Left atrial appendage 2D-strain assessed by transesophageal echocardiography is associated with thromboembolic risk in patients with atrial fibrillation

OBJECTIVE
The aim of this study was to determine the relationship of left atrial appendage (LAA) mechanics assessed using 2-dimensional (2D)-strain analysis of the gray scale images obtained during transesophageal echocardiography (TEE) to the conventional LAA functional parameters, CHA2DS2-VASc score, and the presence of spontaneous echo contrast (SEC) and/or LAA thrombus in patients with non-valvular atrial fibrillation (AF).

METHODS
The study included 126 patients with AF and 30 controls with a sinus rhythm who were referred for TEE. The global, medial, lateral and apical LAA longitudinal 2D-strain of all patients and the CHA2DS2-VASc score of AF patients were evaluated.

RESULTS
The global, medial, lateral, and apical LAA longitudinal 2D-strain results of AF patients were significantly lower than those of the controls and revealed moderate but significant correlations with LAA flow velocity and LAA area change. Patients with a CHA2DS2-VASc score of 0 or 1 had the highest LAA 2D-strain values and the results revealed that the LAAemptying velocity and LAA lateral and medial 2D-strain values were independent correlates of CHA2DS2-VASc score. SEC was detected in 84 patients, of whom, 42 had dense SEC and 27 had thrombus in the LAA. Multivariate analysis indicated that LAA emptying velocity, LAA area change, and LAA medial 2D-strain were independently associated with the presence of dense SEC/thrombus. In ROC analysis, cut-off values for global, medial, apical, and lateral 2D-strain for the presence of dense SEC/ thrombus were 6.0% p=0.011), 8.0% (p=0.032), 6.0% (p=0.033), and 5.4% (p=0.004), respectively.

CONCLUSION
Global and regional LAA mechanics were significantly related to conventional LAA functional parameters and to the presence of LAA-dense SEC/thrombus in patients with AF and may be useful as complementary data for estimating future thromboembolism.