Safety and effects of volume loading during transesophageal echocardiography in the pre-procedural work-up for left atrial appendage closure

BACKGROUND: In patients undergoing left atrial appendage (LAA) closure, an accurate sizing of the LAA is key to optimize device sizing, procedural success and reduce complications. Previous studies have shown that intraprocedural volume loading increases LAA dimensions and improves device sizing. However, the safety and effects on LAA and device sizing of administering a fluid bolus during pre-procedural transesophageal echocardiography (TEE) are unknown. The aim of this study was to determine the safety and impact on LAA dimensions and device sizing of an intravenous (IV) fluid bolus administered during TEE in the setting of the pre-procedural work-up for LAA closure. METHODS: The study included a total of 72 patients who underwent TEE to assess suitability for LAAC and received a 500 ml IV bolus of normal saline. The LAA landing zone (LZ) and depth were measured by TEE before and after volume loading, and these measurements were used to predict the device size implanted during a subsequent percutaneous LAAC procedure. RESULTS: There were no complications associated with volume loading. The baseline mean LZ was 19.6 ± 3.6 mm at 90(o), and 20.2 ± 4.1 mm at 135(o). Following fluid bolus, the maximum diameter increased 1.5 ± 1.0 mm at 90(o) (p<0.001), and 1.3 ± 1.0 mm at 135(o) (p<0.001). The baseline mean depth of the LAA was 26.5 ± 5.5 mm at 90(o), and 23.9 ± 5.8 mm at 135(o). After fluid bolus, the mean depth increased by 1.5 ± 1.8 mm (p<0.001) and 1.6 ± 2.0 (p<0.001), at 90(o) and 135(o), respectively. Sizing based on post-bolus measurements of the LZ significantly improved the agreement with the final device size selection during the procedure in 71.0% of cases (vs. 42.0% with pre-bolus measurements). CONCLUSIONS: Volume loading during ambulatory TEE as part of the pre-procedural work-up of LAAC is safe and significantly increases LAA dimensions. This strategy may become the new standard, particularly in centers performing LAAC with no TEE guidance, as it improves LAA sizing and more accurately predicts the final device size.