PO-03-139 HIGH-RESOLUTION CARDIAC MAGNETIC RESONANCE IMAGING FOR LEFT ATRIAL APPENDAGE SIZING AND THROMBUS EXCLUSION PRIOR TO DEVICE CLOSURE

Transesophageal echocardiography and cardiac computed tomography angiography are currently utilized for left atrial appendage closure (LAAC) planning. The advent of high-resolution magnetic resonance imaging (HR-CMR) now potentially allows adequate spatial resolution LAAC This study sought to assess preoperative HR-CMR with software-based sizing vs intraoperative TEE LAA thrombus exclusion prior LAAC. retrospective conducted at Ohio State University Wexner Medical Center included all patients who underwent Watchman FLX (Boston Scientific, Marlborough, MA) from May September 2022. For HR-CMR, (MRA) late gadolinium enhancement (LGE) sequences were obtained respectively. A proprietary software (TruPlan, Boston Scientific) was analyze the MRA sequence characterize anatomy, predict device size, estimate compression ratio. compared assessing accuracy exclusion, maximum ostial diameter, depth, lobe count, morphology, predicted size. 16 included, baseline characteristics notable 8 (50%) females, age 73 ± 6 years, 30 7 kg/m2 body mass index, 54 8% ventricular ejection fraction, 4 2 CHA2DS2-VASc. 15 (94%) cases successfully completed. There no significant difference in (CMR 14 (88%) (100%) cases, p=0.48), diameter 20.9 4.2 20.6 mm, p=0.99), depth 31.1 7.8 26.8 5.6 p=0.09), count 1.8 0.8 1.4 0.6 lobes, p=0.25), morphology features (p=0.44). assessments summarized Table I. mean devices deployed per case 1.1 0.3. In (13%) a downsize required. 1 aborted due inability access very small ostium. On 45-day or CCTA, peri-device leak ≥5 mm device-related noted. comparison standard contrast-enhanced (CE)-MRA is demonstrated Figure 1. viable modality promising results. may provide utility where CCTA contraindicated unavailable.Tabled 1Table IMeasureHR-CMR (N=16)TEE (N=16)P-valueLAA accurately excluded14 (88%)16 (100%)0.484Minimum (mm)18.0 4.216.6 3.40.335Target (mm)*20.9 4.220.6 4.20.987LAA (mm)31.1 7.826.8 5.60.093Number lobes1.8 0.81.4 0.60.250Morphology0.437Cactus4 (25%)3 (19%)Cauliflower0 (0%)2 (13%)Chicken wing5 (31%)2 (13%)Windsock7 (44%)8 (50%)Other0 (0%)1 (6%)LAA size predicted12 (75%)12 (75%)1.000Values presented as deviation continuous variables n (%) categorical variables. Abbreviations: = high imaging, appendage, transesophageal echocardiography. *Based on measured area-derived HR-CMR. Open table new tab