Abstract 19576: Left Atrial Delayed Computed Tomography Angiography Protocol Markedly Reduces Need for TEEs Prior to Atrial Fibrillation Ablation

Introduction: Delayed computed tomography angiography (CTA) imaging of the left atrial appendage (LAA) has a high negative predictive value (NPV) for LAA thrombus. Many transesophageal echocardiograms (TEEs) are performed to exclude LAA thrombus prior to left atrial ablation for atrial fibrillation and flutter (AF). Because reducing the need for semi-invasive TEEs prior to AF ablation would be beneficial, we evaluated a pre-ablation LAA evaluation strategy based on CTA (with TEEs performed only for abnormal CTA findings). Methods: We tracked outcomes of 124 consecutive AF ablation patients with preablation CTA with delayed LAA imaging (high-pitched acquisition mode, Siemens FLASH, ref mAs 200, ref Kv 120kVp, care kV mode). In Group 1 (CTA-guided, CHADS2 scores ≤ 3, no prior CVA), TEEs were performed only if LAA filling defects were found on CTA. All Group 2 patients (controls) had TEEs regardless of CTA results. In Group 1, negative CTA findings were confirmed by intracardiac echocardiography (ICE) during ablation. Results: The cohort was 61.4 ± 11.6 years old and 27.4% female. 30.7% had persistent arrhythmia, and CHADS2 scores ranged from 0-4. Only 3.3% of Group 1 patients (n=60) required TEEs, while 81.3% of Group 2 patients (n=64) underwent TEEs (Figure). There were no strokes or TIAs in either group within 30 days of ablation. After adjustment for CHADS2 score and persistent arrhythmia, Group 1 was much less likely (OR 0.006, p Conclusions: This integrated pre-ablation imaging strategy safely and dramatically reduced the need for TEEs prior to AF ablation with a low radiation dose from the CTA and no increased risk of thromboembolic events.