Geometry of left atrial appendage assessed with multi-detector row computed tomography: implications for transcatheter closure devices

Abstract

Purpose: Transcatheter left atrial appendage (LAA) occlusion is a feasible alternative to long-term anticoagulation therapy for stroke prevention in patients with atrial fibrillation (AF). Currently, implantation of the Amplatzer Cardiac Plug (ACP) and the Watchman device is planned and guided by echocardiography and fluoroscopy. However, the implications of sizing the LAA with 3D imaging techniques, such as multi-detector row computed tomography (MDCT) are unknown. Methods: 197 patients who underwent MDCT prior to AF ablation were evaluated. Measured indices included key parameters that define procedural feasibility: the maximal cross-sectional diameter and the perimeter of the LAA at level of the ostium and at 10 mm depth, the maximal LAA-length and the LAA diameter on the MDCT plane that resembles the transesophageal echocardiography (TEE) view. Following manufacturer's recommendations the feasibility for each device was assessed based on the maximal diameter, perimeter and the TEE-like MDCT LAA-diameter. Results: The mean maximal diameters of ostium and at 10 mm depth were 28.7±4.4 and 24.6±4.5 mm, resulting in a feasibility of 80.7% for the Watchman, of 84.8% for the ACP and of 91.4% for either one of the two. The mean perimeters of ostium and at 10 mm depth were 79.1±12.2 and 69.8±11.6 mm, resulting in a feasibility of 87.8% for the Watchman, of 92.9% for the ACP and of 96.4% for either one of the two. The mean TEE-like MDCT LAA-diameter was 22.0±3.3 mm, resulting in a feasibility of 93.9% for the Watchman, of 97% for the ACP and of 99.0% for either one of the two (Figure). ![Figure][1] Feasibility Histogram LAA occluders Conclusion: The maximal cross-sectional diameter, perimeter and the TEE-like LAA-diameter measured with MDCT would lead to a respective 91.4%, 96.4% and 99.0% feasibility for transcatheter LAA-occlusion. [1]: pending:yes