Abstract 229: Comparative Diagnostic Yield of Cardiac Computed Tomography Versus Echocardiography for Identifying Cardioembolic Sources in Ischemic Stroke: A Retrospective Single‐center Cohort Study

Background Ischemic stroke remains a leading cause of morbidity and mortality worldwide. Understanding stroke etiology is critical in future stroke prevention. A cardioembolic etiology of stroke makes up a significant proportion of all ischemic stroke. Part of the evaluation for a cardioembolic etiology requires a structural evaluation of the heart to evaluate for sources of thrombus. Traditionally, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) have been utilized for this purpose, although both have limitations. Cardiac computed tomography (CCT) has emerged as a potential alternative, offering non‐invasive imaging with high sensitivity and specificity for detecting intracardiac thrombi. This study aimed to evaluate the diagnostic yield of CCT compared to TTE and TEE in detecting high‐risk cardioaortic sources of embolism, including left ventricular (LV) thrombus, left atrial (LA) thrombus, valvular sources of thrombus, and ulcerated aortic plaques, in patients with ischemic stroke. Methods We conducted a retrospective, single‐center cohort study at Mayo Clinic, Rochester, MN, on patients who underwent CCT within 30 days of stroke onset between March 2019 and June 2023. We compared the diagnostic yields of CCT, TTE, and TEE in detecting structural cardiac sources of embolism. Results 426 patients were included in our study. 87 patients underwent both CCT and TEE, 257 underwent CCT and TTE, and 82 only underwent CCT. The overall diagnostic yield of CCT for detecting high‐risk cardioaortic sources was 15.5%. Specifically, CCT identified LV thrombus in 2.3% of patients, LA thrombus in 4.0%, valvular thrombus in 2.8%, and ulcerated aortic plaques in 7.0%. In comparative analysis, CCT demonstrated a higher yield than TTE (16.0% vs. 3.5%) and a comparable or higher yield than TEE (25.3% vs. 20.7%) in detecting these sources. Conclusions CCT proved to be a viable and potentially superior alternative to traditional echocardiography for identifying some high‐risk structural sources of cardioembolism in ischemic stroke patients. Its non‐invasive nature, coupled with the ability to perform imaging soon after stroke onset, underscores its clinical utility. However, further prospective and blinded studies are required to validate these findings and fully establish the efficacy of CCT in this context.