Prediction of low left atrial appendage velocity from echocardiographic left atrial function parameters in patients with atrial fibrillation undergoing catheter ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Decreased left atrial appendage velocity (LAAV) measured by transesophageal echocardiography is considered a significant risk factor for the presence of thrombus in both the left atrium (LA) and left atrial appendage (LAA). Purpose The aim of the study was to assess the role of echocardiographic LA function parameters in predicting low left atrial appendage velocity (LAAV) in patients with persistent atrial fibrillation (AF) undergoing catheter ablation. Methods We prospectively enrolled consecutive patients with persistent AF undergoing transesophageal echocardiography (TEE) directly before first AF ablation in 2019–2022. All patients underwent conventional two-dimensional (2D) echocardiography and 2D speckle tracking echocardiography on the day of ablation. Patients were divided into two groups according to the presence or absence of decreased LAAV≤25cm/s at TEE. Results Out of total 150 patients enrolled in the study, 29.3% (n=44) had a reduced LAAV ≤25cm/s. Patients with decreased LAAV value exhibited significantly lower left atrial reservoir and conduit strain (LASr and LAScd) (p<0.001 for both); LA emptying fraction (p<0.001) and average e’ value (p<0.001). At the same time, this group presented higher LA stiffness index (LASI) (defined as E/e' ratio/LASr) (p<0.001); LA and right atrial area (p = 0.002 and 0.004 respectively); LA volume index (p<0.001) and E/e’ ratio (p<0.001). In multivariable logistic regression analysis only LASI and LAVI remained significant predictors of the lower LAAV (odds ratio (OR) for LASI 3.065, 95% confidence interval(CI) 1.415–6.639, p<0.001; for LAVI OR 1.05 (1.011–1.091). The diagnostic accuracy of these two parameters in predicting low LAAV value calculated as the area under receiver operating characteristic curves (ROC) were 0.809 (95% CI 0.726–0.892) for LASI and 0.755 (CI 0.676–0.835) for LAVI. A ROC analysis found a LASI threshold of 1.6 with 64% sensitivity and 90% specificity and LAVI threshold of 44.47ml/m2 with 91% sensitivity and 53% specificity in predicting reduced LAAV defined as ≤ 25cm/s. Conclusions Among all noninvasive parameters assessed by conventional 2D and 2D speckle tracking echocardiography, LASI and LAVI were found to be the best predictors of reduced LAAV in patients with persistent non-valvular AF undergoing TEE before catheter ablation, with good sensitivity and specificity.