Exclusion of Left Atrial Appendage Thrombus Using Single Phase Coronary Computed Tomography as Compared to Transesophageal Echocardiography in Patients Undergoing Pulmonary Vein Isolation

Background. Transesophageal echocardiography (TEE) is used for the evaluation of the presence of left atrial appendage (LAA) thrombus prior to pulmonary vein isolation (PVI), while coronary computed tomography angiography (CCTA) is used for anatomic mapping during PVI. Methods. We compared the diagnostic performance of single phase CCTA to TEE in excluding the presence of LAA thrombus in patients undergoing PVI in 172 subjects performed during index hospitalization. Results. The mean age was years, a median CHADS2 score of 1 [IQR25,75 0,1, range 0–3] and a mean periprocedural INR of . The prevalence of an LAA filling defect on single phase CCTA was 9.3% (6/183) and on TEE was 1.2% (2/183). Sensitivity, specificity, positive predictive value, and negative predictive value were 100% (95% CI, 19.8–100%), 91.8% (95% CI, 94–99%), 12.5% (95% CI, 60–76%), and 91.8% (95% CI, 97–100%) for the detection of LAA filling defect, respectively. Conclusion. Given the utility of a preprocedural single phase CCTA for the performance of PVI, the absence of a filling defect negates the need for a subsequent TEE as an adjunct for exclusion of LAA thrombus. 1. Background Transesophageal echocardiography (TEE) historically is the gold standard for the evaluation of the presence of left atrial appendage thrombus in patients with atrial fibrillation. In a recent study, evaluating spontaneous echo contrast (SEC), left atrial (LA) appendage velocities, and aortic plaque TEE variables in the absence of definitive left atrial thrombus (LA) in five hundred and seventy-nine consecutive patients undergoing pulmonary vein isolation (PVI), all variables with the exception of LA thrombus were not predictive of the occurrence of stroke within thirty days on anticoagulation with Vitamin K Antagonist. [1]. This is in contrast to a smaller study of 156 consecutive patients, where functional parameters to include the emptying velocities and SEC were predictive of the presence of LAA thrombus on TEE [2]. Advances in coronary computed tomography angiography (CCTA) imaging have led to high spatial and temporal resolution. CCTA is emerging as a potential screening tool for exclusion of LAA thrombus [3]. Patients routinely undergo TEE before pulmonary vein isolation (PVI) to exclude thrombus and to assess pulmonary venous anatomy and single phase CCTA for incorporation into nonfluoroscopic anatomic mapping systems used during PVI [3]. A number of studies have assessed their application for determining the presence or absence of thrombus. Romero et al. completed a meta-analysis of detection of LAA