Atrial Thrombus Formation Research Articles

Anticoagulation in Atrial Fibrillation Cardioversion: What Is Crucial to Take into Account.

The therapeutic dilemma between rhythm and rate control in the management of atrial fibrillation (AF) is still unresolved and electrical or pharmacological cardioversion (CV) frequently represents a useful strategy. The most recent guidelines recommend anticoagulation according to individual thromboembolic risk. Vitamin K antagonists (VKAs) have been routinely used to prevent thromboembolic events. Non-vitamin K antagonist oral anticoagulants (NOACs) represent a significant advance due to their more predictable therapeutic effect and more favorable hemorrhagic risk profile. In hemodynamically unstable patients, an emergency electrical cardioversion (ECV) must be performed. In this situation, intravenous heparin or low molecular weight heparin (LMWH) should be administered before CV. In patients with AF occurring within less than 48 h, synchronized direct ECV should be the elective procedure, as it restores sinus rhythm quicker and more successfully than pharmacological cardioversion (PCV) and is associated with shorter length of hospitalization. Patients with acute onset AF were traditionally considered at lower risk of thromboembolic events due to the shorter time for atrial thrombus formation. In patients with hemodynamic stability and AF for more than 48 h, an ECV should be planned after at least 3 weeks of anticoagulation therapy. Alternatively, transesophageal echocardiography (TEE) to rule out left atrial appendage thrombus (LAAT) should be performed, followed by ECV and anticoagulation for at least 4 weeks. Theoretically, the standardized use of TEE before CV allows a better stratification of thromboembolic risk, although data available to date are not univocal.

Immunohistological Evaluation of Von Willebrand Factor in the Left Atrial Endocardium and Atrial Thrombi from Cats with Cardiomyopathy.

Simple SummaryDisease of the heart muscle (cardiomyopathy) is very common in the domestic cat and may result in several severe outcomes. These include formation of a thrombus in the left atrium which migrates to the hindlimb cutting off the blood supply, a condition called aortic thromboembolism. Affected cats present with hindlimb paralysis and extreme pain, often requiring euthanasia on humane grounds. Several factors are known to predispose to thrombus formation, including damage to the inner cellular lining of the atrium which exposes proteins that initiates thrombosis. We studied the expression of one such protein called von Willebrand Factor in the left atrium of cats with and without cardiomyopathies and at different stages of disease severity. We found that expression increased in cats with advance disease. Obtaining a greater understanding of the role this protein has in thrombus formation may allow development of novel antithrombotic agents to help prevent this devastating consequence of feline cardiomyopathy.Aortic thromboembolism (ATE) occurs in cats with cardiomyopathy and often results in euthanasia due to poor prognosis. However, the underlying predisposing mechanisms leading to left atrial (LA) thrombus formation are not fully characterised. von Willebrand Factor (vWF) is a marker of endothelium and shows increased expression following endothelial injury. In people with poor LA function and LA remodelling, vWF has been implicated in the development of LA thrombosis. In this study we have shown (1) the expression of endocardial vWF protein detected using immunohistofluorescence was elevated in cats with cardiomyopathy, LA enlargement (LAE) and clinical signs compared to cats with subclinical cardiomyopathy and control cats; (2) vWF was present at the periphery of microthrombi and macrothrombi within the LA where they come into contact with the LA endocardium and (3) vWF was integral to the structure of the macrothrombi retrieved from the atria. These results provide evidence for damage of the endocardial endothelium in the remodelled LA and support a role for endocardial vWF as a pro-thrombotic substrate potentially contributing to the development of ATE in cats with underlying cardiomyopathy and LAE. Results from this naturally occurring feline model may inform research into human thrombogenesis.

Association of Structure and Function of left atrial Appendage with Left atrial appendage Thrombus formation in patients with Rheumatic Heart Disease

Context: In patients with rheumatic heart disease (RHD), left atrial appendage (LAA) dilation and thrombus formation is widely known. LAA thrombus formation is a risk factor for stroke even in patients with sinus rhythm. The aim of this study was to determine an association between LAA structure and function with respect to thrombus formation and differences in LAA size and velocity between patients with sinus rhythm and those with atrial fibrillation (AF). Materials and Methods: We prospectively studied LAA structure and function in 120 patients with RHD by transthoracic echocardiography and/or transesophageal echocardiography by measuring left atrial (LA) dimension, LA area, LAAmax/min, LAA ejection fraction (EF), and LAA emptying velocity. Results: Four out of 48 patients with sinus rhythm had LAA thrombus. In 72 patients with AF, 32 had LAA thrombus. Patients with LAA thrombus had lower mean LAA EF and emptying velocity both variables P-value is same (P<0.0001 and P<0.0001) Patients with LAA thrombus had increased mean LAA max and LAA min as compared to LAA max and LAA min in patients without LAA thrombus (P 0.008 for mean LAA max and P<0.0001 for LAA min respectively). Patients with AF with LAA thrombus had greater LAAmax compared to that in patients with AF without LAA thrombus (P < 0.0001). Doppler demonstrated a recognizable sawtooth LAA outflow velocity pattern in 32 of 36 (88.9%) patients with LAA thrombus versus 32 of 84 (38.1%) patients without LAA thrombus. Conclusions: We conclude that LAA contractility is reduced in RHD with LAA thrombus, and loss of both contractility and LAA dilation is associated with increased risk of thrombus formation and hence the risk of stroke.

Genetic and Clinical Predictors of Left Atrial Thrombus: A Single Center Case-Control Study.

Left atrial (LA) thrombus formation is the presumed origin of thromboembolic complications in patients with atrial fibrillation (AF). Beyond clinical risk factors, the factors causing formation of LA thrombi are not well known. In this case-control study, we analyzed clinical characteristics and genetic thrombophilia markers (factor V Leiden (FVL), prothrombin G20210A (FIIV), Tyr2561 variant of von Willebrand factor (VWF-V)) in 42 patients with AF and LA thrombus (LAT) and in 68 control patients with AF without LAT (CTR). Patients with LAT had more clinical conditions predisposing to stroke (mean CHA2DS2-VASc-score 3.4 ± 1.5 vs. 1.9 ± 1.4; P < 0.001), a higher LA volume (96 ± 32 vs. 76 ± 21 ml, P = 0.002) and lower LA appendage emptying velocity (0.21 ± 0.11vs. 0.43 ± 0.19 m/s, P < 0.001). Prevalence of FVL, FIIV and VWF-V mutations was not different, but in the subgroup of patients <65 years (y) there was a tendency for a higher incidence of VWF-V with a prevalence of 27% (LAT <65 y) vs. 7% (CTR <65 y, P = 0.066). These findings warrant further investigation of the VWF-V as a risk factor for LA thrombogenesis in younger patients.

396: Open and Shut: Acute Mitral Stenosis Secondary to Postoperative Left Atrial Thrombus Formation

396: Open and Shut: Acute Mitral Stenosis Secondary to Postoperative Left Atrial Thrombus Formation

Association of adipocytokines serum levels with left atrial thrombus formation in atrial fibrillation patients on oral anticoagulation (Alert) – A cross-sectional study

Background and aimsOral anticoagulation is effective for stroke prevention in atrial fibrillation (AF). However, strokes may still occur in high-risk individuals. We conducted a prospective trial to assess the association between adipocytokine serum levels and surrogate parameters for thromboembolic events. Methods and resultsIn this cross-sectional multicenter trial, we enrolled 189 patients with AF who were on oral anticoagulation. The primary endpoint was defined as either the presence of spontaneous echo contrast (SEC), a left atrial appendage (LAA), or a left atrial (LA) thrombus on transesophageal echocardiography. We investigated the association of adipocytokine serum levels with the combined endpoint using logistic regression analysis. Forty-eight individuals (25%) were assigned to group 1 (G1) due to the occurrence of at least one of the components of the combined endpoint (41 [21.7%] SEC, 3 [1.6%] LA thrombus, 13 [6.9%] LAA thrombus), whereas the remaining patients formed group 2 (G2). The BMI, logarithmized (loge) leptin (G1: 2.0 ± 1.3 μg/ml, G2: 2.0 ± 1.1 μg/ml, p = 0.746) and visfatin serum levels (G1: 3.4 ± 0.3 ng/ml, G2: 3.4 ± 0.5 ng/ml, p = 0.900) did not significantly differ between the groups. Conversely, logarithmized adiponectin (G1: 3.3 ± 0.6 ng/ml, G2: 3.1 ± 0.7 ng/ml, p = 0.036) and resistin levels (G1: 1.8 ± 0.5 ng/ml, G2: 1.6 ± 0.5 ng/ml, p = 0.009) were higher in patients with the primary endpoint. Multivariate logistic regression analysis using a score that combined the individual adiponectin and resistin values in each patient corroborated this association. ConclusionsOur results suggest that adiponectin and resistin may act as potential biomarkers to identify individuals with AF who are at high thromboembolic risk.

A pro-thrombotic left atrial haemodynamic profile is present in older individuals with cardiovascular risk factors even without atrial fibrillation

Abstract Background Atrial fibrillation (AF), by inducing left atrial (LA) stasis and thrombus formation, is a major cause of ischaemic embolic stroke. However, up to 25% of embolic strokes occur in the absence of AF or any other identifiable mechanism. We hypothesised that exposure to risk factors leads to a prothrombotic LA haemodynamic profile, with a consequent risk of thrombus formation and embolic stroke even in sinus rhythm (SR). Purpose To quantify the relative effects of AF and risk factors on LA function and haemodynamics in three groups: (1) patients with persistent AF before and after cardioversion, (2) patients in SR with no history of AF who were matched to AF patients for stroke risk, and (3) healthy controls. Methods Ninety-five participants were recruited: 37 AF patients scheduled for cardioversion [median CHA2DS2-VASc = 2 (1.5–3.5); median age 69 years], 35 matched non-AF patients [median CHA2DS2-VASc 3 (2.0–4.0); median age 69 years], and 23 healthy subjects [median CHA2DS2-VASc 0 (0–0); median age 33 years]. Advanced cardiovascular MRI was used to assess LA function and 4D flow. Results Patients with persistent AF displayed significantly lower LA emptying fraction (LAEF), reservoir strain, and peak blood flow velocities compared to both control groups in SR, as well as profound alterations in atrial blood flow patterns and vortex volume ratio (all p&amp;lt;0.001 vs both control groups). In the 65% of patients who were in SR at ≥4 weeks post cardioversion, all LA parameters were significantly improved (all paired p&amp;lt;0.001 vs baseline scan in AF; red vs blue in Figure 1), but LA haemodynamics were now no longer different from those in matched non-AF patients (all p=ns; blue vs green in Figure 1 C-D). However, both AF patients cardioverted to SR and matched non-AF patients had significantly impaired LA function (LA EF and LA reservoir strain) and LA haemodynamics (lower peak velocity and higher vortex volume ratio), compared to heathy controls (all p&amp;lt;0.01; blue/green vs grey in Figure 1). Conclusions We found evidence of a gradient of LA haemodynamic dysfunction, where the most marked phenotype was seen in patients scanned in AF, but with significant abnormalities remaining after restoration of SR in AF patients, and intriguingly, also present to a similar degree in matched non-AF patients. Advanced atrial imaging offers the potential to select patients with an adverse pathophysiological substrate directly predisposing to LA thrombus formation for future clinical trials of anticoagulation in SR. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): NIHR Oxford Biomedical Research Centre

Consideration of non-valvular atrial fibrillation with left atrial appendage thrombus formation despite under appropriate oral anticoagulation therapy

Abstract Background Atrial fibrillation (AF) is the most frequently sustained cardiac arrhythmia, with a prevalence of about 2–3% in the general population. In accordance with CHADS2 or CHA2DS2-VASc score, appropriate oral anticoagulation therapy such as warfarin or direct oral anticoagulants (DOAC) significantly reduced the risk of thromboembolic events. However, left atrial (LA) thrombus can be detected in the LA appendage (LAA) in AF patients despite appropriate oral anticoagulation therapy. Purpose Our purpose was to investigate the associated factors of LAA thrombus formation in non-valvular atrial fibrillation (NVAF) patients despite under appropriate oral anticoagulation therapy. Methods We retrospectively studied consecutive 286 NVAF patients for scheduled catheter ablation or electrical cardioversion for AF in our institution between February 2017 and September 2019. Mean age was 67.1±9.4 years, 79 patients (29.5%) were female, and 140 (52.2%) were paroxysmal AF. All patients underwent transthoracic and transesophageal echocardiography before catheter ablation or electrical cardioversion. All patients received appropriate oral anticoagulation therapy including warfarin or DOAC for at least 3 weeks prior to transesophageal echocardiography based on the current guidelines. LAA thrombus was defined as an echodense intracavitary mass distinct from the underlying endocardium and not caused by pectinate muscles by at least three senior echocardiologists. Results Of 286 NVAF patients with under appropriate oral anticoagulation therapy, LAA thrombus was observed in 9 patients (3.3%). Univariate logistic regression analysis showed that age, paroxysmal AF, CHADS2 score ≥3, left ventricular end-diastolic volume index (LVEDVI), left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI), LA volume index (LAVI), mitral inflow E and mitral e' annular velocities ratio (E/e'), and LAA flow were associated with LAA thrombus formation. It was noteworthy that multivariate logistic regression analysis showed that LAA flow was independent predictor of LAA thrombus (OR: 0.72, 95% CI: 0.59–0.89, p&amp;lt;0.005) as well as LVEF. Furthermore, receiver operating characteristic (ROC) curve analysis identified the optimal cutoff value of LAA flow for predicting LAA thrombus as ≤15cm/s, with a sensitivity of 88%, specificity of 93%, and area under the curve (AUC) of 0.95. Conclusions LAA flow was strongly associated with LAA thrombus formation even in NVAF patients with appropriate oral anticoagulation therapy. According to our findings, further strengthen of oral anticoagulation therapy or percutaneous transcatheter closure of the LAA may be considered in NVAF patients with appropriate oral anticoagulation therapy but low LAA flow, especially &amp;lt;15cm/s. Funding Acknowledgement Type of funding source: None

Left atrial thrombus formation within a few days of hospitalization in semi-acute ischemic heart disease despite no atrial fibrillation and mitral stenosis: a case report

BackgroundCurrently, the occurrence of left atrial thrombus despite the provision of heparinization within a few days of hospitalization without atrial fibrillation (AF) and mitral stenosis (MS) is rarely reported.Case presentationA 71-year-old woman presented with chest discomfort and dyspnea. Examination revealed ST elevation with sinus rhythm, congestive heart failure, and moderate mitral regurgitation (MR) by transthoracic echocardiography (TTE). Diuretics, a coronary vasodilator, and unfractionated heparin (15,000 units/day) were administered. Four days after hospitalization, her C-reactive protein level had increased; therefore, TTE was repeated, revealing a thrombus in the left atrial appendage, which was probably affected by heparin resistance because of low antithrombin (49%). On day 5, the patient underwent emergency removal of the thrombus, mitral valve replacement, and coronary artery bypass.ConclusionPatients can exhibit low left ventricular contractility, even sinus rhythm without MS. Thus, TTE and subsequent coagulation tests including antithrombin must be performed to prevent thrombus.

Mitigation of Late Cardiac Toxicity following Radiotherapy through Abrogation of cGAS/STING-dependent Interferon (IFN)

The pathogenesis of radiation (XRT) induced cardiac toxicity remains poorly understood. We sought to identify the molecular mechanisms of late cardiac toxicity using a mouse model with goal of elucidating potential therapeutic targets. Protocols were approved by our institution’s animal care and use committee. Cardiac XRT was delivered to adult wild type C57BL/6 mice aged 8-12 weeks via a precision small animal irradiator (X-Rad 225Cx). Principal cardiac tissues were acutely harvested and enzymatically isolated into cell type specific populations and analyzed by RNAseq and quantitative RT-PCR. Subsequent studies were carried out using Cgas-/-, Tmem173-/-, Ifnar-/-, and Mavs-/- strains (Jackson Laboratories). Acutely harvested heart tissues following survival studies were examined by histopathologic evaluation. Statistical analyses were carried out using t-test with multiple comparison adjustment where appropriate, and log-rank method for survival analysis. RNAseq analysis of cardiac fibroblasts, myocytes and endothelium after cardiac XRT with 12 Gy revealed strong activation of Irf7, an interferon activating transcription factor, in fibroblasts (p < 10-78) and to a lesser degree in myocytes one month after XRT, but not in endothelial cells. GSEA analysis of all upregulated genes 28 days after XRT revealed enrichment for multiple Ifn transcription factors in fibroblasts (p < 10-21), but not in endothelium. Because radiation might elicit specific damage associated molecular pattern (DAMP) signaling, we hypothesized that this Ifn signaling resulted from cGAS/STING activation following DNA damage. Indeed, RT-PCR for Irf7 in cardiac fibroblasts from wild-type and Mavs-/- (which are deficient in RNA mediated DAMP recognition) mice showed strong activation (p < 0.001 compared to sham XRT), but Cgas-/- animals lacked this response (p = NS compared to sham XRT, p < 0.001 compared to wild-type and Mavs-/- after XRT). Cgas-/- (HR = 0.40, p = 0.034) and Tmem173-/- (HR = 0.15, p = 0.002) animals had significantly improved survival after cardiac XRT as compared to wild-type mice, while Ifnar-/- animals showed a trend for improvement as well (HR = 0.47, p = 0.094). Histopathologic analysis of cardiac tissues at time of death revealed consistent widespread atrial and ventricular mural thrombus formation and cardiomyocyte atrophy in irradiated wild-type animals, but markedly reduced in Tmem173-/- counterparts. Our system establishes a contemporary, genetically defined mouse model of XRT-induced cardiac toxicity. In doing so, we find cardiac irradiation elicits cGAS/STING- (and not MAVS-) dependent, delayed, chronic interferon activation in cardiac fibroblasts. Eliminating this signaling rescues radiation induced cardiac toxicity and improves survival. Inhibitors the cGAS/STING pathway are soon to begin early stage clinical trials and may be candidate drugs for mitigation of late cardiac toxicity following radiotherapy.

The Efficacy of Non-Vitamin K Antagonist Oral Anticoagulants in the Prevention of Left Atrial Thrombus in Patients With Atrial Fibrillation Compared With Vitamin K Antagonists: A Meta-Analysis.

There is still a paucity of data on the efficacy of non-vitamin K antagonist oral anticoagulants (NOACs) in the prevention of left atrial thrombus (LAT) formation before cardioversion or catheter ablation. To assess the efficacy of NOACs in the prevention of LAT in patients with non-valvular atrial fibrillation (NVAF) compared with vitamin K antagonists (VKAs), we conducted a meta-analysis. We searched PubMed, Embase, and the Cochrane Library databases. For meta-analysis, dichotomous variables were analyzed by using the odds ratios (OR) computed using the Mantel Haenszel method (random models). All results were reported with 95% confidence intervals (CI). A total of 13 studies (one randomized controlled investigation and 12 observational studies) were included in the meta-analysis. There was no statistically significant difference between the NOACs and VKAs groups with respect to the odds of LAT/LAAT formations (OR 0.79; 95% CI: 0.52-1.21; P = .29; (I2 = 14%). NOACs were as effective as VKAs in the prevention of LAT/LAAT formation in patients with NVAF. Though patients on NOACs therapy showed a lower incidence of LAT/LAAT formation compared with VKAs, it was not significant (P = .29).

Post-Market Clinical Follow-Up With the Patent Foramen Ovale Closure Device IrisFIT (Lifetech) in Patients With Stroke, Transient Ischemic Attack, or Other Thromboembolic Events

BackgroundA patent foramen ovale (PFO) has been associated with embolic strokes and transient ischemic attacks (TIAs). Catheter closure of PFO is effective in preventing recurrent events. Residual shunts and procedure or device related complications can occur, including atrial fibrillation and thrombus formation. This study examines the initial experience with a new PFO closure device, the IrisFIT PFO-Occluder (Lifetech Scientific, Shenzhen, China). Methods95 patients with indications for PFO closure underwent percutaneous closure with the IrisFIT PFO-Occluder. The primary endpoint was the rate of accurate device placement with no/small residual shunt at 3 or 6 months follow-up. All patients underwent transoesophageal echocardiography (TEE) after 1 to 6 months. In case of a residual shunt, an additional TEE was performed after 12 months. Clinical follow-up was performed up to a mean of 33.1 ± 3.6 months. ResultsThe device was successfully implanted in 95 (100%) patients with no relevant procedural complications. At final TEE follow-up (7.6 ± 3.9 months) the effective closure rate was 96.8% with 1 moderate and 2 large residual shunts. There were 8 cases of new onset atrial fibrillation and 2 TIAs. There were no cases of device embolization or erosion. ConclusionThe IrisFIT occluder is a new PFO closure device with several advantages compared to other devices. In this small study cohort, technical success rate, closure rate and adverse event rate were comparable to other devices. The rate of new onset atrial fibrillation was higher in comparison to other studies and warrants further investigation.

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.

Management of thrombus formation after electrical isolation of the left atrial appendage in patients with atrial fibrillation.

Left atrial appendage (LAA) electrical isolation (LAAEI) in addition to pulmonary vein isolation is an emerging catheter-based therapy to treat symptomatic atrial fibrillation. Previous studies found high incidences of LAA thrombus formation after LAAEI. This study sought to analyse therapeutic strategies aiming at the resolution of LAA thrombi and prevention of thromboembolism. Left atrial appendage electrical isolation was conducted via creation of left atrial linear lesions or cryoballoon ablation. Follow-up including transoesophageal echocardiography was conducted. In patients with LAA thrombus, oral anticoagulation (OAC) was adjusted until thrombus resolution was documented. Percutaneous LAA closure (LAAC) under use of a cerebral protection device was conducted in case of medically refractory LAA thrombi. Left atrial appendage thrombus was documented in 54 of 239 analysed patients who had undergone LAAEI. Thrombus resolution was documented in 39/51 patients (72.2%) with available follow-up after adjustment of OAC. Twenty-nine patients underwent LAAC and 10 patients were kept on OAC after LAAEI. No thromboembolic events or further LAA thrombi were documented after 553 ± 443 days of follow-up in these patients. Persistent LAA thrombi despite adaption of OAC was documented in 12/51 patients. One patient remained on OAC until the end of follow-up, while LAAC with a cerebral protection device was performed in 11 patients in the presence of LAA thrombus without complications. Left atrial appendage thrombus formation is common after LAAEI. Adjustment of OAC leads to LAA thrombus resolution in most patients. Left atrial appendage closure in the presence of LAA thrombi might be a feasible option in case of failed medical treatment.

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 m2 (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.

Idiopathic dilatation of the right atrium: a not so benign entity.

Idiopathic dilatation of the right atrium is an isolated enlargement of the right atrium in the absence of other cardiac lesions. This rare anomaly has a clinical spectrum ranging from asymptomatic to heart failure or even sudden death. It can be associated with atrial arrhythmias and thrombus formation. Antiplatelet therapy is prescribed in most cases reported in the literature, and reduction plasty is indicated when there is rapid growth of the right atrium, compression of adjacent structures, or refractory arrhythmias. We report four cases of idiopathic dilatation of the right atrium diagnosed during prenatal screening. We describe the intrauterine course and management in postnatal life until early childhood.

Late left atrial appendage closure device displacement and massive thrombus formation: a case report.

Background Left atrial appendage (LAA) closure with the WATCHMAN device is an alternative to anticoagulation therapy for the prevention of stroke in selected patients with atrial fibrillation (AF). Infrequently, left atrial (LA) device-related thrombus formation occurs and it is poorly understood. Thrombus formation due to incomplete covering of the LAA is even rarer and may occur within the first few months after device implantation.Case summary Here, we present a case of a 68-year-old male patient with permanent AF, drug- and hepatitis induced liver cirrhosis (CILD Score B), and prior aortic valve replacement. The patient had a history of percutaneous LAA closure using a WATCHMAN device. He developed massive peri-device leak and thrombus arising from the space between the device and appendage cleft 2 years after implantation. Because of the high bleeding risk with a HAS-BLED score of 5 points, surgery was chosen as the therapy of choice instead of long-term anticoagulation. The patient was discharged in good clinical condition and has been scheduled for a yearly follow-up.Discussion This case emphasizes the importance of choosing appropriately sized LAA occluder devices and planning for regular post-interventional follow-ups to minimize the risk of per-device leaks and thrombi.

P1702 Libman-Sacks endocarditis of the mitral valve combined with right atrial thrombus formation

Abstract Case presentation A 46-years old female with a history of systemic lupus erythematosus (SLE) was admitted to hospital care after the manifestation of a tonic-clonic generalized seizure. Since this had been the first neurological event, a thorough diagnostic work-up was performed. CT- and MRI-imaging of the brain revealed cerebral microangiopathy and two small fresh ischemic lesions in the left frontal and temporobasal regions, respectively. While the microangiopathy could be reconciled with cerebral SLE-vasculitis, the ischemic lesions pointed to thromboembolism whose source could be potentially cardiogenic. Findings. In fact, the transesophageal echocardiogram showed a small vegetation (5x8 mm) on the posteromedial cusp of the posterior mitral leaflet (P3) with moderate regurgitation, likely to represent Libman-Sacks endocarditis and a potential source of systemic embolization. In addition, a mass of was visible protruding from the fossa ovalis into the right atrium, see figure. It represented a thrombus according to MRI which was subsequently performed. Since no interatrial passage of microbubbles occurred, the foramen ovale was unlikely to be patent and to allow for paradoxical embolism into the brain. However, the right atrial thrombus was compatible with a history of repeated deep venous thrombosis and pulmonary embolism in the recent past. Discussion This case exemplifies the combination of Libman-Sacks endocarditis on the mitral valve with right atrial thrombus formation and ensuing embolism both into the venous and arterial system. It demonstrates the importance of closely monitoring and treating coagulopathies in SLE patients which makes them prone to thrombus formation both in the systemic and pulmonary circulation. Abstract P1702 Figure.

An illustrative case of endocardial fibroelastosis and recalcitrant intracardiac thrombosis: a case report

BackgroundEndocardial Fibroelastosis is diffuse, accentuated proliferation of ventricular endocardium causing a rare form of restrictive cardiomyopathy in both children and adults. It is an incompletely understood cause of heart failure predominantly in Sub-Saharan Africa associated with high morbidity and mortality. Atrial fibrillation and thrombus formation are common accompanying complications and portend a poor prognosis. Due to rarity of the condition in the developed countries and lack of evidence based options, the optimal strategy for anticoagulation is unclear.Case presentationHerein, we describe a relatively asymptomatic patient with endocardial fibroelastosis who has been found to have atrial fibrillation and a large thrombus in the right atrium. Currently, there is no evidence-based strategy in the management of endocardial fibroelastosis-associated intracardiac thrombus. This case report illustrates a scenario by which the use of apixaban potentially benefited or prevented the thrombus formation compared with warfarin as demonstrated by imaging findings.ConclusionsThe patients with endocardial fibroelastosis are at risk of developing intracardiac thrombus due to sticky substrate lining cardiac chambers while being relatively asymptomatic. No directed therapy is known for the management of heart failure and any complications of subsequent arrhythmias. The general recommendations follow those of same conditions in other hosts. Novel oral anticoagulant agents can be considered in the treatment of atrial thrombus in the appropriate settings.

Left atrial thrombosis secondary to blunt cardiac injury in two dogs

Two dogs, victims of motor vehicle accidents, were hospitalised at our Veterinary Teaching Hospital with multiple injuries. Electrocardiographic abnormalities were observed in both dogs: case 1 showed ventricular arrhythmias, while...