These findings suggest that the use of TTE-derived parameters may be a valuable way of refining the available clinical risk schemes for the detection of surrogate markers of stroke. Follow-up studies using clinical endpoints will be necessary to confirm this hypothesis.

BackgroundLeft atrial (LA) size is a predictor of cardiovascular outcomes in patients in sinus rhythm, whereas conflicting results have been found in atrial fibrillation (AF). This study aims to: (1) Evaluate the accuracy of LA size to identify surrogate markers of an increased thromboembolic risk in patients with AF; (2) Assess the best method to evaluate LA size in this setting.MethodsCross-sectional study enrolling 500 consecutive patients undergoing transthoracic and transesophageal echocardiography evaluation during a non-valvular AF episode. LA size was measured on transthoracic echocardiography using several methods: anteroposterior diameter, area in four-chamber view, and volumes by the ellipsoid, single- and biplane area-length formulas. Surrogate markers of stroke were evaluated by transesophageal echocardiography: LA appendage (LAA) thrombus, LAA low flow velocities, dense spontaneous echocardiographic contrast and LA abnormality.ResultsExcept for non-indexed anteroposterior diameter, increased LA size quantified by all the other methods showed a moderate to high discriminatory power to identify all the surrogate markers of stroke. A higher accuracy was observed for indexed LA area in four-chamber view (LAA thrombus: AUC = 0.708, CI95% 0.644- 0.772, p<0.001; LAA low flow velocities: AUC = 0.733, CI95% 0.674- 0.793, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.693, CI95% 0.638- 0.748, p<0.001; LA abnormality: AUC = 0.705, CI95% 0.654-0.755, p<0.001), indexed single-plane area-length volume (LAA thrombus: AUC = 0.701, CI95% 0.633-0.770, p<0.001; LAA low flow velocities: AUC = 0.726, CI95% 0.660-0.792, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.673, CI95% 0.611-0.736, p<0.001; LA abnormality: AUC = 0.687, CI95% 0.629-0.744, p<0.001), and indexed biplane area-length volume (LAA thrombus: AUC = 0.707, CI95% 0.626-0.788, p<0.001; LAA low flow velocities: AUC = 0.737, CI95% 0.664-0.810, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.651, CI95% 0.578-0.724, p<0.001; LA abnormality: AUC = 0.683, CI95% 0.617-0.749, p<0.001), without significant difference between them. Indexed LA area in four-chamber view and indexed area-length volumes also were independent predictors of surrogate markers of stroke.ConclusionsLeft atrium enlargement is associated with an increased prevalence of surrogate markers of stroke in patients with non-valvular AF. Indexed LA area in four-chamber view and indexed area-length volumes displayed the strongest association.

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BackgroundMean platelet volume has been associated with stroke in patients with atrial fibrillation. However, its role as a predictor of left atrial stasis, assessed by transesophageal echocardiography, in patients with non-valvular atrial fibrillation has not yet been clarified.MethodsSingle center cross-sectional study comprising 427 patients admitted to the emergency department due to symptomatic atrial fibrillation and undergoing transesophageal echocardiogram evaluation for exclusion of left atrial appendage thrombus before cardioversion. All patients had a complete blood count performed in the 12 hours prior to transesophageal echocardiogram. Markers of left atrial stasis were sought: left atrial appendage thrombus, dense spontaneous echocardiographic contrast and low flow velocities in the left atrial appendage. The presence of at least one of the former markers of left atrial stasis was designated left atrial abnormality. Binary logistic multivariate analysis was used for obtaining models for the prediction of transesophageal echocardiogram endpoints.ResultsLeft atrial appendage thrombus was found in 12.2%, dense spontaneous echocardiographic contrast in 29.7%, low flow velocities in 15.3% and left atrial abnormality in 34.2%. Mean platelet volume (exp β = 3.41 p = 0.048) alongside with previous stroke or transient ischemic attack (exp β = 5.35 p = 0.005) and troponin I (exp β = 5.07 p = 0.041) were independent predictors of left atrial appendage thrombus. Mean platelet volume was also incorporated in the predictive models of dense spontaneous echocardiographic contrast, low flow velocities and left atrial abnormality, adding predictive value to clinical, echocardiographic and laboratory variables.ConclusionsThese findings suggest that mean platelet volume may be associated with the presence of markers of left atrial stasis, reinforcing a likely cardioembolic mechanism for its association with stroke in patients with non-valvular atrial fibrillation.

BackgroundSpeckle tracking-derived strain and strain rate are recently available parameters to assess left atrial (LA) deformation. We hypothesized that such new parameters could be of interest to evaluate the risk of LA stasis among patients with atrial fibrillation (AF).MethodsSingle-centre study enrolling all patients with non-valvular AF lasting longer than 48 hours for whom no therapeutic anticoagulation was given in the preceding 3 weeks and who were assessed through transesophageal and transthoracic echocardiogram during a 6 month time interval. LA deformation was assessed by transthoracic echocardiogram through speckle tracking analysis, whereas LA stasis parameters were sought on transesophageal echocardiogram.ResultsAmong the 82 assessed patients, LA appendage thrombi or sludge were found in 16 (19.5%). A moderate positive correlation was found between peak positive strain rate and maximum emptying velocity (r = 0.589; P <0.001) and peak positive strain rate and maximum filling velocity of the LA appendage (r = 0.651; P <0.001). Peak negative strain rate was also found to be associated with both maximum emptying velocity (r = -0.513; P <0.001) and maximum filling velocity of the LAA (r = -0.552; P <0.001). AF duration, peak negative strain rate and time-to-peak positive strain were independent predictors of LAA thrombi or sludge on multivariate analysis logistic regression. The area under the curve for the estimated probabilities using the obtained logistic regression model was 0.89 (95%CI 0.81-0.96; P <0.001).ConclusionOur findings suggest that LA mechanical dysfunction assessed through speckle tracking may be of interest to predict LA stasis in the setting of AF.

Background: It is currently unknown if the increased risk of stroke in subjects with chronic kidney disease and atrial fibrillation (AF) is due to the presence of left atrial stasis or to any other vascular or systemic conditions. Methods: This was a retrospective study of 372 subjects undergoing evaluation during an AF episode. The following markers of left atrial stasis were sought on transesophageal echocardiogram: left atrial or left atrial appendage thrombus (LAAT), dense spontaneous echocardiographic contrast (DSEC), and low flow velocities (LFV) in the left atrial appendage. Subgroup comparisons were performed according to the level of estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration equation as follows: ≥90, 45–89.9, and <45 ml/min/1.73 m². Results: LAAT was found in 11.6%, DSEC in 29.0%, and LFV in 14.9% of cases. A significant increase in the prevalence of DSEC was observed in the lower categories of eGFR: 37.8% in eGFR <45 ml/min, 30.7% in eGFR 45–89.9 ml/min, and 17.0% in eGFR ≥90 ml/min (p = 0.009; γ for trend = 0.297, p = 0.002). The same was observed when assessing left atrial abnormality, i.e. the presence of at least one of the former transesophageal echocardiogram changes. On multivariate analysis, clinical parameters from CHADS₂ (congestive heart failure, hypertension, age ≥75, diabetes mellitus and stroke) and CHA₂DS₂-VASc (age 65–74, history of vascular disease, and female gender along with the clinical variables from CHADS₂) were predictors of transesophageal echocardiogram changes and an additive predictive value was found for eGFR. Conclusions: Our results suggest an association between compromised renal function as assessed through eGFR and markers of left atrial stasis in patients with AF. The increased risk of stroke in this population may be due to thromboembolism.

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