Characteristics Of Left Atrial Appendage Research Articles

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.
 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.
 Conclusion: The most common LAA morphology in patients with atrial fibrillation is “windsock”. Gender has little association with left atrial appendage morphology.

Morphometrical features of left atrial appendage in the atrial fibrillation patients subjected to left atrial appendage closure.

This study aimed to evaluate the morphometrical features of left atrial appendage (LAA) in patients with atrial fibrillation, subjected to LAA percutaneous closure (LARIAT) for stroke prevention. Computed tomography (CT) scans of 51 patients with atrial fibrillation subjected to LARIAT procedure were comparatively evaluated with 50 patients with sinus rhythm (control group). Three-dimensional reconstructions were created using volume-rendering for evaluation. No differences were found in LAA types of distribution (cauliflower: 25.5 vs. 34.0%, chicken wing: 45.1 vs. 46.0%, arrowhead: 29.4 vs. 20.0%, all p > 0.05) between groups. However, the study group was characterized by LAAs with a lower number of lobes. The LAA orifice anteroposterior and transverse diameters (19.3 ± 4.12 vs. 17.2 ± 4.0 mm, p = 0.01 and 25.1 ± 5.1 vs. 20.5 ± ± 4.4 mm, p = 0.001), orifice area (387.2 ± 133.9 vs. 327.1 ± 128.3 mm2, p = 0.02) and orifice perimeter (70.2 ± 12.5 vs. 61.2 ± 11.6 mm, p = 0.04) was significantly larger in atrial fibrillation patients. More oval LAA orifices was found in atrial fibrillation group (94.0 vs. 70.4%, p = 0.001). No statistically significant differences were found in LAA body length (47.4 ± 15.4 vs. 43.7 ± 10.9 mm, p = 0.17), body width (24.7 ± 5.6 vs. 24.4 ± 5.8 mm, p = 0.81), and chamber depth (17.7 ± 3.5 vs. 16.5 ± 3.8 mm, p = 0.11). Calculated LAA ejection fraction was significantly lower in study group compared to healthy patients (16.4 ± 14.9 vs. 48.2 ± 12.9%, p = 0.001). Important morphometrical differences in LAA orifice have been found, which was significantly larger and more oval in patients with atrial fibrillation compared to healthy controls. Although no difference in LAA body type and size was observed; the LAA ejection fraction was significantly lower in atrial fibrillation rhythm patients.

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]
 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. 
 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 > 34ml/m2) had a larger mouth diameter and area than the group without left atrial dilatation (p< 0,001 and 0,008). 
 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.

The role of cardiac imaging before and after left atrial appendage standalone thoracoscopic exclusion.

To assess the characteristics of left atrial appendage (LAA) stump and left atrial (LA) volume after standalone totally thoracoscopic LAA exclusion in 40 patients with nonvalvular atrial fibrillation (NVAF) and contraindications to oral anticoagulation (OAC), using cardiac computed tomography (CCT) and transoesophageal echocardiography (TOE). Using CCT and TOE, we evaluated correct AtriClip Pro II positioning, the presence and characteristics of the LAA stump and the postprocedural LA volume, at 3 months' follow-up. Stump depth was measured with both CCT and TOE using a new method, based on left circumflex artery (LCX) course. After placement of AtriClip, all 40 patients discontinued OAC, and no stroke occurred. LAA exclusion was achieved in 40/40 patients at 3 months' follow-up. LAA stump (depth <10 mm in 12/18 stump, 67%) was observed in 18 patients. The overall (LA + LAA) volume and isolated LA volume were statistically different when comparing cases with and without LAA stump (P < 0.02). LAA ostium dimensions (perimeter and area) and LAA volume correlate with stump depth (P < 0.02). There was a high correlation between CCT and TOE in stump identification and depth measurement (P < 0.02). Compared with the baseline, CCT LA volume increased (P < 0.01) at 3 months' follow-up. Preprocedural and postprocedural CCT and TOE are useful and comparable in patients undergoing standalone totally thoracoscopic exclusion of LAA, because these imaging methods can identify anatomical LAA and LA characteristics predisposing for a postprocedural residual stump.

Features of Left Atrial Appendage Thrombosis in Patients With Persistent Nonvalvular Atrial Fibrillation After COVID-19.

Aim To evaluate the incidence and characteristic features of left atrial appendage (LAA) thrombosis in patients with persistent nonvalvular atrial fibrillation (AF) after COVID-19.Material and methods Transesophageal echocardiography (TEE) was performed for 469 patients (57.4 % males; mean age, 64.0 [58.0; 70.0] years) with persistent nonvalvular AF before scheduled sinus rhythm restoration. In 131 of these patients (27.9 %), the most recent episode of arrhythmia developed during the coronavirus infection. The time from the onset of COVID-19 to TEE was 145 [62; 303] days. All patients received an adequate anticoagulant therapy, in most cases, with direct oral anticoagulants for at least 3 weeks preceding the study.Results A LAA thrombus was detected in 20 (5.9 %) patients who have had no coronavirus infection and in 19 (14.5 %) patients after COVID-19 (р=0.0045). 18 of 19 (94.7 %) thrombi found in patients who have had COVID-19 were mural whereas only 5 (25.0 %) of such thrombi were found in patients who have had no COVID-19 (p&lt;0.0001). In the absence of LAA thrombus, the LAA emptying velocity was 32.0 [25.0; 40.0] cm/sec whereas in the presence of a mural thrombus, it was 25.0 [20.0; 32.3] cm/sec, and in the presence of a typical thrombus, it was 17.0 [13.5; 20.0] cm/sec (р&lt;0.0001). A Kaplan-Meier analysis showed that the median time of mural thrombus dissolution was 35.0 (95 % confidence interval (CI), 24.0-55.0) days and for a typical thrombus, this time was 69.0 (95 % CI, 41.0-180.0) days (р=0.0018).Conclusion Patients with persistent AF who have had COVID-19 had LAA thrombosis 2,5 times more frequently and, in most cases, the thrombus was mural. Mural thrombi, in contrast to typical, are not associated with a pronounced decrease in LAA emptying velocity and dissolve twice as fast as typical thrombi with an adequate anticoagulant treatment.

The left atrial appendage thrombosis of in patients with persistent atrial fibrillation after the novel coronavirus infection

Aim To evaluate the incidence and features of left atrial appendage (LAA) thrombosis in patients with persistent atrial fibrillation (AF) after novel coronavirus infection (COVID-19).Material and methods Percutaneous echocardiography (pcEchoCG) was performed for 128 patients with persistent AF prepared for cardioversion, 36 (28.1 %) of whom had had COVID-19. In 3 (8.3 %) patients, the lung lesion area was 50-75 %; in 31 (86.1 %) patients, 25-50 %; in 1 (2.8 %) patient, less than 25 %. One patient had no lung lesion. Median time from the onset of COVID-19 to the patient enrollment in the study was 76.5 days. At the time of enrollment, the polymerase chain reaction test for SARS-CoV-2 was negative in all patients.Results Patients after COVID-19 and those who had not had COVID-19 were comparable by age (62.5±9.2 and 62.4±9.1 years, respectively; р=0.956), gender (men 52.8 and 59.8 %, respectively; р=0.471), and risk of stroke (score 2.19±1.28 and score 1.95±1.35, respectively; р=0.350). Duration of the last arrhythmia episode was longer for patients after COVID-19 than for the comparison group (76.5 and 45.0 days, respectively; р=0.011). All patients received oral anticoagulants. 55.6 % of COVID-19 patients received rivaroxaban, whereas 62.0% of patients who had not had COVID-19 were treated with apixaban. Median duration of the anticoagulant treatment was longer for COVID-19 patients than for the comparison group (61.5 and 32.0 days; р=0.051). LAA thrombus was detected in 7 (19.4 %) patients after COVID-19 and in 6 (6.5 %) patients of the comparison group (р=0.030). In COVID-19 patients, the thrombus adhered to LAA wall over the entire thrombus length whereas in patients who had not have COVID-19, the thrombus had a free part that formed a sharp angle with LAA walls. In the presence of LAA thrombus, the LAA blood flow velocity was considerably higher for COVID-19 patients than for the comparison group (31.0±8.9 and 18.8±4.9 cm/sec, respectively; p=0.010). At the follow-up examination performed at 24.0 days on the average, the thrombus was found to be dissolved in 80 and 50% of patients after and without COVID-19, respectively (р=0.343).Conclusion In patients with persistent AF after the novel coronavirus infection, LAA thrombosis was detected more frequently than in patients who had never had COVID-19; it was characterized by mural localization and was not associated with a decrease in LAA blood flow velocity.

Prevalence of markers of atrial cardiomyopathy in embolic stroke of undetermined source: A systematic review

BackgroundEmerging evidence suggests the potential role of atrial cardiomyopathy (AC) as a direct thromboembolic determinant in embolic stroke of undetermined source (ESUS). ObjectiveWe aimed to quantify the prevalence of potential AC markers among ESUS, non-cardioembolic (NCE) and cardioembolic (CE) stroke patients. MethodsPubMed and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched for publications from inception to October 2021, with duplicate data extraction and risk of bias assessment. The Newcastle-Ottawa assessment scale was used to evaluate study quality. ResultsAmong 398 screened studies, 11 observational studies with 2009 ESUS patients (mean age 66.5 years) fulfilled the inclusion criteria. Of electrocardiographic markers, increased P-wave terminal force in lead V1 was more prevalent in ESUS vs NCE (OR=2.26, 95%CI: 1.40–3.66). Of imaging markers, left atrial volume index (LAVI) and left atrial diameter (LAd) were higher in ESUS vs NCE (OR=1.04, 95%CI: 1.02–1.06 and OR=3.41, 95%CI: 1.35–8.61 respectively). Non-chicken wing morphology of the left atrial appendage was more frequent in ESUS compared to NCE patients in the majority of studies. Of serum biomarkers, the prevalence of NT-proBNP >250 pg/ml did not differ among ESUS vs NCE (OR=0.73, 95%CI: 0.39 -1.35). ConclusionsElectrocardiographic, echocardiographic markers and advanced imaging modalities able to assess the morphologic characteristics of left atrial appendage and left atrial function may be important tools to discriminate AC among ESUS vs NCE stroke patients. Prospective studies exploring the association of potential AC markers with ESUS occurrence are warranted to validate their clinical utility.

Left atrial, pulmonary vein, and left atrial appendage anatomy in Indigenous individuals: Implications for atrial fibrillation.

BackgroundIndigenous Australians experience a greater burden of AF. Whether this is in-part due to differences in arrhythmogenic structures that appear to contribute to AF differences amongst other ethnicities is not known.MethodsWe studied forty individuals matched for ethnicity and other AF risk factors. Computed tomography imaging was used to characterise left atrial (LA), pulmonary vein (PV), and left atrial appendage (LAA) anatomy.ResultsThere were no significant differences in LA diameters or volumes between Indigenous and non-Indigenous Australians. Similarly, we could not detect any consistent differences in PV number, morphology, diameters, or ostial characteristics according to ethnicity. LAA analyses suggested that Indigenous Australians may have a greater proportion of non chickenwing LAA type, and a tendency for eccentric, oval-shaped LAA ostia; however, there were no other differences seen with regards to LAA volume or depth. Indexed values for LA, PV and LAA anatomy corrected for body size were broadly similar.ConclusionsIn a cohort of individuals matched for AF risk factors, we could find no strong evidence of ethnic differences in LA, PV, and LAA characteristics that may explain a predisposition of Indigenous Australians for atrial arrhythmogenesis. These findings, in conjunction with our previous data showing highly prevalent cardiometabolic risk factors in Indigenous Australians with AF, suggest that it is these conditions that are more likely responsible for the AF substrate in these individuals. Continued efforts should therefore be directed towards risk factor management in an attempt to prevent and minimise the effects of AF in Indigenous Australians.

Left atrial appendage size in patients with atrial fibrillation in Japan and the United States.

Left atrial appendage (LAA) evaluation is important to select the optimal LAA closure device for patients with atrial fibrillation (AF). The LAA characteristics of Japanese patients remain uninvestigated. We compared the LAA size and morphology between 212 Japanese AF patients before catheter ablation and 119 AF patients undergoing LAA closure in the United States (US). We measured the LAA ostial dimension and depth by transesophageal echocardiography in all patients and determined the LAA morphology types of Japanese patients by multidetector cardiac computed tomography and those of US patients by LAA angiography. The maximum LAA ostial dimension was significantly larger in Japanese patients than in US patients (22.6 ± 4.1mm vs. 21.5 ± 3.5mm, P = 0.02). Also, Japanese patients had larger maximum dimension and depth corrected by body surface area than US patients in both paroxysmal and nonparoxysmal AF groups. The angle showing the maximum dimension was 0° or 135° in approximately 75% of patients in both groups. The common LAA morphology types were "cauliflower" and "chicken wing" in Japanese patients and "cactus" and "windsock" in US patients. In this study, Japanese patients had a larger LAA size than US patients. Because the maximum LAA dimension was obtained at the same angles, the LAA measurement method for US patients can be applicable to Japanese patients.

Clinical characteristics of left atrial appendage thrombus in patients with hypertrophic cardiomyopathy and non-valvular atrial fibrillation

Objective: To investigate the incidence and clinical characteristics of left atrial appendage (LAA) thrombus in patients with hypertrophic cardiomyopathy (HCM) and non-valvular atrial fibrillation (AF) . Methods: Data from 10 440 patients with AF who had undergone transesophageal echocardiography (TEE) before cardioversion or catheter ablation at Beijing Anzhen Hospital from April 2006 to December 2018 were retrospectively screened. Two hundred and five HCM patients were included, 820 AF patients with the same CHA(2)DS(2)-VASc score over the same period were selected as the control group. HCM patients were divided into two subgroups based on presence or absence of LAA thrombus/sludge. The baseline of clinical information, transthoracic echocardiographic and TEE measures were compared among all the groups. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of left atrial diameter (LAD) for LAA thrombus/sludge. Multivariate logistic regression analysis was applied to analyze the correlative factors of LAA thrombus/sludge in HCM patients. Results: The incidences of LAA thrombus or sludge were higher in HCM group than in control group (10.7% (22/205) vs. 0.7% (6/820); 8.8% (18/205) vs.7.0% (57/820), P<0.001) . In HCM patients, LAD was significantly larger in LAA thrombus/sludge subjects than in those without thrombus/sludge ((48.9±5.1)mm vs. (45.2±6.1) mm, P<0.001). CHA(2)DS(2)-VASc score was similar between the two subgroups ((2.0±1.4) vs. (1.8±1.4), P>0.05). There was no difference in the rate of patients with a CHA(2)DS(2)-VASc scores ≥2 between the subgroups(62.5% (25/40) vs. 57.0% (94/165), P=0.525). The incidences of LAA thrombus in HCM and AF patients with CHA(2)DS(2)-VASc scores of 0, 1 and 2 were 8.8% (3/34) , 9.6% (5/52) , 11.8% (11/119) , respectively; and the rate of LAA sludge were 8.8% (3/52) , 7.7% (4/52) , 9.2% (11/119) , respectively. The cut off value of LAD for the diagnosis of LAA thrombus/sludge was 44.5 mm. Multivariate logistic regression analysis showed that LAD≥44.5 mm (OR=5.134, 95%CI 1.862-14.156, P=0.002) , non-paroxysmal AF (OR=2.782, 95%CI 1.238-6.252, P=0.013) , previous thromboembolism or stroke (OR=1.820, 95%CI 0.774-4.227, P=0.017) were independent determinants of LAA thrombus/sludge. Conclusions: The incidence of LAA thrombus/sludge is higher in patients with HCM and AF than in AF patients without HCM. The CHA(2)DS(2)-VASc score is similar between HCM and AF patients with LAA thrombus/sludge and those without thrombus/sludge. Patients with CHA(2)DS(2)-VASc score 0-1 are also likely to suffer LAA thrombus/sludge. Left atrial enlargement is associated with LAA thrombus/sludge.

Thromboembolism in Atrial Fibrillation: Role of the Left Atrial Appendage.

Atrial fibrillation (AF) is the most common arrhythmia. Patients with AF have a higher risk for thromboembolism than individuals without AF. The left atrial appendage (LAA) is the main source of thromboembolism because of its anatomic, mechanical, and electrophysiologic properties, and accounts for more than 90% of thrombus formation in patients with AF. Advancement in imaging expands knowledge about anatomic and physiologic characteristics of LAA. The risk of thromboembolism events in patients with AF depends on clinical comorbidities and structural and physiologic parameters of atria, especially LAA. This article discusses AF-related thromboembolic events and the role of the LAA.

P3730Left atrial appendage perimeter measurement by cardiac CT is superior to transesophageal echocardiography for Watchman device sizing

Abstract Background Left atrial appendage occlusion with Watchman device traditionally relies on accurate left atrial appendage (LAA) ostium diameter measurement by 2D or 3D transesophageal echocardiogram (TEE). Alternate methods of ostium measurement including area-derived diameter and perimeter-derived diameter using cardiac computed tomography (CT) have been proposed. Purpose We aim to use CT technology with an advanced medical imaging application to measure LAA ostium perimeter for improved pre-procedural device sizing. Methods We performed a retrospective analysis of 92 patients with atrial fibrillation (Afib) who underwent Watchman implantation with pre-procedural TEE and cardiac CT between May 2015 and December 2018. LAA characteristics including ostial or landing zone perimeter, minimum and maximum diameters were acquired utilizing 3mensio Structural Heart Imaging Program. Proposed Watchman device size was estimated utilizing ostium perimeter by CT and compared to the current standard utilizing ostium diameter by 2D-TEE. Both measurements were then compared to actual implanted Watchman device size which met the P.A.S.S. criteria of position, anchor, size and seal. Results Watchman device sizing based on novel LAA landing zone perimeter size by CT had a very high correlation with the actual implanted Watchman size (Pearson coefficient r=0.94, p&lt;0.001). Traditional TEE based Watchman sizing only had a modest correlation with the implanted Watchman size (Pearson coefficient r=0.66, p&lt;0.001). CT predicted Watchman size had a significantly higher agreement compared to current standard TEE based sizing (93.4% vs 47.8%), inter-rater agreement was very high for CT based Watchman sizing compared to current standard TEE based sizing (Cohen's kappa = 0.91 vs Cohen's kappa = 0.32, p&lt;0.001, p&lt;0.001 respectively). Bland-Altman analysis also showed better correlation with CT based sizing compared to TEE (see Figure 1). Figure 1 Conclusion CT LAA perimeter sizing is superior to the current standard TEE based Watchman sizing. Larger, multi-center studies may be necessary to further validate our results.

Abstract WMP72: High Risk Left Atrial Appendage Morphology (LAA-H) is Associated With Cardioembolic and Embolic Stroke of Unknown Source Subtypes

Background: The left atrial appendage (LAA) is the main source of thrombus in atrial fibrillation (AF); biomarkers of LAA dysfunction are associated with ischemic stroke (IS) risk in patients with AF. We hypothesized that high risk LAA features [High risk morphology (LAA-H), LAA volume (LAAV), and LAA orifice surface area (LAAOSA)] would be more prevalent among patients with cardioembolic (CE) stroke and embolic stroke of undetermined source (ESUS) than among those with non-cardioembolic stroke (NCS). Methods: Consecutive patients with IS from a prospective comprehensive stroke center registry who previously underwent a clinically-indicated qualifying chest CT were included. Patients underwent inpatient diagnostic evaluation for ischemic stroke, and stroke subtype was determined based on ESUS criteria. LAA morphology [Low risk morphology was defined as two lobes with an acute angle between them or chicken wing morphology and LAA-H defined as all others], LAAOSA (measured in a plane parallel to the left atrium), and LAAV (measured using a volumetric analysis software) were determined using contrast enhanced thin-slice chest CT (≤2.5 mm thickness) by investigators blinded to stroke subtype. Results: Of 1234 patients with ischemic stroke, 329 (26.7%) patients had a qualifying chest CT performed (126 CE, 116 ESUS, and 87 NCS). The baseline characteristics of patients with and without chest CT were similar. When compared to NCS, LAA-H was more prevalent in ESUS (86.4% vs. 70.1%, p=0.018) and CE stroke (82.5% vs. 70.1%, p=0.042). The LAAOSA and volume did not significantly differ between the 3 groups (Table). Conclusion: LAA characteristics associated with cardioembolic stroke are also more prevalent in patients with ESUS. Larger studies are needed to confirm that LAA features are a risk factor for stroke among patients without AF, and whether anticoagulation is effective in patients with high-risk LAA features.

Morphologic and functional features of left atrial appendage in Iranian population: an echocardiographic study.

Introduction: Cardioembolic events are accompanied by left atrial appendage (LAA) in patients suffering from atrial fibrillation (AF); therefore, the LAA closure is implemented as a preventive strategy. The detection of LAA morphologies and function is a paramount step before establishing the LAA closure. Herein, we sought to determine the morphologic features of the LAA in an Iranian population using echocardiographic evaluation. Methods: Seventy-two near-normal heart patients were investigated by conducting a cross-sectional study. All patients were examined using the 2-dimensional and 3-dimensional transesophageal echocardiography (2D- and 3D-TEE) method. The anatomical features and functions of LAA were examined. All images were stored and analyzed offline. Results: The patients’ mean age was 39 ± 15.5 year and 33 (45.8%) were female. The most frequent shape of LAA was wind sock . More LAA lobes was observed in patients with AF compared to those with NSR. In comparison with AF group, the NSR had higher LAA flow velocity (P < 0.01). The paroxysmal AF had greater LAA flow velocity and LAA ejection fraction in comparison with the chronic AF (39 ± 19 vs. 75 ± 22, P < 0.01; and 49±4 vs. 72±14, P < 0.003; respectively). The paroxysmal AF had smaller systolic LAA orifice area in comparison with the chronic AF (P < 0.02). Conclusion: The morphologic features of LAA in Iranian population were within the range of other studies and LAA length and orifice diameters in 2D- and 3D-TEE were consistent. In addition, AF influenced the morphologies and functions of LAA compared to sinus rhythm.

Silent thrombosis of a WATCHMAN device after Left Atrial Appendage ClosureDate from the RESET registry

Left atrial appendage (LAA) closure (LAAC) is recommended in patients (pts) with non-valvular atrial fibrillation (AF) and a contra indication (CI) to long-term oral anticoagulation (OAC).We sought to determine incidence and risk factors for WATCHMAN device (WM) thrombosis. LAAC with a WM was done in 100 consecutive pts prospectively included in the monocentric RESET Registry. No thromboembolic event occurred. Transoesophageal echocardiography (TOE) was done in 57 pts at a median of 53 days (22–460) and Cardiac Computed Tomography Angiography (CCTA) in 62 at a median of 175 days (33–792). LAA thrombus against the device was detected by TOE or CCTA in 5 pts. We compared characteristics of the group with (DT) or without (N-DT) device thrombosis. A major bleeding was the CI for OAC in 77 pts (96%) and only 8 received anticoagulation for 45 days after LAAC. Thereafter, 58 received aspirin (73%), 20 no treatment (25%) and 2 an OAC. LAA thrombus was detected in 2 pts by TOE (51 and 98 days) and 3 by CCTA (178, 183 and 447 day) and resolved on OAC. Incidence at 1 year was 5.1% (4/78). No significant difference was observed between the 2 groups. Although DT had a tendency of higher CHA2DS2-VASc (5 ± 1.6 vs. 4.6 ± 1.4) or HAS-BLED (4.6 ± 0.5 vs. 4.4 ± 1) scores, permanent AF (60% vs. 48%), intracranial haemorrhage (80% vs. 48%), no difference in term of history of stroke/TIA (60% vs. 70%) or antiplatelet treatment (80% vs. 60%) was noted. Morphology of LAA was in all cases a non-chicken-wing (vs. 67%). Although LAAC is limited to patients with multiple comorbidities that are reluctant to TOE, incidence of LAA thrombosis after WM implantation is high enough to strongly recommend device surveillance. Nevertheless, the optimal timing for imaging remains unclear and repetitive studies could be necessary in specific conditions. Medical history and morphologic characteristics of LAA are of limited help to identify high-risk patients.

PO337 Anatomic and Functional Characteristics of Left Atrial Appendage in Relation to the Need of Anti Coagulation in Patients With 0-1 Chadvasc Score

PO337 Anatomic and Functional Characteristics of Left Atrial Appendage in Relation to the Need of Anti Coagulation in Patients With 0-1 Chadvasc Score

VORTEX CHARACTERISTIC RESEARCH OF LEFT ATRIAL APPENDAGE IN ATRIAL FIBRILLATION PATIENTS BY TRANSOESOPHAGEAL ECHOCARDIOGRAPHY WITH VECTOR FLOW MAPPING

Objective: Analyze vorticity parameters and explore the hemodynamic characteristics of left atrial appendage(LAA) in atrial fibrillation(AF) patients using transoesophageal echocardiography(TEE) by vector flow mapping (VFM). Methods: 27 AF patients, mean age(51±11.50), were enrolled in this study

Left Atrial Appendage Parameters Assessed by Real-Time Three-Dimensional Transesophageal Echocardiography Predict Thromboembolic Risk in Patients With Nonvalvular Atrial Fibrillation.

In nonvalvular atrial fibrillation (NVAF) patients, the effect of left atrial appendage (LAA) morphology, structure, and hemodynamic characteristics evaluated by real-time 3D transesophageal echocardiography (RT3D-TEE) on thromboembolic risk has not been elucidated. A total of 444 NVAF patients who underwent clinically indicated RT3D-TEE were enrolled in the study. The orifice size, orifice area, depth, and volume measurements of the LAA were assessed using Philips QLAB 9.0. The LAA characteristics were compared among different CHA2 DS2 -VASc thromboembolic risk subgroups, as well as between the thromboembolic event and nonevent groups. The orifice size, orifice area, and end-diastolic volumes of the LAA were increased with an increasing CHA2 DS2 -VASc risk score in the NVAF patients, whereas the emptying rate was decreased. The NVAF patients with LAA thrombus exhibited a significantly increased end-diastolic volume (7.39 ± 3.47 versus 5.21 ± 2.59 mL, P = .003) and higher prevalence of the cauliflower shaped LAA (64.3% versus 25%, P = .004) compared with those without thrombus. Logistic regression indicated that the LAA end-diastolic volume (P = .002; odds ratio 1.556; 95% confidence interval 1.176-2.057) and cauliflower shape (P = .001; odds ratio, 10.177; 95% confidence interval, 2.458-42.140) were independent predictors of thromboembolic events in patients with NVAF following adjustment for the CHA2 DS2 -VASc score. The LAA end-diastolic volume and cauliflower phenotype predict thromboembolic events independent of the CHA2 DS2 -VASc score, and these data improve stroke prediction in NVAF patients.

Left Atrial Appendage characteristics in patients with Persistent Atrial Fibrillation undergoing catheter ablation (LAAPAF Study).

Despite technological and scientific efforts, the recurrence rate of persistent atrial fibrillation (AF) remains high. Several studies have shown that in addition to pulmonary vein (PV) isolation other non-PV triggers, particularly left atrial appendage may be the source of initiation and maintenance of AF. There are few studies showing the role of left atrial appendage (LAA) isolation in order to obtain higher success rate in persistent AF patients. We analyzed the LAA volume, volume index and shape relative to the LA in patients with persistent AF undergoing AF ablation. Fifty-nine consecutive patients with persistent AF who underwent catheter ablation were enrolled. Computerized tomography (CT) was performed in order to assess left atrial and PV anatomy including the LAA. Digital subtraction software (GE Advantage Workstation 4.3) was used to separate the LAA from the LA and calculate: LA volume (LAV), LA volume index (LAV/body surface area), LAA volume (LAAV), LAA volume index (LAA volume/LA volume), and LAA morphology [chicken wing (CW) or non-chicken wing (NCW)]. The mean age was 64.6 ± 9.8 years, 44 % male, and LA diameter 47.6 ± 7.8 mm. Median follow-up (FU) was 13 months. All patients had antral isolation of PVs and ablation of complex fractionation ± linear ablation (roof line/superior coronary sinus/mitral line). Among 59 patients with persistent AF, 26 (44 %) patients were diagnosed with AF recurrences. Mean LAV was 145.0 ± 45.9 ml, LAVI 68.9 ± 20.0 ml/m2, LAAV 10.3 ± 4.0 ml, and LAAVI 7.3 ± 2.7 ml/m2. LAA shape was non-chicken wing (NCW) in the majority of patients (51 %). LAA parameters were not significantly different between patients with and without AF recurrence (LAAV 11.0 ± 4.3 ml vs. 9.7 ± 3.8 ml, p=0.26; LAAVI 7.5 ± 3.0 ml/m2 vs. 7.2 ± 2.5 ml/m2, p=0.71; LAA shape of NCW 50 % vs 52 %, p=0.75, respectively). LAV was significantly correlated with the LAAV (r: o.47, p=0.009). The incidence of NCW LAA was significantly higher in patients with previous stroke/TIA (80 % vs. 20 %, p=0.04). The LAA anatomical characteristics (volume/volume index and the shape) were comparable in patients with/out AF recurrence post PVI. It remains to be determined if additional LAA isolation will impact outcomes in patients with persistent AF.

TCT-621 Left atrial appendage characteristics evaluated by computed tomography following closure with Watchman device

Closure of the left atrial appendage (LAA) utilizing the Watchman device has been demonstrated to be an efficacious prophylaxis for stroke. Characterization of the LAA has been performed with both transesophageal echocardiography (TEE) and computed tomography (CT). The LAA is a dynamic, compliant