Left atrial thrombus in patients with atrial fibrillation and under oral anticoagulant therapy; 3-D transesophageal echocardiographic study

Incidence and predictors of left atrial thrombus in patients with atrial fibrillation under anticoagulation therapy

BACKGROUND

Left atrial thrombus (LAT) formation is associated with thromboembolic events.

OBJECTIVE

To investigate the incidence and associated factors of LAT in patients with atrial fibrillation (AF) who had been receiving anticoagulation therapy for more than 4 weeks, and to develop a prediction model using clinical and echocardiographic features.

METHODS

Medical records of 1,122 patients with AF (mean age, 59.4 ± 11.0 years, 58.3% male) who were on anticoagulation more than 4 weeks and underwent transesophageal echocardiography (TEE) were evaluated. The main outcome was the presence of LAT on TEE.

RESULTS

Warfarin and non-vitamin K oral anticoagulants were used in 74.4% and 25.6% of the patients at the time of examination, respectively. LAT was present in 60 patients (5.3%). Presence of LAT on TEE was associated with age ≥ 75 years (odds ratio [OR] 2.13 [95% confidence interval, 0.94-4.58]), persistent/permanent AF (OR 2.61 [1.42-4.93]), CHA2DS2-VASc score ≥ 3 points (OR 1.91 [1.05-3.48]), left ventricular ejection fraction < 40% (OR 2.35 [1.07-4.81]), and severe left atrial enlargement (OR 3.52 [1.89-6.79]). The presence of moderate-to-severe mitral regurgitation was associated with a lower risk of LAT (OR 0.13 [0.04-0.34]). A scoring system composed of the aforementioned predictors showed excellent discrimination performance (area under the curve 0.791 [95% CI, 0.727-0.854]).

CONCLUSIONS

LAT was present in a considerable number of patients who were already receiving anticoagulation therapy. A prediction model that combines clinical and echocardiographic predictors could be useful in distinguishing patients who require imaging evaluations before left atrial intervention.

The correlation between ultrasonographic morphology and structure of the left atrial appendage, blood flow velocity, and plasma galectin-3 levels with thrombus formation in the left atrial appendage of patients with atrial fibrillation

Background

To explore the correlation between left atrial appendage morphology, blood flow velocity and plasma galectin-3 and thrombosis in patients with atrial fibrillation.

Methods

Patients with atrial fibrillation who received treatment and completed ultrasound examination in hospital from 2022 to December 2023 were enrolled. According to whether there was left atrial appendage thrombosis, the patients were divided into a control group (no left atrial appendage thrombosis was found) and a study group (left atrial appendage thrombosis was found). The morphology and structure of the left atrial appendage, blood flow velocity and plasma galectin-3 level were recorded exploring its correlation with left atrium thrombosis.

Results

A total of 330 patients with atrial fibrillation were enrolled, including 278 in the control group and 52 in the study group. Left group and the control group of morphological structure differences (P < 0.05). The main lobe length, ostial area, longest diameter, shortest diameter, left atrial appendage volume and left atrial volume in the study group were higher than those in the control group (P < 0.05). The left atrial appendage emptying velocity, filling velocity and left ventricular ejection fraction of the study group were lower than those of the control group, and the left ventricular end-diastolic diameter was higher than that of the control group (P < 0.05). Group of white blood cell count, neutrophils/lymphocyte ratio, plasma galactose lectin-3 levels were higher than control group (P < 0.05). ROC curve analysis of left atrial appendage emptying velocity, left atrial appendage filling velocity, left atrial enddiastolic diameter and left atrial ejection fraction had higher diagnostic value (P < 0.05).

Conclusions

Left atrial appendage morphology, blood flow velocity and plasma galectin-3 level are important factors to evaluate the risk of left atrial appendage thrombosis in patients with atrial fibrillation. This study improves the understanding of thrombosis, further elucidates the risk factors for thrombosis, and improves patient prognosis.

Ischaemic stroke in a patient with non-valvular atrial fibrillation (NVAF) despite non-vitamin K oral anticoagulant (NOAC) therapy

Primary stroke prevention in non-valvular atrial fibrillation (NVAF) is primarily with non-vitamin K oral anticoagulant (NOAC) therapy. However, 20-36% of ischaemic strokes seem to occur in patients with atrial fibrillation while already on anticoagulation. We present a case of an ischaemic stroke in an elderly female in her 70s with medical history significant for hypertension and NVAF. She had a CHA2DS2-VASc score of 3 and was on apixaban for thromboprophylaxis. She presented with neurological deficits consistent with a left middle cerebral artery stroke, confirmed via head imaging; the most likely stroke aetiology was determined to be cardioembolic in the setting of NVAF. She was treated with continuation of her apixaban at the same dosage She displayed improved function, although with residual expressive aphasia at her 2-month neurology follow-up. Cardioembolic ischaemic stroke in NVAF despite current NOAC therapy does not have current management guidelines.

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.

Finding low CHA2DS2-VASc scores unreliable? Why not give morphological and hemodynamic methods a try?

Patients with atrial fibrillation (AF) suffer from a high risk of thrombosis. Currently, the CHA2DS2-VASc score is the most widely used tool for risk stratification in patients with AF, but it has disappointing accuracy and limited predictive value, especially in those with low scores. Thrombi in patients with AF mostly grow in their left atrial appendages (LAA), which is directly related to the abnormal morphology of the LAA or the left atrium and the unusual hemodynamic state around LAA, which may sensitively evaluate the risk of thrombosis complications in patients with AF and bring bases to clinical plans of medication and operation. Therefore, we investigated the research progress of hemodynamic and morphological studies about the predictive value of thrombosis risk in patients with AF, intending to discuss the prediction potential of morphological and hemodynamic indexes when compared with the presently used CHA2DS2-VASc system and how to build a more precise thromboembolic event prediction model for patients with AF.

Left Atrial Appendage Thrombosis and Oral Anticoagulants: A Meta-Analysis of Risk and Treatment Response

Left atrial appendage thrombus (LAAT) is the main cause of cardioembolism in patients with nonvalvular atrial fibrillation (AF). Emerging evidence indicates that direct oral anticoagulants (DOACs) may be a preferred, safer choice for patients with LAAT. However, current guidelines indicate vitamin K antagonist (VKA) as the preferred treatment for LAAT. We conducted a meta-analysis to compare the efficacy of VKA and DOAC for the treatment of LAAT. Methods: The search was conducted in the PubMed, Embase, Google Scholar, and Cochrane Library databases from inception to July 2022, with the language restricted to English. A first analysis was conducted to evaluate the risk of LAAT under VKA or DOAC treatment. A second analysis was conducted to compare the resolution of LAAT under VKA and DOAC treatment. Results: In 13 studies comparing LAAT incidence rates under VKA and DOAC treatment, significant superiority of DOAC was detected (pooled RR = 0.65, 95% CI = 0.47–0.90, p = 0.009) with moderate heterogeneity being identified in the pooled studies. In 13 studies comparing LAAT resolution under VKA and DOAC use, treatment with DOAC exhibited a significantly increased probability of LAAT resolution compared with VKA (pooled odds ratio = 1.52, 95% CI = 1.02–2.26, p = 0.040). Conclusions: This meta-analysis suggests a superiority of DOAC over VKA with respect to LAAT incidence in people with AF and the likelihood of LAAT resolution. Due to their established safety profile, DOAC is a preferable choice for anticoagulation, although further randomized controlled studies are warranted to provide further evidence of their suitability as a new recommended treatment.

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.

Enterococcus durans Cardiac Implantable Electronic Device Lead Infection and Review of Enterococcus durans Endocarditis Cases

Introduction: Cardiac implantable electronic device (CIED) infections present a growing problem in medicine due to a significant increase in the number of implanted devices and the age of the recipient population. Enterococcus spp. are Gram-positive, facultative anaerobic, lactic acid bacteria; they are relatively common pathogens in humans, but uncommon as the cause of CIED lead infections. Only eight cases of Enterococcus durans endocarditis have been reported in the literature thus far; however, there are no reported cases of Enterococcus durans CIED lead infection. Case presentation: A 58-year-old gentleman with a previously implanted St. Jude Medical single-chamber implantable cardioverter–defibrillator (ICD) due to tachy/brady arrhythmias presented with nonspecific constitutional symptoms (i.e., low-grade fevers, chills, fatigue), and was found to have innumerable bilateral pulmonary nodules via computed tomography angiography of the chest. Many of these pulmonary nodules were cavitated and highly concerning for septic pulmonary emboli and infarcts. Within 24 h from presentation, blood cultures in all four culture bottles grew ampicillin- and vancomycin-susceptible Enterococcus durans. Transthoracic echocardiogram confirmed vegetations on the ICD lead in the right ventricle. The patient underwent laser extraction of the ICD lead with generator removal and recovered completely after a 6-week intravenous antibiotic course. Conclusion: To our knowledge, this is the first report of CIED lead infection caused by Enterococcus durans. In this case, management with antibiotics along with ICD lead extraction led to complete recovery. Clinicians should be aware of this rare but potentially devastating infection in patients with native and artificial valves, but also in those with CIEDs.

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.

Prevalence of Left Atrial Thrombus in Anticoagulated Patients With Atrial Fibrillation

BACKGROUND

The prevalence of left atrial (LA) thrombus in patients with atrial fibrillation (AF) or atrial flutter (AFL) on guideline-directed anticoagulation is not well known, yet this may inform transesophageal echocardiogram (TEE) use before cardioversion or catheter ablation.

OBJECTIVES

The purpose of this study was to quantify LA thrombus prevalence among patients with AF/AFL on guideline-directed anticoagulation and to identify high-risk subgroups.

METHODS

EMBASE, MEDLINE, and CENTRAL were systematically searched from inception to July 2020 for studies reporting on LA thrombus prevalence among patients with AF/AFL undergoing TEE following at least 3 weeks of continuous therapeutic oral anticoagulation with vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs). Meta-analysis was performed using random effects models.

RESULTS

Thirty-five studies describing 14,653 patients were identified. The mean-weighted LA thrombus prevalence was 2.73% (95% confidence interval [CI]: 1.95% to 3.80%). LA thrombus prevalence was similar for VKA- and DOAC-treated patients (2.80%; 95% CI: 1.86% to 4.21% vs. 3.12%; 95% CI: 1.92% to 5.03%; p = 0.674). Patients with nonparoxysmal AF/AFL had a 4-fold higher LA thrombus prevalence compared with paroxysmal patients (4.81%; 95% CI: 3.35% to 6.86% vs. 1.03%; 95% CI: 0.52% to 2.03%; p < 0.001). LA thrombus prevalence was higher among patients undergoing cardioversion versus ablation (5.55%; 95% CI: 3.15% to 9.58% vs. 1.65%; 95% CI: 1.07% to 2.53%; p < 0.001). Patients with CHA₂DS₂-VASc scores ≥3 had a higher LA thrombus prevalence compared with patients with scores ≤2 (6.31%; 95% CI: 3.72% to 10.49% vs. 1.06%; 95% CI: 0.45% to 2.49%; p < 0.001).

CONCLUSIONS

LA thrombus prevalence is high in subgroups of anticoagulated patients with AF/AFL, who may benefit from routine pre-procedural TEE use before cardioversion or catheter ablation.

Prevalence of left atrial thrombus by real time three-dimensional echocardiography in patients undergoing electrical cardioversion of atrial fibrillation: A contemporary cohort study

BACKGROUND

The prevalence of left atrial thrombi in patients scheduled for electrical cardioversion (ECV) of atrial fibrillation (AF) remains unknown in contemporary real-life practice.

METHODS AND RESULTS

Patients scheduled for ECV underwent transesophageal echocardiography (TEE) regardless of AF duration and type of anticoagulant. Of 277 consecutive patients (65% men, mean age 71 ± 10 years, CHA₂ DS₂ -VASc 3.1 ± 1.4), 92 were on direct oral anticoagulants (DOACs) and 99 on antivitamin K (AVK) oral agents for at least 3 weeks before and 4 after ECV. Eighty-five patients with paroxysmal AF on low-molecular-weight heparin were also considered. Real time three-dimensional TEE detected left atrial appendage (LAA) thrombus in 7% of patients, without significant difference among three groups (P = .334). Anticoagulation was ineffective in eight patients on AVK oral agents, two of them had thrombus. Eight patients assumed incorrectly DOACs, four of them had thrombus. Among the 175 patients on effective anticoagulation, five showed thrombus, three on AVK oral agents, and two on DOACs (P = .716). Effective anticoagulation was associated with reduced risk of thrombosis (OR: 0.16, 95%CI: 0.06-0.45, P = .001). In patients with correct anticoagulation, predictors of thrombus were CHA₂ DS₂ VASc (for each point of increment OR: 1.97, 95%CI: 1.08-3.61, P = .029), low left ventricular ejection fraction (OR: 0.92, 95%CI: 0.86-0.99, P = .026), and degree of spontaneous echo-contrast (for each point increase OR: 10, 95%CI: 2-39, P < .0001).

CONCLUSION

Patients with AF, on effective anticoagulation, had a prevalence of thrombus not negligible regardless of type of anticoagulant. TEE is prudent before ECV and mandatory if unsuccessful anticoagulation is proved or suspected.