Atrial fibrillation type and renal dysfunction as important predictors of left atrial thrombus

Construction and validation of a predictive model for intracardiac thrombus risk in patients with dilated cardiomyopathy: a retrospective study

BACKGROUND

Systemic embolic events due to exfoliation of intracardiac thrombus (ICT) are one of the catastrophic complications of dilated cardiomyopathy (DCM). This study intended to develop a prediction model to predict the risk of ICT in patients with DCM.

METHODS

Data from 632 patients with DCM from a hospital was collected. ICT was identified based on the results of transthoracic echocardiography. Basic information, vital signs, comorbidities, and biochemical data were measured and collected from each patient. The least absolute shrinkage and selection operator (LASSO) regression was used for the final model variable screening. Four classifiers including Logistic Regression, support vector machine (SVM), Random Forest, and eXtreme Gradient Boosting (XGBoost) were used for model construction respectively. The area under of the curve (AUC) with 95% confidence interval (CI), sensitivity, specificity, and accuracy of the models were calculated to assess the predictive ability of the models.

RESULTS

Of these 632 DCM patients, 88 (13.92%) had ICT and 544 (86.08%) did not. Eleven clinical variables were selected for the construction of predictive models. The AUC of the Logistic Regression model to predict ICT probability was 0.854 (95%CI: 0.811-0.896), the SVM model was 0.769 (95%CI: 0.715-0.824), the Random Forest model was 0.917 (95%CI: 0.887-0.947), and the XGBoost model was 0.947 (95%CI: 0.924-0.969). The Delong test demonstrated that the XGBoost model had the highest AUC for predicting the ICT probability compared to other models (P < 0.05). Moreover, D-dimer, age, and atrial fibrillation contributed the most to the XGBoost model among these 11 variables.

CONCLUSION

The XGBoost model has a good predictive ability in predicting ICT risk in patients with DCM and may assist clinicians in identifying ICT risk.

Radiomics prediction models of left atrial appendage hypercoagulability based on machine learning algorithms: an exploration about cardiac computed tomography angiography imaging

Transesophageal echocardiography (TEE) is the standard method for diagnosing left atrial appendage (LAA) hypercoagulability in patients with atrial fibrillation (AF), which means LAA thrombus/sludge, dense spontaneous echo contrast and slow LAA blood flow velocity (< 0.25 m/s). Based on machine learning algorithms, cardiac computed tomography angiography (CCTA) radiomics features were adopted to construct prediction models and explore a suitable approach for diagnosing LAA hypercoagulability and adjusting anticoagulation. This study included 652 patients with non-valvular AF. The univariate analysis were used to select meaningful clinical characteristics to predict LAA hypercoagulability. Then 3D Slicer software was adopted to extract radiomics features from CCTA imaging. The radiomics score was calculated using the least absolute shrinkage and selection operator logistic regression analysis to predict LAA hypercoagulability. We then combined clinical characteristics and radiomics scores to construct a nomogram model. Finally, we got prediction models based on machine learning algorithms and logistic regression separately. The area under the receiver operating characteristic curve of radiomics score was 0.8449 in the training set and 0.7998 in the validation set. The nomogram model had a concordance index of 0.838. The final machine-learning based prediction models had good performances (best f1 score = 0.85). Radiomics features of long maximum diameter and high uniformity of Hounsfield unit in left atrial were significant predictors of the hypercoagulable state in LAA, with better predictive efficacy than clinical characteristics. Our combined models based on machine learning were reliable for hypercoagulable state screening and anticoagulation adjustment.

Influencing factors and predictive model for left atrial appendage emptying velocity in nonvalvular AF patients

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia, significantly increasing the risk of death and stroke. The left atrial appendage (LAA) plays a crucial role in the development of AF. Reduced left atrial appendage emptying velocity (LAAEV) is an important indicator of nonvalvular AF, associated with thrombosis and recurrence after catheter ablation. This study aims to identify factors influencing LAAEV and construct a predictive model for LAAEV in nonvalvular AF patients.

Methods

This retrospective cohort study included 1,048 nonvalvular AF patients hospitalized at the Second Hospital of Hebei Medical University from January 1, 2015, to December 31, 2021. Patients underwent transthoracic and transesophageal echocardiography and had complete laboratory data. Statistical analyses included binary logistic regression and multiple linear regression to identify independent predictors of reduced LAAEV and construct a predictive model.

Results

Patients were divided into two groups: reduced LAAEV (<40 cm/s) and normal LAAEV (≥40 cm/s). The reduced LAAEV group included 457 patients (43.61%), with significant differences in age, gender, alcohol consumption, heart failure (HF), ischemic stroke, AF type, resting heart rate, CHA2DS2-VASc score, serum creatinine (SCR), serum uric acid (SUA), estimated glomerular filtration rate (eGFR), glycated hemoglobin (HbA1C), β2 macroglobulin (B2M), left atrial diameter (LAD), and left ventricular ejection fraction (LVEF) compared to the normal LAAEV group. Logistic regression analysis identified age (OR 0.974, 95% CI 0.951-0.997, P = 0.028), HF (OR 0.637, 95% CI 0.427-0.949, P = 0.027), AF type [Persistent AF vs. PAF (OR 0.063, 95% CI 0.041-0.095, P = 0) Long-standing Persistent AF vs. PAF (OR 0.077, 95% CI 0.043-0.139, P = 0)], LAD (OR 0.872, 95% CI 0.836-0.91, P < 0.001), and LVEF (OR 1.057, 95% CI 1.027-1.089, P = 0) as independent predictors of reduced LAAEV. Multiple linear regression analysis included age, AF type, LAD, and LVEF in the final predictive model, explaining 43.5% of the variance in LAAEV (adjusted R² = 0.435).

Conclusion

Age, HF, type of AF, LAD, and LVEF are independent predictors of reduced LAAEV. The predictive model (LAAEV = 96.567-15.940 × AFtype-1.309 × LAD-0.18 × Age + 37.069 × LVEF) demonstrates good predictive value, aiding in the initial assessment and management of nonvalvular AF patients.

Simple scores to predict 1-year mortality in atrial fibrillation

BACKGROUND

Traditional scores as CHADS2 and CHA2DS2-Vasc are suitable for predicting stroke and systemic embolism in patients with atrial fibrillation (AF) and have shown to be also associated with mortality. Other more complex scores have been recommended for survival prediction. The purpose of our analysis was to test the performance of different clinical scores in predicting 1-year mortality in AF patients.

MATERIAL AND METHODS

CHADS2 and CHA2DS2-Vasc scores were calculated for AF patients of the BLITZ-AF register and compared to R2-CHADS2, R2-CHA2DS2-Vasc and CHA2DS2VASc-RAF scores in predicting 1-year survival. Scores including renal function were calculated both with glomerular filtration rate (GFR) and creatinine clearance.

RESULTS

One-year vital status (1960 alive and 199 dead) was available in 2159 patients. Receiver-operating characteristic curves displayed an association of each score to all-cause mortality, with R2(ClCrea)-CHADS2 being the best [area under the curve (AUC) 0.734]. Differences among the AUCs of the eight scores were not so evident, and a significant difference was found only between R2(ClCrea)-CHADS2 and CHADS2, CHA2DS2VASc, (ClCrea)-CHA2DS2-VASC-RAF.All the scores showed a similar performance for cardiovascular (CV) mortality, with CHA2DS2VASc-RAF being the best (AUC 0.757), with a significant difference with respect to CHADS2, CHA2DS2VASc, and (ClCrea)CHA2DS2Vasc-RAF.

CONCLUSIONS

More complex scores, even if with better statistical performance, do not show a clinically relevant higher capability to discriminate alive or dead patients at 12 months. The classical and well known CHA2DS2VASc score, which is routinely used all around the world, has a high sensitivity in predicting all-cause mortality (AUC 0.695; Sensit. 80.4%) and CV mortality (AUC 0.691; Sensit. 80.0%).

GRAPHICAL ABSTRACT

http://links.lww.com/JCM/A632.

Artificial intelligence in detecting left atrial appendage thrombus by transthoracic echocardiography and clinical features: the Left Atrial Thrombus on Transoesophageal Echocardiography (LATTEE) registry

AIMS

Transoesophageal echocardiography (TOE) is often performed before catheter ablation or cardioversion to rule out the presence of left atrial appendage thrombus (LAT) in patients on chronic oral anticoagulation (OAC), despite associated discomfort. A machine learning model [LAT-artificial intelligence (AI)] was developed to predict the presence of LAT based on clinical and transthoracic echocardiography (TTE) features.

METHODS AND RESULTS

Data from a 13-site prospective registry of patients who underwent TOE before cardioversion or catheter ablation were used. LAT-AI was trained to predict LAT using data from 12 sites (n = 2827) and tested externally in patients on chronic OAC from two sites (n = 1284). Areas under the receiver operating characteristic curve (AUC) of LAT-AI were compared with that of left ventricular ejection fraction (LVEF) and CHA2DS2-VASc score. A decision threshold allowing for a 99% negative predictive value was defined in the development cohort. A protocol where TOE in patients on chronic OAC is performed depending on the LAT-AI score was validated in the external cohort. In the external testing cohort, LAT was found in 5.5% of patients. LAT-AI achieved an AUC of 0.85 [95% confidence interval (CI): 0.82-0.89], outperforming LVEF (0.81, 95% CI 0.76-0.86, P < .0001) and CHA2DS2-VASc score (0.69, 95% CI: 0.63-0.7, P < .0001) in the entire external cohort. Based on the proposed protocol, 40% of patients on chronic OAC from the external cohort would safely avoid TOE.

CONCLUSION

LAT-AI allows accurate prediction of LAT. A LAT-AI-based protocol could be used to guide the decision to perform TOE despite chronic OAC.

Is there a reduced confidence towards direct oral anticoagulants compared to vitamin K antagonists in patients scheduled for an elective electrical cardioversion? The results of the BLITZ-AF study

OBJECTIVE

To study the confidence of cardiologists in performing an electrical cardioversion in patients on oral anticoagulation (OA) with or without transoesophageal echocardiography (TOE).

METHODS

Data about atrial fibrillation (AF) patients admitted to cardiology wards for elective cardioversion (ECV) were extrapolated from the BLITZ-AF study. Percentage of vitamin K antagonists (VKAs), direct oral anticoagulants (DOAC) and heparin prescription were analysed in relation to the use of TOE before ECV.

RESULTS

Overall rate of TOE was 33.7% (240/713); it was used before ECV in 124/313 (39.6%) of DOACs patients and in 96/372 (25.8%) of the patients on VKAs, showing a significant reduced resort to TOE in VKAs patients (p = 0.0001). Among non-valvular patients TOE was more frequently performed in males, at younger ages and in patients on heparin when compared to patients treated with OA. TOE was also more frequently performed in tertiary hospitals and in hospitals with cardiology wards and electrophysiology labs, when compared to hospital provided only with cardiology wards. At multivariable analysis there was a significant less recourse to TOE in patients on VKAs (OR 0.47; 95% CI: 0.33-0.67) and higher recourse in the heparin group (OR: 3.85; 95% CI:1.59-9.28) with respect to patients on DOACs; a higher recourse to TOE was observed also in tertiary hospitals (OR 4.25; 95% CI 2.69-6.69) and in hospitals with cardiology wards and electrophysiology (EP) labs (OR 1.87; 95% CI 1.23-2.82).

CONCLUSION

our study shows the reluctance in cardioverting patients on DOACs respect to VKAs without a previous TOE, despite adequate anticoagulant treatment.

Serum Fibrinogen and Renal Dysfunction as Important Predictors of Left Atrial Thrombosis in Patients with Atrial Fibrillation

BACKGROUND

As has been shown previously, patients with atrial fibrillation (AF) who have left atrial thrombus (LAT) also have elevated plasma concentrations of fibrinogen. In this study, we tried to determine if this is the consequence of a genetic trait and whether elevated concentrations of fibrinogen could be used to predict LAT in patients with AF.

METHODS

We recruited 181 consecutive patients scheduled for pulmonary vein isolation (PVI) or direct current cardioversion. The primary endpoint was the presence of LAT on transesophageal echocardiography (TOE). We recorded routine clinical and biochemical data as well as the polymorphism type of the fibrinogen gene for the β chain. To control potentially interfering variables, we performed propensity score matching (PSM). Multivariable and univariable logistic regression models (LRM) were computed using the CHA2DS2-Vasc score, the fibrinogen concentration and creatinine clearance as estimated by the Cockcroft-Gault equation.

RESULTS

60 of 181 patients had LAT as detected by TOE. As expected, patients with LAT had significantly higher concentrations of fibrinogen (3.9 vs. 3.6 g/L); p = 0.01 in the unadjusted analysis. After performing PSM, there were no statistically significant differences between the groups, except for creatinine clearance (79.9 vs. 96.8 mL/min); p = 0.01. There were also no differences regarding the -455 G/A βfibrinogen polymorphism distribution between the two groups. After constructing the LRM, we found no performance enhancement for the CHA2DS2-Vasc score by adding the fibrinogen concentration or creatinine clearance alone, but when all three variables were put together, there was a significant improvement in LAT prediction (AUC 0.64 vs. 0.72), p = 0.026.

CONCLUSION

Our study found no evidence of elevated levels of circulating fibrinogen in patients with LAT or a connection between those levels and the A/A and A positive polymorphism. When used together with renal function markers such as creatinine clearance, plasma fibrinogen concentrations can provide additional power to the CHA2DS2-Vasc score for predicting LAT.

Epidemiology and Risk Factors for Stroke in Chronic Kidney Disease: A Narrative Review

Patients with chronic kidney disease (CKD) have a higher risk ofboth ischemic and hemorrhagic stroke. This association appears to be partly independent from the higher prevalence of established risk factors for stroke in patients with CKD, including hypertension and atrial fibrillation. In the present review we aim to discuss the impact of CKD on the risk of stroke and stroke-related consequences, and explore the pathophysiology underpinning the increased risk of stroke in patients with CKD. We cover the clinical association between renal dysfunction and cerebrovascular disease including stroke, silent brain infarct, cerebral small vessel disease, microbleeds, and white matter hyperintensity, and discuss the underlying mechanisms.

Ischemic stroke risk factors not included in the CHADS-VASC score in patients with non-valvular atrial fibrillation

BACKGROUND

In patients with atrial fibrillation, the CHA2DS2-VASC score guides stroke prevention using anticoagulants, but it is an imperfect score. Other potential risk factors such as renal failure, the type of atrial fibrillation, active smoking, cancer, sleep apnea or systemic inflammation have less well been investigated.

OBJECTIVE

To assess the impact of these factors on ischemic stroke risk in patients with non-valvular atrial fibrillation.

METHODS

On a population of 248 patients (124 patients with acute ischemic stroke and 124 controls), we performed a logistic regression to assess the impact of multiple non-classic risk factors for the prediction of acute ischemic stroke. Their impact on mortality was assessed by performing a survival analysis.

RESULTS

A high CHA2DS2-VASc score (OR 1.75; 95% CI 1.13-2.70; p = 0.032), treatment with anticoagulants (OR 0.19; 95% CI 0.07-0.51; p < 0.001) and permanent atrial fibrillation (OR 6.31; 95% CI 2.46-16.19; p < 0.001) were independently associated with acute ischemic stroke. Renal failure and chronic obstructive pulmonary disease predicted a higher mortality. After adjusting for age, sex, the CHA2DS2-VASc score and the use of anticoagulants, the only risk factor predictive for acute ischemic stroke was the permanent type of AF (OR: 8.0 [95% CI 2.5-25.5], p < 0.001).

CONCLUSIONS

The CHA2DS2-VASc score, the absence of anticoagulants and the permanent type of atrial fibrillation were the main predictive factors for the occurrence of acute ischemic stroke. Larger studies are necessary for conclusive results about other factors.

Risk factors associated with left atrial appendage thrombosis in patients with non-valvular atrial fibrillation by transesophageal echocardiography

PURPOSE

This study investigated possible mechanism of left atrial appendage (LAA) thrombosis and constructed a model to evaluate the future risk of LAA thrombosis and spontaneous echo contrast (SEC) in non-valvular atrial fibrillation (NVAF) patients.

METHODS

This retrospective study included 2591 patients diagnosed with NVAF. Patients were divided based on the presence of transesophageal echocardiography (TEE) into a thrombus group, SEC group, and control group. General, biochemical, and echocardiography data of the three groups were analyzed. The variables independently associated with LAA thrombosis and SEC were determined by the logistic regression analysis. A nomogram was constituted based on the regression analysis and the discriminatory ability was analyzed by receiver operating characteristic (ROC) curve.

RESULTS

LAA thrombosis and SEC were present in 110 (4.2%) patients and 103 (3.9%) patients, respectively. AF type (OR = 1.857), previous stroke (OR = 1.924), fibrinogen (OR = 1.636), diameters of the left atria (OR = 1.094), left ventricular ejection fraction (OR = 0.938), and LAA maximum caliber (OR = 1.238) resulted as independent risk factors for LAA thrombosis and SEC. The area under curve of the nomogram established by multivariate logistic regression was 0.824. Conclusions; Through the study, 6 independent risk factors related to the LAA thrombosis and SEC were found, and an effective nomogram was constructed to predict the LAA thrombosis and SEC in NVAF patients.

Percutaneous left atrial appendage closure in patients with hypertrophic cardiomyopathy and persistent atrial fibrillation: 3-year-followed case series

Hypertrophic cardiomyopathy (HCM) patients with atrial fibrillation (AF) are at high risk for stroke. Left atrial appendage closure (LAAC) is a promising alternative for stroke prevention in AF patients. We aimed to review the clinical outcomes of patients with AF and HCM at our center. We reviewed 673 patients who underwent LAAC implantation from 2014 to 2021 in a tertiary center, of whom 15 had HCM. AF Patients with HCM were compared with sex and age matched controls who also underwent LAAC. From 2014 to 2021, 673 AF patients received LAAC in a single center, of whom, 15 patients had HCM. LAAC devices were successfully implanted in 14 HCM patients and 59 patients in the control group. During the follow-up period (median 1151 days range: 132-2457 days), 2 HCM patient had ischemic strokes. There were another 2 HCM patients who had sudden cardiac death (SCD). Compared with the control, HCM patients had higher cumulative rate of combined death and stroke (26.67% vs 3.33%, P = .024). In our initial clinical experience, the cumulative stroke and death rate of the HCM patients was significantly higher than that of the non-HCM patients.

Treatment of Persistent Left Atrial Appendage Thrombus in Patients with Atrial Fibrillation on Adequate Oral Anticoagulation: Pathways of Care for All-comers and Heart Failure Patients

In patients with AF, the presence of left atrial/left atrial appendage (LA/LAA) thrombus is related to an increased risk of thromboembolic events. Anticoagulation therapy, either with vitamin K antagonists or novel oral anticoagulants (NOACs) is therefore mandatory in AF with LA/LAA thrombus in order to lower the risk of stroke or other systemic embolic events. Despite the efficacy of these treatments, some patients will have persistent LAA thrombus remaining or may have contraindications to oral anticoagulation. Currently, little is known about the occurrence, risk factors and resolution rate of LA/LAA thrombus in patients who are already under optimal chronic oral anticoagulation, including vitamin K antagonists or NOACs. The common action in clinical practice in this scenario is switching from one to another anticoagulant drug exhibiting a different mechanism of action. Repeated cardiac imaging is then advised within several weeks to visually verify thrombus dissolution. Finally, there is a substantial scarcity of data on the role and optimal use of NOACs after LAA occlusion. The aim of this review is to critically evaluate data and provide up-to-date information on the best antithrombotic strategies in this challenging clinical scenario.

Clinical Characteristics and Predictors of Long-Term Prognosis of Acute Peripheral Arterial Ischemia Patients Treated Surgically

BACKGROUND

Acute peripheral arterial ischemia is a rapidly developing loss of perfusion, resulting in ischemic clinical manifestations. This study aimed to assess the incidence of cardiovascular mortality in patients with acute peripheral arterial ischemia and either atrial fibrillation (AF) or sinus rhythm (SR).

METHODS

This observational study involved patients with acute peripheral ischemia treated surgically. Patients were followed-up to assess cardiovascular mortality and its predictors.

RESULTS

The study group included 200 patients with acute peripheral arterial ischemia and either AF (n = 67) or SR (n = 133). No cardiovascular mortality differences between the AF and SR groups were observed. AF patients who died of cardiovascular causes had a higher prevalence of peripheral arterial disease (58.3% vs. 31.6%, p = 0.048) and hypercholesterolemia (31.2% vs. 5.3%, p = 0.028) than those who did not die of such causes. Patients with SR who died of cardiovascular causes more frequently had a GFR <60 mL/min/1.73 m² (47.8% vs. 25.0%, p = 0.03) and were older than those with SR who did not die of such causes. The multivariable analysis shows that hyperlipidemia reduced the risk of cardiovascular mortality in patients with AF, whereas in patients with SR, an age of ≥75 years was the predisposing factor for such mortality.

CONCLUSIONS

Cardiovascular mortality of patients with acute ischemia did not differ between patients with AF and SR. Hyperlipidemia reduced the risk of cardiovascular mortality in patients with AF, whereas in patients with SR, an age of ≥75 years was a predisposing factor for such mortality.

The Comparative Effectiveness and Safety of Different Anticoagulation Strategies for Treatment of Left Atrial Appendage Thrombus in the Setting of Chronic Anticoagulation for Atrial Fibrillation or Flutter

PURPOSE

To compare effectiveness of different treatments for atrial fibrillation (AF) patients who were scheduled for cardioversion (CV) or ablation (CA) presenting with left atrium appendage (LAA) thrombus despite chronic oral anticoagulation therapy (OAC).

METHODS

This was a retrospective cohort study. We analyzed 2014-2019 medical records of patients scheduled for CV or CA of AF who were diagnosed with LAA thrombus despite optimal OAC and had a follow-up transesophageal echocardiogram (TOE). Changes in treatment were divided into the following groups: switch to a drug with different mechanism of action, switch to a drug with similar mechanism of action, initiation of combination therapy, or deliberate no change in treatment. Patients with contraindications to non-vitamin K antagonists were excluded from the analysis.

RESULTS

We analyzed data of 129 patients comprising 181 cycles of treatment. The overall effectiveness of LAA thrombus dissolution was 51.9% regardless of the number of cycles and 42.6% for the first cycle of treatment. Any change of treatment was more effective than deliberate no change-OR 2.97 [95% CI: 1.07-8.25], P = 0.031, but no particular strategy seemed to be more effective than the other. Left atrium area (OR 0.908 [95% CI: 0.842-0.979]) and number of treatment cycles (OR 0.457 [95% CI: 0.239-0.872]) were both adversely related to thrombus resolution. There was one ischemic and three bleeding adverse events during the treatment.

CONCLUSION

LAA thrombus resolution in patients already on OAC may require a change of previous OAC treatment but the overall effectiveness of dissolution seems to be about 50%.

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.

The risk factors of thrombus formation and the effect of catheter ablation on repetitive thrombus formation in patients with atrial fibrillation: a single center retrospective study in China

BACKGROUND

Atrial fibrillation (AF) predisposes patients to the formation of atrial thrombi. The CHA₂DS₂-VASc score does not include all risk factors for atrial thrombosis. The present study is designed to explore the influencing factors of thrombus formation in patients with AF and to investigate the effect of catheter ablation (CA) on recurrent thrombosis in patients with a history of intracardiac thrombus.

METHODS

(1) This study consisted of 1726 patients that underwent CA, among which 58 patients had a history of intracardiac thrombus prior to CA. The risk factors for thrombus formation were explored by comparing the baseline clinical characteristics of patients with and without atrial thrombus. (2) The left atrial appendage flow velocity (LAAFV) in patients with a history of intracardiac thrombus who were willing to undergo transesophageal echocardiography (TEE) at the latest follow-up were examined, and comparisons of the LAAFV was made before and after CA.

RESULTS

The median follow-up period is 13 months. Persistent AF was found to be the only independent risk factor affecting the formation of atrial thrombus among the investigated factors (OR 3.152; 95%CI 1.806-5.500; p < 0.001). Twenty-seven patients agreed to undergo TEE during follow-up, no clinical ischemic stroke events were recorded, no recurrent intracardiac thrombus formation was detected in patients, 15 patients maintained sinus rhythm (55.6%) during follow-up; successful CA significantly increased LAAFV (difference between latest evaluation prior to CA 17.46 ± 14.81 cm/s, p < 0.001).

CONCLUSIONS

Persistent AF is the only independent risk factor for thrombus formation. Successful CA may improve the LAAFV and thereby decrease the risk of intracardiac thrombus formation.

Characteristics, Thrombus Resolution, and Long-Term Outcomes in Patients with Nonvalvular Atrial Fibrillation and Atrial Thrombus

To assess the prevalence and management of atrial thrombus in patients with nonvalvular atrial fibrillation (NVAF) and identify the risk factors of the nonresolution of atrial thrombus. This single-center retrospective observational study consecutively enrolled patients with NVAF and atrial thrombus detected using transesophageal echocardiography (TEE) or cardiac computed tomography angiography (CTA) from January 2012 to December 2020. Patients with prior left atrial appendage (LAA) intervention were excluded. The primary endpoint was the presence of atrial thrombus, while the secondary endpoint was the complete resolution of atrial thrombus. The prevalence of atrial thrombus in patients with NVAF was 1.4%. Ninety patients with atrial thrombus (mean age 62.8 ± 11.9 years and 61.1% men) were finally analyzed. Atrial thrombus was in the LAA in 82 (91.1%) patients. During follow up, 60% of the patients showed complete resolution of atrial thrombus. Congestive heart failure (odds ratio [OR]: 8.94; 95% confidence interval [CI]: 1.67-47.80) and a history of ischemic stroke (OR: 8.28; 95% CI: 1.48-46.42) were independently associated with the risk of the nonresolution of atrial thrombus. The presence of atrial thrombus in patients with NVAF who received anticoagulation therapy is non-negligible. Even in anticoagulated patients, TEE or cardiac CTA might still be needed. Congestive heart failure and a history of ischemic stroke are risk factors of the nonresolution of atrial thrombus.

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.

Construction of a Clinical Predictive Model of Left Atrial and Left Atrial Appendage Thrombi in Patients with Nonvalvular Atrial Fibrillation

BACKGROUND

The purpose of this study was to investigate the risk factors of left atrial (LA) or left atrial appendage (LAA) thrombi in patients with nonvalvular atrial fibrillation (NVAF) and to establish and validate relevant predictive models. It might improve thromboembolic risk stratification in patients with NVAF.

METHODS

This study retrospectively included 1210 consecutive patients with NVAF undergoing transesophageal echocardiography (TEE), of whom 139 patients had thrombi in LA or in LAA. Through literature review and the ten events per variable (10EPV) principle, 13 variables were finally identified for inclusion in multivariate analysis. Models were constructed by multivariate logistic stepwise regression and least absolute shrinkage and selection operator (lasso) regression.

RESULTS

After logistic regression, five variables (AF type, age, B-type natriuretic peptide, E/e' ratio, and left atrial diameter) were finally screened out as model 1. After Lasso regression, AF type, age, gender, B-type natriuretic peptide, E/e' ratio, left atrial diameter, and left ventricular ejection fraction were finally screened as model 2. After comparing the two models, the simpler model 1 was finally selected. The area under the ROC curve (AUC) of the model 1 was 0.865 (95% CI: 0.838-0.892), the Hosmer-Lemeshow test = 0.898, and the AUC = 0.861 after internal validation. The clinical decision curve showed that the new clinical prediction model could achieve a net clinical benefit when the expected threshold was between 0 and 0.6.

CONCLUSION

This study constructed a new clinical prediction model of LA or LAA thrombi, with a higher discriminative degree than the CHADS2 and CHA2DS2-VASc scoring systems (AUC: 0.865 vs. 0.643; AUC: 0.865 vs 0.652).

Risk factors for left atrial thrombus in younger patients (aged < 65 years) with atrial fibrillation or atrial flutter: Data from the multicenter left atrial thrombus on transesophageal echocardiography (LATTEE) registry

Background

Our aim was to assess the characteristics and to identify predictors of left atrial thrombus (LAT) in patients under age 65 with atrial fibrillation (AF) or atrial flutter (AFl).

Methods

We conducted a subanalysis of a multicenter, prospective, observational study [the LATTEE registry]. Consecutive AF/AFl patients referred for cardioversion or ablation were enrolled.

Results

Of the 3,109 patients included in the study, 1,276 were under age 65 (41%). Compared to non-LAT patients, those with LAT (n = 76) had higher CHA2DS2-VASc score (p < 0.001), more frequently had non-paroxysmal AF/AFl (p < 0.001), heart failure (p < 0.001), history of diabetes mellitus (p = 0.001), transient ischemic attack (p = 0.04), coronary artery disease (p = 0.02), and chronic kidney disease (p < 0.001). The LAT patients were also more often smokers (p = 0.004) and were more frequently treated with vitamin K antagonists (VKAs) (p < 0.001). Transthoracic echocardiography revealed a higher left atrial area (p < 0.001), lower left ventricular ejection fraction (LVEF) (p < 0.001), and lower value of LA appendage emptying volume in LAT than in non-LAT patients (p < 0.001). LVEF (OR 2.95; 95% CI: 1.32-6.59, p = 0.008), non-paroxysmal AF/AFl (OR 7.1; 95% CI: 2.05-24.63, p = 0.002) and treatment with VKAs (OR 4.92; 95% CI: 2.48-9.75, p < 0.001) were identified as independent predictors of LAT in younger patients.

Conclusions

Our study, which focused on younger patients with AF/AFl, indicated substantial clinical and echocardiographic differences between participants with and without LAT. In the AF/AFl patients younger than age 65, the independent predictors of LAT included non-paroxysmal AF/AFl, lower LVEF, and treatment with VKAs.

Increased Body Mass Index and Risk of Left Atrial Thrombus in Nonvalvular Atrial Fibrillation Patients-Data from the Left Atrial Thrombus on Transesophageal Echocardiography (LATTEE) Registry

An increased body mass index (BMI) is associated with a higher incidence of atrial fibrillation (AF) and a higher risk of thromboembolic complications in AF patients. The aim of this study was to investigate the effect of BMI on the risk of left atrial thrombi (LATs) in patients with nonvalvular AF/atrial flutter (AFl) (NV AF/AFl). Patients diagnosed with NVAF/AFl (between November 2018 and May 2020) were selected from the multicenter, prospective, observational Left Atrial Thrombus on Transesophageal Echocardiography (LATTEE) registry that included AF/AFl patients referred for cardioversion or ablation followed by transesophageal echocardiography. A total of 2816 AF/AFl patients (63.6% males; mean age 65.8 years; mean BMI 29.8 kg/m2) were included in the study. Two hundred and twenty-two of them (7.9%) had LATs. Compared with normal-weight patients, those with BMIs ≥ 25 kg/m2 more frequently presented clinical factors potentially provoking LATs, such as non-paroxysmal AF/AFl (p = 0.04), hypertension (p < 0.001), and diabetes (p < 0.001); had higher CHA2DS2 scores (p < 0.001); and had larger LA dimensions (LA diameter and LA area) (p < 0.001 for both parameters). On the other hand, they showed some features negatively related to thromboembolic risk; for example, they were younger (p < 0.001) and were more often male (p = 0.002). In addition, patients with abnormal BMIs were more likely to be smokers (p = 0.006) and to be treated with oral anticoagulants (p = 0.005). Despite these differences in the prevalence of thromboembolic risk factors, the incidence of LATs was not increased in patients with abnormal body weight (overweight and obese compared to normal-weight patients) in this large real-life cohort of AF/AFl patients. This is probably due to the balanced composition regarding the prevalence of positive and negative thromboembolic risk factors.

Heart failure and the risk of left atrial thrombus formation in patients with atrial fibrillation or atrial flutter

AIMS

The aim of the study was to evaluate the prevalence of left atrial thrombus (LAT) on transoesophageal echocardiography (TOE) in patients with atrial fibrillation or atrial flutter (AF/AFl) with reference to the presence of heart failure (HF) and its subtypes.

METHODS AND RESULTS

The research is a sub-study of the multicentre, prospective, observational Left Atrial Thrombus on Transoesophageal Echocardiography (LATTEE) registry, which comprised 3109 consecutive patients with AF/AFl undergoing TOE prior to direct current cardioversion or catheter ablation. TOE parameters, including presence of LAT, were compared between patients with and without HF and across different subtypes of HF, including HF with preserved (HFpEF), mid-range (HFmrEF), and reduced ejection fraction (HFrEF). HF was diagnosed in 1336 patients (43%). HF patients had higher prevalence of LAT than non-HF patients (12.8% vs. 4.4%; P < 0.001). LAT presence increased with more advanced type of systolic dysfunction (HFpEF vs. HFmrEF vs. HFrEF: 7.4% vs. 10.5% vs. 20.3%; P < 0.001). Univariate analysis revealed that HFrEF (odds ratio [OR] 4.13; 95% confidence interval [95% CI]: 3.13-5.46), but not HFmrEF or HFpEF, was associated with the presence of LAT. Multivariable logistic regression indicated that lower left ventricular ejection fraction (OR per 1%: 0.94; 95% CI 0.93-0.95) was an independent predictor of LAT formation. Receiver operator characteristic analysis showed LVEF ≤48% adequately predicted increased risk of LAT presence (area under the curve [AUC] 0.74; P < 0.0001).

CONCLUSION

The diagnosis of HFrEF, but neither HFmrEF nor HFpEF, confers a considerable risk of LAT presence despite widespread utilization of adequate anticoagulation.

External validation and comparison of CHA2DS2-VASc-RAF and CHA2DS2-VASc-LAF scores for predicting left atrial thrombus and spontaneous echo contrast in patients with non-valvular atrial fibrillation

PURPOSE

CHA₂DS₂-VASc-RAF (R is renal dysfunction, and AF is atrial fibrillation type) and CHA₂DS₂-VASc-LAF (L is left atrial diameter, and AF is atrial fibrillation type) scores have been developed to estimate the risk of left atrial thrombus (LAT) and spontaneous echo contrast (SEC) in patients with non-valvular atrial fibrillation (NVAF). However, few external validations have been conducted to assess their accuracy. Thus, this study aimed to validate and compare the two modified scores for predicting LAT/SEC in patients with NVAF.

METHODS

This study included 399 patients with NVAF who underwent transesophageal echocardiography. Risk factors related to LAT/SEC were identified through logistic regression analysis, and predictive value and diagnostic efficiency were evaluated using receiver operating characteristic (ROC) curve.

RESULTS

Approximately 9.8% (39/399) of the patients with NVAF had LAT/SEC. Multivariate logistic regression analysis showed that history of stroke/transient ischemic attack, congestive heart failure, non-paroxysmal atrial fibrillation, lack of anticoagulation therapy, enlarged left atrial diameter, enlarged left ventricular end diastolic diameter, decreased left ventricular ejection fraction, decreased left atrial appendage emptying velocity, and decreased estimated glomerular filtration rate were independent risk factors for LAT/SEC. The CHA₂DS₂-VASc-LAF (area under the ROC curve [AUC] = 0.839) and CHA₂DS₂-VASc-RAF (AUC = 0.829) scores showed larger predictive values than the CHA₂DS₂-VASc (AUC = 0.737) and CHADS₂ (AUC = 0.736) scores. The AUC of the CHA₂DS₂-VASc-RAF score was similar to that of the CHA₂DS₂-VASc-LAF score (Z = 0.432; P = 0.666).

CONCLUSION

This study validated that the CHA₂DS₂-VASc-RAF and CHA₂DS₂-VASc-LAF scores are useful prognostic scoring systems for predicting LAT/SEC in patients with NVAF.

Left Ventricular Ejection Fraction Can Predict Atrial Thrombosis Even in Non-High-Risk Individuals with Atrial Fibrillation

Background—Current guidelines do not recommend routine use of transesophageal echocardiography (TOE) in anticoagulated patients with atrial fibrillation (AF). The aim of our study was to identify predictors for left atrial thrombosis (LAT) in patients with AF that would require TOE despite anticoagulation therapy, using clinical, laboratory and echocardiographic data which are usually obtained in those patients in a real-world setting. Methods—We analyzed data from electronic medical records (EMR) of consecutive AF patients referred to two university hospitals between January 2014 and December 2017 for pulmonary vein isolation (PVI) or direct current cardioversion. The primary endpoint was the presence of left atrial thrombus on TOE. Multivariable and univariable logistic regression models were computed using variables that were significantly different between the LAT and the control groups. Results—A total of 838 patients were included, of whom 132 (15.8%) had LAT. After controlling for other variables, only the left ventricle ejection fraction (LVEF) remained statistically significant with an OR of 0.956 (95% CI 0.934−0.979), p < 0.01. Regression models including LVEF had significantly higher areas under the receiver operating characteristic (ROC) curves, including in subgroups with non-high thromboembolic risk (CHA2DS2-Vasc = 0 or 1), with an area under the curve (AUC) of 0.76 (95% CI 0.71−0.81), p < 0.0001. Conclusions—The LVEF is an independent predictor of LAT, and it might improve thromboembolic risk stratification in future models. LVEF significantly increased the predictive value of the CHA2DS2-Vasc model and was able to identify LAT in non-high-risk patients.

Prediction model based on machine learning for short- and long-term adverse events in left atrial appendage closure

Background

At present, the prediction of adverse events (AE) had practical significance in clinic and the accuracy of AE prediction model after left atrial appendage closure (LAAC) needed to be improved. To identify a good prediction model based on machine learning for short- and long-term AE after LAAC.

Methods

In this study, 869 patients were included from the Department of Cardiovascular Medicine of Shanghai University of Medicine and Health Sciences Affiliated Zhoupu Hospital during 2017 and 2021. Univariate and multivariate analyses were conducted for short-term AE after LAAC to determine possible risk factors related with AE. We compared 8 machine learning algorithms for prediction short-term AE, and XGBoost was found to have the best performance. In addition, Cox-regression was used for long-term AE to find out the risk factors and establish a prediction model.

Results

In univariate and multivariate analysis, body mass index (BMI) [odds ratio (OR) =0.91], congestive heart failure, hypertension, age ≥75 years, diabetes, stroke₂ attack (CHADS₂) score (OR =0.49) and bleeding history or predisposition, labile international normalized ratio (INR), elderly, drug/alcohol usage (BLED) score (OR =1.71) were shown to be significant risk factors for short-term AE. The XGbosst algorithm was used to predict short-term AE based on 15 possible risk factors. For long-term AE, Cox regression was used for the prediction. The CHADS₂ score [hazard ratio (HR) =1.43], hypertension (HR =2.18), age more than 75 (HR =0.49), diabetes (HR =0.57), BLED score (HR=0.28), stroke (HR =19.8), hepatopathy (HR =3.97), nephropathy (HR =2.93), INR instability (HR =4.18), drinking (HR =2.67), and drugs (HR =2.36) were significant risk factors for long-term AE. The XGBoost had a good receiver operating characteristic (ROC) curve and area under the curve (AUC) was 0.85. The accuracy of the XGBoost model stayed at nearly 0.95.

Conclusions

In short- and long-term AE, CHADS₂ score and BLED score were the most obvious risk factors. Several other risk factors also played roles in AE of LAAC. The incidence of long-term AE is under 15% and LAAC is effective and safe. The XGBoost model had good prediction accuracy and ROC curve.

Left Atrial Thrombus in Atrial Fibrillation/Flutter Patients in Relation to Anticoagulation Strategy: LATTEE Registry

Background: Atrial fibrillation (AF) and flutter (AFl) increase the risk of thromboembolism. The aim of the study was to assess the prevalence of left atrial thrombus (LAT) in AF/AFl in relation to oral anticoagulation (OAC). Methods: LATTEE (NCT03591627) was a multicenter, prospective, observational study enrolling consecutive patients with AF/AFl referred for transesophageal echocardiography before cardioversion or ablation. Results: Of 3109 patients enrolled, 88% were on chronic, 1.5% on transient OAC and 10% without OAC. Of patients on chronic OAC, 39% received rivaroxaban, 30% dabigatran, 14% apixaban and 18% vitamin K antagonists (VKA). Patients on apixaban were oldest, had the worst renal function and were highest in both bleeding and thromboembolic risk, and more often received reduced doses. Prevalence of LAT was 8.0% (7.3% on chronic OAC vs. 15% without OAC; p < 0.01). In patients on VKA, prevalence of LAT was doubled compared to patients on non-VKA-OACs (NOACs) (13% vs. 6.0%; p < 0.01), even after propensity score weighting (13% vs. 7.5%; p < 0.01). Prevalence of LAT in patients on apixaban was higher (9.8%) than in those on rivaroxaban (5.7%) and dabigatran (4.7%; p < 0.01 for both comparisons), however, not after propensity score weighting. Conclusions: The prevalence of LAT in AF is non-negligible even on chronic OAC. The risk of LAT seems higher on VKA compared to NOAC, and similar between different NOACs.

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.

Left Atrial Appendage Depth and Tachycardia Bradycardia Syndrome as Important Predictors of Left Atrial Appendage Thrombus in Patients with Nonvalvular Atrial Fibrillation

Background

Atrial fibrillation (AF) is the most common heart rhythm disorder that has been shown to be associated with a significant increase in stroke and systemic embolism risk. The left atrial appendage (LAA) is a finger-like extension originating from the left atrium; the formation of thrombus in LAA is the main reason of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF). This study is aimed at finding out the risk of left atrial appendage thrombus (LAAT) in patients with nonvalvular atrial fibrillation (NVAF).

Method

We retrospectively examined the clinic and left atrial computer tomography angiography (CTA) features of patients assessed in Zhengzhou No. 7 People's Hospital between January 2020 and January 2021 derivation. Student's t-test, chi-square test, receiver operating characteristics (ROC) curves, and logistic regression analysis were used to identify predictors of LAAT.

Result

Of 480 patients included in the analysis, LAAT was found in approximately 9.2% of all patients. Univariate demographic predictors of LAAT included left atrium top and bottom diameter (LTD), left atrial appendage depth (LAAD), CHA2DS2-VASc, tachycardia bradycardia syndrome (TBS), and nonparoxysmal atrial fibrillation (PAF). In a multiple logistic regression analysis, the independent predictors of thrombus were LAAD > 23.45 mm (odds ratio: 4.216, 95% CI: 1.869-9.510, P = 0.001), TBS (odds ratio: 4.076, 95% CI: 1.655-10.038, P = 0.002), and non-PAF (odds ratio: 2.896, 95% CI: 1.183-7.094, P = 0.02).

Conclusion

In NVAF patients with LAAT, evidence suggested that larger LAAD, non-PAF, and TBS present a high risk of LAAT. This is the first report demonstrating that the LAAD and TBS are associated with LAAT in patients with NVAF.

Refinement of CHADS2 and CHA2DS2-VASc scores predict left atrial thrombus or spontaneous echo contrast in nonvalvular atrial fibrillation patients

Objective

To investigate the risk factors of left atrial thrombus (LAT)/spontaneous echo contrast (SEC) in patients with nonvalvular atrial fibrillation (AF).

Methods

This retrospective study analysed the data from consecutive patients with nonvalvular AF that underwent transoesophageal echocardiography. Logistic regression analysis was performed to identify risk factors of LAT/SEC. Receiver operating characteristic curve analysis was undertaken compare the new scales with CHADS2 and CHA2DS2-VASc scores.

Results

A total of 558 patients with AF were included in the study. LAT/SEC was detected in 137 (24.6%) patients. The independent risk factors of LAT/SEC beyond CHADS2 or CHA2DS2-VASc scores included non-paroxysmal AF and left atrial diameter >37.5 mm. These two variables were added into the CHADS2 or CHA2DS2-VASc score to build new scales. Areas under the curve for the new scales based on CHADS2 and CHA2DS2-VASc scores were significantly higher than the CHADS2 or CHA2DS2-VASc score both in the overall study cohort and in patients at a high risk of thromboembolism.

Conclusions

Non-paroxysmal AF and increased left atrial diameter beyond the CHADS2 or CHA2DS2-VASc score were independent risk factors of LAT/SEC and may help to improve the current risk stratification, especially for patients with nonvalvular AF at a high risk of thromboembolism.

Left Atrial Appendage Thrombus in Patients with Nonvalvular Atrial Fibrillation before Catheter Ablation and Cardioversion: Risk Factors beyond the CHA2DS2-VASc Score

Left atrial appendage thrombus (LAAT) is a surrogate of thromboembolic events in patients with nonvalvular atrial fibrillation (NVAF). We aimed to investigate the risk factors for LAAT formation before catheter ablation and cardioversion beside the CHA2DS2-VASc score. In this case-control study, patients with NVAF who underwent transesophageal echocardiography (TEE) were included. Demographic data, laboratory results, and echocardiographic measurements were retrospectively collected. Logistic regression analysis was performed to determine risk factors predicting LAAT. Of the 543 included patients, LAAT was identified in 50 patients (9.2%). Multivariable logistic regression analysis for the entire cohort showed that NT-proBNP (per 500 ng/L increase, OR (95% CI): 1.09 (1.00–1.19), p = 0.038) and LDL-C (per 1 mmol/L increase, OR (95% CI): 1.70 (1.05–2.77), p = 0.032) were independently correlated with the presence of LAAT after the adjustment for CHA2DS2-VASc score and anticoagulant therapy. The subgroup analysis of patients without anticoagulant therapy also yielded similar results. Regarding patients with CHA2DS2-VASc scores ≤ 1, a higher level of LDL-C (per 1 mmol/L increase, OR (95% CI): 6.31 (2.38–16.74), p < 0.001) independently correlated with the presence of LAAT. The present study suggests that beyond CHA2DS2-VASc score, raised NT-proBNP and LDL-C are additional predictors for LAAT in NVAF patients.

Clinical prediction scores and early anticoagulation therapy for new-onset atrial fibrillation in critical illness: a post-hoc analysis

Purpose

This study sought to describe the epidemiology of anticoagulation therapy for critically ill patients with new-onset atrial fibrillation (NOAF) according to CHA2DS2-VASc and HAS-BLED scores and to assess the efficacy of early anticoagulation therapy.

Method

Adult patients who developed NOAF during intensive care unit stay were included. We compared the patients who were treated with and without anticoagulation therapy within 48 h from AF onset. The primary outcome was a composite outcome that included mortality and ischemic stroke during the period until hospital discharge.

Results

In total, 308 patients were included in this analysis. Anticoagulants were administered to 95 and 33 patients within 48 h and after 48 h from NOAF onset, respectively. After grouping the patients into four according to their CHA2DS2-VASc and HAS-BLED bleeding scores, we found that the proportion of anticoagulation therapy administered was similar among all groups. After adjustment using a multivariable Cox regression model, we noted that early anticoagulation therapy did not decrease the composite outcome (adjusted hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.47‒1.23). However, in patients without rhythm control drugs, early anticoagulation was significantly associated with better outcomes (adjusted HR 0.46; 95% CI; 0.22‒0.87, P = 0.041).

Conclusions

We found that clinical prediction scores were supposedly not used in the decision to implement anticoagulation therapy and that early anticoagulation therapy did not improve clinical outcomes in critically ill patients with NOAF.

Trial registration UMIN-CTR UMIN000026401. Registered 5 March 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02235-8.

Relations between left atrial appendage contrast retention and thromboembolic risk in patients with atrial fibrillation

Left atrial appendage (LAA), a blind pouch, accounts for more than 90% of the source of cardiac thrombus formation. Contrast retention (CR) in the LAA has been frequently observed during left atrial appendage occlusion (LAAO) procedures, especially in patients with stroke history. This study was designed to assess the relations between LAA contrast retention and thrombogenesis risk of the LAA in patients with non-valvular atrial fibrillation. A total of 132 consecutive patients who underwent LAAO were enrolled. The data collected from computed tomography (CT), transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) and blood samples were analyzed. Univariate and multivariate logistic regression models were constructed to assess the association between CR, left atrial appendage thrombus (LAAT) and other factors. Contrast retention was observed in 33 patients, accounting for 25% of the population. Compared to the non-CR group, patients in the CR group had a larger left atrium anteroposterior diameter (49.64 ± 11.57 vs. 42.42 ± 7.04, P = 0.002), higher CHADS₂ (3.88 ± 0.99 vs. 2.97 ± 1.35, P = 0.001) and CHA₂DS₂-VASc scores (5.79 ± 1.14 vs. 4.89 ± 1.56, P = 0.003), a higher rate of prior stroke (90.9% vs. 66.7%, P = 0.007), more LAA lobes (3.13 ± 1.18 vs. 2.64 ± 1.12, P = 0.038), and a higher prevalence of LAAT (63.6% vs. 13.1%, P < 0.001). After having adjusted the logistic model, only contrast retention, LAA cauliflower morphology and left ventricular ejection fraction (LVEF) were independently associated with LAAT. Patients with LAA contrast retention have a higher risk of left atrial appendage thrombosis. Contrast retention may be a cardiac factor strongly associated with cardiogenic stroke.

Type of atrial fibrillation and outcomes in patients without oral anticoagulants

BACKGROUND

The effect of type of atrial fibrillation (AF) on adverse outcomes in Chinese patients without oral anticoagulants (OAC) was controversial.

HYPOTHESIS

The type of AF associated with adverse outcomes in Chinese patients without OAC.

METHODS

A total of 1358 AF patients without OAC from a multicenter, prospective, observational study was included for analysis. Univariable and multivariable Cox regression models were utilized. Net reclassification improvement analysis was performed for the assessment of risk prediction models.

RESULTS

There were 896(66%) patients enrolled with non-paroxysmal AF (NPAF) and 462(34%) with paroxysmal AF (PAF). The median age was 70.9 ± 12.6 years, and 682 patients (50.2%) were female. During 1 year of follow-up, 215(16.4%) patients died, and 107 (8.1%) patients experienced thromboembolic events. Compared with the PAF group, NPAF group had a notably higher incidence of all-cause mortality (20.2% vs. 9.4%, p < .001), thromboembolism (10.5% vs. 3.8%, p < .001). After multivariable adjustment, NPAF was a strong predictor of thromboembolism (HR 2.594, 95%CI 1.534-4.386; p < .001), all-cause death (HR 1.648, 95%CI 1.153-2.355; p = .006). Net reclassification improvement analysis indicated that the addition of NPAF to the CHA₂ DS₂ -VASc score allowed an improvement of 0.37 in risk prediction for thromboembolic events (95% CI 0.21-0.53; p < .001).

CONCLUSIONS

In Chinese AF patients who were not on OAC, NPAF was an independent predictor of thromboembolism and mortality. The addition of NPAF to the CHA₂ DS₂ -VASc score allowed an improvement in the accuracy of the prediction of thromboembolic events.

Trends in the Prescription of Non-Vitamin K Antagonist Oral Anticoagulants for Atrial Fibrillation: Results of the Polish Atrial Fibrillation (POL-AF) Registry

Background: Current guidelines do not suggest in which groups of patients with atrial fibrillation (AF) individual non-vitamin K antagonist oral anticoagulants (NOACs) should be used for the prevention of thromboembolic complications. The aim of this study was to evaluate the frequency of use of apixaban, dabigatran, and rivaroxaban, and attempt to identify factors predisposing their administration. Methods: The Polish Atrial Fibrillation (POL-AF) registry is a prospective, non-interventional study, including consecutive patients with AF hospitalized in ten Polish cardiology centers during the period ranging from January to December 2019. In this study, all patients were treated with NOACs. Results: Among the 2971 patients included in the analysis, 40.4% were treated with rivaroxaban, 32% with apixaban, and 27.6% with dabigatran. The mean age of the total population was 72 ± 11.5 years and 43% were female. A reduced dose of NOAC was used in 35% of patients treated with apixaban, 39.7% of patients treated with dabigatran, and 34.4% of patients treated with rivaroxaban. Independent predictors of the use of apixaban were previous bleeding (OR 2.37, CI 1.67–3.38), GFR < 60 mL/min (OR 1.38, CI 1.25–1.64), heart failure (OR 1.38, CI 1.14–1.67) and age (per 5 years) (OR 1.14, CI 1.09–1.19). GFR < 60 mL/min (OR 0.79, CI 0.66–0.95), female (OR 0.8, CI 0.67–0.96) and age (per 5 years) (OR 0.95, CI 0.91–0.99) diminished the chance of using dabigatran. Previous bleeding (OR 0.43, CI 0.28–0.64), vascular disease (OR 0.84, CI 0.70–0.99), and age (per 5 years) (OR 0.94, CI 0.90–0.97) diminished the chance of choosing rivaroxaban. Conclusions: In hospitalized patients with AF, the most frequently chosen NOAC was rivaroxaban. Apixaban was chosen more often in patients after bleeding, and in those who were advanced in years, with heart failure and impaired renal function. Impaired renal function and female gender were factors that diminished the chance of using dabigatran. Previous bleeding and vascular disease was the factor that diminished the chance of using rivaroxaban. Dabigatran and rivaroxaban have been used less frequently in elderly patients.

Decreased left atrial appendage emptying velocity as a link between atrial fibrillation type, heart failure and older age and the risk of left atrial thrombus in atrial fibrillation

INTRODUCTION

Decreased left atrial appendage emptying velocity (LAAV) is a known predictor of LAA thrombus in atrial fibrillation (AF). The aim of our study was to identify which of the clinical risk factors for LAA thrombus are associated with decreased LAAV.

METHODS

The study included 1476 consecutive AF patients who underwent transesophageal echocardiography (TEE) before AF direct current cardioversion or ablation in two high-reference cardiology departments. Patients were divided into two groups: 71 (4.8%) patients with LAAV < 20 cm/s and 1405 patients (95%) with LAAV ≥ 20 cm/s.

RESULTS

Compared with patients with LAAV ≥ 20 cm/s, those with decreased LAAV were older, more often had non-paroxysmal AF, were burdened with more concomitant diseases (including hypertension, diabetes, vascular disease, and heart failure [HF]) with higher median CHA₂ DS₂ -VASc score (3 [2-4] vs 2 [1-3], P < .0001), and had lower glomerular filtration rate (GFR). Prevalence of LAA thrombus was higher in patients with decreased LAAV compared with those with LAAV ≥ 20cm/s (20% vs 4.6%, P < .0001). In patients with decreased LAAV, there was no difference in the frequency of LAA thrombus between those treated with VKA and those receiving NOAC, while in patients with LAAV ≥ 20 cm/s a trend was observed towards a benefit with NOAC. In multivariate logistic regression, non-paroxysmal AF, HF and age ≥ 65 years predicted both LAAV < 20 cm/s and LAA thrombus, while GFR < 60 mL/min/1.73 m² predicted only the presence of LAA thrombus.

CONCLUSION

One in five AF patients with decreased LAAV had LAA thrombus, regardless of the type of OAC. Non-paroxysmal AF, HF and age ≥ 65 years might increase LAA thrombus risk via reduced LAAV.

Determinants of left atrial thrombus or spontaneous echo contrast in nonvalvular atrial fibrillation

BACKGROUND

The CHADS₂ and CHA₂DS₂-VASc scores are well-established clinical scales to estimate the risk of stroke in patients with atrial fibrillation (AF). However, the predictive power of the two scales concerning left atrial thrombus (LAT) or spontaneous echo contrast (SEC) has not been well investigated. Therefore, we investigated the predict power of CHADS₂ and CHA₂DS₂-VASc scores concerning LAT/SEC; identified clinical, echocardiographic and laboratory predictors of LAT/SEC in addition to the CHADS₂ and CHA₂DS₂-VASc scores; and derived a new scale to predict LAT/SEC accurately, it might improve thromboembolic risk stratification in patients with nonvalvular atrial fibrillation.

METHODS

We identified 1102 consecutive AF patients who underwent transesophageal echocardiography (TEE) for the purpose of the exclusion of LAT before catheter ablation, cardioversion or left atrial appendage occlusion. The clinical, echocardiographic and laboratory characteristics of patients were collected from the electronic medical record system.

RESULTS

In the study, the prevalence of LAT/SEC was only 4.36%. In the multivariate logistic analysis, hypertension, left atrial enlargement, prior stroke/TIA, left ventricular dysfunction, and renal dysfunction were predictors of LAT/SEC. Receiver operating characteristic curve analysis showed that c-statistics of the CHADS₂ and CHA₂DS₂-VASc scores concerning LAT/SEC were 0.673 and 0.643, respectively. We derived a new scale composed of variables from the multivariate logistic analysis that showed a higher c-statistic value (0.761) than the CHADS₂ and CHA₂DS₂-VASc scores for the prediction of LAT/SEC.

CONCLUSION

In our cohort, we found two variables not included in the CHA₂DS₂-VASc score (renal dysfunction, left atrial enlargement) were independent predictors of LAT/SEC. A new scale combining clinical, echocardiographic and laboratory predictors might improve thromboembolic risk stratification. And there is a great need to carry out a new prospective and multicenter study, with a population more homogenous and including all the determinants for LAT/SEC to establish the independent degree of each variable and the applicability in clinical practice, facilitating the emergence of a new score of thromboembolic risk in patients with nonvalvular atrial fibrillation.

Left Atrial Appendage Thrombus Formation Despite Continuous Non-Vitamin K Antagonist Oral Anticoagulant Therapy in Atrial Fibrillation Patients Undergoing Electrical Cardioversion or Catheter Ablation: A Comparison of Dabigatran and Rivaroxaban

Left atrial appendage thrombus (LAAT) may be detected by transesophageal echocardiography (TOE) in patients with atrial fibrillation (AF) despite continuous anticoagulation therapy. We examined the factors predisposing to LAAT in patients treated with the anticoagulants dabigatran and rivaroxaban. We retrospectively evaluated 1,256 AF patients from three centres who underwent TOE before electrical cardioversion (n = 611, 51.4%) or catheter ablation (n = 645, 48.6%) from January 2013 to December 2019 and had been on at least three weeks of continuous dabigatran (n = 603, 48%) or rivaroxaban (n = 653, 52%) therapy. Preprocedural TOE diagnosed LAAT in 51 patients (4.1%), including 30 patients (5%) treated with dabigatran and 21 patients (3.2%) treated with rivaroxaban (p=0.1145). In multivariate logistic regression, predictors of LAAT in patients treated with dabigatran were non-paroxysmal AF (vs. paroxysmal AF) (OR = 6.2, p=0.015), heart failure (OR = 3.22, p=0.003), and a eGFR <60 ml/min/1.73 m2 (OR = 2.65, p=0.012); the predictors in patients treated with rivaroxaban were non-paroxysmal AF (vs. paroxysmal AF) (OR = 5.73, p=0.0221) and heart failure (OR = 3.19, p=0.116). In ROC analysis of the dabigatran group, the area under the curve (AUC) for the CHA2DS2-VASc-RAF score was significantly higher (0.78) than those for the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores (0.67, 0.70, and 0.72, respectively). In the rivaroxaban group, the CHA2DS2-VASc-RAF score also performed significantly better (AUC of 0.77) than the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores (AUC of 0.66, 0.64, and 0.67, respectively). The risk of LAAT was the same for patients in both treatment groups. In all patients, non-paroxysmal AF or heart failure, and in patients treated with dabigatran an eGFR <60 ml/min/1.73 m2, were independent predictors of LAAT. The new CHA2DS2-VASc-RAF scale had the highest predictive value for LAAT in the entire study population.

Risk factors for left atrial appendage thrombus

Background: Atrial fibrillation (AF) is the most common persistent rhythm disorder that has been shown to be associated with a significant increase in stroke risk. Left atrial appendage (LAA) thrombi are responsible for most of strokes of cardiac origin. CHA₂DS₂-VASc is a risk scoring system to identify patients' indications for anticoagulation in nonvalvular AF patients. The aim of our study was to investigate CHA₂DS₂-VASc score, the other risk factors, echocardiographic data and blood parameters for LAA thrombus.Methods: Two hundred and sixty-four patients who were admitted to our adult cardiology outpatient clinic and who underwent a transesophageal echocardiography procedure between June 2017 and June 2019 included in our study. Patient's demographic data, transthoracic echocardiographic examinations, and laboratory results were recorded retrospectively.Results: LAA thrombus was detected in 39 (14.7%) patients. The rates of coronary artery disease and systolic dysfunction were significantly higher in patients with LAA thrombus (p = .017, p = .016, respectively). When AF subtypes were examined in detail, thrombus rate was significantly higher in persistent AF (51 vs. 25.7%, p = .002). Although the CHA₂DS₂-VASc score was slightly higher in the thrombus group, there was no statistically significant difference between the two groups (3.0 ± 1.65 vs. 2.78 ± 1.66).Conclusions: In conclusion, CHA₂DS₂-VASc score system itself was not informative about LAA thrombus formation although some of its components were related with LAA thrombus formation. According to a multiple regression analysis, the independent determinants of LAA thrombus were the presence of AF and coronary artery disease.

Prevalence and risk factors of left atrial thrombus in patients with atrial fibrillation and lower class (IIa) recommendation to anticoagulants

Background

Oral anticoagulation therapy (OAT) prevents ischaemic incidents in patients with atrial fibrillation (AF). CHA₂DS₂-VASc risk score of ≥2 points in men and ≥3 in women is a class I indication for OAT. OAT should also be considered as a prevention of thromboembolism in AF men with a CHA₂DS₂-VASc score of 1 point and women with 2 points, but the class of recommendation is lower (IIa). This study aims to assess the occurrence of left atrial appendage thrombus (LAAT) and risk factors of its formation in patients with lower class recommendation to oral antiocoagulation treatment.

Methods

The study group consisted of 1,858 patients: 555 patients with class IIa indication to OAT (IIa group) and 1,303 patients with class I indication as a control group (I group). Patients were admitted to three cardiology departments. All subjects underwent transoesophageal echocardiography.

Results

The incidence of LAAT was comparable in both IIa and I group: LAAT was confirmed in 30 (5.4%) subjects of IIa group and in 77 (5.9%) of I group. The prevalence of LAAT in IIa group was higher on treatment with VKAs (in comparison to NOACs) (8.4% vs. 3.4%, P=0.010), and lower in case of paroxysmal AF (in comparison to non-paroxysmal AF) (2.4% vs. 9.8%, P=0.0002). Multivariate logistic regression revealed the following variables as the independent predictors of LAAT in IIa group: treatment with VKAs (OR 2.99, 95% CI: 1.33-6.69; P=0.007), paroxysmal AF (OR 0.26, 95% CI: 0.11-0.62; P=0.002) and eGFR <60 mL/min/1.73 m² (OR 3.19, 95% CI: 1.42-7.16; P=0.005).

Conclusions

The prevalence of LAAT in AF patients with lower class (IIa) recommendation to anticoagulants was comparable to higher (I). Treatment with VKAs, along with non-paroxysmal type of AF and eGFR <60 mL/min/1.72 m² were identified as the strongest predictors of LAAT in IIa group.

CHA2DS2-VASc Score as a Predictor for Left Atrial Thrombus or Spontaneous Echo Contrast in Patients with Nonvalvular Atrial Fibrillation: A Meta-Analysis

Objective

This meta-analysis aimed at exploring the predictive value of CHA₂DS₂-VASc score for the left atrial thrombus (LAT) or left atrial spontaneous echo contrast (LASEC) in patients with nonvalvular atrial fibrillation (NVAF).

Methods

PubMed, Embase, Web of Science, ScienceDirect, Cochrane Library, and Chinese core journals of the CNKI and Wanfang databases were searched to identify all the relevant papers that were published up to January 2020. The data were extracted for pooled odds ratios (ORs) with 95% confidence intervals (CIs), heterogeneity, subgroup, publication bias, and sensitivity analysis.

Results

Overall, 15 studies containing 6223 patients with NVAF were enrolled. All studies were evaluated for LAT, and 12 studies were evaluated for LASEC. The pooled analysis using a random-effects model showed that a high CHA₂DS₂-VASc score was related with LAT/LASEC (pooled OR = 1.59, 95% CI: 1.35–1.88, P < 0.001) with high heterogeneity (I² = 76.9%, P < 0.001) and LAT (pooled OR = 1.83, 95% CI: 1.44–2.33, P < 0.001) with high heterogeneity (I² = 79.4%, P < 0.001). The subgroup analysis demonstrated that the sample size may be the main source of heterogeneity. Although the Begg's funnel plot based on 15 studies for LAT/LASEC (P = 0.029) and 12 studies for LAT (P = 0.046) indicated the presence of publication bias among the included studies, the trim-and-fill method verified the stability of the pooled outcomes. In addition, sensitivity analysis indicated that all effects were stable.

Conclusion

The results of this meta-analysis showed that the CHA₂DS₂-VASc score is related with LAT and LASEC in patients with NVAF. However, more studies are warranted to address this issue.

Does the CHA2DS2-VASc scale sufficiently predict the risk of left atrial appendage thrombus in patients with diagnosed atrial fibrillation treated with non-vitamin K oral anticoagulants?

The CHA2DS2-VASc scale does not include potential risk factors for left atrial appendage thrombus (LAAT) formation such as a form of atrial fibrillation (AF) and impaired kidney function. The real risk of thromboembolic complications in AF patients is still unclear as well as an optimal anticoagulant treatment in males with a CHA2DS2-VASc score of 1 and females with a CHA2DS2-VASc score of 2.The aim of this study was to compare the predictive value of the CHA2DS2-VASc scale and other scales to estimate the risk of LAAT formation in AF patients treated with non-vitamin K oral anticoagulants (NOACs) and to assess the prevalence of thrombi in patients at intermediate risk of stroke.The observational study included consecutive patients with a diagnosis of non-valvular AF treated with NOACs, admitted to 3 high-reference institutions between 2013 and 2018. All individuals underwent transoesophageal echocardiography before cardioversion or ablation.Out of 1163 enrolled AF patients (62.1% male, mean age 62 years) the LAAT had been detected in 50 individuals (4.3%). Among patients with LAAT, 1 patient (2.0%) was classified as a low-risk category, 9 (18.0%) were at intermediate-risk, and 40 (80.0%) were at high risk of thromboembolic complications according to CHA2DS2-VASc scale. All patients were treated with NOACs: 51.0% rivaroxaban, 47.1% dabigatran, and 1.9% apixaban.Patients at intermediate stroke-risk with detected LAAT had higher R2CHADS2 score (2.1 ± 1.2 vs 1.2 ± 0.8, P = .007), higher CHA2DS2-VASc-RAF score (6.4 ± 4.4 vs 3.7 ± 2.6, P = .027) and more often had an estimated glomerular filtration rate below 56 mL/min/1.73 m (44.4% vs 13.2%, P = .026) compared to patients without LAAT. The receiver operating characteristics revealed that the CHA2DS2-VASc-RAF scale had better predictive ability to distinguish between patients with and without LAAT in the study group than CHA2DS2-VASc (P = .0006), CHADS2 (P = .0006) and R2CHADS2 scale (P = .0140).The CHA2DS2-VASc scale should be supplemented with an assessment of renal function and form of AF to improve stroke risk estimation. The application of additional scales to estimate the risk of LAAT might be especially useful among males with a CHA2DS2-VASc score of 1 and females with a CHA2DS2-VASc score of 2.

Thrombus in the left atrial appendage in patients with atrial fibrillation treated with non-vitamin K antagonist oral anticoagulants in clinical practice-A multicenter registry

BACKGROUND

The prevalence and predictors of left atrial appendage thrombus (LAAT) in patients with non-valvular atrial fibrillation (AF) who have been treated with non-vitamin K antagonist oral anticoagulants (NOACs) are not well defined. We aimed to assess the occurrence and predictors of LAAT on transesophageal echocardiography (TOE) in patients with non-valvular AF treated with NOACs for at least 3 weeks.

METHODS

Consecutive patients with non-valvular AF who underwent TOE before catheter ablation or electrical cardioversion in three high-reference centers between 2014 and 2018 were included. Patients on apixaban were excluded from the study due to low numbers in this category. All patients received NOACs for at least 3 weeks before TOE.

RESULTS

A total of 1148 patients (female, 38.1%; mean age, 62.1 years) referred to our centers for catheter ablation of AF (52.1%) or electrical cardioversion (47.9%) were included. Patients were on rivaroxaban (51.9%) or dabigatran (48.1%). Preprocedural TOE revealed LAAT in 4.4% of all patients. Multivariable logistic regression analysis showed the CHA2DS2-VASc score ≥2 points (OR = 2.11; 95% CI, 1.15-3.88; P = .0161), non-paroxysmal AF (OR = 6.30; 95% CI, 2.22-17.91; P = .0005), and GFR <60 mL/min/1.73 m² (OR = 2.05; 95% CI, 1.14-3.67; P = .0160) were independent predictors of LAAT in patients treated with NOACs.

CONCLUSIONS

In non-valvular AF patients treated with NOACs, the prevalence of LAAT was 4.4% before electrical cardioversion or ablation. In addition to the CHA2DS2-VASc score, the type of AF and renal function should be considered in the stratification of thromboembolism risk in AF patients and qualification for a preprocedural TOE.

Left Ventricular Ejection Fraction Is Associated with the Risk of Thrombus in the Left Atrial Appendage in Patients with Atrial Fibrillation

Introduction

Atrial fibrillation (AF) is associated with high risk of ischemic stroke. The most frequent thrombus location in AF is the left atrial appendage (LAA). Transthoracic echocardiography (TTE) is a basic diagnostic examination in patients (pts) with AF.

Objectives

To analyse the relations between basic echocardiographic features, well-established stroke risk factors, type of AF, and anticoagulation therapy with the incidence of left atrial appendage thrombus (LAAT). Patients and Methods. The study group consisted of 768 pts with AF (mean age, 63 years), admitted to three high-reference cardiology departments. Five hundred and twenty-three pts were treated with non-vitamin K antagonist oral anticoagulants (NOACs) and 227 (30%) with vitamin K antagonists (VKAs). The subjects underwent TTE and transesophageal echocardiography (TEE) before cardioversion or ablation.

Results

LAAT was significantly more frequent in pts with reduced left ventricular ejection fraction (LVEF): in 10.6% (7 pts) with LVEF < 40% and in 9.0% (9 pts) with LVEF 40-49%, while only in 5.5% (33 pts) with LVEF > 50%. Compared to pts without LAAT, those with LAAT presented with lower LVEF and higher left atrial diameter (LAD). Multivariate logistic regression revealed the following variables as independent predictors of LAAT: previous bleeding, treatment with VKA, and LVEF.

Conclusion

LAAT is related to lower LVEF and higher LAD. LVEF is one of the independent predictors of LAAT. Even in the case of adequate anticoagulant therapy, it might be prudent to consider TEE before cardioversion or ablation in patients with low LVEF and LA enlargement, especially in the coexistence of other thromboembolic risk factors.