Background: Left atrial appendage (LAA) occlusion is an established therapy for patients with atrial fibrillation that are anticoagulant ineligible at high risk for stroke. Device sizing for this procedure is usually based upon measurements performed during TEE. Preliminary data suggested that measures performed intraprocedurally during general anesthesia (GA) are not identical to those performed without GA potentially contributing to device misizing. We aimed to compare measures of images obtained from a preintervention study with those obtained intraprocedurally during GA.
Methods: Using images obtained in 63 patients undergoing LAA occlusion, post hoc measurements were performed in three distinct angles 0, 45 and 90 degrees. Measurements of the ostium and the landing zone (a site 1 cm deep of the ostium) were performed as appropriate for sizing for the Amplatzer Cardiac Plug. Accuracy and precision assessments were performed between the studies as well as correlations with hemodynamic and demographic variables.
Results: No significant difference was detectable in the device landing zone diameters between the two studies. However, measures of the ostium were found to be smaller during the intra-procedural studies particularly at 45° (23.2+4.8 vs 23.6+5.3 mm; p=0.001) and 90° (22.8+4.5 vs 23.6+4.4 mm p=0.004). Eccentricity index (longest/shortest axes) was significantly larger pre-procedurally for both LZ (1.22+0.21 vs 1.13+0.14 p=0.001) and ostium (1.21+0.15 vs 1.16+0.16 p=0.004). Negative correlation between blood pressure and ostial differences at angulation 90° were found (R spearman -0.35 to -0.42 p<0.05).
Conclusion: A significant morphological change of the LAA was demonstrated to occur during TEE studies performed during GA. The LAA ostium appears to be more sensitive to the hemodynamic changes with GA. These changes should be taken into consideration when sizing is exclusively based on intraprocedural measures, to avoid undersizing and a potentially increased embolization risk.
