Mean platelet volume is associated with the presence of left atrial stasis in patients with non-valvular atrial fibrillation.

BACKGROUND: Mean 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. METHODS: Single 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. RESULTS: Left 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 ß = 3.41 p = 0.048) alongside with previous stroke or transient ischemic attack (exp ß = 5.35 p = 0.005) and troponin I (exp ß = 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. CONCLUSIONS: These 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.

Mean corpuscular volume and red cell distribution width as predictors of left atrial stasis in patients with non-valvular atrial fibrillation.

BACKGROUND: The role of erythrocyte indexes for the prediction of left atrial stasis, assessed by transesophageal echocardiography in patients with non-valvular atrial fibrillation, has not been previously clarified. METHODS: Single center cross-sectional study comprising 247 consecutive patients admitted to the emergency department due to symptomatic atrial fibrillation and undergoing transesophageal echocardiogram evaluation for exclusion of left atrial appendage thrombus (LAAT) before cardioversion. All patients had a complete blood count performed up to 12 hours prior to the transesophageal echocardiogram. Markers of left atrial stasis were sought: LAAT, dense spontaneous echocardiographic contrast (DSEC) and low flow velocities (LFV) in the left atrial appendage. Erythrocyte indexes' accuracy for detecting transesophageal echocardiogram changes was evaluated through receiver operating curve analysis. Binary logistic multivariate analysis, using solely erythrocyte indexes and in combination with other variables (i.e. CHADS2, CHA2DS2VASc classifications and left ventricle ejection fraction), was used for transesophageal echocardiogram endpoints prediction. RESULTS: LAAT was found in 8.5%, DSEC in 26.1% and LFV in 12.1%. Mean corpuscular volume and red cell distribution width were independent predictors of LAAT and DSEC. Despite adding incremental predictive value to each other, when clinical risk factors from CHADS2 and CHA2DS2VASc classifications and left ventricle ejection fraction were added to the models, only mean corpuscular volume remained an independent predictor of LAAT and DSEC. CONCLUSIONS: These findings suggest that mean corpuscular volume and red cell distribution width may be linked to left atrial stasis markers.

Cardioversion safety in patients with nonvalvular atrial fibrillation: which patients can be spared transesophageal echocardiography?

The objective of this study was to derive and test a score that can accurately predict the presence of left atrial or left atrial appendage thrombus (LAAT) in order to identify patients with nonvalvular atrial fibrillation who can be spared transesophageal echocardiogram (TEE) and safely cardioverted. This cross-sectional observational study including 180 individuals (37.2% women) undergoing clinical, echocardiographic and laboratory evaluation (including cardiac troponin I and C reactive protein; CRP) during an atrial fibrillation episode. LAAT was sought on TEE and predictors of this transesophageal echocardiographic finding were assessed. Based on predictors of LAAT (CRP, atrial volume, troponin, episode duration and stroke or embolism) we derived the CATES score and tested its accuracy through receiver operating curve analysis. LAAT was found in 9.4%. CHADS2 and CHA2DS2-VASc had a modest performance in predicting these changes displaying a 0.620 (c-statistic) in average. Using CATES score displayed a higher area under the curve value 0.816 for LAAT. No patients with LAAT were observed in patients with CATES scores ranging from '0' to '2', which corresponded to 49.4% (n = 89) of the sample. We developed a score that presented a very good accuracy for the detection of LAAT in our sample. Further studies in other populations, such as with bigger dimensions, are needed to validate this score and confirm its capability of selecting a very low risk group of patients that can be spared transesophageal echocardiography.