Comparison of left atrial and atrial appendage mechanics to stratify the risk of left atrial/atrial appendage stasis in patients with non-valvular atrial fibrillation

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Left atrial appendage (LAA) and left atrial (LA) dysfunction are associated with the presence of thrombus and spontaneous echo contrast (SEC) within LAA. However, the role of LAA mechanical dispersion (MD) in contributing to thrombogenesis has not been fully addressed and compared with LA MD or LA/LAA GLS. We sought to investigate the relationship of LAA MD with LAA dense SEC or thrombus, and to compare its additional value with other LA/LAA mechanical parameters in patients with nonvalvular atrial fibrillation (AF). Methods We conducted a cross-sectional study of 493 consecutive patients with AF (median age 65, male 66.9%) who underwent echocardiography prior to catheter ablation. Of these, 70(14.2%) patients had dense SEC or thrombus in LAA. We measured the LAA and LA longitudinal strain using speckle-tracking echocardiography (STE). LAA MD and LA MD was defined as the standard deviation (SD) of time to peak positive strain corrected by the R-R interval. Results Patients with LAA dense SEC/thrombus (n=70) had significantly higher LAA MD (median 14.20% (11.60%,16.80%) vs 9.35 % (6.23%,12.07%)) than controls (n = 423). Areas under the receiver-operating curve (AUC) for CHA2DS2-VASc score plus LAA MD, LAA GLS or LA GLS were comparable (0.843,0.830 and 0.809) and superior to that combined with LA MD (0.762, p<0.01). Multivariable analysis showed that LAA MD was an independent determinant of LAA dense SEC/thrombus in four different models (Odds ratio, 1.23-1.24; P < 0.001), and provided additional diagnostic value over clinical and standard echocardiographic parameters. Whereas LA MD was not significantly associated with LAA dense SEC/thrombus and had no incremental predictive value. Conclusion LAA mechanical dispersion provided incremental information over conventional risk factors in the identification of LAA dense SEC or thrombus in AF patients and is superior to LA mechanical dispersion.