Echocardiographic predictors of left atrial appendage thrombus formation

The role of multi-modality imaging for the assessment of left atrium and left atrial appendage: a clinical consensus statement of the European Association of Cardiovascular Imaging (EACVI), European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC)

Structural, architectural, contractile, or electrophysiological alterations may occur in the left atrium (LA). The concept of LA cardiopathy is supported by accumulating scientific evidence demonstrating that LA remodelling has become a cornerstone diagnostic and prognostic marker. The structure and the function of the LA and left atrial appendage (LAA), which is an integral part of the LA, are key elements for a better understanding of multiple clinical conditions, most notably atrial fibrillation, cardioembolism, heart failure, and mitral valve diseases. Rational use of various imaging modalities is key to obtain the relevant clinical information. Accordingly, this clinical consensus document from the European Association of Cardiovascular Imaging, in collaboration with the European Heart Rhythm Association, provides comprehensive, up-to-date, and evidence-based guidance to cardiologists and cardiac imagers for the best practice of imaging LA and LAA for the diagnosis, management, and prognostication of the patients.

Association between left atrial function and pulmonary vein stump thrombus after left upper lobectomy: insights from cine-MRI

The purpose of this study is to evaluate left atrial function using cine-magnetic resonance imaging (cine-MRI) in patients with pulmonary vein stump thrombus (PVST) after left upper lobectomy (LUL). The study population comprised 91 patients (30 with PVST and 61 without PVST) who underwent LUL for pulmonary lesions and evaluation by cine-MRI. Left atrial functional parameters were evaluated and compared between patients with and without the development of PVST after LUL using the Mann-Whitney U test. The diagnostic capabilities of these parameters for predicting PVST development were assessed using receiver-operating characteristic (ROC) curve analysis. Clinical and left atrial functional parameters were analyzed by multivariate logistic regression models to determine predictors of PVST. Left atrial end-systolic volume (LAESV), left atrial end-diastolic volume (LAEDV), LAESV index (LAESVI), and LAEDV index (LAEDVI) were significantly greater in patients who developed PVST than in those without PVST (p = 0.009, < 0.001, 0.004, and < 0.001, respectively). Left atrial ejection fraction (LAEF) was significantly lower in patients who developed PVST than in those without PVST (p < 0.001). The area under the ROC curve for predicting PVST was 0.668, 0.769, 0.688, 0.792, and 0.803 for LAESV, LAEDV, LAESVI, LAEDVI, and LAEF, respectively. In the multivariate logistic regression analysis, only LAEF was identified as an independent predictor of PVST (OR 0.896; 95% CI 0.846-0.950). In conclusion, left atrial enlargement and left atrial dysfunction were associated with the development of PVST after LUL.

Antithrombotic therapy in atrial flutter: To anticoagulate or not, that is the question

Atrial fibrillation (AF) represents an arrhythmia fraught with significant morbidity, mortality, and financial burden for the health care system. Less attention is given to atrial flutter (AFL), which may occur as a stand-alone arrhythmia or coexist with AF in the same patient. Moreover, it is known that AF frequently develops after AFL ablation. Despite different pathophysiologies of AF and AFL, current guidelines provide identical indications for anticoagulation therapy in both arrhythmias, given the lack of trials in patients with AFL. This study attempts at providing an up-to-date literature review on the thromboembolic risk profile in AFL, focusing on differences between AFL and AF. Echocardiographic studies showed that the presence of spontaneous echocardiographic contrast (SEC) and thrombus are much less prevalent in patients with AFL than in those with AF. Patients with AFL had overall better left atrial appendage (LAA) function and lower coagulation marker levels than did patients with AF. Observational studies showed a significantly lower risk of stroke in patients with AFL than in those with AF. One study found a significantly higher ischemic stroke incidence in the AFL cohort only at CHA2DS2-VASc scores from 5 to 9 than in patients without AF or AFL. These findings imply that the thromboembolic risk inherent in AFL seems lower than that in AF. This should be considered in the context of a high chance of permanent AFL termination after successful cavotricuspid isthmus ablation, in contrast to the chronic clinical nature of AF. Although thromboembolic risk exists in AFL, prospective studies are warranted to establish the true prothrombotic properties of AFL, allowing the reassessment of anticoagulant treatment strategy.

ACR Appropriateness Criteria® Preprocedural Planning for Left Atrial Procedures in Atrial Fibrillation

This document summarizes the relevant literature for the selection of preprocedural imaging in three clinical scenarios in patients needing endovascular treatment or cardioversion of atrial fibrillation. These clinical scenarios include preprocedural imaging prior to radiofrequency ablation; prior to left atrial appendage occlusion; and prior to cardioversion. The appropriateness of imaging modalities as they apply to each clinical scenario is rated as usually appropriate, may be appropriate, and usually not appropriate to assist the selection of the most appropriate imaging modality in the corresponding clinical scenarios. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The value of left atrial longitudinal strain in evaluating left atrial appendage spontaneous echo contrast in non-valvular atrial fibrillation

Background

Spontaneous echo contrast (SEC) observed in transesophageal echocardiography (TEE) is a reliable predictor of the risk of future ischemic stroke in patients with non-valvular atrial fibrillation (NVAF). Left atrial strain globally reflects atrial function, remodeling and distensibility. The left atrial appendage (LAA) is a myogenic remnant of the left atrium, which can actively relax and contract. The left atrial appendage (LAA) is an important part of releasing the pressure of the left atrium. The key role of the left atrium is to regulate the left ventricular filling pressure, act as a reservoir for pulmonary venous return during ventricular contraction, and act as a conduit, transferring blood to the Left ventricle during early ventricular diastole. The purpose of this study was to explore the relationship between left atrial function and left atrial appendage spontaneous echo contrast (LAASEC).

Methods

A retrospective study of 338 patients with non-valvular AF was conducted. Two-dimensional speckle-tracking echocardiography provided the following metrics of LA strain: LA strain during the reservoir phase (LASr), LA strain during the conduit phase (LAScd). LA or LAA has the dense SEC of more than grade 3, which is defined as mud like change or pre thrombosis.

Results

Patients with level 3 SEC (n = 81) has lower LASr than those with lower grades of SEC (n = 257) (7.20 ± 3.70 vs. 17.48 ± 8.67, P < 0.001). Multivariate logistic regression model showed that the type of atrial fibrillation (persistent∼), increased heart rate, decreased LASr were independently associated with the dense LAASEC (OR (CI 95%), 5.558 (1.618-19.09), 1.016 (1.006-1.026) 0.002, 1.224 (1.085-1.381), both P < 0.01). Venn Diagram showed that lower CHADVASC2 score groups had dense SEC cases. Receiver operating characteristic (ROC) curve was used for analyzing results and selecting cut off values. The cut off point for LASr < 8.85% and CHADVASC2 score was >2 scores with sensitivity and specificity were 79% and 85%.

Conclusion

Lower LASr is independently associated with the dense LAASEC in NVAF and has incremental values superior to clinical scores. The decrease of LASr may be a potential non-invasive parameter for evaluating the higher risk of LAA thrombosis.

Left atrial enlargement and high uric acid level are risk factors for left atrial thrombus or dense spontaneous echo contrast in atrial fibrillation patients with low to moderate embolic risk assessed by CHA2DS2-VASC score

Aims

To investigate the correlation and predictive value of left atrial diameter and blood uric acid levels with the occurrence of left atrial thrombus or dense spontaneous echo contrast in atrial fibrillation patients with low to moderate CHA₂DS₂-VASc scores.

Methods and results

A total of 849 inpatients diagnosed with atrial fibrillation who had low to moderate CHA₂DS₂-VASc scores and complete transesophageal echocardiography were included in this study. Among them, 66 patients had left atrial thrombus or dense spontaneous echo contrast. When different models were used to correct other known risk factors, acid levels and abnormal left atrial diameter were identified as additional risk factors for left atrial thrombus or dense spontaneous echo contrast. The incidence of left atrial thrombus or dense spontaneous echo contrast was higher in patients with abnormal serum uric acid levels than in the control group (12.4% vs. 5.6%, p < 0.05), and this difference persisted after correcting the baseline data with propensity score matching (10.6% vs. 4.1%, p < 0.05). Abnormal left atrial diameter was another risk factor suggested by regression analysis, with an increased incidence of left atrial thrombus or dense spontaneous echo contrast in the abnormal left atrial diameter group compared to the control group, both before (18.0% vs. 3.5%, p < 0.05) and after (15.5% vs. 5.2%, p < 0.05) propensity score matching. The best predictive value was obtained by adding both abnormal serum uric acid levels and abnormal left atrial diameter.

Conclusion

Left atrial enlargement and high uric acid levels increase the risk of left atrial thrombus or dense spontaneous echo contrast in atrial fibrillation patients with low to moderate CHA₂DS₂-VASc scores.

Predicting Intracardiac Thrombus Formation in the Left Atrial Appendage Using Machine Learning and CT Images

This paper proposes a comprehensive method for estimating thrombus formation factors in the left atrial appendage (LAA). First, using 3D CT (Computer Tomography) image data as input, classification of thrombus presence/absence is learned using 3D ResNet. Besides, 3D Grad-CAM is applied to the prediction results to visualize regions of interest in thrombus formation. Second, features are extracted based on the visualization of regions of interest. Using the extracted features and numerical data obtained from the hospital as input, a regression analysis is performed to predict the presence/absence of thrombus using LightGBM. Visualization of regions of interest using 3D ResNet and 3D Grad-CAM shows that the right inferior pulmonary vein and the LAA were particularly correlated with thrombus formation. Estimation of important factors for thrombus formation using LightGBM shows that the LAA ostium area has the greatest influence on thrombus formation.Clinical Relevance-This paper shows the factors that contribute to thrombus formation in the LAA from the viewpoint of three-dimensional structure. In addition, the features considered important in thrombus formation were identified by comparing a variety of features.

Identifying Patients at High Risk of Left Atrial Appendage Thrombus Before Cardioversion: The CLOTS-AF Score

Background Transesophageal echocardiography-guided direct cardioversion is recommended in patients who are inadequately anticoagulated due to perceived risk of left atrial appendage thrombus (LAAT); however, LAAT risk factors remain poorly defined. Methods and Results We evaluated clinical and transthoracic echocardiographic parameters to predict LAAT risk in consecutive patients with atrial fibrillation (AF)/atrial flutter undergoing transesophageal echocardiography before cardioversion between 2002 and 2022. Regression analysis identified predictors of LAAT, combined to create the novel CLOTS-AF risk score (comprising clinical and echocardiographic LAAT predictors), which was developed in the derivation cohort (70%) and validated in the remaining 30%. A total of 1001 patients (mean age, 62±13 years; 25% women; left ventricular ejection fraction, 49.8±14%) underwent transesophageal echocardiography, with LAAT identified in 140 of 1001 patients (14%) and dense spontaneous echo contrast precluding cardioversion in a further 75 patients (7.5%). AF duration, AF rhythm, creatinine, stroke, diabetes, and echocardiographic parameters were univariate LAAT predictors; age, female sex, body mass index, anticoagulant type, and duration were not (all P>0.05). CHADS2VASc, though significant on univariate analysis (P<0.001), was not significant after adjustment (P=0.12). The novel CLOTS-AF risk model comprised significant multivariable predictors categorized and weighted according to clinically relevant thresholds (Creatinine >1.5 mg/dL, Left ventricular ejection fraction <50%, Overload (left atrial volume index >34 mL/m2), Tricuspid Annular Plane Systolic Excursion (TAPSE) <17 mm, Stroke, and AF rhythm). The unweighted risk model had excellent predictive performance with an area under the curve of 0.820 (95% CI, 0.752-0.887). The weighted CLOTS-AF risk score maintained good predictive performance (AUC, 0.780) with an accuracy of 72%. Conclusions The incidence of LAAT or dense spontaneous echo contrast precluding cardioversion in patients with AF who are inadequately anticoagulated is 21%. Clinical and noninvasive echocardiographic parameters may identify patients at increased risk of LAAT better managed with a suitable period of anticoagulation before undertaking cardioversion.

Left atrial CT volume and CHA2DS2-VASc score predict early pulmonary vein stump thrombus after left upper lobectomy

The purpose of this study is to clarify the feasibility of left atrial (LA) volume measurement and CHA₂DS₂-VASc score for predicting the development of pulmonary vein (PV) stump thrombus after left upper lobectomy (LUL). The study population comprised 50 patients who underwent LUL for pulmonary lesions. All patients were evaluated for the development of PV stump thrombus at 7 days after LUL. LA volume was measured using preoperative CT and the CHA₂DS₂-VASc score was evaluated. LA volume and CHA₂DS₂-VASc score were compared between patients with and without the development of PV stump thrombus using the Mann-Whitney U test. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the accuracy of prediction of PV stump thrombus development. PV stump thrombus was detected in 17 (33.4%) of the 50 patients. LA volume was significantly greater in patients who developed PV stump thrombus than in those without thrombus (79.7 ± 19.4 vs. 66.6 ± 17.0 mL, p = 0.040). CHA₂DS₂-VASc score was significantly higher in patients with PV stump thrombosis than in those without thrombus (3.4 ± 1.5 vs. 2.5 ± 1.5, p = 0.039). Area under the ROC curve values for predicting PV stump thrombus were 0.679, 0.676, and 0.714 for LA volume, CHA₂DS₂-VASc score, and their combination, respectively. In conclusion, LA volume measured using preoperative CT and CHA₂DS₂-VASc score may help predict the development of PV stump thrombus after LUL.

Left atrial appendage thrombus formation, potential of resolution and association with prognosis in a large real-world cohort

Comprehensive data on factors influencing left atrial appendage (LAA) thrombus formation, resolution and impact on survival are limited. In this single-center, retrospective study 7759 (2010-2015) patients with symptomatic ongoing atrial fibrillation (AF) on admission were screened for LAA thrombi. 450 patients had LAA thrombi. 481 patients without LAA thrombi were randomly selected as controls. We assessed clinical, echocardiographic, laboratory parameters and long-term survival of both groups. Patients with LAA thrombi compared to controls were older, had more strokes, higher CHA₂DS₂ -VASc scores, worse renal function, less controlled diabetes, advanced heart failure, lower LAA emptying velocities, higher levels of cardiac and inflammatory markers (all p < 0.001). 56.3% of followed-up patients (304) dissolved their LAA thrombi. Chances of thrombus resolution increased with rising LAA flow velocities (OR 1.061, p = 0.022), whereas advanced age (OR 0.950, p < 0.001) and presence of permanent AF (OR 0.354, p < 0.001) decreased chances of thrombus resolution. Presence of LAA thrombi was associated with a markedly reduced 10-year survival probability (31% versus 69%). LAA thrombus formation is promoted by advanced structural heart disease, inflammation, diabetes and impaired renal function. Younger age, non-permanent AF and higher LAA flow velocities were predictors of thrombus resolution. Thrombus formation was associated with poor prognosis.

Relationship between left ventricular diastolic function and the risk of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

In patients with nonvalvular atrial fibrillation (NVAF), the impact of left ventricular diastolic function on the risk of left atrial appendage (LAA) thrombus has rarely been studied. This prospective study aimed to investigate the relationship between diastolic function and the risk of LAA thrombus in patients with NVAF. Seventy-six patients with NVAF admitted to receive radiofrequency catheter ablation were prospectively enrolled. All the patients underwent transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in 24 h before ablation. Diastolic function was estimated by TTE including left atrial volume index (LAVI) and E/e', as well as invasive left atrial pressure (LAP) measured during the ablation procedure. LAA peak emptying velocity (LAA-PEV) and the intensity of spontaneous echo contrast (SEC) were determined by TEE. Average E/e', LAVI and mean LAP had a significant positive correlation with the intensity of SEC, the coefficient of correlation were 0.344 (p = 0.002), 0.416 (p < 0.001) and 0.402 (p < 0.001), respectively. After adjustment for CHA₂DS₂-VASc score and type of AF, multivariate regression analysis revealed that increased LAP (OR 1.144, 95% CI 1.012-1.293, p = 0.031) independently correlated with the risk of LAA thrombus (SEC ≥ Grade 2). LAA-PEV showed a significantly inverse relationship with mean LAP in patients with AF (r =  - 0.525, p < 0.001), and in the assessment of elevated LAP with TEE, the LAA-PEV cut-off of 0.40 m/s had a sensitivity of 80%, specificity of 81%. Left ventricular diastolic dysfunction may constitute a potential risk for LAA thrombus and stroke. Furthermore, evaluation of LAA emptying with use of TEE is helpful for assessing the LAP status of patients with AF.

Echocardiographic predictors of thrombus in left atrial appendage—The role of novel transthoracic parameters

Introduction

The left atrium appendage thrombus (LAAT) formation is a complex process. A CHA2DS2-VASc scale is an established tool for determining the thromboembolic risk and initiation of anticoagulation treatment in patients with atrial fibrillation or flutter (AF/AFL). We aimed to identify whether any transthoracic echocardiography (TTE) parameters could have an additional impact on LAAT detection.

Methods

That is a sub-study of multicenter, prospective, observational study LATTEE (NCT03591627), which enrolled 3,109 consecutive patients with AF/AFL referred for transesophageal echocardiography (TEE) before cardioversion or ablation.

Results

LAAT was diagnosed in 8.0% of patients. The univariate logistic regression analysis [based on pre-specified in the receiver operating characteristic (ROC) analysis cut-off values with AUC ≥ 0.7] identified left ventricular ejection fraction (LVEF) ≤ 48% and novel TTE parameters i.e., the ratios of LVEF and left atrial diameter (LAD) ≤ 1.1 (AUC 0.75; OR 5.64; 95% CI 4.03–7.9; p &lt; 0.001), LVEF to left atrial area (LAA) ≤ 1.7 (AUC 0.75; OR 5.64; 95% CI 4.02–7.9; p &lt; 0.001), and LVEF to indexed left atrial volume (LAVI) ≤ 1.1 (AUC 0.75, OR 6.77; 95% CI 4.25–10.8; p &lt; 0.001) as significant predictors of LAAT. In a multivariate logistic regression analysis, LVEF/LAVI and LVEF/LAA maintained statistical significance. Calculating the accuracy of the abovementioned ratios according to the CHA2DS2-VASc scale values revealed their highest predictive power for LAAT in a setting with low thromboembolic risk.

Conclusion

Novel TTE indices could help identify patients with increased probability of the LAAT, with particular applicability for patients at low thromboembolic risk.

Effect of mitral regurgitation on stroke risk in patients with non-rheumatic atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) carries a thrombotic risk related to blood stasis in the left atrium. In patients with rheumatic valve disease and AF, the presence of severe mitral regurgitation (MR) has been shown to reduce the risk of atrial thrombosis and stroke. However, in patients without rheumatic disease, the results are controversial.

AIM

To analyse the association between MR and the incidence of stroke in patients with non-rheumatic AF.

METHODS

We analysed data from the retrospective CardioCHUVI-AF registry, which includes 15,720 patients with AF (without mechanical prostheses or rheumatic valvular disease) in the Vigo area of Spain, during 2014-2018. We grouped the patients according to MR grades: 0-2 (n=15,194) and 3-4 (n=526). We performed univariate and multivariable competitive risk analyses to analyse the association between MR and stroke, with death as the competitive event.

RESULTS

During a median (interquartile range [IQR]) follow-up of 4.9 (2.8-4.9) years, 859 patients (5.5%) suffered a stroke. The stroke incidence was 1.3 per 100 person-years (95% confidence interval [95% CI]: 1.2-1.4), with no difference between the MR groups. In univariate analysis, no relationship was observed between MR grade and stroke (subdistribution hazard ratio [sHR]: 1.12, 95% CI: 0.79-1.60; P=0.53); likewise after multivariable analysis (sHR: 0.98, 95% CI: 0.68-1.41; P=0.90). This same relationship was evaluated in subgroups of interest (patients with and without: oral anticoagulation, CHA₂DS₂-VASc≥2, prior heart failure, aortic valve disease, left ventricular ejection fraction≤40%, and moderate-severe left atrial dilation), with results consistent with the overall population.

CONCLUSION

In our large registry of patients with non-rheumatic AF, we did not find a protective effect of grade 3-4 MR on the risk of stroke.

Left Atrial Appendage Mechanical Dispersion Assessed by Speckle-Tracking Echocardiography as a Determinant of Left Atrial Appendage Blood Stasis in Patients With Atrial Fibrillation

Aims

We sought to investigate the relationship of left atrial appendage (LAA) mechanical dispersion (MD) with LAA dense spontaneous echo contrast (SEC) or thrombus, and to compare its usefulness in the identification of thrombogenesis with left atrial (LA) MD or LA/LAA strain parameters in patients with atrial fibrillation (AF).

Methods

We conducted a cross-sectional study of 493 consecutive patients with AF [65(58.5–71.0) years, male 66.9%] who underwent echocardiography prior to catheter ablation. We measured the LAA and LA global longitudinal strain (GLS) using speckle-tracking echocardiography (STE). LAA MD and LA MD was defined as the standard deviation (SD) of time to peak positive strain corrected by the R-R interval.

Results

Patients with LAA dense SEC/thrombus (n = 70) had significantly higher LAA MD than controls (n = 423) [median 14.2(11.6–16.8)% vs 9.4(6.2–12.1)%, p &lt; 0.01]. Multivariable analysis showed that LAA MD was independently associated with LAA dense SEC/thrombus in four different models (Odds ratio, 1.23–1.24; p &lt; 0.01), and provided additional diagnostic value over clinical and standard echocardiographic parameters. Whereas, LA MD was not independently associated with LAA dense SEC/thrombus and had no incremental value over other LA/LAA mechanical parameters.

Conclusion

LAA mechanical dispersion was an independent determinant of LAA dense SEC/thrombus in AF patients, incremental to conventional risk factors and superior to LA mechanical dispersion.

Left Atrial Thrombus in Patients With Non-valvular Atrial Fibrillation: A Cross-Sectional Study in China

Background

Stroke is predominately attributed to left atrial thrombus (LAT) in patients with non-valvular atrial fibrillation (NVAF), however, its detection rate in real clinical practice has been few reported in China.

Objective

This study aimed to investigate the prevalence and associated factors of LAT in patients with NVAF in China.

Methods

All adult NVAF patients undergoing transesophageal echocardiography (TEE) in the China Atrial Fibrillation Center database from January 2017 to January 2022 were enrolled in this study. The prevalence of LAT was calculated, and associated factors were identified.

Results

A total of 36,007 NVAF inpatients from 602 hospitals in 30 provinces/autonomous regions/municipalities were included in the final analysis, with a median age of 66 years and 39.4% were female. LAT was present in 1,467 (4.1%) patients overall, 2.7, 5.7, and 6.8% in patients with paroxysmal, persistent, and long-standing persistent AF, respectively. In subgroup analysis, including age ≥ 65 years, CHA2DS2-VASC score ≥ 2, left atrial diameter (LAD) ≥ 50 mm, left ventricular ejection fraction (LVEF) < 50%, and anticoagulation, patients with paroxysmal AF always had the lowest LAT prevalence, followed by patients with persistent and long-standing persistent AF. Patients treated with anticoagulants had less prevalent LAT than those without anticoagulation (2.1 vs. 5.0%, p < 0.001). In multivariate analysis, AF pattern (both persistent AF and long-standing persistent AF), hypertension, chronic heart failure, coronary heart disease, transient ischemic attack/stroke, diabetes mellitus, and LAD (per 5 mm) were associated with an increased prevalence of LAT. However, LVEF (per 5%) and anticoagulation were associated with a reduced prevalence of LAT.

Conclusion

LAT was found in 4.1% of Chinese adult NVAF inpatients underwent TEE in real-world experience. The prevalence of LAT mainly associated with non-paroxysmal AF, cardiovascular diseases, diabetes mellitus, enlarged left atrium, lower LVEF, and lack of anticoagulation therapy.

Prevalence of left atrial appendage thrombus in patients with acute ischaemic stroke and sinus rhythm: a cross-sectional study

OBJECTIVE

Thrombi originating in the left atrial appendage (LAA) mainly form because of atrial fibrillation (AF) and are a known cause of cardioembolic stroke. We aimed to investigate the prevalence of LAA thrombus in patients with acute ischaemic stroke (AIS) and sinus rhythm on 12-lead ECG.

METHODS

From June 2019 to February 2021, we conducted a cross-sectional study wherein we performed transoesophageal echocardiography (TEE) in patients with AIS and sinus rhythm on 12-lead ECG who were referred for detection of LAA thrombus. After TEE, all patients underwent 24-hour ECG monitoring to screen for paroxysmal AF. Predictors of LAA thrombus were determined using logistic regression analysis.

RESULTS

Overall, 223 patients (age: 66.2±11.3 years, men: 61.4%) were included in the study. LAA thrombus was detected in 15 patients (6.7%). Paroxysmal AF was detected in 14 of the 15 patients during 24-hour ECG monitoring. Compared with the non-thrombus group, the thrombus group had a statistically significant higher rate of spontaneous echo contrast (SEC), longer LAA, lower peak LAA emptying velocity and predominantly bilateral stroke. In the adjusted model, the presence of SEC increased the probability of LAA thrombus (OR 9.04; 95% CI 2.12 to 38.54; p=0.003).

CONCLUSIONS

In patients with AIS and sinus rhythm on 12-lead ECG, our study revealed that the prevalence of LAA thrombus was 6.7% with the most prevalent aetiology being paroxysmal AF. The presence of SEC can be a predictor of LAA thrombus in these patients.

Left Atrial Volume Index as a Predictor for Large-Vessel Occlusion in Cardiogenic Cerebral Infarction: A Single-Center Cohort Study

OBJECTIVE

The left atrial volume index (LAVI) is considered to be the most accurate index to estimate the size of the left atrium (LA). In this study, we investigated the relationship between LA size measured by LAVI and the occurrence of large-vessel occlusion (LVO) in patients with cardiogenic cerebral infarction (CCI).

METHODS

This retrospective single-center cohort study involved 118 patients with CCI within the internal carotid artery (ICA) or middle cerebral artery regions seen between January 2015 and July 2020. In all patients, the type of CCI was determined according to the Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Scores (TOAST) subtype diagnosis criteria. LVO was defined as positive when magnetic resonance imaging and computed tomography angiography showed ICA, M1, or M2 occlusion, with all others defined as non-LVO. Clinical characteristics, including LAVI, were evaluated in the records of several patients to investigate if they were risk factors for developing LVO.

RESULTS

Seventy patients (59%) were diagnosed as having LVO infarction (ICA occlusion, n = 19 [16%]; M1 occlusion, n = 26 [22%]; and M2 occlusion, n = 25 [21%]). Echocardiography showed no difference between LVO and non-LVO in terms of the ejection fraction (P = 0.64), LA dimension (P = 0.93), and LA volume (P = 0.06). However, LAVI significantly differed between the LVO and non-LVO groups (P = 0.02). Multivariate logistic regression analysis showed larger LAVI as a significant risk factor for LVO (P = 0.01).

CONCLUSIONS

Our findings suggest that a larger LAVI is a predictor of developing LVO in patients with CCI.

Prevalence and predictors of left atrial thrombosis in atrial fibrillation patients treated with non-vitamin K antagonist oral anticoagulants

BACKGROUND

Few data are available regarding the prevalence of left atrium (LA) thrombi in atrial fibrillation (AF) patients treated with non-vitamin K antagonist oral anticoagulants (NOACs). Methods: We evaluated the prevalence and predictors of LA/LA appendage (LAA) thrombi in non-valvular AF patients treated with NOACs referring to a single centre for a scheduled electrical cardioversion (ECV) or catheter ablation (CA). Transesophageal echocardiography (TEE) was performed within 12 h prior to the index procedure.

RESULTS

A total of 352 consecutive patients with non-valvular AF treated with NOACs were included in this analysis (ECV group n = 176 and CA group n = 176) between 2013 and 2018. 85 patients (24.2%) were on dabigatran, 150 (42.7%) on rivaroxaban, 104 (29.6%) on apixaban and 13 (3.7%) on edoxaban. A LA/LAA thrombus was detected by TEE in 27 (7.7%) patients, 18 in the ECV group and nine in the ablation group; 18 (5.1%) patients presented dense LA/LAA spontaneous echo contrast (SEC). Predictors of LA/LAA thrombi were a CHA₂DS₂-VASc score > 3 (OR 4.54, 95% CI 1.50 - 13.70, p value = .007) and obesity (OR 6.01, 95% CI 1.95 - 18.50, p value = .001).

CONCLUSIONS

Among real-world patients with non-valvular AF treated with NOACs, we found a high incidence of LA/LAA thrombi compared to previous reports. The main predictors of LA/LAA thrombosis were a CHA₂DS₂-VASc score > 3 and obesity.

Nomogram to Predict Left Atrial Thrombus or Spontaneous Echo Contrast in Patients With Non-valvular Atrial Fibrillation

Background: The predictive power of the CHADS₂ and CHA₂DS₂-VASc scores for the presence of Left atrial thrombus (LAT)/ spontaneous echo contrast (SEC) in non-valvular atrial fibrillation (NVAF) is modest. The aim of this analysis is to define clinical and ultrasonic variables associated with LAT/SEC and to propose nomograms for individual risk prediction.

Methods: Data on 1,813 consecutive NVAF patients who underwent transesophageal echocardiography (TEE) from January 2016 to January 2021 were collected. The univariate and multivariate logistic regression analyses were used to construct a nomogram. We examined the predictive ability of the risk scores by calculating the area under the curve (AUC). Moreover, the performance of the nomogram was assessed with respect to calibration, discrimination, and clinical usefulness.

Results: LAT/SEC was found in 260 (21.0%) and 124 (21.6%) patients in the training and validation cohorts, respectively. On multivariate analysis, independent factors for LAT/SEC were Age, left atrial diameter (LAD), left ventricular ejection fraction (LVEF), hypertension (HTN), previous stroke or transient ischemic attack, Non-paroxysmal AF and a nomogram was built based on these variables. The calibration curve for the probability of LAT/SEC showed good prediction agreement with actual observation. The nomogram achieved good concordance indexes of 0.836 and 0.794 in predicting LAT/SEC in the training and validation cohorts, respectively. Decision curve analysis demonstrated that the nomogram would be clinically useful.

Conclusions: In this study, a nomogram was constructed that incorporated six characteristics of NVAF patients. The nomogram may be of great value for the prediction of LAT/SEC in NVAF patients.

Effect of Mitral Regurgitation on Thrombotic Risk in Patients With Nonrheumatic Atrial Fibrillation: A New CHA2DS2-VASc Score Risk Modifier?

The current study assessed the effect of mitral regurgitation (MR) on thrombotic risk in nonrheumatic atrial fibrillation (AF). AF carries a thrombotic risk related to left atrial blood stasis. The prevalence of atrial thrombosis, defined as the presence of left atrial appendage thrombus and/or left atrial spontaneous echo contrast grade >2, was determined in 686 consecutive nonrheumatic AF patients without (adequate) anticoagulation scheduled for transesophageal echocardiography before electrical cardioversion and was related to the severity of MR adjusted for the CHA₂DS₂-VASc score. A total of 103 (15%) patients had severe MR, 210 (31%) had moderate MR, and 373 (54%) had no-mild MR; the median CHA₂DS₂-VASc score was 3.0 (interquartile range 2.0 to 4.0). Atrial thrombosis was observed in 118 patients (17%). The prevalence of atrial thrombosis decreased with increasing MR severity: 19.9% versus 15.2% versus 11.6% for no-mild, moderate, and severe MR, respectively (p value for trend = 0.03). Patients with moderate and severe MR had a lower risk of atrial thrombosis than patients with no-mild MR, with adjusted odds ratios of 0.51 (95% confidence interval 0.31 to 0.84) and 0.24 (95% confidence interval 0.11 to 0.49), respectively. The protective effect of MR was present across all levels of the CHA₂DS₂-VASc risk score and the presence of moderate-severe MR in patients with an intermediate CHA₂DS₂-VASc score (2 to 3) lowered the atrial thrombotic risk to the level of patients with a low CHA₂DS₂-VASc score (0 to 1). In conclusion, our data show that the presence of MR attenuated the atrial thrombotic risk by more than 50% in patients with nonrheumatic AF.

Risk of left atrial appendage thrombus and stroke in patients with atrial fibrillation and mitral regurgitation

OBJECTIVE

To investigate the association of mitral regurgitation (MR) on thromboembolic risk of patients with non-valvular atrial fibrillation (NVAF) undergoing transoesophageal echocardiography (TEE)-guided cardioversion.

METHODS

Data for consecutive patients who underwent TEE-guided cardioversion for NVAF between 2000 and 2012 were analysed. MR severity was assessed by Doppler echocardiography and classified as ≤mild, moderate or severe. Left atrial appendage emptying velocities were averaged for five consecutive cycles. Multivariable regression models were used to identify independent predictors of left atrial appendage thrombus (LAAT) and stroke.

RESULTS

2950 patients (age, 69.3±12.2 years, 67% men) were analysed. 2173 (73.7%) had ≤mild MR; 631 (21.4%), moderate MR; and 146 (4.9%), severe MR. Patients with moderate (age, 72.4±10.7 years) and severe (age, 72.8±12.1 years) MR were older than those with ≤mild MR (age, 68.2±12.5 years). The prevalence of LAAT was 1.5% (n=43). CHA₂DS₂-VASc scores (≤mild MR, 3.0±1.6; moderate MR, 3.5±1.5; severe MR, 3.9±1.5; p<0.001) and heart failure frequency (≤mild MR, 38.4%; moderate MR, 48.0%; severe MR, 69.2%; p<0.001) were increasingly higher with greater MR severity. Multivariable logistic regression analysis showed no association of moderate MR (OR 0.77, 95% CI 0.38 to 1.56) or severe MR (OR 0.55, 95% CI 0.21 to 1.49) with LAAT. During a mean follow-up of 7.3±5.1 years (median 7.5, IQR, 2.7-10.9), 216 patients had an ischaemic stroke. Adjusted Cox regression analysis showed no significant association of moderate MR (HR 1.22, 95% CI 0.88 to 1.68) or severe MR (HR 0.73, 95% CI 0.31 to 1.46) with stroke.

CONCLUSIONS

Among patients with NVAF, the presence or severity of MR was not associated with a decreased risk of LAAT or stroke.

Predictors of left atrial thrombus in acute ischemic stroke patients without atrial fibrillation: A single-center cross-sectional study

INTRODUCTION

The present study aimed to determine independent predictors of left atrial thrombus (LAT) in acute ischemic stroke (AIS) patients without atrial fibrillation (AF) using transesophageal echocardiography (TEE).

METHODS

In this single-center, retrospective study, we enrolled 149 consecutive AIS patients. All of the patients underwent a TEE examination to detect LAT within 10 days following admission. Multivariate logistic regression analysis was performed to assess independent predictors of LAT.

RESULTS

Among all cases, 14 patients (9.3%) had a diagnosis of LAT based on the TEE examination. In a multivariate analysis, elevated mean platelet volume (MPV), low left-ventricle ejection fraction (EF), creatinine, and reduced left-atrium appendix (LAA) peak emptying velocity were independent predictors of LAT. The area under the receiver operating characteristic curve analysis for MPV was 0.70 (95%CI: 0.57-0.83; p = 0.011). With the optimal cut-off value of 9.45, MPV had a sensitivity of 71.4% and a specificity of 63% to predict LAT.

CONCLUSION

AIS patients with low ventricle EF and elevated MPV should undergo further TEE examination to verify the possibility of a cardio-embolic source. In addition, this research may provide novel information with respect to the applicability of MPV to predict LAT in such patients without AF.

Left atrial size and risk of recurrent ischemic stroke in cardiogenic cerebral embolism

BACKGROUND

Left atrial enlargement (LAE) was reported to be associated with ischemic stroke and its recurrence. Limited data are available on the relationship of LAE and cardiogenic cerebral embolism (CCE). Our aim is to access the association of left atrial size and the recurrence of ischemic stroke in CCE.

METHODS

We prospectively included 303 CCE patients who underwent transthoracic echocardiography (TTE). Left atrial size was estimated with left atrial diameter (LAD), diameter/height (LAD/H), and left atrial diameter/body surface area (LAD/BSA). The endpoint was one-year recurrent ischemic stroke. Cox proportional hazard models were performed to access the association between left atrial size and recurrent ischemic stroke.

RESULTS

During follow-up, 27 patients suffered recurrent ischemic stroke. In multivariate COX regression models adjusted for confounders including age, gender, hypertension, diabetes, and history of stroke or transient ischemic attack (TIA), platelet count, fasting blood glucose (FBG), antithrombotic drugs at discharge, stroke volume, and cardiac output, LAD, LAD/H, and LAD/BSA all were independent risk factors of recurrent ischemic stroke [LAD: HR 1.065, 95% CI (1.006-1.128), p = .029; LAD/H: HR 1.157, 95% CI (1.066-1.255), p < .001; LAD/BSA: HR 1.128, 95% CI (1.059-1.202), p < .001]. Receiver-operator characteristic curves showed that LAD/BSA had better predicting effect. The area under the curve (AUC) was 0.543 [95%CI (0.444-0.642), p = .461) for LAD, 0.626 [95%CI (0.530-0.723), p = .03] for LAD/H, and 0.655 [95%CI (0.558-0.752), p = .008] for LAD/BSA.

CONCLUSION

LAE is an independent risk factor for one-year recurrence of ischemic stroke in patients with CCE.

A novel risk score for predicting left atrial and left atrial appendage thrombogenic milieu in patients with non-valvular atrial fibrillation

BACKGROUND

Although the CHADS2 and CHA2DS2-VASc scoring systems are commonly used as measures of thromboembolic risk in patients with nonvalvular atrial fibrillation (NVAF), data are inconsistent as to their value in predicting the presence of left atrial (LA) and/or left atrial appendage (LAA) thrombogenic milieu (TM). The present study aimed to establish a novel risk score to assess the risk of LA and/or LAATM in NVAF patients.

METHODS

This is a retrospective case-control study that included 125 consecutive patients with NVAF plus TM, as evidenced by transesophageal echocardiography (TEE) during a period from1 January 2010 to 1 February 2017. The controls were 1098 NVAF patients without TM during the same period. Risk factors for LA and/or LAATM were identified using univariable analysis and multivariable logistic regression. The risk score model was developed based on 10-fold validation and multiple regression. Risk model performance was evaluated using receiver operating characteristic (ROC) curves. Net reclassification improvement (NRI) was used for the comparison of C-statistics. The AUCs were compared using the Z test.

RESULTS

Among all 1223 NVAF patients, 125 (10.22%) patients had LA and/or LAATM. A score system (0-12) was developed based on the following 6 independent variables identified by 10-fold validation with sequential methods. Different points were assigned for each variable, according to multivariable regression using relative coefficients (coefficient of the index risk factor divided by the lowest coefficient among the 6 risk factors; rounded to closest integer): 1 for blood type A and N-terminal B-type natriuretic peptide (NT-proBNP) ≥864.85 pg/mL; 2 for LAD ≥43.5 mm and age ≥ 73.5 years old; 3 for previous heart failure and previous stroke or TIA. The present risk score system had a sensitivity of 58.3%, specificity of 91.4 and accuracy of 81.6%. The area under the ROC curve (AUC) was 0.832, (95% CI: 0.784-0.881; P < 0.001). The negative predictive value (NPV) was 92% when we set the cut-off point at 4; when the cut-off point was set at 8, the positive predictive value (PPV) was 85.7%. Compared with CHADS2 and CHA2DS2-VASc score, the present novel risk score has better predictive power [net reclassification improvement (NRI) +96.3% and +66.2%, respectively; all P < 0.001].

CONCLUSION

This study developed a novel risk score to help predicting LA and/or LAATM in NVAF patients, which had higher accuracy than CHADS2 and CHA2DS2-VASc score system.

Predicting Left Atrial Appendage Thrombus from Left Atrial Volume and Confirmation by Computed Tomography with Delayed Enhancement

Assessing thromboembolic risk is crucial for proper management of patients with atrial fibrillation. Left atrial volume is a promising predictor of cardiac thrombosis. To determine whether left atrial volume can predict left atrial appendage thrombus in patients with atrial fibrillation, we conducted a prospective study of 73 patients. Left atrial and ventricular volumes were evaluated by cardiac computed tomography with retrospective electrocardiographic gating and then indexed to body surface area. Left atrial appendage thrombus was confirmed or excluded by cardiac computed tomography with delayed enhancement. Seven patients (9.6%) had left atrial appendage thrombus; 66 (90.4%) did not. Those with thrombus had a significantly higher mean left atrial end-systolic volume index (139 ± 55 vs 101 ± 35 mL/m2; P =0.0097) and mean left atrial end-diastolic volume index (122 ± 45 vs 84 ± 34 mL/m2; P =0.0077). On multivariate logistic regression analysis, left atrial end-systolic volume index (per 10 mL/m2 increase) was significantly associated with left atrial appendage thrombus (odds ratio [OR]=1.24; 95% CI, 1.03-1.50; P =0.02); so too was the left atrial end-diastolic volume index (per 10 mL/m2 increase) (OR=1.29; 95% CI, 1.05-1.60; P =0.02). These findings suggest that increased left atrial volume increases the risk of left atrial appendage thrombus. Therefore, patients with atrial fibrillation and an enlarged left atrium should be considered for cardiac computed tomography with delayed enhancement to confirm whether thrombus is present.

Predictors of movable type left atrial appendage thrombi in patients with atrial fibrillation

Left atrial appendage thrombi (LAAT) are the main cause of thromboembolic events. Especially, movable type LAAT is high-risk for thromboembolic events. We aimed to investigate the predictors of the movable type LAAT in patients with atrial fibrillation (AF). We retrospectively studied 827 consecutive patients who underwent transthoracic echocardiography (TEE) prior to cardioversion or catheter ablation for AF. Sixty-nine patients who underwent cardiac surgery or significant valvular disease were excluded. The remaining 758 patients (age 67.6 ± 9.3, 535 males) were included in this study. Clinical data were evaluated at the time of TEE. The LAAT were classified into movable and fixed type LAAT by three independent observers who did not know clinical data. LAAT were detected in 57 (11 with movable and 46 with fixed type) of 758 patients (7.5%). Patients with movable type LAAT had an elevated E/e' ratio, lower left ventricular ejection fraction (LVEF), larger left atrial volume index, elevated C-reactive protein, higher prevalence of non-paroxysmal AF, patients taking warfarin (73% vs. 21%, P < 0.0001), and structural heart disease than control group (fixed type LAAT and without LAAT). On multivariate analysis, E/e' ratio, LVEF, and taking warfarin were significantly associated with movable type LAAT. The rate of movable type LAAT was the highest (7 of 49 patients, 14.3%) in patients with elevated E/e' ratio (> 12.7) and decrease LVEF (< 44%). E/e' ratio and LVEF could predict movable type LAAT in patients with AF. High-risk patients might need powerful antithrombotic therapy or taking early TEE.

Cardiac wall motion abnormality as a predictor for undetermined stroke with embolic lesion-pattern

OBJECTIVES

Several strokes of potential embolism do not clearly meet the definitions of embolic stroke with unknown source, cryptogenic stroke, or cardioembolic (CE) stroke. Considering the high mortality and recurrence of CE strokes, it is very important to detect treatable cardiac sources of embolism. Although regional wall motion abnormality (RWMA) of the left ventricle (LV) seems to be related to CE stroke, association between cerebral embolic risk and RWMA remains unclear. The purpose of this study was to investigate the influence of RWMA on undetermined stroke with embolic lesion-pattern (USELP).

PATIENTS AND METHODS

Among a total of 2327 patients with acute ischemic stroke, we excluded 148 patients without a transthoracic echocardiography (TTE). According to a stepwise approach, we excluded patients without an embolic lesion-pattern. Finally, we divided patients into two groups (USELP, 119, and non-embolic stroke, 1237). We classified patients' RWMAs into three major arterial territories according to the standard 17-segment model of TTE.

RESULTS

Among the included 1356 patients, those with USELP had larger internal dimension at diastole and systole in LV, reduced LV ejection fraction, increased E/A ratios, mitral valve disease, and RWMA. After adjusting for multiple variables, binary logistic regression revealed that RWMA was significantly associated with USELP (OR 7.02, 95 % CI: 3.51-14.01, p<0.001).

CONCLUSION

This study provides significant information to support that RWMA can be a predictor for undetermined embolic stroke. In this regard, RWMA were highly correlated with patients whose imaging supported an embolic source compared to those without this radiographic pattern.

Diagnosis and Management of Left Atrium Appendage Thrombosis in Atrial Fibrillation Patients Undergoing Cardioversion

Atrial fibrillation is the most common cardiac arrhythmia and is associated with an increased risk of stroke and thromboembolic complications. A rhythm control strategy with both electrical and pharmacological cardioversion is recommended for patients with symptomatic atrial fibrillation. Anticoagulant therapy for 3–4 weeks prior to cardioversion is recommended in order to avoid thromboembolic events deriving from restoring sinus rhythm. Transesophageal echocardiography has a pivotal role in this setting, excluding the presence of left atrial appendage thrombus before cardioversion. The aim of this review is to discuss the epidemiology and risk factors for left atrial appendage thrombosis, the role of echocardiography in the decision making before cardioversion, and the efficacy of different anticoagulant regimens on the detection and treatment of left atrial appendage thrombosis.

Does mitral regurgitation reduce the risks of thrombosis in atrial fibrillation and flutter?

AIMS

Blood stasis is the main cause of left atrial thrombosis (LAT) in atrial tachyarrhythmias. The high-velocity flow inside the left atrium, due to mitral valve regurgitation, may prevent clot formation but the topic has never been investigated in large-scale studies. The aim of our study was to evaluate whether the presence and degree of mitral regurgitation have a protective role against LAT risk.

METHODS

A total of 1302 consecutive adult patients with paroxysmal or persistent atrial fibrillation or flutter undergoing cardioversion, submitted to transesophageal echocardiography, were retrospectively enrolled in the study. The study population was divided into three groups according to the mitral regurgitation degree: absent, mild-to-moderate and severe.

RESULTS

Among 1302 patients enrolled in the study, patients without mitral regurgitation were 248 (19%), those with mild-to-moderate 970 (75%), whereas 84 had severe mitral regurgitation (6%). LAT incidence was significantly lower in patients with severe mitral regurgitation compared with those with mild-to-moderate (mitral regurgitation) (2.4 vs. 8.9%, P < 0.05), and similar to subjects without mitral regurgitation (2.4%).

CONCLUSION

Despite patients with severe regurgitation having clinical and echo characteristics predisposing to LAT (higher age, heart failure, higher atrial size, lower ventricular function) thrombosis prevalence was significantly lower than for those with mild-to-moderate mitral regurgitation. The percentage of LAT in severe mitral regurgitation cases was very low and similar to that of cases without regurgitation which were characterized by lower age, normal left ventricular function or other risk factors, reinforcing the hypothesis of a protecting role against atrial thrombosis of mitral regurgitation.

Real-world survival data of device-related thrombus following left atrial appendage closure: 4-year experience from a single center

This study aimed to estimate the incidence and risk factors of device-related thrombus (DRT) following percutaneous left atrial appendage closure (LAAC) in real-world practices. Between February 2012 and December 2016, 319 consecutive patients with atrial fibrillation underwent percutaneous LAAC using WATCHMAN, WATCHMAN Flx, Amplatzer cardiac plug, and Amulet devices. All patients underwent transesophageal echocardiography (TEE) at a minimum of three time points; periprocedurally, at 45 days, and at 6 months. Other clinical parameters were also evaluated, and a comparison between patients with DRT and those not suffering from DRT was done. The percutaneous LAAC was successfully performed in 97.8% of the patients. DRT was detected in 14 (4.49%) patients; of the 14 patients, DRT was detected in 3 patients at acute phase, 8 patients at subacute phase, 2 patients at late phase and 1 patient at very late phase. Most of the DRT originated from the central screw of device. In 6 out of 14 patients, DRT was successfully resolved by oral anticoagulation. Higher HAS-BLED score (4.1 ± 1.2 vs. 3.5 ± 1.1, p = 0.042) was more frequent in patients with DRT. Multivariable analysis showed that residual peri-device leak may result in a predisposition to DRT (p = 0.023). The incidence of DRT after percutaneous LAAC was acceptable, as a part of the DRT was resolved with oral anticoagulation. Residual peri-device leak was associated with DRT. Optimal implantation without peri-device gap, individual antithrombotic regimens, and careful monitoring with TEE follow-up could be conducive to the prevention of DRT.

Average e' velocity on transthoracic echocardiogram is a novel predictor of left atrial appendage sludge or thrombus in patients with atrial fibrillation

BACKGROUND

Studies have demonstrated the value of transthoracic echocardiogram (TTE) diastolic parameters in predicting left atrial appendage (LAA) thrombus; however, these studies have been small. We aim to clarify the relationship between TTE diastolic parameters, in particular average e', and LAA thrombus or sludge.

METHODS

A case-control review was conducted of subjects with non-valvular atrial fibrillation (n = 2263) who had undergone TEE (transesophageal echocardiogram) and had a TTE within 1 year of TEE. Cases of LAA sludge or thrombus were matched to controls by age, sex, left ventricular ejection fraction (LVEF), and anticoagulation status.

RESULTS

Forty-three subjects (mean age 73 ± 12, 65% male, LVEF 47%, 44% on anticoagulation) with LAA sludge or thrombus were identified. Compared to matched controls, average TTE e' (7.3 ± 2.1 cm/s vs 8.7 ± 2.1 cm/s, P < 0.001) and the E:e' ratio (15 ± 7 cm/s vs 12 ± 5 cm/s; P = 0.005) were significant predictors of LAA sludge or thrombus. Average TTE e' value of >11 cm/s had 100% sensitivity for ruling out LAA sludge or thrombus.

CONCLUSION

In individuals with atrial fibrillation, average e' >11 cm/s on TTE is a promising independent predictor of the absence of LAA sludge or thrombus on TEE.

THROMBOSIS OF LEFT ATRIAL APPENDAGE DURING THERAPY WITH DIRECT ORAL ANTICOAGULANT. CLINICAL CASE

The article presents a clinical observation of the left atrial appendage thrombosis in a 51-year-old female patient with a paroxysmal form of nonvalvular atrial fibrillation which occurred despite long-term anticoagulant therapy with apixaban in a full dose (5 mg b.i.d.), and the patient’s management. The patient was admitted with recurrent symptomatic paroxysm for more than 48 hours, because of which, in accordance with the recommendations, transesophageal echocardiography was performed before an emergency rhythm restoration. Thrombus in the left atrial appendage 0.5×1.03 cm in size was detected. It was decided to refrain from the immediate restoration of the rhythm due to the very high risk of thromboembolic complications. In connection with the categorical refusal of the patient from warfarin, it was decided to replace apixaban with another direct oral anticoagulant – dabigatran 150 mg bid for a period of 4 weeks followed by performing a control transesophageal echocardiographic study. As a result, no thrombus was found on control echocardiography. The particularity of this observation is concomitant hypertrophic cardiomyopathy and diabetes mellitus type 1 in this patient.

Real-Time Pathophysiologic Correlates of Left Atrial Appendage Thrombus in Patients Who Underwent Transesophageal-Guided Electrical Cardioversion for Atrial Fibrillation

Although current guidelines advocate using the CHA₂DS₂-VASc score to assess the risk of stroke in patients with atrial fibrillation (AF), compared with transesophageal echocardiography (TEE), its ability to predict left atrial appendage thrombus (LAAT) is limited. We studied 3,324 consecutive patients with sustained AF from our prospective registry of patients who underwent first-time TEE-guided electrical cardioversion (ECV) from May 2000 through March 2012. The association of CHA₂DS₂-VASc score or TEE risk factors with the occurrence of LAAT was analyzed. The mean (SD) age was 69 (12.5) years and 67% were men. LAAT was identified in 49 (1.5%) during pre-ECV TEE. Compared with patients without LAAT, those with LAAT had lower peak left atrial appendage emptying velocity (LAAEV) (17.2 ± 8.5 vs 36.6 ± 20.8; p <0.001) and left ventricular ejection fraction (LVEF) (39.9 ± 17.6 vs 51.4 ± 13.7; p <0.001); their CHA₂DS₂-VASc score also was higher, but the difference was not statistically significant (3.6 ± 1.4 vs 3.2 ± 1.6; p = 0.06). Multivariate logistic regression analysis identified an LVEF ≤40% (adjusted odds ratio 2.48, 95% confidence interval 1.38 to 4.46), LAAEV 20.3 to 33.9 cm/s (odds ratio 12.19, 95% confidence interval 1.53 to 96.86), and LAAEV ≤20.2 cm/s as independent predictors of LAAT. An LAAEV cut-point of 20 cm/s and an LVEF ≤40% were optimal for detecting LAAT (sensitivity 75% and 62%; specificity 77% and 75%; area under the curve 0.822 and 0.776, respectively). On follow-up, LAAT was an independent risk factor of subsequent ischemic stroke but did not influence survival. In conclusion, reduced LVEF and reduced LAAEV are important pathophysiologic correlates of left atrial appendage thrombogenesis and subsequent ischemic stroke in patients who underwent TEE-guided ECV for AF.

Incremental value of left atrial mechanical dispersion over CHA2 DS2 -VASc score in predicting risk of thrombus formation

PURPOSE

To assess the potential ability of two-dimensional speckle tracking analysis (STE) during atrial fibrillation (AF) to identify patients with LA appendage thrombi (LAAT).

METHODS

This study involved 93 patients with AF (39% female, 67.1 ± 9.5 years) who were referred for a clinical indication for transesophageal echocardiography (TEE). TEE revealed LAAT in 39 (42%) patients. We analyzed standard parameters of the left ventricle (LV) and LA in transthoracic echocardiography. Using STE, we assessed LV global longitudinal strain (LVGLS), peak atrial longitudinal strain (PALS), and intra-atrial asynchrony. The PALS was calculated using the global strain curve (GPALS) and as the mean of peaks derived from segmental strain curves (MPALS).

RESULTS

Patients were comparable with regard to the clinical data. A subgroup with LAAT had lower LV ejection fraction (LVEF) and a lower absolute value of the LVGLS, as well as greater impairment in the LA standard parameters, PALS, and asynchrony. Receiver operating characteristic curve analysis revealed that the LVEF of 30% (P < .001), the LVGLS of -7% (P < .0001), the GPALS of 11% (P < .005), and the LA asynchrony of 22% (P < .01) were the optimal cutoff values for distinguishing both subgroups. LA asynchrony, LVEF, and LVGLS were independently associated with the presence of LAAT in multivariate analyses, and PALS had additional significance over the CHA₂ DS₂ -VASc score.

CONCLUSIONS

Left ventricular systolic dysfunction characterized by both LVEF and LVGLS is an independent factor for LAAT. LA asynchrony provides additional diagnostic value for discriminating between patients with and without LAAT.

Relation between left atrial measurements and thromboembolic risk markers assessed by echocardiography in patients with nonvalvular atrial fibrillation: A cross-sectional study

Background

Left atrium (LA) dilatation has been associated with adverse cardiovascular outcomes in patients with sinus rhythm and atrial fibrillation (AF).

Aim of the study

We aimed to evaluate the accuracy of left atrial (LA) size to predict transesophageal echocardiographic (TEE) markers of increased thromboembolic risk left atrial appendage (LAA) thrombus, low LAA velocities and dense spontaneous echocardiographic contrast (SEC), and also to assess the best method to evaluate LA size.

Patients and methods

Cross-sectional study included 64 patients with nonvalvular AF undergoing transthoracic and transesophageal echocardiographic (TTE and TEE) evaluation. LA size was measured on TTE by several methods including the following: anteroposterior diameter (AP), LA area in four and two apical chamber views and volumes by ellipsoid, single plane (1P) and biplane area-length (2P) formulas. All these measures were indexed to the body surface area (BSA). Thromboembolic markers including LAA thrombus, low LAA velocities, dense SEC and LA abnormality (LA ABN) which means the presence of one or more of the previous three parameters were evaluated by TEE.

Results

There was statistically significant increase in indexed and non-indexed LA parameters in patients with LA ABN compared to patients without LA ABN. According to ROC curve, the study found that all indexed LA parameters were predictive for LAA thrombus with the highest AUC was indexed LA 1P area length volume (AUC 0.91, CI 95% 0.81-1.01, p < 0.000), for LAA low flow velocity were indexed and non-indexed LA AP diameters with the highest AUC was indexed LA AP diameter (AUC 0.89, CI 95% 0.80-0.98, p < 0.000), for LA dense SEC were indexed LA ellipsoid volume (AUC 0.78, CI 95% 0.66-0.96, p = 0.002) and indexed LA 1P area length volume (AUC 0.78, CI 95% 0.66-0.90, p = 0.002) and for LA ABN were all LA parameters with the highest AUC was indexed LA 1P area length volume (AUC 0.87, CI 95% 0.79-0.96, p < 0.000). On multivariate logistic regression analysis of TEE parameters, the study found that the most predictive LA measurement for LAA thrombus was indexed LA AP diameter with cutoff 3 cm/m² (OR 7.5, 95% CI 1.24-45.2, p = 0.02), for LAA low flow velocity was LA AP diameter with cutoff 6 cm (OR 17.6, 95% CI 3.23-95.84, p = 0.001), for LA dense SEC was indexed LA ellipsoid volume with cutoff 42 cm³/m² (OR 6.5, 95% CI 1.32-32.07, p = 0.02), and for LA ABN was indexed LA ellipsoid volume with cutoff 42 cm³/m² (OR 10.45, 95% CI 2.18-51.9, p = 0.008).

Conclusion

LA enlargement is suitable to predict thromboembolic markers in patients with non-valvular AF. The indexed and non-indexed LA AP diameter and indexed LA ellipsoid volume were the most accurate parameters for predicting thromboembolic markers.

Left Atrial Strain Predicts Pro-Thrombotic State in Patients with Non-Valvular Atrial Fibrillation

Background and Purpose

Atrial fibrillation (AF) has a high prevalence in the population and it is responsible for up to the 25% of the strokes in elderly people. The aim of our study was to assess the correlations of left atrial (LA) functional parameter, global peak atrial longitudinal strain (PALS), derived from speckle tracking echocardiography (STE), with transesophageal echocardiography (TEE) findings in patients with persistent AF undergoing TEE before electrical cardioversion or ablation procedures.

Methods

79 patients (58 males, 21 females) with persistent AF waiting for cardioversion were included in the study. The patients underwent conventional two-dimensional (2D) and 2D speckle tracking echocardiogram. PALS were measured in all subjects. Patients were divided into two groups according to the presence of reduced LA appendage (LAA) emptying velocity (<25 cm/s) and/or thrombus in the LAA at TEE examination.

Results

Patients with reduced LAA emptying velocity and/or thrombus at TEE examination showed a significantly higher LA volume and increased E/E' ratio. 4-chamber, 2-chamber and global PALS were significantly lower in patients with reduced LAA emptying velocity and/or thrombus (6.8 ± 2.0% vs. 27.5 ± 5.4%, P < 0.0001; 8.6 ± 3.5% vs. 29.4 ± 7.1%, P < 0.0001; 7.9 ± 3.2% vs. 28.5 ± 6.1%, P <0.0001, respectively). Among all variables analyzed, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.92) and, with a cut-off value less than 8.1%, good sensitivity and specificity of 87% and 94%, respectively, to predict LAA thrombus and/or reduced LAA emptying velocity.

Correlation between plasma brain natriuretic peptide levels and left atrial appendage flow velocity in patients with non-valvular atrial fibrillation and normal left ventricular systolic function

BACKGROUND

The left atrial appendage (LAA) flow velocity is an important factor for thrombus formation in patients with non-valvular atrial fibrillation (NV-AF). Recently, the relation of plasma brain natriuretic peptide (BNP) levels and thromboembolism has been reported in patients with NV-AF. The aim of this study was to determine whether the plasma BNP is predictive of lower LAA flow velocity in patients with NV-AF and normal left ventricular (LV) systolic function.

METHODS AND RESULTS

A total of 184 patients with NV-AF (132 men; 65 ± 12 years, LV ejection fraction; 65 ± 10%) underwent transthoracic echocardiography, transesophageal echocardiography (TEE), and measurement of plasma BNP. The LAA flow velocity was obtained by pulsed Doppler TEE. Multivariate logistic regression analysis demonstrated that plasma BNP levels, left atrial volume index (LAVI), LV mass index (LVMI), and the CHADS₂ score were independent predictors of lower LAA flow velocity (< 20 cm/s). Plasma BNP levels (r = - 0.58, p < 0.001) were correlated with LAA flow velocity. The area under the curve (AUC) for BNP (AUC 0.803) was larger than that for the CHADS₂ score (AUC 0.712), LAVI (AUC 0.664) and LVMI (AUC 0.608) with an optimal BNP cut-off value of 164 pg/ml (sensitivity 75.7%, specificity 71.1%).

CONCLUSIONS

This study showed that a higher plasma BNP was associated with a lower LAA flow velocity in patients with NV-AF and normal LV systolic function. The plasma BNP may complement the role of the CHADS₂ score in predicting lower LAA flow velocity.

Left Atrial Size and Long-Term Risk of Recurrent Stroke After Acute Ischemic Stroke in Patients With Nonvalvular Atrial Fibrillation

BACKGROUND

Among patients with ischemic stroke and atrial fibrillation, which ones are at high risk of recurrent stroke is unclear. This study aimed to determine whether left atrial size was associated with long-term risk of stroke recurrence in patients with nonvalvular atrial fibrillation.

METHODS AND RESULTS

In this multicenter prospective cohort study, nonvalvular atrial fibrillation patients hospitalized for acute ischemic stroke were enrolled and followed up after discharge. Indexed-left atrial diameter was obtained by dividing left atrial diameter by body surface area. Cause-specific and subdistribution hazard ratios of recurrent stroke were estimated by Cox proportional hazards and Fine-Gray models, respectively. Risk prediction was evaluated by integrated discrimination improvement and net reclassification improvement. In total, 1611 patients (77.8±10.2 [mean±SD] years, 44.5% female) were included. During follow-up for 2.40±1.63 (mean±SD) years, 251 patients had recurrent stroke and 514 patients died. An increased indexed-left atrial diameter (per 1 cm/m²) was significantly associated with elevated risk of stroke recurrence (hazard ratio 1.60, 95% CI 1.30-1.98). The association was maintained when death was regarded as the competing risk and in 1464 patients who were treated with anticoagulants (hazard ratio 1.59, 95% CI 1.27-2.00). Risk prediction for recurrent stroke was significantly improved by adding indexed-left atrial diameter to the baseline model composed of the factors in the CHADS₂ score or those in the CHA₂DS₂-VASc score.

CONCLUSION

These findings suggest that left atrial enlargement is associated with an increased risk of recurrent stroke in nonvalvular atrial fibrillation patients with ischemic stroke.

Association between left atrial function assessed by speckle-tracking echocardiography and the presence of left atrial appendage thrombus in patients with atrial fibrillation

Objective:

The aim of the study was to investigate whether the deformation of left atrium (LA) measured by speckle-tracking analysis (STE) is associated with the presence of LA appendage thrombus (LAAT) during non-valvular atrial fibrillation (AF).

Methods:

Eighty-seven patients (mean age 67 years, 59% men) were included to retrospective cross-sectional study. On top of standard echocardiography we assessed: LA longitudinal systolic strain (LS), systolic (LSSR) and early diastolic strain rate (LESR) in four-chamber and two-chamber apical views. All patients underwent transesophageal echocardiography disclosing LAAT in 36 (41%) patients.

Results:

Subgroups with and without thrombi did not differ with regard to clinical characteristics. Univariate factors associated with LAAT were as follows: CH₂ADS₂-VASc Score, left ventricular ejection fraction (LVEF), LV mass, and STE measurements. In a multivariate model only LVEF (p=0.002), LS (p=0.02), LESR (p=0.008), and LSSR (p=0.045) were independently associated with LAAT presence. Moreover, LVEF and LA STE measurements provided incremental value over the CH₂ADS₂-VASc Score.

Conclusion:

Speckle-tracking TTE may be used to describe LA reservoir and conduit function during AF, allowing the identification of patients with higher risk of LAAT and providing incremental value over the CH₂ADS₂-VASc Score.

Association of CHADS2 and CHA2DS2-VASc Scores with Left Atrial Thrombus with Nonvalvular Atrial Fibrillation: A Single Center Based Retrospective Study in a Cohort of 2695 Chinese Subjects

The main mechanism of the CHADS₂ and CHA₂DS₂-VASc scores to predict stroke in nonvalvular atrial fibrillation (NVAF) is still controversial. We evaluated the association of the CHADS₂ and CHA₂DS₂-VASc scores with left atrial thrombus (LAT) as detected by transesophageal echocardiographic (TEE) and compared the predictive ability of these risk stratification schemes with nonvalvular atrial fibrillation (NVAF). Data from 2,695 consecutive NVAF patients in whom TEE was performed for screening LAT from July 2007 to February 2014 were analyzed. Only 3% of the subjects had LAT. Presence of LAT was not significantly associated with either CHADS₂  (P = 0.07) or CHA₂DS₂-VASc score (P = 0.12). The area under the curve (AUC) concerning LAT prediction using CHADS₂ and CHA₂DS₂-VASc was 0.574 and 0.569, respectively. A composition model includes previous stroke or transient ischemic attack, nonparoxysmal AF, moderate to severe left ventricular systolic dysfunction, left atrial enlargement, and cardiomyopathy which improved the discrimination significantly (AUC = 0.743). In our cohort, both CHADS₂ and CHA₂DS₂-VASc scores were of limited value for predicting LAT in patients with NVAF. This questions the CHADS₂/CHA₂DS₂-VASc score predicting stroke mainly through the mechanism of cardiogenic embolism. A scoring scheme combining clinical and echocardiographic parameters may better predict LAT as a surrogate for cardioembolic risk in NVAF patients.

Embolic stroke and after-admission atrial fibrillation

BACKGROUND

Although atrial fibrillation (AF) is a leading cause of recurrent embolic stroke, secondary AF after stroke has been reported frequently. Because of the different treatment each uses, it is important to detect the exact stroke-etiology.

OBJECTIVES

The aim of this study was to compare the embolic stroke in patients with known AF and after-admission AF (AAAF).

METHODS

Between October 2002 and July 2009, those who were diagnosed with AF (n=354) were enrolled in our study out of a total of 2026 acute ischemic stroke (IS) patients. The embolic lesion patterns were assessed by two stroke specialists who were blinded to the clinical information.

RESULTS

Among 354 IS patients with AF, the number of patients with embolic stroke was 314. Patients with embolic stroke were younger and more likely to have larger left atrial (LA)/Aortic diameter ratio. Approximately 90.4% of those with known AF had embolic stroke, while <60% of patients with AAAF had embolic stroke. Nevertheless, anticoagulants were prescribed similarly in both groups at discharge. The LA/Aortic diameter ratio<1.5 was significantly related to AAAF. After adjusting for multiple co-variables, compared to the patients with known AF, patients with AAAF had reduced risk of embolic stroke (Odds ratio 0.11, 95% Confidence interval 0.03-0.36, p-value<0.001).

CONCLUSIONS

Compared to AAAF after stroke, known AF was associated with embolic stroke. Therefore, we suggest that stroke etiology and some novel echocardiographic indicators such as LA enlargement might be contemplated before routine using of anticoagulants in IS patients with AF.

Stroke risk assessment in atrial fibrillation: risk factors and markers of atrial myopathy

Atrial fibrillation (AF) is a complex phenomenon associated with electrical, mechanical, and structural abnormalities of the atria. Ischaemic stroke in AF is only partially understood, but the mechanisms are known to be related to the atrial substrate as well as the atrial rhythm. The temporal dissociation between timing of AF and occurrence of stroke has led to the hypothesis that fibrotic, prothrombotic atrial tissue is an important cause of thrombus formation in patients with AF, independent of the atrial rhythm. Current stroke risk scores are practical, but limited in their capacity to predict stroke risk accurately in individual patients. Stroke prediction might be improved by the addition of emerging risk factors, many of which are expressions of atrial fibrosis. The use of novel parameters, including clinical criteria, biomarkers, and imaging data, might improve stroke risk prediction and inform on optimal treatment for patients with AF and perhaps individuals only at risk of AF.

Impact of Diastolic Function Parameters on the Risk for Left Atrial Appendage Thrombus in Patients with Nonvalvular Atrial Fibrillation: A Prospective Study

BACKGROUND

In patients with nonvalvular atrial fibrillation (NVAF), the impact of left ventricular diastolic function on the risk for left atrial appendage (LAA) thrombus has not been prospectively studied.

METHODS

At two academic medical centers, patients with NVAF were prospectively enrolled to undergo investigational transthoracic echocardiography immediately before clinically indicated transesophageal echocardiography. Mitral inflow E velocity and tissue Doppler septal and lateral mitral annulus velocities (e') were measured, and E/e' ratios were calculated.

RESULTS

Among 266 subjects (mean age, 65 years; 32% women), 17 (6.4%) had LAA thrombus. Patients with LAA thrombus had a higher mean CHA2DS2-VASc score (4.6 ± 1.7 vs 3.0 ± 1.8, P < .001), a higher mean lateral E/e' ratio (19.4 ± 10.1 vs 10.2 ± 5.6, P < .001), and a lower mean lateral e' velocity (7.0 ± 3.2 vs 10.4 ± 3.7 cm/sec, P = .001). There was a good discriminative capacity for E/e' (area under the curve, 0.83; P < .001) and e' velocity (area under the curve, 0.76; P = .001). None of the patients with normal E/e' ratios or normal e' velocities had LAA thrombus. Both E/e' (odds ratio, 1.13 per point; 95% CI, 1.06-1.20; P < .001) and e' velocity (odds ratio, 0.76 per 1 cm/sec; 95% CI, 0.63-0.92; P = .005) provided independent and incremental predictive value beyond the CHA2DS2-VASc score; however, E/e' provided greater incremental value than e' velocity (P = .036). Analyses using septal and averaged E/e' and septal e' velocity yielded similar results. Diastolic function parameters were also associated with the presence and intensity of left atrial spontaneous echo contrast, a precursor of LAA thrombus.

CONCLUSIONS

This prospective and concomitant evaluation of diastolic function and LAA thrombus in patients with NVAF demonstrates that E/e' ratio and e' velocity are associated with LAA thrombus, independent of CHA2DS2-VASc score, and may play a role in identifying patients at low risk for LAA thrombus. These data suggest that diastolic function assessment may improve stroke prediction in patients with NVAF.

Relevance of transthoracic left atrial appendage wall velocity measurement in addition to left atrial volume for noninvasive and quantitative assessment of left atrial thrombogenesis in patients with atrial fibrillation and normal D-dimer levels

PURPOSE

This study examined the role of left atrial (LA) appendage wall velocity (LAAWV) measurement in addition to LA size for the noninvasive assessment of thrombogenesis in patients with atrial fibrillation (AF) and normal plasma D-dimer levels.

METHODS

In 58 non-valvular AF patients, LAAWV and the LA volume index (LAVI) were determined by transthoracic echocardiography. LA appendage flow velocity and severity of spontaneous echo contrast (SEC) were determined by transesophageal echocardiography.

RESULTS

LAAWV was strongly correlated with LA appendage flow velocity (r = 0.82), and LAVI was weakly correlated with LA appendage flow velocity (r = -0.37). As SEC severity increased, LAAWV decreased (p < 0.001) and LAVI increased (p < 0.001). Among 52 patients with normal D-dimer levels, LAAWV < 10 cm/s had 71 % sensitivity and 94 % specificity for diagnosing severe SEC. Severe SEC was not found in 18/32 large LAVI patients (>34 mL/m(2)), but 17 of the 18 patients (94 %) had LAAWV < 10 cm/s. Severe SEC was found in 3/20 patients with normal LAVI, but all of them showed LAAWV < 10 cm/s.

CONCLUSION

The noninvasive measurement of transthoracic LAAWV in addition to LA volume is clinically relevant for quantitatively assessing thrombogenesis in AF patients with normal D-dimer levels.