Abstract WP283: Association of High-Risk Cardioembolic Sources on Cardiac CT With Acute Ischemic Stroke: A Case-Control Study

Abstract

Background: Cardiac CT is increasingly used to detect a source of cardioembolism in stroke patients. We assessed the association between sources of embolism on cardiac CT, which were predefined as high-risk, and acute ischemic stroke. Methods: We analyzed data from Mind the Heart, a prospective, single-center, observational cohort study, and included consecutive patients with a suspected stroke who underwent ECG-gated cardiac CT during the initial stroke imaging protocol. Cases were patients with a final diagnosis of acute ischemic stroke (AIS), established by an adjudication committee. Controls were patients with stroke mimics (SMi). We excluded patients with a transient ischemic attack. Cardiovascular radiologists diagnosed structural high-risk sources of cardioembolism on cardiac CT according to predefined criteria. High-risk sources on cardiac CT were: cardiac thrombi, signs of endocarditis, recent myocardial infarction, prosthetic valve abnormalities, atrial myxomata and signs of rheumatic valvular disease. We used logistic regression, adjusting for age, sex, history of atrial fibrillation, and history of myocardial infarction. Results: Of 607 included patients, 452 had AIS (74%, median age 72, 59% male) and 155 had a SMi (26%, median age 70, 46% male). Diagnoses in the SMi group were: seizures (45/155, 29%) peripheral vestibulopathy (22/155, 14%), functional neurologic symptoms (16/155, 10%), benign headache disorder (8/155, 5%), intoxication (7/155, 5%), and other diagnoses (57/155, 37%). Cardiac CT detected a structural high-risk cardioembolic source in 52/452 AIS patients (12%) and in 5/155 SMi patients (3%, three patients with seizures, one with peripheral vestibulopathy and one with traumatic brain injury, aOR: 4.1, 95%CI 1.7-12.1). Cardiac thrombi were the most commonly observed high-risk sources of embolism and were detected in 38 (8%) AIS patients and in 2 (1%) SMi patients (aOR 7.0, 95%CI 2.1-43.9). Discussion and conclusion: A high-risk source of cardioembolism was detected on cardiac CT four times more often in patients with acute ischemic stroke than in patients with a stroke mimic. These data substantiate the clinical relevance of using acute CT to search for sources of cardioembolism in ischemic stroke patients.