229-05: Signal density gradient of left atrial appendage on computed tomography correlates with left atrial appendage flow velocity on trans-esophageal echocardiography

Abstract

Background: Cardiac contrast computed tomography (CT) is frequently performed for anatomical assessment before catheter ablation of atrial tachyarrhythmia. While the usefulness of this modality for detection of left atrial thrombus has been reported, the ability for risk stratification of thromboembolic events has not been elucidated. Methods: Total of 81 consecutive patients who underwent catheter ablation for atrial tachyarrhythmia at our institution from April 2014 to September 2015 were enrolled. Patients lacking the cardiac contrast CT or TEE data were excluded, leading to 53 patients (37 male, median age 69 years [interquartile range 62–75]) for analysis. From the CT image, the left atrial appendage [LAA] signal density gradient defined as the difference between the CT density of ostium and apex of LAA were obtained, and correlation with LAA flow velocity on TEE were analyzed. Results: In the correlation analysis, LAA signal density gradient showed significant relatively strong correlation with the LAA flow velocity (r = 0.551, P < 0.001). In multiple regression analysis, LAA signal density gradient remained to be independent predictor of LAA flow velocity, even after adjustment with other cofounders (b = 0.001, β = 0.381, P = 0.010). Conclusion: LAA signal density gradient of CT significantly correlates with LAA flow velocity of TEE in patients undergoing catheter ablation for atrial tachyarrhythmia. This variable may be used for risk stratification for future thromboembolic events in this patient population.