (morphology of the LAA, dimensions of the LAA and choice of device) and cardiac and thoracic assessments. Follow-up involves CT examination to check for correct placement of the device and to detect any complications. On the basis of the results of currently available published research, a panel of experts has issued recommendations regarding cardiac CT angiography prior to percutaneous LAA closure device placement, which were further endorsed by the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV).

Incidence and clinical relevance of left atrial appendage membranes: a new congenital heart disease?

AIMS

Left atrial appendage (LAA) membranes are rare congenital anomalies. Those involving the appendage orifice may obstruct its emptying flows, thus promoting blood stasis and clot formation. However, the epidemiology of LAA membranes has never been studied and a correlation with appendage thrombosis has never been proved. Very few case reports described LAA membranes, therefore, their frequency and clinical significance are not known. Moreover, their presence and degree are of crucial importance in planning LAA percutaneous closure, a procedure whose indication is evolving, and whether their presence can represent technical issues during the device implantation is not known. This study aimed to evaluate the incidence and the clinical significance of LAA membranes.

METHODS AND RESULTS

A population of 6030 consecutive transoesophageal echo (TOE) studies has been retrospectively reviewed in order to find those patients in whom an LAA membrane has been found. A literature research has been performed to review previous described cases. Among 6030 TOE cases, an LAA membrane has been described in 6 (prevalence of 1/1000). In one case, the membrane was associated to a severe LAA hypoplasia and in another case to an LAA thrombus (these represent the first cases ever described). All patients had an atrial fibrillation (AF) history and two were in AF during the TOE exam.

CONCLUSION

LAA membranes are rare congenital abnormalities occasionally discovered during a TOE exam, frequently in patients affected by AF. In half of the cases, they obstruct the LAA flow, thus theoretically pre-disposing to clot formation. They may be rarely associated to an appendage hypoplasia. During a TOE exam, cardiac imagers should always rule out their presence.

Epicardial fat pad within the transverse sinus mimicking a left atrial appendage thrombus

The presence of left atrial thrombus is a contraindication to cardioversion or catheter ablation in patients with atrial fibrillation, due to the increased risk of systemic thromboembolism. Management of this situation includes changes in the anticoagulation regimen and repeat imaging tests. Accurate diagnosis of left atrial appendage thrombus is therefore essential but can sometimes be challenging. Multiple imaging modalities may sometimes be required in the setting of anatomical variations of the left atrial appendage and surrounding structures. We present the case of a patient awaiting ablation for atypical atrial flutter, who underwent a transthoracic echocardiogram that showed an echodense, mobile structure within the vicinity of the left atrial appendage, suggesting a possible thrombus. A cardiac CT demonstrated the image to correlate with an epicardial fat pad within the transverse sinus.

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

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

Left Atrial Appendage Ostial Stenosis: A Case Report and Literature Review

Patient: Female, 34-year-old

Final Diagnosis: Left atrial appendage ostial stenosis

Symptoms: No symptoms

Medication:—

Clinical Procedure: —

Specialty: Cardiology

Clinical and diagnostic imaging findings in dogs with atrial appendage aneurysm: 7 cases (2014-2020)

INTRODUCTION/OBJECTIVE

Atrial appendage aneurysm in dogs is a rare condition and has not been well described. The aim of this study is to describe clinical and diagnostic imaging findings, especially computed tomography (CT), of atrial appendage aneurysms in dogs.

ANIMALS

Seven client-owned dogs with a presumptive diagnosis of left or right atrial appendage aneurysm.

MATERIALS AND METHODS

Retrospective study. Medical records were searched to identify dogs with a presumptive diagnosis of left (LAAA) or right atrial appendage aneurysm (RAAA). Signalment, history, examination findings, diagnostic test results, and imaging procedures were reviewed. Archived diagnostic images were retrieved and evaluated by two board-certified radiologists and a board-certified cardiologist. Data analysis was descriptive.

RESULTS

Six cases were diagnosed with RAAA and one with LAAA with a median age of 8 years. Five affected dogs were small to medium-breed male dogs. All dogs underwent a thoracic CT examination for various reasons and all cases of RAAA were incidental findings. CT was useful to identify and assess the atrial appendage aneurysm, as well as neighboring structures, although possible pericardial defects could not be visualized. Five dogs had a concurrent echocardiographic examination, which successfully identified the LAAA and two RAAA.

CONCLUSIONS

This case series described the clinical and CT findings in seven dogs with atrial appendage aneurysm, as well as echocardiographic findings in five of these cases. Right atrial appendage aneurysms appear to be mainly incidental findings. CT seems to be more sensitive than echocardiography in the detection of atrial appendage aneurysm.

Morphology of the Left Atrial Appendage: Introduction of a New Simplified Shape-Based Classification System

BACKGROUND

The left atrial appendage (LAA) is a heart structure with known prothrombogenic and pro-arrhythmogenic properties.

AIM

The aim of this study was to evaluate the specific anatomy of the LAA and to create a simple classification system based on the shape of its body.

METHOD AND RESULTS

This study investigated 200 randomly selected autopsied human hearts (25.0% females, 46.6±19.1 years old). Three (3) types of LAAs were distinguished: the cauliflower type (no bend, limited overall length, compact structure [36.5%]); the chicken wing type (substantial bend in the dominant lobe [37.5%]), and the arrowhead type (no bend, one dominant lobe of substantial length [26.0%]). Additional accessory lobes were present in 55.5% of all LAAs. Significant variations between category types were noted in LAA length (chicken wing: 35.7±9.8 mm, arrowhead: 30.8±10.1 mm, cauliflower: 22.3±9.6 mm [p<0.001]) and in the thickness of pectinate muscles located within the LAA apex (arrowhead: 1.2±0.7 mm; cauliflower: 1.1±0.6 mm; chicken wing: 0.9±0.6 mm [p<0.001]). Left atrial appendage volume and orifice size were not affected by the type of LAA shape. The age of the donor was positively correlated with LAA volume (r=0.29, p=0.005), body length (r=0.26, p=0.012), and area of the orifice (r=0.36, p<0.001). Donors with an oval LAA orifice were significantly older than those with round orifices (50.2±16.6 vs 43.7±20.4 years [p=0.014]) and had significantly heavier hearts (458.2±104.8 vs 409.6±114.1g [p=0.002]).

CONCLUSIONS

This study delivered a new simple classification system of the LAA based on its body shape. An increase in age and heart weight was associated with LAA enlargement and a more oval-shaped orifice. Results of current study may help to estimate the different thrombogenic properties associated with each LAA type and be an assistance during planning and performing interventions on LAA.

Successful WATCHMAN Device Placement Despite Left Atrial Appendage Perforation in Two Cases

The WATCHMAN (Boston Scientific, Marlborough, USA) is a device used to occlude the left atrial appendage (LAA) in patients of non-valvular atrial fibrillation (NVAF) with a high CHA₂DS₂-VASc score who are poor candidates for oral anticoagulation. LAA perforation is a well-known complication of the WATCHMAN device placement. Here we present two cases of NVAF where oral anticoagulation was not advisable due to recurrent bleeding episodes. They underwent the WATCHMAN procedure for stroke prevention. During the placement of the WATCHMAN device into the left atrial appendage (LAA) in both cases, pericardial staining was noted that worsened over the next few minutes. It was decided to deploy the 27 mm WATCHMAN device into the LAA. In one case, satisfactory hemostasis was achieved with the device deployment eliminating the need for cardiothoracic surgery. However, the second case led to pericardial tamponade and was managed by the placement of a pericardial window. To our knowledge, this is the first case series describing the use of a WATCHMAN device upon detection of LAA perforation.

Nonvisualization of the Left Atrial Appendage and Role of Multimodality Imaging

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LAA has a pathologic association with stroke and a role in AF.

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The incidence of congenitally absent or rudimentary LAA is unknown.

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Highlight multimodality imaging to identify congenitally absent and diminutive LAA.

Modification of the left atrial appendage and its role in stroke risk reduction with non-valvular atrial fibrillation

Atrial fibrillation is one of the most common cardiovascular disorders encountered by clinicians in clinical practice. Patients with atrial fibrillation are at risk of cerebrovascular and systemic embolic events, which may be attenuated by commencement of anticoagulation therapy. Even so, due to extremely high bleeding risk certain patients may not be suitable for long-term anticoagulation therapy. The left atrial appendage is a common site for thrombus formation in patients with atrial fibrillation. Left atrial appendage exclusion, either surgical or percutaneous, has been performed to ostensibly reduce the risk of cerebrovascular events and potentially minimise or omit anticoagulation therapy in select patients. This review summarises the role of the left atrial appendage in cerebrovascular events, current evidence with modification of the left atrial appendage and future trials that may change practice with these procedures.

Reference value of perimeter-derived diameter assessed by three-dimensional transesophageal echocardiography in left atrial appendage occluder size selection

BACKGROUND

The aim of this study was to investigate the utility of perimeter-derived diameter (PDD) measured by three-dimensional (3D) transesophageal echocardiography (TEE) in predicting the size of left atrial appendage (LAA) occluder.

METHODS AND RESULTS

Left atrial appendage landing zone diameter (LZD) was measured by two-dimensional (2D) TEE, 3DTEE, and digital subtraction angiography (DSA) as LZD-2Dmax, LZD-2Dmean, LZD-3Dmax, LZD-3Dmean, LZD-PDD, LZD-DSAmax, respectively, before and during transcatheter LAA closure with Watchman devices in 100 patients. A difference of one or more device size intervals between the predicted size and the size actually implanted was defined as mismatching. Seventy-eight patients were followed up by TEE to obtain occluder compression ratio. The correlation between LZD and the final implanted occluder size was 0.559, 0.641, 0.754, 0.760, 0.782, and 0.848 for LZD-2Dmax, LZD-2Dmean, LZD-3Dmax, LZD-3Dmean, LZD-PDD and LZD-DSAmax, respectively (P < .001). Matching ratio between the size predicted by retrospective measurements of LZD and the device size actually implanted was 65%, 57%, 66%, 63%, 70%, and 83% for LZD-2Dmax, LZD-2Dmean, LZD-3Dmax, LZD-3Dmean, LZD-PDD and LZD-DSAmax, respectively. There was no significant difference in LZD value, matching ratio, and compression ratio between the patients with eccentric and noneccentric LAA landing zone (P > .05). Compression ratio of the mismatching subjects was higher than that in the matching subjects when evaluated by LZD-2Dmean, LZD-3Dmean, and LZD-PDD (P < .05).

CONCLUSIONS

Landing zone diameter derived from LAA perimeter measured by preprocedure 3DTEE showed reference value for LAA occluder size selection, providing superior correlation and matching ratio with the final implanted size and indicating the adjustment of oversizing.