Left Atrial Appendage Morphology Research Articles

The Correlation between Ultrasonographic Morphology and Structure of the Left Atrial Appendage, Blood Flow Velocity, and Plasma Galectin-3 Levels with Thrombus Formation in the Left Atrial Appendage of Patients with Atrial Fibrillation

Background: To explore the correlation between left atrial appendage morphology, blood flow velocity and plasma galectin-3 and thrombosis in patients with atrial fibrillation. Methods: Patients with atrial fibrillation who received treatment and completed ultrasound examination in hospital from 2022 to December 2023 were enrolled. According to whether there was left atrial appendage thrombosis, the patients were divided into a control group (no left atrial appendage thrombosis was found) and a study group (left atrial appendage thrombosis was found). The morphology and structure of the left atrial appendage, blood flow velocity and plasma galectin-3 level were recorded，exploring its correlation with left atrium thrombosis. Results: A total of 330 patients with atrial fibrillation were enrolled, including 278 in the control group and 52 in the study group. Left group and the control group of morphological structure differences (P < 0.05). The main lobe length, ostial area, longest diameter, shortest diameter, left atrial appendage volume and left atrial volume in the study group were higher than those in the control group (P < 0.05). The left atrial appendage emptying velocity, filling velocity and left ventricular ejection fraction of the study group were lower than those of the control group, and the left ventricular end-diastolic diameter was higher than that of the control group (P < 0.05). Group of white blood cell count, neutrophils/lymphocyte ratio, plasma galactose lectin - 3 levels were higher than control group (P < 0.05). ROC curve analysis of left atrial appendage emptying velocity, left atrial appendage filling velocity, left atrial end-diastolic diameter and left atrial ejection fraction had higher diagnostic value (P < 0.05). Conclusion: Left atrial appendage morphology, blood flow velocity and plasma galectin-3 level are important factors to evaluate the risk of left atrial appendage thrombosis in patients with atrial fibrillation, which can be used for clinical diagnosis and decision-making.

Complex left appendage morphology is associated with Embolic Stroke of Undetermined Source.

Variations in the left atrial appendage (LAA) morphology are associated with different embolic risk in patients with atrial fibrillation (AF). Data are scarce regarding the association between LAA morphology and Embolic stroke of undetermined source (ESUS). Using cardiac computed tomography (CCT) scans, LAA morphology was categorized as either chicken wing (CW), cactus, windsock, or cauliflower. Furthermore, we examined the presence of large secondary lobes arising from the main lobe, considering their existence as indicative of a complex LAA morphology. LAA morphologies were compared between ESUS (n = 134) and AF patients (n = 120); and between ESUS patients with (n = 24) and without (n = 110) subsequent AF diagnosis during long-term follow-up. ESUS patients had a significantly higher prevalence of cauliflower morphology compared to AF group (52% vs 34%, respectively, p = 0.01); however, no significant difference was found between the groups when categorizing LAA morphology to either CW or non-CW. ESUS patients had significantly higher prevalence of large secondary lobes compared with AF patients (50% vs 29%, respectively, p = 0.001). When comparing ESUS patients with and without AF diagnosis during follow-up (20-48 months of follow-up, median 31 months), there were no significant differences in the prevalence of the "classical" morphologies, but large secondary lobes were significantly more prevalent among those without subsequent AF diagnosis. ESUS patients have a high prevalence of complex LAA morphology, which might be associated with an increased risk for thrombus formation even in the absence of AF.

Association between Left Atrial Appendage Morphology and Clot Histology in Patients with Embolic Ischemic Stroke: An Exploratory Study.

Acute embolic ischemic stroke poses a significant healthcare challenge. Histological clot features' variability among patients with acute ischemic stroke treated by mechanical thrombectomy has potential implications for determining treatment and etiology. This study investigated the clot histological feature differences among patients who experienced cardioembolic stroke and embolic stroke of undetermined source with different left atrial appendage (LAA) morphologies. We conducted a prospective observational study involving 79 patients with acute embolic ischemic stroke undergoing mechanical thrombectomy. Computed tomography angiography images were used to classify LAA morphologies. An artificial intelligence algorithm assessed the clot fibrin and red blood cell contents. Patients with chicken-wing LAA morphology exhibited lower mean clot fibrin proportions than did those with non-chicken-wing morphology (p < 0.001). Linear regression analysis showed that chicken-wing LAA was significantly associated with a lower clot fibrin proportion (estimate, -0.177; 95% CI [-0.259, -0.096]; p < 0.001). The successful recanalization rate and first-pass effect between the groups did not differ significantly. The chicken-wing LAA morphological type is associated with lower clot fibrin contents, suggesting potentially different embolism mechanisms or diverse embolic sources, compared with the non-chicken-wing LAA types. Further studies are required to investigate this association.

The role of the pulmonary veins on left atrial flow patterns and thrombus formation.

Atrial fibrillation (AF) is the most common human arrhythmia, forming thrombi mostly in the left atrial appendage (LAA). However, the relation between LAA morphology, blood patterns and clot formation is not yet fully understood. Furthermore, the impact of anatomical structures like the pulmonary veins (PVs) have not been thoroughly studied due to data acquisition difficulties. In-silico studies with flow simulations provide a detailed analysis of blood flow patterns under different boundary conditions, but a limited number of cases have been reported in the literature. To address these gaps, we investigated the influence of PVs on LA blood flow patterns and thrombus formation risk through computational fluid dynamics simulations conducted on a sizeable cohort of 130 patients, establishing the largest cohort of patient-specific LA fluid simulations reported to date. The investigation encompassed an in-depth analysis of several parameters, including pulmonary vein orientation (e.g., angles) and configuration (e.g., number), LAA and LA volumes as well as their ratio, flow, and mass-less particles. Our findings highlight the total number of particles within the LAA as a key parameter for distinguishing between the thrombus and non-thrombus groups. Moreover, the angles between the different PVs play an important role to determine the flow going inside the LAA and consequently the risk of thrombus formation. The alignment between the LAA and the main direction of the left superior pulmonary vein, or the position of the right pulmonary vein when it exhibits greater inclination, had an impact to distinguish the control group vs. the thrombus group. These insights shed light on the intricate relationship between PV configuration, LAA morphology, and thrombus formation, underscoring the importance of comprehensive blood flow pattern analyses.

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 data of 649 patients with AF who were scheduled for catheter ablation. Patients underwent cardiac CT and transesophageal echocardiography prior to ablation. LAA morphologies depicted by cardiac CT were categorized into four groups: cauliflower, chicken wing, swan and windsock shapes. Mean age was 61.3±10.5 years, 33.9% were female. Prevalence of stroke/TIA was 7.1%. After adjustment for the main risk factors, LAA flow velocity ≤35.3 cm/sec (OR=2.18; 95%CI=1.09-4.61; p=0.033) and swan LAA shape (OR=2.69; 95%CI=0.96-6.86; p=0.047) independently associated with higher risk of stroke/TIA, while windsock LAA morphology proved to be protective (OR=0.32; 95%CI=0.12-0.77; p=0.017) as compared to cauliflower LAA shape. When comparing the differences between LAA morphology groups, we measured 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, while LAA flow velocity did not differ significantly. Reduced LAA function and swan LAA morphology were independently associated with higher prevalence of stroke/TIA, while windsock LAA shape proved to be protective. When comparing the differences between the various LAA morphology types, significantly lower LAA volume and LAA orifice area were measured in windsock LAA shape as compared to cauliflower LAA shape.

Cardiac imaging correlates and predictors of stroke in patients with atrial fibrillation: a meta-analysis.

New nonclinical parameters are needed to improve the current stroke risk stratification schemes for patients with atrial fibrillation. This study aimed to summarize data on potential cardiac imaging correlates and predictors of stroke or systemic embolism in patients with atrial fibrillation. MEDLINE, EMBASE, and Web of Science were searched to identify all published studies providing relevant data through 16 November 2022. Random effects meta-analysis method was used to pool estimates. We included 64 studies reporting data from a pooled population of 56 639 patients. Left atrial spontaneous echo-contrast [adjusted odds ratio (aOR) 3.32, 95% confidence interval (CI) 1.98-5.49], nonchicken wing left atrial appendage (LAA) morphology (aOR 2.15, 95% CI 1.11-4.18), left atrial enlargement (aOR 2.12, 95% CI 1.45-3.08), and higher LAA orifice diameter (aOR 1.56, 95% CI 1.18-2.05) were highly associated with stroke. Other parameters associated with stroke included higher left atrial sphericity (aOR 1.14, 95% CI 1.01-1.29), higher left atrial volume (aOR 1.03, 95% CI 1.01-1.04), higher left atrial volume index (aOR 1.014, 95% CI 1.004-1.023), lower left atrial reservoir strain [adjusted hazard ratio (aHR) 0.86, 95% CI 0.76-0.98], higher left ventricular mass index (aOR 1.010, 95% CI 1.005-1.015) and E / e' ratio (aOR 1.12, 95% CI 1.07-1.16). There was no association between LAA volume (aOR 1.37, 95% CI 0.85-2.21) and stroke. These cardiac imaging parameters identified as potential predictors of thromboembolism may improve the accuracy of stroke risk stratification schemes in patients with atrial fibrillation. Further studies should evaluate the performance of holistic risk scores including clinical factors, biomarkers, and cardiac imaging.

Comparison of left atrial appendage measurements between conventional transesophageal echocardiography and "Virtual TEE" reconstructed from computed tomography for pre-procedural planning of device closure.

For pre-procedural planning of left atrial appendage (LAA) closure, sizing is crucial. Although transesophageal echocardiography (TEE) is a standard modality, cardiac computed tomography (CT) is also widely used. The virtual TEE (V-TEE) that our group developed enables us to reconstruct images similar to TEE images from CT images. The software should be helpful to understand and plan the procedure strategy. Accordingly, we investigated the utility of V-TEE. Sixty-six patients at 4 participating sites who completed both CT and TEE prior to LAA closure were included. The LAA diameter at the landing zone (LZ) for WATCHMAN™ device implantation was statistically compared at 0°, 45°, 90°, and 135° between V-TEE and TEE. Among 66 cases, only 3 cases were excluded due to poor imaging quality, and 63 cases were analyzed. The device LZ diameters based on V-TEE were strongly correlated with those based on TEE, despite the significantly greater diameter based on V-TEE with mean differences of 2.4 to 3.0mm (all of them: P < 0.001). The discordances (V-TEE/TEE ratio) at most angles were significantly larger in the elliptical LAAs. V-TEE provides a valuable method for the evaluation of the LAA diameters. V-TEE-based measurements were larger than conventional TEE-based measurements, especially in cases of elliptical LAAs. The assessment by V-TEE has the potential benefit of ensuring proper device sizing regardless of the LAA morphology.

Left atrial appendage thrombus with severe mitral stenosis: Responders and non-responders to anticoagulation

Introduction and objectiveMitral stenosis (MS) is one of the most frequently observed valvular heart lesions in developing countries and is due to different etiologies. The effects of anticoagulation in different types of left atrial appendage (LAA) are unknown. The current study aimed to determine the resolution of LAA thrombus on transesophageal echocardiography (TEE) after three months of optimal anticoagulation in patients with different types of LAA at baseline cardiac computed tomography of patients with severe MS. MethodsThis prospective cohort study observed the frequency of LAA thrombus resolution after three months of anticoagulation therapy in patients with severe MS. The response rate in different morphologies of LAA and locations was also assessed. Thrombus resolution after three months of warfarin therapy was assessed on repeat TEE. ResultsA total of 88 patients were included, mean age 37.95±11.87 years. Repeat TEE showed thrombus resolution in only 27.3% of patients. The rate of thrombus resolution was 8/12 (66.7%), 4/28 (14.3%), 8/36 (22.2%), and 4/12 (33.3%) for patients with cactus, cauliflower, chicken wing, and windsock LAA type, respectively. The resolution rate was 0/12 (0%), 4/44 (9.1%), and 20/32 (62.5%) for patients with thrombus in the base, body, and tip of the LAA, respectively. ConclusionThe cactus type of LAA morphology and thrombus at the LAA tip responded well to three months of anticoagulation, however, patients with thrombus in the LAA base and body and cauliflower and chicken wing morphology were non-responders and could benefit from early referral for surgical management.

THE LEFT ATRIAL APPENDAGE MORPHOLOGY IN PATIENTS WITH ATRIAL FIBRILLATION BY CARDIAC COMPUTED TOMOGRAPHY

Purpose: To describe the morphological characteristics of left atrial appendage (LAA) on multislice computed tomography in patients with atrial fibrillation.&#x0D; Materials and methods: A prospective descriptive study on 44 patients diagnosed with atrial fibrillation (AF) and underwent multislice computed tomography at Bach Mai Hospital from August 2022 to July 2023. Results: Mean age 64.45 ± 10.50. The most common morphology of LAA is “windsock” with 40.91%, followed by “chicken wing” with 34.09%, then “cauliflower” with 13.64%, and finally “cactus” with 11.36%. The most common LAA orifice position is in the middle (63.64%), the average length of the LAA is 47.03 ± 11.69 mm, and the mean volume of the LAA is 14.39 ± 8.00 ml. There is little relationship between gender and morphological characteristics of the LAA.&#x0D; Conclusion: The most common LAA morphology in patients with atrial fibrillation is “windsock”. Gender has little association with left atrial appendage morphology.  

Left atrial appendage morphology and mitral annular plane systolic excursion predict stroke in patients with atrial fibrillation and high thromboembolic risk

Abstract Background Previous research has revealed a relationship between the morphology and function of the left atrial appendage (LAA) and the rate of thromboembolic events in patients with atrial fibrillation (AF). There is limited data on the impact of the left ventricular (LV) function on LAA thrombus formation. Emptying of the LAA depends on the active contraction of this structure as well as on the passive motion due to external compression from the LV base during ventricular diastole. Purpose Given these considerations the goal of this study was to investigate by transesophageal and transthoracic echocardiography the morphology and function of the LAA in relationship with the LV function and to assess the impact on incidence of stroke in a group of patients with AF with high thromboembolic risk who underwent TEE-guided direct current cardioversion. Methods We included 148 patients (age 65 ±11 yrs, 79men, median CHA2DS2-VASc score 4 (IQR 2-6), left ventricular ejection fraction 48±11%), who underwent transesophageal echocardiography before cardioversion. During a median follow-up period of 23 months (range 1-107) 34 patients developed stroke or TIA. Results The distribution of the four LAA morphologies (Figure 1) was: Cactus [47 (32%)], Cauliflower [30 (20%)], Windsock [38(26%)], and Chicken Wing [33 (22%)]. During the follow-up period stroke/TIA occurred significantly more frequently in patients with cactus or cauliflower LAA morphology vs. patients with windsock or chicken wing morphology (25 (35%) vs 9 (11%); p value=0.001). Patients who developed stroke or TIA had significantly lower MAPSE vs patients with event free survival (8±3 vs 12±3mm; p value=0.001). Kaplan-Meier survival curves for different categories of MAPSE and LAA morphology are shown in Figure 2. The significant relationship between MAPSE and stroke-free survival was retained in Cox multivariable analysis that included LAA morphology, CHA2DS2-VASc score and AF types. This association was present whether MAPSE was entered into the multivariable model as a continuous or dichotomized variable. Conclusions In patients with high thromboembolic risk, MAPSE predicts the occurrence of stroke independent of LAA morphology and CHA2DS2-VASc score. This phenomenon could be related to the impact LV diastole on LAA emptying.

Left atrial appendage morphology and function predict thromboembolic risk in patients with embolic stroke of undetermined sources

Abstract Introduction Embolic stroke of undetermined sources (ESUS) is supposed to be associated with intracardiac thrombus formation, in particular in the left atrial appendage (LAA). We aimed to investigate the impact of LAA morphology and function on thromboembolic risk condition (TRC) and LAA thrombus in ESUS patients. Methods 185 ESUS patients (mean age 68 ±13 years, 33% female) without history of AF were included. All patients underwent clinical evaluation by CHA2DS2-VASc and complete transthoracic and transesophageal echocardiography shortly after index ESUS (4 days, IQR 3-6). LAA function and LAA morphology were evaluated by conventional 2D and 3D echocardiography and speckle tracking strain. TRC was defined as combination of thrombus, sludge and spontaneous echo contrast (SEC) in LAA. Results In 185 study patients, following LAA types were found: chicken wing (LAA CW) 79 (43%), windsock 64 (34%), cactus 35 (19%), cauliflower 7 (4%) and multilobate LAA, defined as LAA with ≥ 1 lobe, in 115 (62%) of patients. TRC was found in 123 (67%) and thrombus formation in 29 (16%). LAA CW and multilobate LAA were independent predictors of TRC (OR 2.3 (CI 1.2 - 4.5), p= 0. 01 and OR 2.2 (CI 1.2 - 4.2), p= 0.02, respectively) and furthermore, LAA CW and LAA-Sr were independent predictors of LAA thrombus (OR 2.5 (CI 1.1 - 5.8), p=0.04 and OR 0.9 (CI 0.8 – 1.0), p&amp;lt;0.01, respectively), all adjusted for CHA2DS2-VASc-score. Conclusion LAA type CW, multilobate LAA and novel LAA strain predicted independently TRC and LAA thrombus, respectively. These results indicate that LAA morphology and function are important in assessment of thromboembolic risk in ESUS patients.Table 1.

Refining the prognosis of patients with AF using 3D transesophageal echocardiography of the left atrial appendage

Abstract Background Left atrial (LA) volume is considered an echocardiographic marker of thrombosis risk and prognosis in atrial fibrillation (AF). Limited data is available on the prognostic value of left atrial appendage (LAA) volume in AF as evaluated with three-dimensional (3D) transoesophageal echocardiography (TEE). Purpose We hypothesized that 3D LAA volume is associated with prognosis in patients hospitalized with AF. Methods We prospectively evaluated 206 patients hospitalized for AF with two-dimensional transthoracic echocardiography (TTE) and 3D TEE of the LAA within 24 hours of admission. 3D parameters were analysed off-line using Tomtec software (4D Cardio-View, Generic Volume, Philips). The primary composite outcome was all-cause death during at 2 years follow up. Results The median age of the study group was 66.3 ± 11.5 years with 129 (62.6%) men. In the global population, at admission, the median 3D LAAV was 9.02 (6.96-12.15) ml. Patients were divided into two groups according to the median 3D LAAV: Group 1: LAAV &amp;lt; 9ml (103 patients) and Group 2: LAAV ≥ 9ml (103 patients). Patients with LAAV ≥ 9ml had more frequently a history of heart failure and chronic obstructive pulmonary disease. There were no significant intergroup differences in CHA2DS2-VASc score. Patients with LAAV ≥ 9ml had higher values of BNP and CRP and lower LVEF, higher LA volumes, higher E/e’, lower LAA emptying flow velocity, and higher 3D ES LAA ostium area. There were no statistical differences in LAA spontaneous echo contrast and LAA morphology between groups (Table 1). Kaplan–Meier curves demonstrated a significant difference in survival according to the 3D ES LAAV: 3 deaths occurred in the group with 3D ES LAA volume &amp;lt; 9mL and 11 in the group with 3D ES LAA Volume≥9mL (p=0.0315) (Figure 1). Conclusion Among LAA parameters, 3D LAA end-systolic volume is significantly associated with a worse outcome in patients with AF. Further investigations are needed to evaluate this unique parameter against usual geometric and functional LA/LAA parameters.

Morphological features of the left atrial appendage on multislices computed tomography in patients with non-valvular atrial fibrilation

Objective: To study morphological characteristics of left atrial appendage on computed tomography in patients with non-valvular atrial fibrillation. [1]&#x0D; Methods: A cross-sectional descriptive study was conducted in 66 patients with non-valvular atrial fibrilation who underwent multislices computed tomography at Hanoi Heart Hospital from August 2020 to October 2022. Data of medical history, clinical examination, ECG, echocardiography were collected. We assessed the length, lobe number, and morphological classification of their LAAs on multislices computed tomography. &#x0D; Result: From 8/2020 to 10/2022, 66 patients were included in the study, the mean age was 58,4 ± 10,8 with male/femail ratio of 3/1. The proportion of left atrium morphology including chicken wing, wind sock, cauliflower and cactus is 56,6%; 19,7%; 12,1% and 10,6%, respectively. Most of the left atrium in the study group had 2 lobé (51,5%), 3 lobes (21,2%), 1 lobe (18,2%) and 4 lobes (9,1%). There was no diference in left atrial appendage morphology according to CHA2DS2-VASc score, and risk factors for atrial fibrillation (gender, heart failure, hypertension, diabetes, stroke). Patients with left atrial dilatation (LAVi &gt; 34ml/m2) had a larger mouth diameter and area than the group without left atrial dilatation (p&lt; 0,001 and 0,008). &#x0D; Conclusion: The left atrial appendage has 4 main morphologies: chicken wing, wind sock, cauliflower and cactus, in which the chicken wing shape is the most common. Most of the left atrial appendage have 2 lobes and 3 lobes. There was no difference in left atrial appendage morphology by age group, atrial fibrillation risk factors.

Left atrial appendage volume is an independent predictor of atrial arrhythmia recurrence following cryoballoon pulmonary vein isolation in persistent atrial fibrillation.

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation in persistent AF (persAF), and cryoballoon PVI emerged as an initial ablation strategy. Symptomatic atrial arrhythmia recurrence following successful PVI in persAF is observed more frequently than in paroxysmal AF. Predictors for arrhythmia recurrence following cryoballoon PVI for persAF are not well described, and the role of left atrial appendage (LAA) anatomy is uncertain. Patients with symptomatic persAF and pre-procedural cardiac computed tomography angiography (CCTA) images undergoing initial second-generation cryoballoon (CBG2) were enrolled. Left atrial (LA), pulmonary vein (PV) and LAA anatomical data were assessed. Clinical outcome and predictors for atrial arrhythmia recurrence were evaluated by univariate and multivariate regression analysis. From May 2012 to September 2016, 488 consecutive persAF patients underwent CBG2-PVI. CCTA with sufficient quality for measurements was available in 196 (60.4%) patients. Mean age was 65.7 ± 9.5 years. Freedom from arrhythmia was 58.2% after a median follow-up of 19 (13; 29) months. No major complications occurred. Independent predictors for arrhythmia recurrence were LAA volume (HR 1.082; 95% CI, 1.032 to 1.134; p = 0.001) and mitral regurgitation ≥ grade 2 (HR, 2.49; 95% CI 1.207 to 5.126; p = 0.013). LA volumes ≥110.35 ml [sensitivity: 0.81, specificity: 0.40, area under the curve (AUC) = 0.62] and LAA volumes ≥9.75 ml (sensitivity: 0.56, specificity 0.70, AUC = 0.64) were associated with recurrence. LAA-morphology, classified as chicken-wing (21.9%), windsock (52.6%), cactus (10.2%) and cauliflower (15.3%), did not predict outcome (log-rank, p = 0.832). LAA volume and mitral regurgitation were independent predictors for arrhythmia recurrence following cryoballoon ablation in persAF. LA volume was less predictive and correlated with LAA volume. LAA morphology did not predict the clinical outcome. To improve outcomes in persAF ablation, further studies should focus on treatment strategies for persAF patients with large LAA and mitral regurgitation.

Accuracy and Reliability of Left Atrial Appendage Morphology Assessment by Three-Dimensional Transesophageal Echocardiographic Glass Rendering Modality: A Comparative Study With Computed Tomography

Contrast-enhanced computed tomography is the reference-standard imaging technique to assess left atrial appendage (LAA) morphology. The aim of this study was to evaluate the accuracy and reliability of two-dimensional and new three-dimensional (3D) transesophageal echocardiographic rendering modalities in assessing LAA morphology. Seventy consecutive patients who underwent both computed tomography and transesophageal echocardiography (TEE) were retrospectively enrolled. The traditional LAA morphology classification system (LAAcs; chicken wing, cauliflower, cactus, and windsock) and a new simplified LAAcs based on the LAA bend angle were used for the analysis. LAA morphology was independently assessed by two trained readers using three different modalities: two-dimensional TEE, 3D TEE with multiplanar reconstruction, and a new 3D transesophageal echocardiographic rendering modality with improved transparency (Glass). The new LAAcs and traditional LAAcs were compared in terms of intra- and interrater reliability. With the new LAAcs, two-dimensional TEE was fairly accurate in identifying LAA morphology (κ=0.43, P<.05), with moderate interrater (κ=0.50, P<.05) and substantial intrarater (κ=0.65, P<.005) agreement. Three-dimensional TEE showed higher accuracy and reliability: 3D TEE with multiplanar reconstruction had almost perfect accuracy (κ=0.85, P<.001) and substantial (κ=0.79, P<.001) interrater reliability, while 3D TEE with Glass had substantial accuracy (κ=0.70, P<.001) and almost perfect (κ=0.84, P<.001) interrater reliability. Intrarater agreement was almost perfect for both 3D transesophageal echocardiographic modalities (κ=0.85, P<.001). Accuracy was considerably lower when the traditional LAAcs was used, with 3D TEE with Glass being the most reliable technique (κ=0.75, P<.05). The new LAAcs showed higher inter- and intrarater reliability compared with the traditional LAAcs (interrater, κ=0.85 vs κ=0.49; intrarater, κ=0.94 vs κ=0.68; P<.05). Three-dimensional TEE is an accurate, reliable, and feasible alternative to computed tomography in assessing LAA morphology with the new LAAcs. The new LAAcs shows higher reliability rates than the traditional one.

Left atrial dimensions and left atrial appendage morphology: differences in paroxysmal versus persistent atrial fibrillation patients

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein isolation (PVI) is an effective treatment strategy in symptomatic atrial fibrillation (AF) patients. However, this approach shows worse long-term results in individuals suffering from persistent compared to the paroxysmal type. Purpose The objective was to investigate differences of left atrial (LA) as well as left atrial appendage (LAA) anatomy in persistent AF (persAF) and paroxysmal (PAF) and patients. Methods An observational single center study with a blinded retrospective analysis of cardiac computed tomography angiography (CCTA) images was conducted. Dimensions of LA, posterior wall box, pulmonary veins (PV) as well as LAA size and morphology were assessed and statistically analyzed. All important measures are depicted in the attached figure. Results From 2012 to 2016 a total of 1.103 patients underwent second generation cryoballoon PVI. Prior to PVI, CCTA was available for 725 (65.7%) patients with sufficient quality for measuring in 473 (65.2%). Mean age was 66.3±9.5 years; PAF was present in 277 (58.6%) participants. In persAF LA volume [mL] (111.8; 128.8; p&amp;lt;0.001), posterior wall box area [cm2] (11.9; 13.3; p&amp;lt;0.001) and pulmonary vein ostial dimensions were significantly larger compared to PAF. LAA volume [mL] (9.0; 10.0; p=0.01) and LAA ostial perimeters (66.5; 70.0; p=0.003) were also identified to be larger in persAF. However, there was no difference in LAA morphology (overall distribution: "windsock" 51%; "chicken-wing" 20%; "cauliflower" 15% and "cactus" 13%). Conclusion Compared to PAF, persAF patients had significantly larger LA volumes, posterior wall box areas, PV ostial dimensions as well as LAA volumes and LAA ostial perimeters. LAA morphological types were distributed equally in both groups.

PO-01-083 PERCUTANEOUS CLOSURE OF PERI-DEVICE LEAK FOLLOWING LEFT ATRIAL APPENDAGE CLOSURE USING AN AMPLATZER DUCT OCCLUDER

Percutaneous left atrial appendage (LAA) closure has been recognised as an alternative therapy for stroke prevention in selected patients with non-valvular atrial fibrillation (AF) who have difficulties with long-term oral anticoagulation. Peri-device leaks (PDLs) are frequently diagnosed after LAA closure procedures, regardless of closure methods. PDL > 5mm is related with further embolic events. Nevertheless, management of severe PDL has been a challenging concern which requires multiple teams involved. To report our single centre experiences of percutaneous closure of sever PDL using an Amplatzer closure device. Patients with PDL >5mm after the LAA closure at our centre were reviewed for secondary percutaneous closure. In a case-specific approach, an Amplatzer occluder was implanted under TEE and fluoroscopic guidance depending on the morphology of the defect. Patients' characteristics, procedural details and clinical outcomes was collected and analysed. Three patients (average age 67 ± 9 years old, 2 female) with severe PDL using either Watchman device (n=1) or Lariet device (n=2) were studied. The CHADs2VASC2 score was 4 ± 2, with HASBLED score of 4 ± 1. They all have multilobed LAA morphology (bi-lobar in 2 patients) and one patient suffered TIA in 6 weeks post LAA closure. PDLs with a neck size of 8.3 ± 2.9 mm (range 5-10 mm) were demonstrated on transoesophageal echocardiogram (TOE) and left atrium computed tomography. The percutaneous closure of PDLs were underwent at 10 ± 2 months after their LAA closure under general anaesthesia and TOE guidance. Three Amplatzer Duct Occluder II (ADO II) with an average size of 6.3 ± 0.2 mm were delivered to close the leaks successfully (Please see example cases in Figure 1). No peri-device residual flow was identified on TOE and LAA angiography after the secondary closure. No procedural complication occurred. There was no residual leak or peri-device thrombus formation on follow-up TOE in 60 days and anticoagulation was then stopped after the TOE confirmation. No further thromboembolic event was reported during an average follow-up of 9 ± 5months. Percutaneous closure of PDL using a tailored approach using ADO II device represents a safe, and feasible management associated with favourable clinical outcomes.

Subject-specific factors affecting particle residence time distribution of left atrial appendage in atrial fibrillation: A computational model-based study.

Atrial fibrillation (AF) is a prevalent arrhythmia, that causes thrombus formation, ordinarily in the left atrial appendage (LAA). The conventional metric of stroke risk stratification, CHA2DS2-VASc score, does not account for LAA morphology or hemodynamics. We showed in our previous study that residence time distribution (RTD) of blood-borne particles in the LAA and its associated calculated variables (i.e., mean residence time, tm , and asymptotic concentration, C ∞) have the potential to improve CHA2DS2-VASc score. The purpose of this research was to investigate the effects of the following potential confounding factors on LAA tm and C ∞: (1) pulmonary vein flow waveform pulsatility, (2) non-Newtonian blood rheology and hematocrit level, and (3) length of the simulation. Subject-Specific data including left atrial (LA) and LAA cardiac computed tomography, cardiac output (CO), heart rate, and hematocrit level were gathered from 25 AF subjects. We calculated LAA tm and C ∞ based on series of computational fluid dynamics (CFD) analyses. Both LAA tm and C ∞ are significantly affected by the CO, but not by temporal pattern of the inlet flow. Both LAA tm and C ∞ increase with increasing hematocrit level and both calculated indices are higher for non-Newtonian blood rheology for a given hematocrit level. Further, at least 20,000 s of CFD simulation is needed to calculate LAA tm and C ∞ values reliably. Subject-specific LA and LAA geometries, CO, and hematocrit level are essential to quantify the subject-specific proclivity of blood cell tarrying inside LAA in terms of the RTD function.

Does left atrial appendage morphology and dimension differ amongst etiological stroke subtypes in patients without known atrial fibrillation? Results from the left atrial appendage morphology and dimension assessment by TEE in patients with stroke without known atrial fibrillation (LAMDA-STROKE) study

ContextComplex left atrial appendage (LAA) morphology is increasingly associated with cryptogenic ischemic stroke as compared to cardioembolic stroke due to atrial fibrillation (AF). However, data on such an association in patients with other etiological stroke subtypes in the absence of AF is limited. AimThe study aimed to assess the LAA morphology, dimension and other echocardiographic parameters by transesophageal echocardiography (TEE) in patients with embolic stroke of undetermined source (ESUS) and compare it with other etiological stroke subtypes without known AF. MethodsThis was a single-Centre, observational study involving comparison of echocardiographic parameters including LAA morphology and dimension in ESUS patients (group A; n = 30) with other etiological stroke subtypes i.e., TOAST (Trial of Org 10172 in Acute Stroke Treatment) class I-IV without AF (group B; n = 30). ResultsComplex LAA morphology was predominant in group A (18 patients in group A versus 5 patients in group B, p-Value = 0.001). Mean LAA orifice diameter (15.3 + 3.5 mm in group A versus 17 + 2.0 mm in group B, p-Value = 0.027) and LAA depth were significantly lower in group A (28.4 + 6.6 mm in group A versus 31.7 + 4.3 mm in group B, p-Value = 0.026). Out of these three parameters only complex LAA morphology was found to be independently associated with ESUS [OR = 6.003, 95% CI {1.225–29.417}, p = 0.027]. ConclusionComplex LAA morphology is a predominant feature in ischemic stroke patients with ESUS and may contribute to an increased risk of stroke in these patients.

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

PurposeWe aimed to correlate left atrial appendage (LAA) morphology with thrombus formation in patients with severe aortic valve stenosis and atrial fibrillation.MethodsWe 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.ResultsThe 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%).ConclusionWe 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.