Use of echocardiography in stratifying the risk of AF-related stroke: comparison of left atrial and left atrial appendage mechanical function

Background Left atrial (LA) and left atrial appendage (LAA) mechanical dysfunction have been shown to be associated to atrial fibrillation (AF)-related stroke. However, the contribution of LA and LAA mechanical function in the mechanism of strokes related to AF has not been fully compared. We aimed to investigate the association of LA and LAA mechanics with stroke and to compare their incremental values in improving risk stratification in AF-related stroke. Methods A total of 572 consecutive patients with AF (median age 65 years, 67% male, 49% persistent AF) who underwent echocardiography before catheter ablation were prospectively included. Speckle-tracking echocardiography was used to measure LA and LAA global longitudinal strain (GLS) and mechanical dispersions (MD). MD were defined as the standard deviation (SD) of time to peak positive strain corrected by the R-R interval. Results Patients with a history of stroke or transient ischemic attack (TIA) (n = 81) showed significantly higher LA and LAA MD than those without (n = 491) (LA MD,11±3% vs 8±3%; LAA MD,13±4% vs 8±3%, both P < 0.01). LA and LAA MD were independently associated with stroke/TIA in three multivariate models (Odds ratio, 1.44-1.46, 1.49-1.51, respectively, both P < 0.01), with an incremental improvement over clinical and conventional echocardiographic parameters. The best fit cut-offs for LA MD (11.0%) and LAA MD (>9.9%) had sensitivity and specificity of 53.1%, 86.4% and 87.7%,66.6%, respectively. In contrast, LA and LA GLS didn’t remain independent contributors for identifying strokes. Conclusions Higher LA and LAA mechanical dispersion based on speckle tracking echocardiography are independently associated with stroke/TIA in AF patients, incremental to clinical risk factors and conventional echocardiographic parameters, and superior to LA GLS and LAA GLS. logo