Cardiac magnetic resonance imaging for preprocedural assessment in patients undergoing left atrial appendage closure

Background Limited data exist validating cardiac magnetic resonance imaging (cMRI) as a preprocedural assessment tool for left atrial appendage closure (LAAC). Preprocedural imaging is essential for device sizing and procedural planning, however CT imaging is often challenging in patients with renal dysfunction. This study evaluates the feasibility of cMRI as an alternative imaging modality for LAAC planning. Purpose To evaluate the feasibility of cMRI for preprocedural assessment in patients undergoing percutaneous LAAC. Methods This prospective, single-center interventional study enrolled 108 patients with non-valvular atrial fibrillation at high risk of stroke and bleeding who underwent LAAC between September 2021 and July 2023. All patients underwent both transesophageal echocardiography (TEE) and cMRI before the procedure. cMRI images were imported into 3mensio software for analysis, generating TEE-like images at corresponding angles. Blinded certified specialists independently performed TEE and cMRI measurements. Based on estimated glomerular filtration rate (eGFR), patients were categorized into the CKD group (eGFR <60, N=79) and the non-CKD group (eGFR ≥60, N=29). Ostial diameter, depth, and morphology of LAA were compared between TEE and cMRI using Spearman’s correlation and Bland-Altman analyses. Results In the 108 patients included in the study, the mean age was 76.5 ± 7.8 years, with 71.8% of participants being male. The mean CHA2DS2-VASc score was 4.7 ± 1.5, and the mean HAS-BLED score was 3.3 ± 1.1. Major bleeding history was documented in 54.5% of patients. LAA ostial diameter correlated strongly between TEE and cMRI (r = 0.6–0.7) with no significant CKD-related differences (Figure 1). Bland-Altman analysis confirmed good agreement between modalities (Figure 2). In contrast, LAA depth measurements exhibited weak correlation (r = 0.06–0.51), particularly at 0° and 45°. Bland-Altman analysis demonstrated a consistent negative bias, indicating that TEE systematically overestimated LAA depth compared to cMRI. LAA morphology assessment showed no significant differences between TEE and cMRI. Conclusions While TEE and cMRI demonstrate strong agreement in ostial diameter measurements, TEE systematically overestimates LAA depth. Given cMRI’s superior spatial resolution and 3D imaging capabilities, it may provide a more accurate representation of LAA anatomy. These findings suggest cMRI as a reliable alternative for ostial diameter assessment and a more precise tool for LAA depth evaluation, optimizing LAAC procedural planning.Figure 1 Figure 2