Left Atrial Appendage Peak Flow Velocity Research Articles

Impact of left atrial appendage flow velocity on thrombus resolution and clinical outcomes in patients with atrial fibrillation and silent left atrial thrombi: insights from the LAT study.

Blood stasis is crucial in developing left atrial (LA) thrombi. LA appendage peak flow velocity (LAAFV) is a quantitative parameter for estimating thromboembolic risk. However, its impact on LA thrombus resolution and clinical outcomes remains unclear. The LAT study was a multicentre observational study investigating patients with atrial fibrillation (AF) and silent LA thrombi detected by transoesophageal echocardiography (TEE). Among 17 436 TEE procedures for patients with AF, 297 patients (1.7%) had silent LA thrombi. Excluding patients without follow-up examinations, we enrolled 169 whose baseline LAAFV was available. Oral anticoagulation use increased from 85.7% at baseline to 97.0% at the final follow-up (P < 0.001). During 1 year, LA thrombus resolution was confirmed in 130 (76.9%) patients within 76 (34-138) days. Conversely, 26 had residual LA thrombi, 8 had thromboembolisms, and 5 required surgical removal. These patients with failed thrombus resolution had lower baseline LAAFV than those with successful resolution (18.0 [15.8-22.0] vs. 22.2 [17.0-35.0], P = 0.003). Despite limited predictive power (area under the curve, 0.659; P = 0.001), LAAFV ≤ 20.0 cm/s (best cut-off) significantly predicted failed LA thrombus resolution, even after adjusting for potential confounders (odds ratio, 2.72; 95% confidence interval, 1.22-6.09; P = 0.015). The incidence of adverse outcomes including ischaemic stroke/systemic embolism, major bleeding, or all-cause death was significantly higher in patients with reduced LAAFV than in those with preserved LAAFV (28.4% vs. 11.6%, log-rank P = 0.005). Failed LA thrombus resolution was not rare in patients with AF and silent LA thrombi. Reduced LAAFV was associated with failed LA thrombus resolution and adverse clinical outcomes.

Left atrial appendage peak flow velocity predicts improvement in mitral regurgitation after atrial fibrillation ablation

BackgroundMitral regurgitation (MR) is associated with an increased risk of developing atrial fibrillation (AF) and high AF recurrence ratio after ablation. Left atrial appendage (LAA) is involved in left atrium (LA) pressure modulation and LAA peak flow velocity (LAAV) is validated as an indicator of LA contractile and reservoir function. LA function is related to the MR pathology, but the relationship between LAAV and improvement in MR after ablation remains unknown. MethodsThe present study included AF patients with moderate or severe MR from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry. We evaluated MR severity one-year post-ablation and assigned the patients based on MR improvement (at least a one-grade improvement in MR over one year) and investigated the impact of the relevant factors, including LAAV, on MR improvement. ResultsThis study population included a total of 289 patients [paroxysmal AF (PAF), 112 patients; persistent AF (PerAF), 177 patients]. Kaplan-Meier analysis demonstrated that the patients with MR improvement had a significantly lower risk of late arrhythmia recurrence than those without (log-rank p < 0.001). MR improvement was observed in 56.3 % (63/112) of PAF patients and 55.4 % (98/177) of PerAF patients. Multiple regression analysis showed that LAAV was an independent and significant determinant of MR improvement post-ablation in both PAF and PerAF patients (p = 0.037 and p = 0.018, respectively), in addition to age and hemoglobin in PerAF patients (p = 0.045 and p = 0.048, respectively). ConclusionLAAV can predict an improvement in MR after catheter ablation in both PAF and PerAF patients.

Relationship between left atrial appendage peak flow velocity and nonvalvular atrial fibrillation recurrence after cryoablation.

Previous studies revealed the connection between left atrial appendage peak flow velocity (LAA-PEV) and postoperative persistent atrial fibrillation (AF) recurrence. Yet, this association is not necessarily generalizable to persistent AF patients undergoing initial cryoballoon ablation due to current gaps in the literature. We prospectively studied 74 consecutive individuals with persistent atrial fibrillation undergoing a cryoballoon ablation for the first time between January 2018 and January 2020. Before ablation, LAA-PEV was documented by transesophageal echocardiography (TEE). Subsequently, demographic information and other clinical characteristics of these participants were collected. A 96-h continuous cardiac monitor was reviewed regularly for recurrence of atrial fibrillation. Cox proportional hazards regression was used to investigate LAA-PEV as well as other clinical characteristics as a predictor of AF recurrence. Our study found that AF recurrences had lower LAA-PEV than those without AF recurrence. A nonlinear relationship between the LAA-PEV and AF recurrence was observed in this study, which had an inflection point of 34.9. Subgroup analysis of female participants showed that LAA-PEV had a positive correlation with AF recurrence [β = 0.8, 95% CI (0.7, 0.9), p < 0.05]. A low LAA-PEV is related to recurrence of atrial fibrillation and may predict AF recurrence after initial cryoballoon ablation for persistent atrial fibrillation. This finding may help improve treatment and care strategies for patients with persistent atrial fibrillation.

Abstract 11162: Low Left Atrial Appendage Flow Velocity Predicts Treatment Failure in Patients With Left Atrial Thrombi: Insight From the LAT Trial

Background: Blood stasis is one of the important pathogeneses in the formation of left atrial (LA) thrombi. The LA appendage peak flow velocity (LAAV) is an established quantitative parameter for estimating the thromboembolic risk. However, it remains unknown whether the LAAV affects the successful resolution of LA thrombi even after prescribing an appropriate oral-anticoagulation treatment. Purpose: To evaluate whether the LAAV is associated with successful resolution of LA thrombi. Methods: The analysis was performed from the LAT trial, a multicenter observational study investigating the outcomes of silent LA thrombi detected by trans-esophageal echocardiography (TEE) or computed tomography. Management of oral anticoagulants was at the physician’s discretion, and resolution of LA thrombi was checked by follow-up TEE. Of 297 patients registered in the trial, we enrolled 236 patients (median age, 69 years; 28% female; 100% atrial fibrillation) whose baseline LAAV data was available in this study. Results: The prescription rates of oral-anticoagulants at baseline and the final follow-up were 83.5% and 93.6%, respectively (p = 0.002). During a median follow-up of 387 (interquartile range, 367-414) days after the thrombi detection, LA thrombi successfully resolved in 145 (61.4%) patients by altering the oral anticoagulants. Patients with resolved LA thrombi had a higher baseline LAAV than those without (28.4 ± 18.5 vs. 19.8 ± 9.3 cm/s, p &lt; 0.001). A receiver operating curve analysis revealed that the best cut-off value for predicting treatment success or failure was 25 cm/s (area under the curve: 0.651, p &lt; 0.001). After adjusting for age, gender, body mass index, heart failure, and warfarin use, an LAAV ≤ 25 cm/s was a significant predictor of failed resolution of LA thrombi (hazard ratio, 1.54; 95% confidence interval, 1.09-2.18; p = 0.015). Conclusions: In the LAT trial, one third of patients failed thrombolysis even 1 year after identifying silent LA thrombi. An LAAV ≤ 25 cm/s at baseline independently predicted treatment failure with oral anticoagulants.

The prognostic significance of left atrial appendage peak flow velocity in the recurrence of persistent atrial fibrillation following first radiofrequency catheter ablation.

BackgroundAtrial fibrillation (AF) relapse following radiofrequency catheter ablation (RFCA) for persistent atrial fibrillation (PeAF) continues to be a concern. This study establishes a connection between left atrial appendage peak flow velocity (LAAV) and recurrence of AF in individuals having PeAF following first RFCA.MethodsWe retrospectively studied 164 successive PeAF patients who had first RFCA between January 2018 and December 2019. Before the ablation, the LAAV was recorded using transesophageal echocardiography (TEE). The demographic and clinical data of the individuals were gathered. Participants were monitored at regular intervals to monitor for recurrence of AF. We employed Cox proportional hazards regression to determine if LAAV, as well as other clinical indicators, were predictive of AF recurrence in follow-up.ResultsIn this study, AF relapse was seen in 43 patients (26.2%) following a median follow-up of 15 [interquartile range (IQR): 12–18] months. It was shown that the LAAV was decreased in individuals who had recurrences of AF (0.36±0.05 vs. 0.45±0.17 m/s, P=0.004). Using Kaplan-Meier analysis, it was discovered that the low LAAV (0.37 m/s) group had a poorer event-free survival rate compared to the high LAAV (>0.37 m/s) group (17.6 vs. 21.2 months, log-rank P=0.002) group. Based on the results of the multivariate Cox regression analysis, a LAAV of fewer than 0.37 m/s [hazard ratio (HR): 2.32; 95% confidence interval (CI): 1.177–4.227; P=0.014] was shown to be an independent predictor of AF recurrence following RFCA.ConclusionsA low LAAV is associated with AF relapse, and it is a predictor of AF relapse following the first RFCA for PeAF. This discovery may be useful in the optimization of treatment strategies and the care of patients with PeAF.

The Relationship Between Epicardial Adipose Tissue Thickness and Presence of Left Atrial Thrombus in Mitral Stenosis Patients.

ObjectiveTo examine the relationship between the left atrial (LA) thrombus presence and the epicardial adipose tissue (EAT) thickness.MethodsThree hundred and twelve consecutive rheumatic mitral valve stenosis (RMVS) patients with mitral valve area (MVA) < 2 cm2 were included in this cross-sectional study. Patients were divided into two groups, those with and those without LA thrombus. Routine biochemical analysis and electrocardiographic examinations were carried out. EAT was measured using transthoracic echocardiography.ResultsLA thrombus was determined in 84 (26.9%) RMVS patients. In echocardiographic examinations, higher mean gradient and LA diameter as well as lower MVA were found in the group with LA thrombus (P<0.001). In this group, higher C-reactive protein (CRP) and EAT values were also determined (P<0.001). There was significant correlation between EAT and MVA, CRP, LA appendage peak flow velocity, LA anteroposterior diameter, and mean gradient (P<0.001). Higher EAT values were identified as independently associated with the presence of LA thrombus (odds ratio 59.5; 95% confidence interval 12.1-290.10; P<0.001).ConclusionTransthoracic echocardiography, routinely used in patients with RMVS, can measure EAT to determine patients who are under risk for thrombus.

The feasibility of substituting left atrial wall strain for flow velocity of left atrial appendage

Objective: Non-valvular atrial fibrillation (NVAF) is frequently complicated by thromboembolism. Left atrial appendage (LAA) flow is a predictor of LAA thrombosis. LAA flow is measured by transesophageal echocardiography (TEE), which is a semi-invasive diagnostic tool. Recently, speckle-tracking methods have been adapted for the evaluation of local cardiac function. We hypothesised that if we could determine LAA wall motion utilising a speckle tracking technique, we could non-invasively analyse LAA flow.Methods: Sixty-three NVAF patients including 38 with chronic atrial fibrillation (CAF), 14 with paroxysmal AF (PAF) and 11 with atrial flutter (AFL) were enrolled in this study. Normal sinus rhythm (NSR) patients with non-thromboembolic cerebral infarction were also included. Immediately after obtaining a 2D movie of the LAA through the aortic oblique short axis view by transthoracic echocardiography, LAA flow velocity was measured by TEE. Mean strains between the posterior and anterior walls were measured using a speckle-tracking technique.Results: Ten patients exhibited a thrombus and 11 had spontaneous echo contrast (SEC) in the auricle. Mean strain value was similar between CAF and PAF, although LAA flow velocity for CAF was significantly reduced compared with PAF (median value 13.7 cm/s versus 36.1 cm/s, p = <.00001). Mean strain of CAF with thrombus/SEC was significantly reduced compared with NSR patients (median value 1.52% versus 3.17%, p = .00181). Furthermore, mean strain was correlated with LAA flow velocity (R = 0.399, R2 = 0.1595, p = .000615).Conclusions: LAA wall strain identified via speckle-tracking methods may presage LAA peak flow velocity. This technique may contribute to stratification of thrombosis risks in the LAA.

Do left atrial appendage morphology and function help predict thromboembolic risk in atrial fibrillation?

Clinical scores (i.e. CHA2DS2-VASc) are the mainstay of thromboembolic risk management in nonvalvular atrial fibrillation. Nonetheless, they bear some limitations to precisely define risk-benefit ratio of oral anticoagulation (OAC), both with vitamin K antagonists and with novel direct oral anticoagulants, especially in patients with low-intermediate scores. Cardiovascular imaging, allowing directly visualization of those pathophysiological alterations, which may lead to the formation of intracardiac thrombi, offers itself as a unique tool helping to refine thromboembolic risk stratification. Many parameters have been tested, focusing primarily on functional and morphological variables of the left atrium and left atrial appendage (LAA). Left atrium volume and LAA peak flow velocity have, for a longtime, been associated with increased thromboembolic risk, whereas some new parameters, such as left atrium fibrosis assessed by late-gadolinium enhanced (LGE) MRI, left atrium and LAA strain and LAA morphology have more recently shown some ability in predicting embolic events in atrial fibrillation patients. Overall, however, these parameters have seen, to date, scarce clinical implementation, especially because of the inconsistency of validated cutoffs and/or strong clinical evidence driven by technical limitations, such as expensiveness of the technologies (i.e. MRI or computed tomography), invasiveness (i.e. transesophageal echocardiography) or limited reproducibility (i.e. LGE MRI). In conclusion, to date, cardiovascular imaging plays a limited role; however, validation and diffusion of the new techniques hereby systematically presented hold the potential to refine thromboembolic risk stratification in nonvalvular atrial fibrillation.

Asymmetric dimethylarginine predicts left atrial appendage thrombus in patients with non-valvular atrial fibrillation

IntroductionAtrial fibrillation (AF) is associated with increased thrombo-embolic events, with thrombi most frequently located in the left atrial appendage (LAA). Asymmetric dimethylarginine (ADMA), a potent endogenous inhibitor of nitric oxide synthase, is elevated in subjects with AF. We investigated the relationship between ADMA and risk of LAA thrombus in patients with non-valvular AF. Methods and resultsA total of 223 consecutive patients with non-valvular AF were enrolled (63±10years, 65% male). LAA thrombus was detected in 27 subjects by transesophageal echocardiography. Serum ADMA was significantly increased (2.5±0.6μmol/L vs 1.8±0.4μmol/L, p<0.001), while serum nitrite/nitrate was significantly reduced in patients with LAA thrombus (30.3±7.1μmol/L vs 48.4±9.3μmol/L, p<0.001). ADMA was positively correlated with age and left atrium diameter, and was negatively correlated with nitrite/nitrate and LAA peak flow velocity. The area under the receiver operating characteristic curve of ADMA predicting thrombus was 0.84. In multivariate logistic regression analysis, ADMA (OR 4.0, 95% CI 1.2–13.0; p=0.003) was one of independent risk factors for LAA thrombus. ConclusionsOur study suggested that high ADMA was independently associated with the presence of LAA thrombus in patients with non-valvular AF.

Low left atrial appendage flow velocity predicts recurrence of atrial fibrillation after catheter ablation of persistent atrial fibrillation

BackgroundRecurrence after catheter ablation of persistent atrial fibrillation (AF) remains an unsolved issue. This study aimed to explore the association between the left atrial appendage peak flow velocity (LAAV) and AF recurrence after ablation in persistent AF patients. MethodsFifty-three consecutive patients who underwent an initial catheter ablation of persistent AF were enrolled [age, 65±10 years; male, 42 (79%)]. The LAAV was obtained by transesophageal echocardiography before ablation. All the patients underwent pulmonary vein isolation and were followed up for 12 months. The LAAV and other clinical factors (AF duration, CHA2DS2VASc score, left atrial diameter, left atrial volume, and left ventricular ejection fraction) were tested using a Cox proportional hazards regression analysis as predictors of AF recurrence during the 1-year follow-up. ResultsAF recurrence occurred in 16 (30%) patients. The patients with AF recurrences had lower LAAVs (23.3±7.2cm/s vs. 33.3±15.1cm/s, p=0.002) than those without AF recurrence. In the multivariable analysis, a low LAAV independently predicted AF recurrence (hazard ratio, 3.04; 95% confidence interval, 1.05–8.79; p=0.040). A Kaplan–Meier analysis also demonstrated a lower survival rate free from AF recurrence in the low LAAV group than in the high LAAV group (p=0.030). ConclusionA low LAAV was associated with AF recurrence after the initial catheter ablation of persistent AF.

Increased Serum Uric Acid Levels Are Correlated with Decreased Left Atrial Appendage Peak Flow Velocity in Patients with Atrial Fibrillation

Objective: We aimed to examine the relationship between serum uric acid levels and left atrial appendage (LAA) peak flow velocity, an indicator of the mechanical functions of the LAA, and atrial fibrillation (AF). Subjects and Methods: Transesophageal echocardiography was performed before cardioversion in 153 patients with AF. The patients were categorized into 2 groups based on their LAA blood flow velocity. Group 1 included 87 patients with a low LAA flow velocity (<35 cm/s), and group 2 comprised 66 patients with a normal LAA flow velocity (≥35 cm/s). The χ² and Student's t tests were used to compare categorical and quantitative data between the groups. Linear regression analyses were performed to demonstrate the independent association between serum uric acid levels and LAA peak flow velocity. Results: The LAA blood flow velocity was 24.62 ± 5.90 cm/s in group 1 and 49.28 ± 13.72 cm/s in group 2, respectively (p < 0.001). The serum uric acid levels were 6.88 ± 1.85 mg/dl in group 1 and 5.97 ± 1.51 mg/dl in group 2, and the difference was statistically significant (p = 0.001). There was a negative correlation between serum uric acid levels and LAA blood flow velocity (r = -0.216, p = 0.007). Multivariate regression analysis showed that serum uric acid levels, age and gender differences were significant predictors of the LAA peak flow velocity. Conclusions: High serum uric acid levels were associated with a low contractile function of the LAA and could provide additional prognostic information on future thromboembolic events in patients with AF.

Significant Impairment of Left Atrial Function in Patients with Cardioembolic Stroke Caused by Paroxysmal Atrial Fibrillation

Patients with cardioembolic stroke (CE) caused by paroxysmal atrial fibrillation (Paf) sometimes show normal sinus rhythm on admission, which makes it difficult to diagnose them as having CE. The present study examined the differences in echocardiographic findings between patients with CE caused by Paf (the Paf-CE group) and those with non-cardiogenic embolic ischemic stroke (the Non-CE group). We examined thirty-two patients with embolic ischemic stroke presenting with a normal sinus rhythm upon admission to our hospital; 13 patients in the Paf-CE group and 19 patients in the Non-CE group. During admission, all patients underwent transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) at a normal sinus rhythm. The left atrial dimension, left ventricular end-diastolic dimension and left ventricular ejection fraction were measured using TTE. The left atrial appendage peak flow velocity (LAAPV), spontaneous echo-contrast in the left atrium (LASEC) and thrombus in the left atrium were evaluated using TEE. Among the clinical background characteristics, hypertension was significantly more frequent in the Non-CE group than in the Paf-CE group (p<0.01). Congestive heart failure was significantly more frequent in the Paf-CE group than in the Non-CE group (p<0.05). LAAPV was significantly lower in the Paf-CE group than in the Non-CE group (34.7 cm/s vs. 64.0 cm/s, p<0.01), and the LASEC grade was significantly higher in the Paf-CE group than in the Non-CE group (p<0.01). A thrombus in the left atrium was detected in two patients in the Paf-CE group, but no thrombi were detected in any of the patients in the Non-CE group. Echocardiographic evaluation is useful, as the above data indicate that the left atrial function is apparently impaired in patients with CE caused by Paf, even in a patient with an apparently normal sinus rhythm.

Relation of the severity of mitral regurgitation to thromboembolic risk in patients with atrial fibrillation

Patients with atrial fibrillation (AF) are at risk for thromboembolism. Although mitral regurgitation (MR) could be protective against left atrial (LA) blood stasis, the relationship between the severity of MR and thromboembolic risk has not been clarified in patients with AF. 271 patients with permanent AF underwent transesophageal echocardiography (TEE). The severity of MR was assessed by Doppler echocardiography. LA blood stasis on TEE and plasma D-dimer levels were used to evaluate the thromboembolic risk. Patients with severe MR (n=20) had significantly higher LA appendage peak flow velocity compared to those with no MR (n=114) and those with only mild MR (n=92) (p<0.05). The grade of LA spontaneous echo contrast (SEC) was lower in patients with severe MR compared to those with no, mild or moderate MR (severe MR 0.7±0.7 grade vs moderate MR 1.7±1.0 grade, mild MR 2.2±1.3 grade, and no MR 1.9±1.3 grade, p<0.05). Multivariate analysis revealed severe MR as a negative predictor of LA blood stasis on TEE findings (odds ratio 0.27; 95% confidence interval 0.09-0.86, p<0.05). By contrast, D-dimer level was significantly higher in patients with moderate MR compared to those with any other type of severity of MR (moderate MR 1.72±1.45 µg/ml vs severe MR 0.76±0.95 µg/ml, mild MR 0.97±1.09 µg/ml, and no MR 0.82±1.15 µg/ml, p<0.05). There is a protective effect of MR on LA blood stasis, but this beneficial effect on thromboembolic risk appears to be limited to patients with severe MR.

Left Atrial Appendage-Flow Velocity Predicts Cardioversion Success in Atrial Fibrillation

Restoration of sinus rhythm by electrical cardioversion is a therapeutic option in appropriately selected patients with atrial fibrillation. It is important to determine predictors of electrical cardioversion outcome in patients with atrial fibrillation. Predictive value of clinical and conventional echocardiographic parameters for predicting cardioversion outcome is limited. The role of left atrial appendage (LAA) function, which may reflect left atrial contractile function, for prediction of cardioversion outcome remains unclear. We conducted a single center prospective study to evaluate the role of LAA function for prediction of cardioversion success in patients with atrial fibrillation. One hundred sixty three patients with atrial fibrillation underwent transthoracic and transesophageal echocardiography (TEE) before electrical cardioversion. LAA functions, including LAA peak flow velocity, LAA area and LAA ejection fraction, were examined. Cardioversion was successful in 133 patients and unsuccessful in 30 patients. Mean LAA peak emptying flow velocity was significantly higher in the patients with successful cardioversion than in those with unsuccessful cardioversion (0.34 +/- 0.14 vs 0.27 +/- 0.1 m/sec; p = 0.013). At multivariate logistic regression analysis, only LAA flow velocity (> 0.28 m/sec, odds ratio = 2.8 ; p = 0.03) proved to be an independent predictor of cardioversion success. LAA area (p = 0.18) and LAA ejection fraction (p = 0.52) were not different between successful and unsuccessful cardioversion groups. Therefore, measurement of LAA flow velocity provides valuable information for prediction of cardioversion outcome in patients with atrial fibrillation before TEE guided cardioversion.

954-2 Transesophageal Echocardiographic and Clinical Predictors for Outcome of Cardioversion of Atrial Fibrillation

To determine the value of transesophageal echo (TEE) and clinical variables in predicting outcome of cardioversion (CVI. we studied 62 patients with nonvalvular atrial fibrillation (AFI. who underwent TEE prior to elective electrical CV We measured left atrial (LA) size, mitral valve annulus (MVA) width, LA appendage (LAA) size and LAA peak flow velocity (pfv), and evaluated presence of LA spontaneous contrast (LASC) and severity (none-mild/moderatesevere) of MV regurgitation (MVR). After CV, sinus rhythm (SR) was restored in 50 patients (81%) and maintained in 29 patients (58%) at 1 year follow-up. Empty CellInitial Outcome1 Year OutcomeEmpty CellAF (n = 12)SR (n = 50)AF (n = 21)Empty CellSR (n = 29)LA size (cm2)23.3 ± 7.422.6 ± 6726.4 ± 5.0*198 ± 6.5MVA width (cm)3.8 ± 0.33.9 ± 034.0 ± 0.2*37 ± 0.3LAA size (cm2)7.8 ± 2.78.8 ± 399.3 ± 3384 ± 3.3LAA-pfv (cm/s)22 ± 929 ± 1519 ± 8*36 ± 15LASC presence51713**4MVR severity7/538/1216/522/7*p &lt; 0.0001**p &lt; 0.005 p &lt; 0.0001 p &lt; 0.005 Outcome was not related to age, gender, etiology of AF, or use of antiarrhythmic drugs. In contrast, duration of AF was of influence on 1 year outcome: AF vs. SR: 6.7 ± 7.3 vs. 2.0 ± 2.4 months; (**). No TEE or clinical variables predict initial success of CV of AF. However, 1 year after initial success, LA size, MVA width, LASC, duration of AF, and particularly LAA-pfv, are highly related to the maintenance of SR.