Abstract 8989: Left Atrial Appendage Volume as a Predictor of Left Atrial Appendage Thrombus and Sludge in Patients With Nonvalvular Atrial Fibrillation: A Three-Dimensional Transesophageal Echocardiographic Study

Abstract

Background: Clinical and echocardiographic predictors for detecting left atrial appendage (LAA) thrombus are well characterized. However, whether the size of LAA measured by two-dimensional transesophageal echocardiography (2D-TEE) predicts the risk of thrombus formation in LAA has been the subject of much controversy.

Purpose: The aim of this study was to investigate the ability of LAA volume derived from real-time three-dimensional transesophageal echocardiography (RT3D-TEE) to predict LAA thrombus and/or sludge in patients with nonvalvular atrial fibrillation (NVAF).

Methods and Results: A total of 71 patients with NVAF lasting ≥ 1 month and without severe valvular regurgitation, who underwent 2D-TEE and RT3D-TEE, were included in the study. They were divided into two groups according to the presence of LAA thrombus and/or sludge. LAA thrombus and/or sludge were detected in 28 patients (39%). In these patients, the prevalence of LAA thrombus and that of LAA sludge were 54% and 100%, respectively. All 2D and 3D measurements of LAA were performed at ventricular end-systole.A trend was only seen for a significant correlation between LAA volume measured by RT3D-TEE and LAA area in the longitudinal section imaged (usually between 60 and 90 dgrees) by 2D-TEE (r = 0.31, p = 0.08). On multivariable analysis, LAA volume and the ratio of early transmitral flow velocity to peak early diastolic mitral annular velocity (E/e') were found to be significantly predictive of LAA thrombus and/or sludge. Conversely, LAA emptying flow velocity predicted freedom from them (Table 1). Receiver operating characteristic analysis yielded an optimal cutoff value of 14.7 cm³ for LAA volume to detect LAA thrombus and/or sludge (area under the curve 0.89). The sensitivity and specificity of this model were 79% and 89%, respectively.

Conclusion: Our data suggest that increased LAA volume measurements by RT3D-TEE can assist in the detection of LAA thrombus and/or sludge in the patients with NVAF.