Value of Cardiac Structural Metrics in Identifying Cardioembolic Stroke

Objectives: Paroxysmal atrial fibrillation (AF) is often challenging to detect in the acute phase of ischemic stroke. This study aimed to assess the diagnostic value of readily available cardiac structural metrics in identifying cardioembolic stroke etiology. Methods: In a single-center cohort study, we enrolled patients who underwent transthoracic echocardiography within 7 days of stroke onset. We measured the left atrium diameter (LAD), right atrium diameter (RAD), left ventricular internal diameter, right ventricular internal diameter, interventricular septal thickness at end-diastole (IVSd), left ventricular posterior wall thickness, and assessed for mitral and aortic regurgitation. The predictive performance of these metrics for cardioembolic stroke was evaluated by calculating the area under the receiver operating characteristic curve (AUC). Results: Among the 1357 enrolled patients, 101 (7.4%) were diagnosed with cardioembolic stroke. After adjusting for potential confounders, LAD, RAD, and IVSd remained independently associated with cardioembolic stroke in both the full population and in patients without AF. LAD demonstrated the highest discriminative ability, with an AUC of 0.744 (95% CI: 0.682-0.806). The AUCs for RAD and IVSd were 0.583 (0.510-0.657) and 0.584 (0.516-0.652), respectively. Conclusions: LAD is a good predictor for identifying cardioembolic stroke, independent of AF status. Cardiac structural metrics, particularly LAD, may aid in etiologic subtyping during the acute phase of ischemic stroke.