Relation of Left Atrial Appendage Morphology Determined by Computed Tomography to Prior Stroke or to Increased Risk of Stroke in Patients With Atrial Fibrillation

Left atrial appendage (LAA) morphology is considered to be associated with ischemic stroke, non-Chicken Wing LAA morphology increases the risk of thromboembolic events. However, existing classification of LAA morphology remains not well quantifiable and therefore may leave room for substantial subjective interpretation. This study aimed to assess interobserver and intraobserver agreements in LAA morphology and its real value in stroke prediction. A total of 2,264 atrial fibrillation patients who underwent computed tomography to explore the LAA anatomy were enrolled. All computed tomography images were given to 3 reviewers to judge the LAA morphology independently. A consensus between all 3 reviewers was only reached in 655 cases (28.9%). In which, 86 patients had previous stroke. Poor intraobserver consistency was observed between 2 times of reading in all the 3 reviewers (Kappa = 0.368, p = 0.014; Kappa = 0.350, p = 0.014; Kappa = 0.333, p = 0.015). Multivariate analysis showed that persistent atrial fibrillation (odds ratio [OR] 1.679; 95% confidence interval [CI] 1.031 to 2.736; p = 0.037), female gender (OR 1.761; 95% CI 1.037 to 2.994; p = 0.036) and age (OR 1.029; 95% CI 1.004 to 1.056; p = 0.025) were associated with previous stroke. LAA morphology was not associated with previous stroke and non-Chicken Wing LAA morphology did not increase the risk of stroke (OR 1.392; 95% CI 0.847 to 2.288; p = 0.192). In conclusion, high interobserver and intraobserver variabilities suggested that existing classification of LAA morphology was unreliable, the interpretation of the relation between LAA morphology and stroke needs caution.