Diagnostic yield of cardiac computed tomography in detecting high-risk cardioaortic embolic sources: A retrospective cohort study

Background: Ischemic stroke remains a leading cause of morbidity and mortality worldwide. Cardioembolic sources account for a significant proportion of these events, necessitating accurate identification of underlying structural heart abnormalities. Traditionally, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) have been utilized for this purpose, although both have limitations. Cardiac computed tomography (CCTA) has emerged as a potential alternative, offering non-invasive imaging with high sensitivity and specificity for detecting intracardiac thrombi. Objective: This study aimed to evaluate the diagnostic yield of CCTA compared to TTE and TEE in detecting high-risk cardioaortic sources of embolism, including left ventricular (LV) thrombus, left atrial (LA) thrombus, valvular thrombus, and ulcerated aortic plaques, in patients with ischemic stroke. Methods: We conducted a retrospective, single-center cohort study at Mayo Clinic, Rochester, MN, including 426 ischemic stroke patients who underwent CCTA within 30 days of stroke onset between March 2019 and June 2023. We compared the diagnostic yields of CCTA, TTE, and TEE in detecting structural cardiac sources of embolism. Results: The overall diagnostic yield of CCTA for detecting high-risk cardioaortic sources was 15.5%. Specifically, CCTA 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, CCTA demonstrated a higher yield than TTE (16.0% vs 3.5%, p < 0.001) and a comparable yield to TEE (25.3% vs 20.7%, p = 0.47) in detecting these sources. Conclusions: CCTA proved to be a viable option for identifying 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 CCTA in this context.