Echocardiographic predictors of cardioembolic stroke due to underlying atrial fibrillation: Reliable left atrial remodeling signs in acute stroke

Introduction: Atrial remodeling due to high-burden atrial fibrillation (AF) is associated with cardioembolic stroke (CES). As not all CESs is caused by AF, we analyzed the diagnostic values of each echocardiographic parameter to distinguish likely AF-related CES in acute stroke patients while in non-AF rhythm.

Methods: The data of consecutive patients with acute ischemic stroke in sinus rhythm between 2012 and 2015 were obtained. The echocardiographic parameters of patients with CES due to underlying AF (n = 61) and control patients (n = 319) with either large artery atherosclerosis or small-vessel occlusion were compared using receiver operating characteristic curves and logistic regression analyses. Each parameter was reassessed in acute stroke patients through a validation study using the same database with different periods of generalization.

Results: CES patients with underlying AF showed a significantly larger left atrial volume index (LAVi), higher mitral inflow E wave (E), and lower A wave (A) than the controls. The area under the curve (AUC) (95% confidence interval) for diagnosing CES due to underlying AF was significantly higher for LAVi/A than for LAVi (0.785 versus 0.696, P < 0.01). Among patients aged >60 years, the E/A ratio had the highest AUC (0.857) of the parameters. The cut-off values were ≥ 0.70 (sensitivity, 55.7%; specificity, 90.9%) and ≥ 0.82 (sensitivity, 71.4%; specificity, 84.1%) for LAVi/A and the E/A ratio, respectively, in patients >60 years. The cut-off values of all parameters showed similar trends in a validation study.

Conclusion: LAVi/A is a useful indicator for distinguishing CES patients with underlying AF regardless of age, and the E/A ratio is reliable among patients aged >60 years in evaluation during acute stroke admission.