Abstract 18983: Complex Left Atrial Appendage Morphology Increases Risk of Cryptogenic Ischemic Stroke

Introduction: A considerable proportion of embolic strokes are currently classified as being cryptogenic. Despite long term monitoring only a minority have been shown to have atrial fibrillation (AF). Thus, further investigation for an alternate source for cardioembolism is indicated for otherwise cryptogenic stroke. The role of Left Atrial Appendage (LAA) morphology in cryptogenic stroke has not been defined. We grouped non-chicken wing (cauliflower, cactus, windsock) including chicken wing with pectinated walls as complex morphology (CLA2M) and defined the rest as simple LAA morphology (SLA2M). Hypothesis: CLA2M is independently associated with cryptogenic stroke. Methods: This is a single-center, retrospective case control study of patients with and without stroke who were imaged by 2D-TEE from 2009 to 2016. A total of 114 patients were enrolled. Patients with mitral stenosis, artificial heart valves, or poor image quality were excluded. Left Atrial Appendage morphology, SLA2M vs CLA2M, was independently characterized by a pair of Cardiologists blinded to the etiology. Stroke etiology was determined using the causative classification system by a Vascular Neurologist. Results: Of the 97 subjects meeting study criteria, 45 (46.4%) had CLA2M. In multivariable regression, CLA2M significantly increased the odds of cryptogenic stroke (OR 5.00, 95%CI 1.05-23.73, p=0.043) even adjusting for age and CHADVASC score (Table). LAA orifice diameter (p=0.4), LAA depth, mean [SD](p=0.7), LAA peak filling and emptying velocity in cm/sec (p=0.3 and p= 0.9 respectively) was not significantly associated. Conclusion: CLA2M is associated with increased risk of cryptogenic strokes indicating that complex LAA morphology may be a nidus for generating thrombus and thus increased stroke risk. Further studies are indicated to understand the complex relation between CLA2M and cryptogenic stroke without atrial fibrillation and devise newer therapeutic approaches.