Is Left Atrial Strain in Non-Valvular Atrial Fibrillation a Noninvasive Predictor of the Left Atrial Appendage Spontaneous Echo Contrast?

Background: The left atrial appendage (LAA) spontaneous echo contrast (SEC) is a surrogate marker of thrombotic state in atrial fibrillation (AF). We investigated the correlation between LA speckle-tracking parameters and the LAA SEC or thrombosis. Methods: This cross-sectional study evaluated 70 AF ablation candidates, irrespective of their rhythm. Complete 2D transthoracic and transesophageal echocardiographic examinations and LA speckle-tracking analyses were performed. Based on the presence of thrombosis and the severity of SEC in the LAA, the patients were divided into 3 groups. Results: Seventy patients (mean age=54 +/- 13.6 y; 37 men) were evaluated. Sinus rhythm was reported in 41 patients and oral anticoagulant consumption in 51. The mean CHA2DS2-VASc score was 1.8 +/- 1.4, and the mean LVEF was 51.1 +/- 7.4%. The LASr in the 2- and 4-chamber views was lower in subjects with AF rhythm (P<0.0001). Patients with LAA thrombosis and moderate-to-severe SEC, all in AF rhythm, had lower LAA velocities (P<0.0001), LASr (4-chamber view=5.2 +/- 1% vs 9 +/- 2.7% vs 20.7 +/- 8.2%; P<0.0001), LAScd (P=0.003), and mean strain rates (P<0.0001) than patients with mild or no SEC. The best correlation with the LAA SEC was found for the LASr in the 4-chamber view (r= -0.58, P<0.0001). There were no differences in the time-to-peak velocities and the time delay of the opposite walls. Conclusions: Patients in AF rhythm had remarkably lower LA strain values than those in sinus rhythm. Significantly lower LA emptying velocities and segmental and global speckle-tracking parameters were observed in patients with moderate-to-severe SEC or LAA thrombosis, and the best correlation was shown with the LASr.