Prevalence of auricular thrombosis before atrial flutter cardioversion: a 17-year transoesophageal echocardiographic study

Prevalence of left atrial thrombus in patients with atrial flutter in comparison to atrial fibrillation

BACKGROUND

Atrial flutter (AFL) and atrial fibrillation (AF) are believed to carry the same risk of systemic thromboembolism. However, there is a paucity of data concerning such risk in patients with AFL in comparison to AF.

OBJECTIVE

The aim of the study was to evaluate the prevalence of left atrial thrombus (LAT) on transesophageal echocardiography in patients with AFL in comparison to AF according to anticoagulation status.

METHODS

The study is the subanalysis of a multicenter, prospective Left Atrial Thrombus on Transesophageal Echocardiography (LATTEE) registry, which enrolled AF and AFL patients referred for ablation or electrical cardioversion regardless of oral anticoagulation (OAC) use. All patients underwent preprocedural transesophageal echocardiography to assess the primary end point of LAT presence.

RESULTS

A total of 3109 patients (AF, n = 2577; AFL, n = 532) were included in the study. Therapeutic OAC, defined as anticoagulation lasting at least 3 weeks, was used by 89.8% of patients in the AF subgroup and 82.5% in the AFL subgroup (P < .001). LAT was present in 8.3% of patients with AF and 6.8% with AFL, regardless of therapeutic OAC use (P = .235). In patients receiving therapeutic OAC, LAT was present in 7.6% in the AF subgroup and 5.7% in the AFL subgroup (P = .167); in patients without therapeutic OAC, LAT was present in 14.9% in the AF subgroup and 11.8% in the AFL subgroup (P = .459).

CONCLUSION

The risk of thrombus formation in AFL seems to be similar to that in AF, supporting similar recommendations concerning OAC use.

Thromboembolic Complications From Atrial Fibrillation and Atrial Flutter in Pediatrics and Young Adults: A Multicenter Study

BACKGROUND

Atrial fibrillation and atrial flutter are relatively rare in young people and the incidence of thromboembolic complications is unknown. These issues contribute to the limited utility of present guidelines regarding anticoagulation in this population.

OBJECTIVE

To report the number of thromboembolic complications in a cohort of pediatric and young adult patients presenting with atrial fibrillation (AFib) or atrial flutter (AFl) while also assessing anticoagulation practice in a multicenter cohort of young patients with these arrhythmias.

METHODS

Multicenter, retrospective cohort of patients aged < 25 years old who presented with atrial flutter (AFl) or atrial fibrillation (AFib) between 2000 and 2019 to several large, quaternary pediatric centers, excluding episodes occurring within 30 days of an invasive cardiac procedure.

RESULTS

There were 311 episodes of AFib/AFl among 210 patients with a median age of 17 (IQR 14, 20) years. Structural heart disease (SHD) was present in 120 patients (57%) and 20 patients (10%) had a primary cardiomyopathy. Twelve AFib/AFl episodes (8 with AFL, 4 with AFib) were associated with a thrombus, of which 8 (67%) patients had SHD, 2 (17%) had cardiomyopathy and 5 (42%) ventricular dysfunction. The CHADSVASc score was 0-3 for all patients with a thrombus. Of patients with no thrombus at presentation who were cardioverted, 102 (34%) patients were discharged on aspirin and 80 (27%) on anticoagulation. Two patients had symptoms concerning for a thromboembolic event on follow-up, but none had a newly documented thrombus.

CONCLUSIONS

Thromboembolic complications occur in children and young adults presenting with AFib/AFl. The majority are associated with SHD, cardiomyopathy, and/or ventricular dysfunction. CHADSVASc was calculated for each patient and was of limited utility. Thromboembolic complications at follow up after cardioversion are rare, and anticoagulation strategies at discharge varied.

Prevalence and predictors of left atrial thrombus in patients with rheumatic atrial fibrillation undergoing cardiac surgery: a cross-sectional study

BACKGROUND

Unlike non-rheumatic atrial fibrillation (AF), where left atrial thrombus (LAT) is predominantly confined to the left atrial appendage (LAA), a significant proportion of LAT in rheumatic AF occurs within the left atrial cavity (LAC). However, LAC thrombosis in rheumatic AF has not been extensively studied. This study aimed to evaluate the prevalence of LAT and its subtypes and identify potential predictors of LAT.

METHODS

This retrospective study included adult patients with rheumatic AF who underwent open-heart surgery for mitral valvular abnormalities between January 2019 and December 2020. LAT was identified through intraoperative inspection and categorized as either LAC thrombus or LAA thrombus. The prevalence of LAT and its subtypes was calculated, and logistic regression analysis was performed to identify predictors of LAT.

RESULTS

A total of 530 patients (mean age: 59.7 ± 9.5 years; male: 29.8%) with a predominance of mitral stenosis (59.6%) were included. LAT was identified in 82 patients (15.5%), including 44 (8.3%) with LAA thrombus and 38 (7.2%) with LAC thrombus. In the multivariable logistic regression model, coronary artery disease (OR: 6.35, 95% CI: 2.79-14.46, p < 0.001), larger left atrial diameter (OR: 1.31 per 10 mm increase, 95% CI: 1.02-1.68, p = 0.03), and moderate-to-severe mitral stenosis (OR: 1.77, 95% CI: 1.00-3.13, p = 0.05) were independently associated with an increased risk of LAT, whereas moderate-to-severe mitral regurgitation was independently associated with a decreased risk of LAT (OR: 0.21, 95% CI: 0.11-0.43, p < 0.001).

CONCLUSION

In patients with rheumatic AF undergoing open-heart mitral valve surgery, LAT can be located in either the LAA or LAC. The presence of LAT was independently associated with coronary artery disease, left atrial enlargement, and mitral valvular abnormalities. Timely screening and management of LAT are crucial to mitigate potentially fatal thromboembolic events.

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

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

Cardiovascular Outcomes in Patients with Atrial Flutter and Oral Anticoagulation: The Predictive Role of Left Atrial Appendage Thrombus in a Long-Term, Prospective, Observational Cohort Study

Background/Objectives: The risks of blood clot formation, stroke, heart failure (HF), and cardiovascular death are enhanced in individuals with atrial flutter (AFL). However, it remains unclear whether left atrial appendage thrombus (LAAT) in individuals with AFL with anticoagulation enhances the risk of cardiovascular morbidity and mortality. Thus, in the current trial, we aimed to evaluate the predictive role of LAAT for cardiovascular outcomes in individuals with AFL who were receiving anticoagulation and admitted for electrical cardioversion. Methods: Ninety patients were included in this prospective observational cohort study. The primary endpoint was the identification of LAAT by transesophageal echocardiographic examination. All participants were observed for a median of 2114.5 (interquartile range, 1487.5-2591) days to identify the secondary endpoints: cardiovascular death, transient ischemic attack (TIA), stroke, systemic thromboembolic complications, hospitalization due to HF, or myocardial infarction. Results: LAAT was identified in nine (10%) patients. No differences in cardiovascular outcomes between patients with and without LAAT were documented. However, a higher CHA2DS2-VASc score, previous myocardial infarction, and previous stroke/TIA/systemic thromboembolism were associated with significantly higher rates of hospitalization due to HF. Decreased left ventricular ejection fraction (LVEF) was associated with significantly higher rates of cardiovascular death, underscoring the significance of this marker in disease prognosis. Conclusions: The impact of LAAT on cardiovascular outcomes was insignificant. Higher CHA2DS2-VASc scores, previous myocardial infarction, previous stroke/TIA/systemic thromboembolism, and lower LVEF significantly affected long-term prognosis and were associated with a poor prognosis.

Comprehensive Analysis of Anticoagulant Therapy in Patients with Isolated Atrial Flutter

Limited comparative data exist regarding the risk of cardiogenic emboli in patients with isolated atrial flutter (AFL). Some studies suggest a lower complication risk in AFL compared to atrial fibrillation (AFib), but methodological limitations and conflicting reports necessitate a comprehensive investigation. Our analysis proposes that isolated AFL carries a lower risk of ischemic events and left atrial thrombus formation than AFib. Importantly, we caution against applying stroke risk assessment approaches designed for AFib to AFL patients, as it may lead to harmful overestimations and unnecessary anticoagulant prescriptions. Furthermore, we highlight the current lack of sufficient data to determine the overall clinical benefit of prolonged anticoagulant therapy in patients with isolated AFL, especially when CHA2DS2-VASc index values are below 4. This review challenges existing perceptions, offering insights into the nuanced risk profiles of the transitional nature of isolated AFL due to the high incidence of AFib development within a year of AFL diagnosis. In conclusion, tailored risk assessments and further research are essential for precise clinical decision-making in this dynamic landscape.

Left Atrial Thrombus-Are All Atria and Appendages Equal?

Although the left atrial appendage (LAA) seems useless, it has several critical functions that are not fully known yet, such as the causes for being the main origin of cardioembolic stroke. Difficulties arise due to the extreme range of LAA morphologic variability, making the definition of normality challenging and hampering the stratification of thrombotic risk. Furthermore, obtaining quantitative metrics of its anatomy and function from patient data is not straightforward. A multimodality imaging approach, using advanced computational tools for their analysis, allows a complete characterization of the LAA to individualize medical decisions related to left atrial thrombosis patients.

Frequency and Clinical Significance of Atrial Cavities in situ Thrombosis: A Large-Scale Study and Literature Review

Background

Atrial tachyarrhythmias are the main cause of atrial thrombosis, and are usually in the left appendage. The prevalence and causes of endocavitarian thrombosis have not been investigated in recent large-scale studies. Aim of our work was to describe the epidemiology, the clinical characteristics and predisposing factors of "extra-appendicular" atrial thrombosis and to report a systematic review of recent literature.

Methods and Results

5,862 consecutive adult patients referred to a transesophageal echocardiographic exam, were enrolled. A total of 175 subjects with Atrial Thrombosis were found with a prevalence of 2.98%; among those 22 was found in left (0.38%) and 2 in the right (0.03%) atrium. Among the 22 patients with left atrial thrombosis, 8 were associated with prosthetic valves, 4 with mitral stenosis and the remaining with hypercoagulative conditions (cancer, septic shock, eosinophilic pneumonia, cardiogenic shock and warfarin under-dosage in permanent atrial fibrillation and decompensated heart failure). Cancer was associated in one of the two patients with a right atrial clot. The review of the literature from 2000 to December 2019 revealed conflicting results of 48 case reports of atrial cavity thrombosis; pooling this data proved the rarity of extra-appendage thrombosis and confirmed its association with a valvular heart disease or a systemic hypercoagulable state.

Conclusions

Atrial "extra-appendage" thrombosis is a rare condition usually associated to "valvular" atrial fibrillation (such as prosthetic valves and mitral stenosis). A minority, but significant, cases are secondary to a thrombophilic conditions. In absence of valvular heart disease an underlying condition should be sought.

Features of Left Atrial Appendage Thrombosis in Patients With Persistent Nonvalvular Atrial Fibrillation After COVID-19

Aim      To evaluate the incidence and characteristic features of left atrial appendage (LAA) thrombosis in patients with persistent nonvalvular atrial fibrillation (AF) after COVID-19.Material and methods  Transesophageal echocardiography (TEE) was performed for 469 patients (57.4 % males; mean age, 64.0 [58.0; 70.0] years) with persistent nonvalvular AF before scheduled sinus rhythm restoration. In 131 of these patients (27.9 %), the most recent episode of arrhythmia developed during the coronavirus infection. The time from the onset of COVID-19 to TEE was 145 [62; 303] days. All patients received an adequate anticoagulant therapy, in most cases, with direct oral anticoagulants for at least 3 weeks preceding the study.Results A LAA thrombus was detected in 20 (5.9 %) patients who have had no coronavirus infection and in 19 (14.5 %) patients after COVID-19 (р=0.0045). 18 of 19 (94.7 %) thrombi found in patients who have had COVID-19 were mural whereas only 5 (25.0 %) of such thrombi were found in patients who have had no COVID-19 (p&lt;0.0001). In the absence of LAA thrombus, the LAA emptying velocity was 32.0 [25.0; 40.0] cm/sec whereas in the presence of a mural thrombus, it was 25.0 [20.0; 32.3] cm/sec, and in the presence of a typical thrombus, it was 17.0 [13.5; 20.0] cm/sec (р&lt;0.0001). A Kaplan-Meier analysis showed that the median time of mural thrombus dissolution was 35.0 (95 % confidence interval (CI), 24.0-55.0) days and for a typical thrombus, this time was 69.0 (95 % CI, 41.0-180.0) days (р=0.0018).Conclusion      Patients with persistent AF who have had COVID-19 had LAA thrombosis 2,5 times more frequently and, in most cases, the thrombus was mural. Mural thrombi, in contrast to typical, are not associated with a pronounced decrease in LAA emptying velocity and dissolve twice as fast as typical thrombi with an adequate anticoagulant treatment.

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 Thrombus-Are All Atria and Appendages Equal?

Although the left atrial appendage (LAA) seems useless, it has several critical functions that are not fully known yet, such as the causes for being the main origin of cardioembolic stroke. Difficulties arise due to the extreme range of LAA morphologic variability, making the definition of normality challenging and hampering the stratification of thrombotic risk. Furthermore, obtaining quantitative metrics of its anatomy and function from patient data is not straightforward. A multimodality imaging approach, using advanced computational tools for their analysis, allows a complete characterization of the LAA to individualize medical decisions related to left atrial thrombosis patients.

Association Between Left Atrial Appendage Morphology and Function and the Risk of Ischaemic Stroke in Patients with Atrial Fibrillation

AF is the most common cardiac arrhythmia and has been identified as an independent risk factor for stroke. The European Society of Cardiology guidelines recommend a thromboembolic event risk assessment based on the CHA₂DS₂-VASc score. However, stroke also occurs in some patients with a low CHA₂DS₂-VASc score. Therefore, it is necessary to find new factors to improve thromboembolic risk stratification in AF patients. Over 90% of embolic strokes are caused by thrombi originating from the left atrial appendage (LAA). Thus, certain anatomical or functional parameters of the LAA could potentially be used to predict cardioembolic stroke. Studies have suggested that some of these factors, such as LAA morphology, number of LAA lobes, LAA dimensions, LAA volume, distance from the LAA ostium to the first bend of LAA, LAA orifice diameter, extent of LAA trabeculations, LAA takeoff, LAA flow velocity and LAA strain rate, are independently associated with a higher risk of stroke in a population of patients with AF and improve the performance of the CHA₂DS₂-VASc score. However, the results are conflicting and, so far, no new parameter has been added to the CHA₂DS₂-VASc score.

The left atrial appendage thrombosis of in patients with persistent atrial fibrillation after the novel coronavirus infection

Aim      To evaluate the incidence and features of left atrial appendage (LAA) thrombosis in patients with persistent atrial fibrillation (AF) after novel coronavirus infection (COVID-19).Material and methods  Percutaneous echocardiography (pcEchoCG) was performed for 128 patients with persistent AF prepared for cardioversion, 36 (28.1 %) of whom had had COVID-19. In 3 (8.3 %) patients, the lung lesion area was 50-75 %; in 31 (86.1 %) patients, 25-50 %; in 1 (2.8 %) patient, less than 25 %. One patient had no lung lesion. Median time from the onset of COVID-19 to the patient enrollment in the study was 76.5 days. At the time of enrollment, the polymerase chain reaction test for SARS-CoV-2 was negative in all patients.Results Patients after COVID-19 and those who had not had COVID-19 were comparable by age (62.5±9.2 and 62.4±9.1 years, respectively; р=0.956), gender (men 52.8 and 59.8 %, respectively; р=0.471), and risk of stroke (score 2.19±1.28 and score 1.95±1.35, respectively; р=0.350). Duration of the last arrhythmia episode was longer for patients after COVID-19 than for the comparison group (76.5 and 45.0 days, respectively; р=0.011). All patients received oral anticoagulants. 55.6 % of COVID-19 patients received rivaroxaban, whereas 62.0% of patients who had not had COVID-19 were treated with apixaban. Median duration of the anticoagulant treatment was longer for COVID-19 patients than for the comparison group (61.5 and 32.0 days; р=0.051). LAA thrombus was detected in 7 (19.4 %) patients after COVID-19 and in 6 (6.5 %) patients of the comparison group (р=0.030). In COVID-19 patients, the thrombus adhered to LAA wall over the entire thrombus length whereas in patients who had not have COVID-19, the thrombus had a free part that formed a sharp angle with LAA walls. In the presence of LAA thrombus, the LAA blood flow velocity was considerably higher for COVID-19 patients than for the comparison group (31.0±8.9 and 18.8±4.9 cm/sec, respectively; p=0.010). At the follow-up examination performed at 24.0 days on the average, the thrombus was found to be dissolved in 80 and 50% of patients after and without COVID-19, respectively (р=0.343).Conclusion      In patients with persistent AF after the novel coronavirus infection, LAA thrombosis was detected more frequently than in patients who had never had COVID-19; it was characterized by mural localization and was not associated with a decrease in LAA blood flow velocity.

A Prospective Study to Evaluate the Effectiveness of Edoxaban for the Resolution of Left Atrial Thrombosis in Patients with Atrial Fibrillation

Available evidence on left atrial (LA) thrombus dissolution in patients with atrial fibrillation (AF) largely refers to the use of vitamin K antagonist oral anticoagulants (VKAs), showing >50% thrombus resolution over a 4-week to 12-month treatment period. Available data on non-vitamin K antagonist anticoagulants (NOACs) in this setting are limited and derive from isolated case reports or observational small-sized investigations with dabigatran, rivaroxaban or apixaban. The aim of this study was to investigate the extent of thrombus resolution with edoxaban therapy in patients with AF and LA thrombosis. We conducted a prospective, observational, open-label pilot study in seven Italian institutions. We included a total of 25 patients with non-valvular AF and LA (or left atrial appendage (LAA)) thrombosis, documented by transesophageal echocardiography (TEE). All patients received edoxaban OD treatment (n = 23 on 60 mg daily; n = 2 on 30 mg daily) and underwent TEE examination after 4 weeks. The primary endpoint was the percentage of patients with complete thrombus resolution by TEE imaging at 4 weeks. The mean age of the study population was 68.3 ± 10.8 years with a female population of 16%. AF was permanent in all cases, with a mean arrhythmia duration of 4.3 ± 1.7 years. CHA2DS2-VASc and HAS-BLED scores were 3.2 ± 1.5 and 1.9 ± 1.1, respectively. We were able to demonstrate a complete thrombus resolution in 14 patients (56%) at 4 weeks. In patients with residual atrial thrombosis (n = 11), we observed a 15.4 ± 14.9% reduction in the thrombus area from baseline. As compared with patients without thrombus dissolution, those with thrombus resolution had a numerically lower-indexed LA diameter (27.9 ± 9.3 vs 34.8 ± 16.1 mm/m2), a smaller maximum thrombus area at baseline (45.5 ± 44.6 vs 63.9 ± 43.5 mm2), a higher left ventricular ejection fraction (47.4 ± 21.0% vs 38.4 ± 20.6%) and higher maximum LAA flow velocities (26.3 ± 15.2 vs 19.3 ± 10.0 cm/s). Figures on the percentage of thrombus resolution in this study are comparable to those reported in the literature for the other OACs. We conclude that, in patients with AF, the use of edoxaban is associated with a >50% resolution of atrial thrombus at 4 weeks, similar to studies using VKAs and the other NOACs (ClinicalTrials.gov identifier number: NCT034899395).

Interim Analysis of Pregnancy Outcomes After Exposure to Dimethyl Fumarate in a Prospective International Registry

Background and Objectives

Oral delayed-release dimethyl fumarate (DMF) is not recommended during pregnancy and should only be used if the potential benefit justifies the potential fetal risk. Although DMF was well tolerated in clinical trials with consistent safety results in postmarketing surveillance, data are limited in pregnant women. The objective was to provide pregnancy outcomes and DMF exposure information from an interim analysis from a prospective, international registry (TecGistry; NCT01911767).

Methods

Women exposed to DMF from the first day of their last menstrual period before conception or during pregnancy were evaluated. Data were obtained at enrollment; 6−7 months' gestation; 4 weeks after estimated due date; and 4, 12, and 52 weeks after birth. Outcomes included live births, gestational size, pregnancy loss, birth defects, and infant or maternal death after delivery. Outcomes were analyzed cumulatively from October 30, 2013 (the start of TecGistry), to April 8, 2020.

Results

Of 345 enrolled patients, median (range) age was 32 (20–43) years. The mean (SD) duration of gestational weeks of DMF exposure was 4.9 (3.8). Most infants were full-term at birth (n = 249/274; 91%) and of average gestational size (n = 190/232; 82%). Of 351 outcomes, 277 were live births; 17 (5%) spontaneous abortions (95% confidence interval [CI] 2.6%–7.1%), including 1 (<1%) molar and 1 (<1%) ectopic pregnancy, were reported. There were 8 (2.9% [95% CI 1.3%–5.6%]) adjudicator-confirmed birth defects among the 277 live births.

Discussion

Interim results from this large registry indicate that early DMF exposure was not significantly associated with adverse pregnancy outcomes. Outcomes are consistent with previous smaller reports and with the general population.

Trial Registration Information

TecGistry; clinical trial registration number: NCT01911767.

Stroke risk assessment in patients with persistent atrial fibrillation to consider performing pre-cardioversion transesophageal echocardiography

Aim. To study the potential of stroke risk assessment to evaluate the probability of detecting left atrial appendage (LAA) thrombus in patients with persistent atrial fibrillation (AF) to consider performing transesophageal echocardiography (TEE) before cardioversion.

Material and methods. TEE before elective cardioversion was performed in 590 patients with persistent AF, of whom 316 (53,6%) had a high stroke risk (valvular AF, hypertrophic cardiomyopathy, CHA2DS2-VASc score >1 in men and >2 in women), and 274 (46,4%) — not high. Adequate anticoagulation at least 3 weeks prior to elective cardioversion was received by 164 (51,9%) patients with a high stroke risk and 151 (55,1%) patients with a low risk. The rest of patients either did not receive adequate anticoagulation or received it for less than 3 weeks.

Results. In the group of patients who received anticoagulation at least 3 weeks, LAA thrombus was detected in 23 (14,0%) patients with a high stroke risk and in 8 (5,3%) patients with a low risk (p<0,05). In patients who did not receive adequate anticoagulation or received it for less than 3 weeks, LAA thrombus was identified in 60 (39,5%) patients with a high stroke risk and in 22 (17,9%) patients with a low risk (p<0,005). Thus, a  high stroke risk almost 3 times increases the likelihood of LAA thrombus detection in patients who did not receive adequate anticoagulation (odds ratio, 2,99; 95% confidence interval: 1,70-5,26;p<0,001) and in patients receiving adequate anticoagulation (odds ratio, 2,92; 95% confidence interval: 1,26-6,74; p=0,012).

Conclusion. In patients with persistent AF with a low stroke risk according to CHA2DS2-VASc score, TEE before sinus rhythm restoration in patients without 3-week anticoagulation should be considered. In patients with a high stroke risk, performing pre-cardioversion TEE is advisable even after adequate anticoagulation.

Right Atrial Appendage Thrombus in Atrial Fibrillation: A Case Report and Review of the Literature

Atrial fibrillation (Afib) is the most common abnormal heart rhythm in adults and has become a significant public health concern affecting 2% to 3% of the population in Europe and North America. Left atrial appendage (LAA) thrombi is the source of 90% of left-sided cardiac thrombi in patients with Afib, which can cause stroke and other systemic vascular events. Right atrial appendage (RAA) thrombi formation in Afib is much less common but complications include pulmonary embolism or paradoxical migration across patent foramen ovale with risk of systemic embolization. The prevalence and subsequent clinical complications of RAA thrombi formation in Afib patients is not well understood. Management of RAA thrombi should be similar to that of LAA thrombi which includes delaying cardioversion and anticoagulating with warfarin therapy to achieve international normalized ratio of 2 to 3.

High rate of cardiac thrombus diagnosed by adding cardiac imaging in acute stroke computed tomography protocol

BACKGROUND

Detection of left atrial appendage thrombus (LAAt) in acute stroke patients can be improved by cardiac computed tomography using prospective electrocardiogram-gated volume acquisition, which was added to the acute stroke computed tomography protocol in our institution in 2018.

AIMS

To evaluate the factors and clinical management associated with LAAt in patients with acute ischemic stroke.

METHODS

We retrospectively included 324 consecutive patients with ischemic stroke from November 2018 to October 2019. Clinical data and post-stroke management were compared in LAAt and no-LAAt patients.

RESULTS

Thirty-five patients (10.8%; 95%CI 7.4-14.2) had LAAt and 289 had no-LAAt. LAAt patients were significantly older (82 ± 12 vs. 74 ± 14 yo for no-LAAt, p = 0.002), predominantly female (71% vs. 45%, p = 0.004), and were more likely to have previous atrial fibrillation (63% vs. 15%, p < 0.001) and previous stroke (32% vs. 14%, p = 0.005). There was no significant difference between groups in stroke localization or severity scales at admission or at hospital discharge. After multivariable analysis, female sex (odds ratio 2.51; 95%CI 1.09-5.77, p = 0.031), previous atrial fibrillation (odds ratio 4.87; 95%CI 2.11-11.22, p < 0.001), and left atrial volume >86 ml (odds ratio 5.33; 95%CI 1.70-16.69, p = 0.004) were independently associated with LAAt. More than a third of LAAt patients (37%) received acute heparin therapy compared to 13% of no-LAAt patients (p < 0.001). Moreover, despite comparable stroke severity at admission, the mortality rate was markedly higher in the LAAt group than in the no-LAAt group (37% vs. 13%, p < 0.001).

CONCLUSIONS

Cardiac computed tomography for left atrial appendage thrombus evaluation in routine acute stroke imaging protocol could be beneficial for decision-making with regard to the initiation of early anticoagulation.

Inverse Correlation Between Left Atrial Appendage Function and CHA2DS2-VASc Score in Patients with Atrial Flutter

Impaired left atrial appendage ejection fraction (LAA-EF) and peak LAA flow velocity (LAA-FV) are associated with high thromboembolic risks in patients with atrial fibrillation (AF). Herein, we examined LAA function among patients with atrial flutter (AFL) stratified by the CHA₂DS₂-VASc score using transesophageal echocardiography (TEE). Of 231 consecutive patients with typical AFL, 84 who fulfilled the inclusion criteria were enrolled. Among them, 57 had ongoing AFL and were divided into the isolated AFL (n = 38) and AFL with paroxysmal AF (PAF) (n = 19) groups, depending on whether they had sporadic AF before TEE. The remaining 27 patients with spontaneous sinus rhythm during TEE were designated as controls. Both the LAA-FV (31.9 cm/s vs. 51.5 cm/s, P = 0.004) and LAA-EF (28.4% vs. 36.5%, P = 0.024) measured during AFL were significantly lower in the AFL + PAF group than in the isolated AFL group. Significant inverse correlations between the CHA₂DS₂-VASc score and LAA-EF were identified in the AFL (P = 0.008) and AFL + PAF (P = 0.032) groups. We observed progressive LAA dysfunction in patients with AFL + PAF compared with that in patients with isolated AFL, and the LAA-EF was inversely correlated with the CHA₂DS₂-VASc score in these patients. Our findings may have implications on the application of thromboprophylactic therapy in patients with AFL.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prevalence of extra-appendage thrombosis in non-valvular atrial fibrillation and atrial flutter in patients undergoing cardioversion: a large transoesophageal echo study

AIMS

The aim of our study was to evaluate the prevalence of left atrial cavity and appendage thrombosis in patients undergoing cardioversion for non-valvular atrial tachyarrhythmias. In persistent atrial tachyarrhythmias, 90% of thromboses are reported to be located inside the left atrial appendage. This prevalence refers to old studies and meta-analysis in a mixed population of valvular and non-valvular atrial fibrillation. Left atrial cavity thrombosis in non-valvular atrial fibrillation has not been investigated recently in large-scale studies.

METHODS AND RESULTS

A total of 1,420 consecutive adult patients with paroxysmal or persistent atrial tachyarrhythmias, candidates to cardioversion, who opted for a transoesophageal echocardiography-guided strategy, were enrolled in the study. Mitral stenosis, rheumatic valve disease and mechanical prostheses were excluded. In total there were 91 thrombi in 87 patients with a prevalence of 6.13% (87/1,420). Patients with left atrial thrombosis had predisposing clinical and echo characteristics (heart failure, lower ventricular function and higher atrial volume). Except for one case in which the thrombus was located in the left atrial cavity (0.07%), and three in the right appendage, all thromboses were detected in the left atrial appendage.

CONCLUSIONS

Extra-appendage thrombosis is a very rare finding in non-valvular persistent and paroxysmal atrial tachyarrhythmias and, when present, a left appendage thrombus is usually concomitant.

Death and thrombo-embolic risk after ablation of atrial flutter compared with atrial fibrillation: a nationwide cohort study

Aims

The aim of this study was to investigate whether there is a similar mortality and thrombo-embolic risk, after an atrial ablation procedure, compared with an atrial fibrillation (AF) procedure.

Methods and results

Using data from nationwide Danish health registries, we identified patients aged 18-75 years undergoing a first-time atrial flutter or an AF ablation procedure in the period 2000-13. Cox proportional hazards regression was used to calculate hazard ratios (HRs) after 5 years of follow-up, adjusting for concomitant risk factors. A total of 1096 and 2266 patients underwent an ablation for atrial flutter or AF, respectively. Age distribution was similar in the two, but atrial flutter patients had more co-morbidities. During 5 years of follow-up, we observed 38 and 36 deaths in the atrial flutter and AF groups, corresponding to an almost two-fold higher mortality rate among atrial flutter patients [crude HR 1.92, 95% confidence interval (CI) 1.22-3.03]. The higher mortality rate persisted after adjustment for age, sex, diabetes mellitus, and hypertension (adjusted HR 1.68, 95% CI 1.05-2.69). The rate of thrombo-embolic events was similar in the two groups (crude HR 1.34, 95% CI 0.71-2.56; adjusted HR 1.22, 95% CI 0.62-2.41).

Conclusion

In this observational study, patients with atrial flutter had a significantly higher all-cause mortality rate compared with those with AF after an ablation procedure, but similar thrombo-embolic event rates. Future studies should elucidate the reason for this difference in mortality.

The left atrial appendage: from embryology to prevention of thromboembolism

The left atrial appendage (LAA) is the main source of thromboembolism in patients with non-valvular atrial fibrillation (AF). As such, the LAA can be the target of specific occluding device therapies. Optimal management of patients with AF includes a comprehensive knowledge of the many aspects related to LAA structure and thrombosis. Here we provide baseline notions on the anatomy and function of the LAA, and then focus on current imaging tools for the identification of anatomical varieties. We also describe pathogenetic mechanisms of LAA thrombosis in AF patients, and examine the available evidence on treatment strategies for LAA thrombosis, including the use of non-vitamin K antagonist oral anticoagulants and interventional approaches.