Comparison of left atrial appendage parameters using computed tomography vs. transesophageal echocardiography for watchman device implantation: a systematic review & meta-analysis

Background: Inaccurate sizing of left atrial appendage (LAA) occlusion devices is associated with increased stroke risk. We compared the LAA size to implant the Watchman device assessed by computed tomography (CT) to transesophageal echocardiography (TEE). Methods: Databases were searched to identify studies comparing LAA anatomical measurements and procedural outcomes across imaging modalities for the Watchman device implantation. Results: Seven studies were included in the analysis (242 patients on TEE, and 232 on CT). The LAA orifice was larger when sized with CT compared to TEE (CT mean vs TEE SMD 0.30 mm, 95%CI 0.09–0.51 mm, P < 0.01; and CT max vs TEE SMD 0.69 mm, 95%CI 0.51–0.87 mm, P < 0.001). Additionally, CT, including CT-based 3-dimensional models, had higher odds of predicting correct device size compared to TEE (OR 1.64; 95%CI 1.05–2.56; P = 0.03). CT resulted in a lower fluoroscopy time vs TEE (SMD −0.78 min, 95% CI −1.39 to −0.18, P = 0.012). No significant differences were found in device clinical outcomes. Conclusion: Compared to TEE, CT resulted in larger LAA orifice measurements, improved odds of predicting correct device size, and reduced fluoroscopy time in patients undergoing LAA occlusion with the Watchman device. There were no significant differences in other procedural outcomes.