Abstract WP260: The Left Atrial Appendage Morphology Improves Prediction of Appendage Stagnant Flow and Stroke Risk in Patients With Atrial Fibrillation Using a Simple Classification System

Abstract

Background and Purpose: Previously we proposed a simple classification system of the left atrial appendage (LAA) morphology, with low risk (LAA-L) defined as one lobe with an acute angle bend arising from the proximal or middle portion and high risk (LAA-H) defined as all other morphologies. We aim to determine the association between LAA morphology (using both classification systems), LAA flow velocity, and stroke rates. Methods: We analyzed consecutive patients with atrial fibrillation (AF) selected for ablation who underwent cardiac CT angiography and transesophageal echocardiogram. The primary correlates were LAA-H and non-chicken wing (NCW) LAA morphology. The primary outcome was the composite endpoint of history of ischemic stroke/TIA or non-lacunar infarct on neuroimaging. Adjusting for CHADS2Vasc score, multivariable models were used to determine associations between LAA morphology and composite outcomes. Results: We identified 379 patients; the primary endpoint occurred in 32/379 patients (8.4%). LAA-H (adjusted OR 3.63, 95% CI 1.44-9.14) and NCW LAA morphology (adjusted OR 2.52, 95% CI 1.15-5.53) were associated with the primary endpoint. LAA flow velocity ≤20 cm/s was more common in LAA-H vs. LAA-L (9.6% vs. 2.8%, p = 0.019), but not in NCW vs. CW LAA morphology (9.7% vs. 3.7%, p = 0.054). Conclusion: The LAA H/L morphological classification system may be superior to the current system in risk stratifying patients with AF and correlates better with impaired LAA flow dynamics.