Left Atrial Appendage Function Research Articles

Analysis of the left atrial appendage function by intracardiac echocardiography in patients with atrial fibrillation

Abstract Introduction Intracardiac echocardiography (ICE) is frequently performed during catheter ablation procedures in order to guide the transseptal puncture and has been recently used to evaluate the morphology of the LAA. Purpose The objective of this study was to evaluate the feasibility of using an ICE catheter placed in the coronary sinus (CS) to delineate the LAA function during catheter ablation for atrial fibrillation. Methods We included 21 consecutive patients (age 62±9 years, 5 women, 6 paroxysmal AF) who underwent catheter ablation for AF. An 8-Fr phased-array ICE catheter was used to obtain images of the LAA, while in sinus rhythm. The LAA was visualized with the ICE probe placed sequentially in the left atrium (LA, Figure A), with the ultrasound section plane parallel to the long axis of the left ventricle (LV), and in the CS, with the ultrasound section plane perpendicular to the LV long axis (Figure B). LAA emptying flow velocity, and LAA fractional area change (FAC) were used to evaluate LAA function. There were no procedural complications. Results ICE imaging was possible in all cases. The LAA peak flow velocity was similar when the ICE catheter was placed in the LA and in the CS (64±7 cm/s and 62±5cm/s respectively, P=NS). The LAA FAC was significantly lower when the ICE catheter was placed in the CS when compared to an LA location (14±6% vs 36±14%; P<0.001). The LAA FAC measured from the LA correlated with the mitral annular plane systolic excursion while the LAA FAC measured from the CS did not. Thus, LAA contraction in a plane perpendicular to the LV long axis is independent of the LV longitudinal contraction. These results suggest that in our patient group most of the LAA contraction was due to the longitudinal movement of the LV base during systole and diastole. Conclusions Imaging of LAA using an ICE probe positioned in the LA and CS was feasible in all cases. The LV longitudinal contraction appears to impact the LAA function.

Assessing Left Atrial Appendage Functions by Transesophageal Echocardiography and Speckle Tracking Imaging to Predict Recurring Atrial Fibrillation Post-Radiofrequency Catheter Ablation.

To predict recurring atrial fibrillation (AF) following radiofrequency catheter ablation by assessing the attributes of the left atrium and the left atrial (LA) appendage (LAA) using transesophageal echocardiography (TEE) and speckle tracking imaging. The structural and functional indices of the LA and LAA of 80 patients with AF who underwent preoperative transthoracic echocardiography and TEE were measured. Recurrence was recorded postoperatively at 3, 6, and 12 months. The independent determinants of recurring AF were identified by logistic regression, and their optimum cutoff values, sensitivity, and specificity were estimated from the receiver operating characteristic (ROC) curves. The recurrent and nonrecurrent groups comprised 17 and 63 patients, respectively. The LA internal diameter, LA end-diastolic and end-systolic volumes, LAA length, diameter and area of the opening of the LAA, and LAA end-diastolic volume were higher in the recurrent group. The LA strain in the reservoir phase, the ejection fraction and filling velocity of the LAA, the LAA emptying velocity (LAAeV), and the LAA strain (LAAS) reduced considerably. Multifactorial regression analyses demonstrated that the LAAeV and LAAS were independent determinants of recurring AF. ROC curve analysis revealed that the LAAeV and LAAS predicted postoperative recurrence at 34.5cm/s (area under the curve [AUC]: 0.954, sensitivity: 94.1%, and specificity: 92.1%) and 11.61% (AUC: 0.925, sensitivity: 82.4%, and specificity: 95.2%), respectively, while the AUC, sensitivity, and specificity of the combined predictors (LAAeV+LAAS) were 0.978, 94.1%, and 93.7%, respectively. The LAAeV and LAAS independently influenced the postoperative recurrence of AF.

Assessment of Coagulation Factors in Patients with Severe Rheumatic Mitral Stenosis in Sinus Rhythm with Left Atrial Appendage Inactivity

BackgroundPatients with severe mitral stenosis (MS) in normal sinus rhythm (NSR), presenting with left atrial appendage (LAA) inactivity and associated left atrial spontaneous echo contrast (LASEC) are prone to left atrium (LA) or LAA thrombus formation. But unlike for atrial fibrillation, oral anticoagulants are not commonly prescribed for this patient subset. This study aimed to compare the levels of procoagulants and fibrinogen in both local (LA) and systemic contexts between patients with severe MS in NSR vs those in healthy control subjects. MethodsThe study involved 35 patients with severe MS in NSR with LAA inactivity and LASEC who were eligible for balloon mitral valvuloplasty vs 35 healthy controls. All patients underwent transthoracic and transesophageal echocardiography to assess MS severity, LAA activity, and LASEC grade, and had blood samples analyzed for procoagulant levels. ResultsResults showed comparable baseline characteristics between groups, with most patients in the New York Heart Association II or III functional classes, and with varying LASEC grades. Patients exhibited significantly higher levels of prothrombin fragment 1 + 2 [patient vs control, 9017 pg/mL (6228.0-10,963.5) vs 1790 pg/mL (842.3-2712), P < 0.0001], thrombin-antithrombin III [patient vs control, 39 ng/mL (5.45-74.85) vs 2.80 ng/mL (1.6-6.5), P < 0.0001], plasminogen activator inhibitor-1 (patients vs controls, 26.09 ± 8.18 ng/mL vs 8.05 ± 3.53 ng/mL, P < 0.0001), and fibrinogen (3.48 ± 0.89 g/L vs 3.01 ± 0.53 g/L, P = 0.029) in the LA of patients, compared to those in control subjects. Systemic procoagulant levels also were elevated in patients, but D-dimer levels were similar between the 2 groups. ConclusionsThe findings suggest a hypercoagulable state in patients, similar to that in patients with atrial fibrillation. The study advocates for consideration of use of oral anticoagulants in these patients until LA and LAA function improves, to mitigate thrombus formation.

Correlation between Anterior Mitral Annular Plane Systolic Excursion and Left Atrial Appendage Stasis in Patients with Nonvalvular Atrial Fibrillation.

Atrial fibrillation (AF) can lead to a decline in left atrial appendage (LAA) function, potentially increasing the likelihood of LAA thrombus (LAAT) and spontaneous echo contrast (SEC). Measuring LAA flow velocity through transesophageal echocardiography (TEE) is currently the primary method for evaluating LAA function. This study aims to explore the potential correlation between anterior mitral annular plane systolic excursion (aMAPSE) and LAA stasis in patients with non-valvular atrial fibrillation (NVAF). A total of 465 patients with NVAF were enrolled between October 2018 and November 2021. Transthoracic echocardiography (TTE) and TEE were performed before scheduled electrical cardioversion. Propensity score matching (PSM) was used to balance confounders between the groups with and without LAAT/dense SEC. Patients in the LAAT/dense SEC group showed increased left atrial (LA) diameter, LAA area, alongside reduced left ventricular ejection fraction (LVEF), LAA velocity, conjunction thickening ratio, aMAPSE, and LAA fraction area change (FAC) compared to those in the non-LAAT/dense SEC group. Multivariate logistic regression analysis identified aMAPSE and LAA FAC as independent predictors for LAAT/dense SEC. Specifically, an aMAPSE of 6.76 mm and an LAA FAC of 29.65% predicted LAAT/dense SEC with high diagnostic accuracy, demonstrated by an area under the curve (AUC) of 0.81 (sensitivity 0.81, specificity 0.80) for aMAPSE, and an AUC of 0.80 (sensitivity 0.70, specificity 0.84) for LAA FAC. Both aMAPSE and LAA FAC independently correlated with and accurately predict LAAT/dense SEC. Incorporating aMAPSE into routine TEE evaluations for LAA function alongside LAA flow velocity is recommended.

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.

Minimally invasive left atrial appendage occlusion plus reduced dose direct oral anticoagulant to prevent stroke in patients with atrial fibrillation-the LAAO-PlusRE.

The onset of atrial fibrillation (AF) has a direct association with left atrial appendage (LAA) function, as demonstrated by recent studies demonstrating the link between left atrial (LA) wall fibrosis, impaired contractility, and the development of AF. Non-valvular AF (NVAF) affects almost 30 million people worldwide, with this number expected to increase in the next 20 years. It is the main cause of ischemic stroke, with significant subsequent economic and social impact. Currently, the mainstay of stroke prevention in patients with NVAF is oral anticoagulation (OAC), which reduces the incidence of ischemic events at the stake of increased hemorrhagic events. Despite the introduction and widespread use of direct oral anticoagulants (DOACs), which almost completely replaced vitamin K antagonists (VKAs), the adherence to OAC is still low, hindering the efficacy of stroke prevention. Percutaneous LAA occlusion (LAAO) is now indicated (class IIB) in patients with NVAF at increased ischemic risk who cannot undergo OAC. Recently published data demonstrated that a reduced dose of DOAC after percutaneous LAAO is superior to long-term dual antiplatelet therapy (DAPT) for stroke prevention in the mid-term. One of the possible pitfalls of percutaneous LAAO is postprocedural peri-device leaks (PDLs) that have been associated with increased thromboembolic events. According to LAAOS III results, surgical LAAO during cardiac surgery brings a 33% reduction in risk of stroke at five years, independently from the OAC regimen with a high rate of complete appendage occlusion. The combination of surgical LAAO and reduced dose DOAC might ensure adequate embolic prevention, lowering the hemorrhagic risk. The present manuscript aims to describe the rationale and design of the Minimally Invasive Left Atrial Appendage Occlusion Plus REduced Dose DOAC To Prevent Stroke In Patients With Atrial Fibrillation Randomized Clinical Trial (LAAO-PlusRE).

Two-dimensional speckle tracking imaging analyses of the correlations between left atrial appendage function and stroke risk in nonvalvular atrial fibrillation patients.

Stroke incidence is the most severe complication associated with atrial fibrillation (AF), and the most common site of thrombus formation in AF patients is the left atrial appendage (LAA). This study was developed to use two-dimensional speckle tracking imaging (2D-STI) to explore associations between LAA strain/strain rate and stroke incidence and to evaluate the value of utilizing LAA strain and strain rate values to support the stratification of nonvalvular AF (NVAF) patients based on stroke risk. A total of 486 AF patients who had undergone transesophageal echocardiography to exclude potential intracardiac thrombosis between March 2021 and November 2022 were consecutively enrolled. Patients meeting the inclusion criteria were separated into two groups according to their history of stroke/transient ischemic attack (TIA). LAA strain and strain rate values in these patients were measured via 2D-STI. Multivariable logistic regression analysis was employed to determine independent risk factors for the construction of a combined predictive model. Of the 333 analyzed patients (134 females, aged 65 (56,72) years), 39 (11.71%, 39/333) had a history of stroke at the time of evaluation. Multivariate logistic regression analysis demonstrated that nonparoxysmal AF, CHA2DS2VASc score, LAA thrombus/spontaneous echo contrast (SEC), LAA strain, and strain rate were all predictors of stroke incidence among NVAF patients. The combined predictive model demonstrated excellent discriminative ability, with an AUC of 0.91 (95%CI 0.87-0.95, P < 0.001), and a sensitivity and specificity of 79.49% and 89.46%, respectively. The Hosmer-Lemeshow test confirmed good calibration, yielding a value of 0.98. Comparative decision curve analysis showed that the model provided superior net benefits compared to the CHA2DS2VASc score. Furthermore, the model exhibited improved predictive performance and reclassification for stroke when compared to the CHA2DS2VASc score (AUC 0.91 vs. 0.88, Z = 2.32, P = 0.02), accompanied by a significant increase in the net reclassification index (+ 5.44%, P < 0.001) and integrated discrimination improvement (8.21%, P < 0.001). These data demonstrate that LAA strain and strain rate, as measured via 2D-STI, can offer value when assessing LAA function in AF patients, potentially providing further predictive value to extant clinical risk scoring strategies.

Efficacy of Low-Dose Isoproterenol Infusion for the Exclusion of a Left Atrial Appendage Thrombus in Patients With Dense Spontaneous Echo Contrast Caused by Atrial Fibrillation.

In patients with atrial fibrillation (AF) and severe blood stasis in the left atrial appendage (LAA), dense spontaneous echo contrast (SEC) disturbs the distinct visualization of the LAA interior, thus making thrombus diagnosis inconclusive. We aimed to prospectively assess the efficacy and safety of a protocol for a low-dose isoproterenol (ISP) infusion to reduce SEC to exclude an LAA thrombus.Methods and Results: We enrolled 17 patients with AF and dense SEC (Grade 4 or sludge). ISP was infused with gradually increasing doses of 0.01, 0.02, and 0.03 μg/kg/min at 3-min intervals. After increasing the dose to 0.03 μg/kg/min for 3 min, or when the LAA interior was visible, the infusion was terminated. We reassessed the SEC grade, presence of an LAA thrombus, LAA function, and left ventricular ejection fraction (LVEF) within 1 min of ISP termination. Compared with baseline, ISP significantly increased LAA flow velocity, the LAA emptying fraction, LAA wall velocities, and LVEF (all P<0.01). ISP administration significantly reduced the SEC grade (median) from 4 to 1 (P<0.001). The SEC grade decreased to ≤2 in 15 (88%) patients, and the LAA thrombus was excluded. There were no adverse events. Low-dose ISP infusion may be effective and safe to reduce SEC and exclude an LAA thrombus by improving LAA function and LVEF.

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.

Left atrial appendage geometry and function using transesophageal three-dimensional echocardiography in atrial fibrillation: a new approach to characterize left atrial thrombogenic milieu

Abstract Background Little data is available on the evaluation of left atrial appendage (LAA) geometry and function using three-Dimensional (3D) transoesophageal echocardiography (TEE). Purpose We hypothesized that 3D LAA geometry evaluated using dedicated TEE software could be integrated in the evaluation of the thromboembolic milieu in patients hospitalized for atrial fibrillation (AF). Methods We prospectively studied 206 hospitalized patients with 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) (Figure 1). Patients were divided into two groups according to the presence (n = 35) or absence (n = 171) of LAA sludge/thrombus on admission. Results Patients with LAA sludge/thrombus had more frequently a history of heart failure together with higher values of BNP, CRP and hemoglobin. These patients received less frequently angiotensin II receptor antagonist treatment on admission. Concerning the echocardiographic characteristics, patients with LAA sludge/thrombus exhibited higher left atrial (LA) volume, lower left ventricular ejection fraction (LVEF) and cardiac output. In the 2D TEE study they had lower LAA emptying and filling flow velocities compared to those without sludge/thrombus. 3D TEE showed overall higher 3D end-systolic (ES) and end-diastolic (ED) LAA measurements (ostium area, length, volume), and more frequently the absence of a chicken wing morphology. There were no intergroup differences regarding the number of LAA lobes (Table 1). Conclusion 3D characterization of LAA geometry and function depicts a degree of appendage remodeling in AF that appears to be associated with the degree of thrombogenicity. Further investigation is needed to determine the impact of this remodeling on outcomes in these patients.

Invasively diagnosed HFpEF in AF associated with functional remodelling of the left atrial appendage: implications for stroke risk

Abstract Background HFpEF commonly coexists with atrial fibrillation (AF). The influence of coexisting HFpEF on function of the left atrial appendage (LAA) and risk of stroke remains unknown. Objective To use invasive hemodynamic assessment and multi-modality imaging to evaluate the influence of underlying HFpEF on LAA function in patients with symptomatic AF. Methods Patients with AF and preserved ejection fraction undergoing AF ablation were prospectively recruited. All participants underwent invasive diagnosis of HFpEF using established hemodynamic criteria. Participants were classified as ‘HFpEF’ when mean left atrial pressure (mLAP) was &amp;gt;15mmHg and ‘early HFpEF’ when mLAP rose to above 15mmHG after infusion of 500mls saline. For LAA assessment, participants underwent 1) contrast-enhanced cardiac CT to evaluate LAA volume, 2) transesophageal echocardiography to investigate emptying velocities (LAAEV), filling velocities (LAAFV) and LAA ejection fraction (LAAEF) and 3) high-density electroanatomic mapping to assess LAA bipolar voltages. Results Of 115 participants recruited, 55 had ‘HFpEF’, whilst 29 had ‘early HFpEF’ and 31 had ‘no HFpEF’. Table 1 demonstrates the baseline characteristics and LAA structural and functional parameters across the three groups. The HFpEF group was characterized by higher BMI (p=0.008) and higher prevalence of hypertension (p=0.023) but there was no significant difference in age (p=0.194) or gender (p=0.376). LAA volume was not significantly different across the three groups (p=0.509). However, the HFpEF group demonstrated reduced LAAEV (p=0.021) and LAAFV (p=0.015) compared to early HFpEF and no HFpEF. HFpEF was also associated with reduced LAAEF (p=0.015) and reduced LAA bipolar voltages in sinus rhythm (p=0.028) compared to no HFpEF. In a multivariable analysis HFpEF group was the only independent predictor of reduced LAAEV (p=0.015). Conclusions Invasively diagnosed HFpEF in AF is common and associated with significantly reduced LAA function. The coexistence of HFpEF may therefore be a determinant of future stroke risk in patients with AF.

The assessment of left atrial and left atrial appendage mechanics in patients with different stages of atrial fibrillation

Abstract Background Atrial fibrillation (AF) is associated with left atrial (LA) mechanical dysfunction, which predisposes to stasis of blood within the LA and thus increases the risk of stroke. However, limited is known about the mechanical functional alterations of left atrial appendage (LAA) in relation to stages of AF. Here, we sought to analyse LA and LAA mechanics during different stages of AF in detail. Methods A total of 92 patients with AF referring for radiofrequency ablation were consecutively enrolled. Patients were categorized according to rhythm and stages of AF:sustained AF(SAF) (n=31), paroxysmal AF with sinus rhythm(PAF-SR)(n=30) andAF rhythm(PAF-AF)(n=31)at the time of echocardiography. Twenty-seven patients without a history of AF were included as controls. Using speckle-tracking echocardiography, LA and LAA global peak positive longitudinal strain (GLS) and mechanical dispersion (MD) were measured in all patients. Mechanical dispersion was defined as the standard deviation of the time to peak of the regional strain corrected by R-R interval. Results Patients with PAF-AF and SAF displayed prominently impaired LA and LAA mechanics(all P &amp;lt; 0.01 vs. PAF-SR and no AF). In the presence of SR, only LAA mechanical function were lower in PAF patients than patients without AF(LAA GLS 20.5±5.7%(no AF) vs 15.9±5.4%(PAF-SR); LAA MD 6.9±3.8%(no AF) vs 9.4±3.9(PAF-SR),both P&amp;lt;0.01). AF stages were independent determinants of LA and LAA mechanics after adjusting for age and comobidities. Conclusions AF affected mechanical function of LA and LAA on their own, and more so if stage of AF has advanced to more persistent forms. In addition, LAA mechanical dysfunction occurred earlier than that of LA.fig 1fig 2

Abstract 15625: Left Atrial Appendage Volumetric and Functional Assessment Using Cardiac CT-Derived Three-Dimensional Models

Introduction: The left atrial appendage (LAA) is the most common site of thrombus formation in atrial fibrillation (AF) patients who develop strokes, yet its dynamic volumetric parameters remain uncharacterized. We present a quantitative analysis of cardiac phase-specific LAA volumes and function using cardiac CT-derived three-dimensional (3D) models of 920 LAA segmentations. Methods: We measured LAA volumes at 10% increments of the cardiac cycle (R-R interval) in patients with AF and controls with sinus rhythm (SR). After identifying the LAA orifice using anatomical landmarks on multiplanar CT images, we performed computational LAA segmentation using specialized software. For precise mapping, we used iterative active region-growing and cutting tools to separate the LAA from surrounding structures. We used the resulting 3D model for volumetric assessment of the LAA during the cardiac cycle. Results: We analysed 580 LAA segmentations in patients with AF and 340 segmentations in patients with SR. Both groups displayed LAA volume increase from 0 to 40% of the cardiac cycle followed by a gradual decrease during diastole. LAA volumes were significantly higher in AF at 0%, 10%, 70%, 80%, and 90% of the cardiac cycle (p =0.01, 0.021, 0.047, 0.025 and 0.011, respectively). LAA volumetric variance within the AF group was significantly greater (p&lt;0.001). LAA ejection fraction was significantly lower in AF compared to SR (40.8±16.1% vs 49.7±12.6%, p=0.003). Polynomial plots of incremental volume changes showed an accelerated rate of LAA filling in early systole in the SR, which was significantly dampened in AF. Conclusions: We present the first comparative analysis of LAA volumetric and functional assessment in patients with AF and SR. We conclude that impaired LAA filling and emptying in AF can contribute to blood stasis and thrombogenicity. Further investigations into the utility of LAA metrics as prognostic and risk-stratification tools in patients with AF are warranted.

Assessment of left atrial appendage flow velocities to unmask atrial fibrillation in cryptogenic stroke

Abstract Funding Acknowledgements Type of funding sources: None. Background Hemostasis in the left atrial (LA) appendage (LAA) is a common cause of stroke, particularly in atrial fibrillation (AF). LAA flow have been determined to quantify LAA function. Objectives To investigate whether LAA peak flow velocities early after cryptogenic stroke have a predictive value for AF occurrence and to determine the determinants of impaired flow. Methods Consecutive cryptogenic stroke patients (139) were enrolled. LAA flow velocities during sinus rhythm were assessed early post-stroke with transesophageal echocardiography. All patients received rhythm monitoring using 7-day Holter and if negative, an implantable cardiac monitor. Results 47 Patients (34%) developed AF during a median follow-up of 554 days, median time to AF diagnosis was 93 days. Both, LAA filling (LAAfv) and emptying (LAAev) velocities were lower in stroke patients who developed AF (resp. 44.3±14.2 cm/s and 50.7±13.3 cm/s) compared with those who didn’t (resp. 59.8±14.0 cm/s and 76.8±17.3 cm/s). LAAev was the strongest predictor of AF with an AUC of 0.878 in ROC curve analysis and with optimal cut-off value of 55 cm/s. Age and mitral regurgitation were independent determinants of reduced LAAev. Conclusions Reduced LAA flow velocities can identify cryptogenic stroke patients at high risk of occult AF, and who may benefit from intensive rhythm monitoring or anticoagulation strategies.

Reduced Left Atrial Appendage Flow Is Associated With Future Atrial Fibrillation After Cryptogenic Stroke

Hemostasis within the left atrial appendage (LAA) is a common cause of stroke, especially in patients with atrial fibrillation (AF). Although LAA flow provides insights into LAA function, its potential for predicting AF has yet to be established. The aim of this study was to explore whether LAA peak flow velocities early after cryptogenic stroke are associated with future AF on prolonged rhythm monitoring. A total of 110 patients with cryptogenic stroke were consecutively enrolled and underwent LAA pulsed-wave Doppler flow assessment using transesophageal echocardiography within the early poststroke period. Velocity measurements were analyzed offline by an investigator blinded to the results. Prolonged rhythm monitoring was conducted on all participants via 7-day Holter and implantable cardiac monitoring devices, with follow-up conducted over a period of 1.5years to determine the incidence of AF. The end point of AF was defined as irregular supraventricular rhythm with variable RR interval and no detectable P waves lasting ≥30sec during rhythm monitoring. During a median follow-up period of 539 days (interquartile range, 169-857 days), 42 patients (38%) developed AF, with a median time to AF diagnosis of 94 days (interquartile range, 51-487 days). Both LAA filling velocity and LAA emptying velocity (LAAev) were lower in patients with AF (44.3±14.2 and 50.7± 13.3cm/s, respectively) compared with patients without AF (59.8±14.0 and 76.8±17.3cm/sec, respectively; P<.001 for both). LAAev was most strongly associated with future AF, with an area under the receiver operating characteristic curve of 0.88 and an optimal cutoff value of 55cm/sec. Age and mitral regurgitation were independent determinants of reduced LAAev. Impaired LAA peak flow velocities (LAAev<55cm/sec) in patients with cryptogenic stroke are associated with future AF. This may facilitate the selection of appropriate candidates for prolonged rhythm monitoring to improve its diagnostic accuracy and implementation.

Characterization of left atrial appendage geometry and function using three-dimensional transesophageal echocardiography in patients in atrial fibrillation

Few data are available on left atrial appendage (LAA) remodeling using three-dimensional (3D) transoesophageal echocardiography (TEE) in patients in atrial fibrillation (AF). The aim of this study was to evaluate LAA thrombogenic milieu, LAA velocities, spontaneous echocardiographic contrast/thrombus, 3D LAA geometry and volume in AF. We prospectively evaluated patients 206 hospitalized for AF with two-dimensional (2D) transthoracic and 3D TEE of the LAA within 24 hours of admission. 3D parameters were off-line analysed using Tomtec software (4D Cardio-View, Generic Volume, Philips) (Fig. 1). Patients were divided into two groups according to the type of AF at admission: paroxysmal AF (62 patients) or persistent AF (144 patients). Patients with persistent AF had higher BMI, more prevalent hypertension and diabetes, as well as history of AF, heart failure, renal failure. They had also higher CHA2DS2-VASc. Patients with persistent AF at admission had lower LVEF, higher left atrial volume, higher E and E/e′ and pulmonary arterial systolic pressure. Patients with persistent AF had more severe LAA spontaneous echo contrast/sludge, lower LAA emptying and filling flow velocity, and higher 3D LAA measurements (ostium area, length, volume) (Table 1). 3D evaluation of the LAA may reflect atrial remodeling in AF and seems to be associated with the burden of AF. Follow-up data are needed to determine the impact of such abnormalities in the risk stratification of such patients.

The novel left atrial appendage strain parameters are associated with thrombosis risk in patients with non-valvular atrial fibrillation.

We sought to explore a novel left atrial appendage (LAA) strain parameter which could represent the cumulative adverse impact of chronic Atrial fibrillation (AF) on the LAA function, and the relationship between the LAA strain parameter and thrombosis risk in patients with non-valvular AF. We enrolled 268 patients with non-valvular AF and 58 sinus rhythm subjects who underwent transesophageal echocardiography in the study. LAA longitudinal strain amplitude (LAA LSA) was defined as the sum of the value of the maximum positive peak strain (LAA PLS) and the absolute value of the minimum negative peak strain (LAA NLS). Dense spontaneous echo contrast (SEC) was defined as grade 3 or 4 SEC. Compared to sinus rhythm group, the global LAA strain parameters were significantly lower in paroxysmal AF (n = 148), and the lowest of them were found in persistent AF (n = 120), which suggested that the global LAA strain parameters could evaluate LAA function in sinus rhythm, paroxysmal AF and persistent AF. Compared with patients in AF without SEC/thrombus (n = 113), the regional and global LAA strain parameters were significantly depressed in AF with SEC/thrombus (n = 155). Multivariate logistic regression analyses showed that LAA global LSA (OR 0.768; 95% CI:0.569, 0.970; p = 0.027) was an independent predicter of the SEC/thrombus. Compared with patients in AF without dense SEC or thrombus (n = 210), the regional and global LAA strain parameters were significantly impaired in the patients with dense SEC/thrombus(n = 58). LAA global LSA (AUC 0.884) had the best predictable accuracy for dense SEC or thrombus, and outperformed LAA PLS, LAA NLS, CHA2DS2-VASc score and conventional LAA functional parameters that have been used in the evaluation blood flow stasis in LAA. LAA LSA showed excellent interobserver and intra-observer agreement beyond LAA PLS and LAA NLS. The novel LAA strain parameters, which were feasible and reproducible parameters for evaluation LAA mechanic function, had good predictive accuracy for blood flow stasis in LAA beyond conventional LAA functional parameters.

Left atrial appendage strain predicts subclinical atrial fibrillation in embolic strokes of undetermined source.

Left atrial (LA) strain is promising in prediction of clinical atrial fibrillation (AF) in stroke patients. However, prediction of subclinical AF is critical in patients with embolic strokes of undetermined source (ESUS). The aim of this prospective study was to investigate novel LA and left atrial appendage (LAA) strain markers in prediction of subclinical AF in ESUS patients. A total of 185 patients with ESUS, mean age 68 ± 13years, 33% female, without diagnosed AF, were included. LAA and LA function by conventional echocardiographic parameters and reservoir strain (Sr), conduit strain (Scd), contraction strain (Sct), and mechanical dispersion (MD) of Sr were assessed with transoesophageal and transthoracic echocardiography. Subclinical AF was detected by insertable cardiac monitors during follow-up. LAA strain was impaired in 60 (32%) patients with subclinical AF compared to those with sinus rhythm: LAA-Sr, 19.2 ± 4.5% vs. 25.6 ± 6.5% (P < 0.001); LAA-Scd, -11.0 ± 3.1% vs. -14.4 ± 4.5% (P < 0.001); and LAA-Sct, -7.9 ± 4.0% vs. -11.2 ± 4% (P < 0.001), respectively, while LAA-MD was increased, 34 ± 24 ms vs. 26 ± 20 ms (P = 0.02). However, there was no significant difference in phasic LA strain or LA-MD. By ROC analyses, LAA-Sr was highly significant in prediction of subclinical AF and showed the best AUC of 0.80 (95% CI 0.73-0.87) with a sensitivity of 80% and a specificity of 73% (P < 0.001). LAA-Sr and LAA-MD were both independent and incremental markers of subclinical AF in ESUS patients. LAA function by strain and mechanical dispersion predicted subclinical AF in ESUS patients. These novel echocardiographic markers may improve risk stratification in ESUS patients.

Assessment of left atrial appendage function by echocardiography.

The left atrial appendage (LAA) is considered not only to be the most frequent site of thrombus formation, but also to play a pivotal role in maintaining normal cardiac function. Transesophageal echocardiography (TEE) is widely used to assess LAA function. TheLAA flow velocityhasbeen used as a surrogate for LAA function, and it varies with multiple interrelated factors including age, hemodynamics, type of arrhythmia, and antiarrhythmic interventions. Relatively great importance ofLAA function is involved with intraatrial thrombus formation and subsequent thromboembolism, and thus, understanding of characteristics and behaviors of the LAA under various clinical conditions may help determine strategies against atrial thrombosis. Also, techniques other than TEE-derived Doppler to assess LAA function, such as tissue Doppler imaging, have been proposed. In this review, we introduce clinical and echocardiographic correlates of LAA function, the LAA flow velocity in particular, its significance, and how to interpret functional patterns of the LAA each relevant to specific clinical settings.

EMCAPT study: the effect of MitraClip treatment on the mitral annulus and left atrial appendage evaluation by transoesophageal echocardiography.

Data on the change in mitral valve annulus diameter (MAD), and left atrial appendage (LAA) structure and function after transcatheter edge-to-edge repair (TEER) of the mitral valve in patients with secondary mitral regurgitation (MR) are lacking. To evaluate the change in these parameters just after the clip insertion and its relationship with prognosis in the long term. A total of 50 patients (age: 71.5 ±11.3 years, 70% male) with moderate-to-severe or severe MR were included in the study. Transthoracic (TTE) and transoesophageal echocardiography (TEE) were performed before and after the procedure. Prognostic data were recorded with post-procedure telephone calls and follow-up visits. TEE performed during the procedure showed that LAA contraction and filling velocity significantly increased (p < 0.001 for all). Systolic pulmonary artery pressure (SPAP), MAD, and LAA landing zone dimension significantly decreased (p < 0.001 for all). There was only a significant correlation between the MAD before clip placement and the MAD change after clip placement (r = 0.6, p < 0.001). During a mean follow-up period of 10.5 ±8.9 months, no significant correlation was found between MAD change, LAA contraction and filling velocity change, and LAA landing zone dimension change and rehospitalization, stroke, mortality, and composite outcome. The contraction and filling velocity of LAA, SPAP, MAD, and LAA landing zone dimension changed significantly immediately after the MitraClip procedure. Although these parameters are not related to composite outcome in our study, MAD, LAA diameter, and velocity need to be compared between successful and unsuccessful procedures to predict their clinical relevance.