Background: The left atrial appendage (LAA) is the thrombi source in more than 90% of atrial fibrillation strokes. Occluding devices offer LAA elimination. Inaccurate orifice sizing may lead to utilization of more than one device per procedure, or inadequate LAA occlusion.
The purpose of this study was to compare the ability of Cardiac Computed Tomography angiography (CCTA) and Trans-Esophageal Echocardiography (TEE) in predicting LAA device size.
Methods: All subjects underwent CCTA and TEE before the procedure and TEE at the procedure. CCTA scans were performed using a 256-slice scanner (ICT Philips).
Assessed parameters included: LAA maximal and minimal diameters (mm). Using these, LAA orifice perimeter was calculated according to an accepted mathematical equation (for CCTA TEE). These values were compared with final calculated perimeter of the implanted device.
Results: This study cohort included 25 patients (17 males, average age 76 years). Two failed procedures were excluded from the comparison cohort; in them, the maximal LAA diameters on both CCTA and TEE scans were > 35 mm. In 4/23 procedures 2 devices were used. Mean perimeter at CCTA was 150 mm, at TEE before the procedure was 121 mm, at TEE at the procedure was 122. Mean device perimeter was 150 mm. The correspondence coefficients were 0.693, 0.448 and 0.403 for the CCTA, TEE at baseline and TEE at the time of the procedure, respectively.
Conclusions: The calculated LAA ostial perimeter on CCTA demonstrated the best correlation with the implanted occluder perimeter. LAA measured maximal diameter > 35 mm on both CCTA and TEE predicted procedure failure.
Thus, CCTA promises to be an important modality for LAA occluder sizing. It proved to accurately predict the appropriate occluder size. CCTA may avoid utilization of multiple devices per procedure, or identify unfavorable anatomy for LAA occluder insertion.
