CHANGES IN LEFT ATRIAL APPENDAGE DIMENSIONS FOLLOWING VOLUME LOADING DURING PERCUTANEOUS CLOSURE

Abstract

Patients with atrial fibrillation who are at high risk of stroke by conventional risk criteria are often at higher risk of bleeding. Percutaneous left atrial appendage (LAA) closure has been shown to be non-inferior to warfarin. Choosing the appropriate device size relies on accurate measurements of LAA dimensions prior to implantation. Pre-implantation measurements are typically performed using trans-esophageal echocardiogram (TEE). Patients are usually fasting for these procedures, and may be volume deplete. The purpose of this observational study was to evaluate the change in LAA dimensions following volume loading. Eight consecutive patients who underwent percutaneous LAA closure (with either the Amplatzer Cardiac Plug or Watchman devices) were included in this study. The patients were fasting prior to the procedure as per standard protocol. After induction with general anesthesia, a TEE probe was inserted. Measurements of the LAA orifice and depth were taken at 90 degrees and 135 degrees. After initial measurements were complete, the patients were given a bolus of approximately one litre of Normal Saline. Measurements of the LAA were repeated after the bolus was complete. The average age of the patients were 75 ± 9.1 years, and the mean CHADS2 score was 3.3 ± 1.4. All patients had underlying atrial fibrillation with contraindications to anticoagulation. The average dimension of the LAA at 90 degrees was 20.9 ± 2.6 mm, and at 135 degrees was 20.3 ± 3.0 mm. Following volume loading, the averaged dimension increased to 22.9 ± 3.0 mm at 90 degrees, and 22.3 ± 2.0 mm at 135 degrees. The depth of the LAA at baseline was 24.3 ± 4.8 mm, and at 135 degrees was 20.9 ± 4.1 mm. After volume loading, the depth of the LAA was26.4 ± 3.5 mm at 90 degrees, and 24.4 ± 3.3 mm at 135 degrees. The average increase in width was 2.0 mm (p=0.0004), and increase in depth was 2.8 mm (p=0.0013). All patients had mean left atrial pressure >15mmHg after volume loading. The dimensions of the LAA increased with normal saline volume loading during percutaneous LAA closure. Given the importance of pre-implantation measurements for accurate device sizing and the increase in LAA dimensions observed in our study with volume loading, operators should ensure that patients are adequately volume loaded prior to making final measurements and device sizing choices during percutaneous LAA closure.