Abstract WP254: Insular Involvement of Ischemic Stroke Suggests a Cardioembolic Mechanism

Abstract

Introduction: The insular cortex controls several aspects of vital function including autonomic regulation, and strokes affecting the insula have been associated with dysautonomia, cardiac dysfunction, and arrhythmias. Previous studies have shown an association between insular strokes, elevated troponin levels, and atrial fibrillation (AF). In this study, we aim to determine the association between cardiac biomarkers and insular involvement of the infarct and hypothesize that insular involvement implicates a cardioembolic source. Methods: We abstracted data from a prospective comprehensive stroke center registry of consecutive patients with a discharge diagnosis of acute ischemic stroke who underwent brain imaging (CT or MRI) and work up to determine stroke mechanism. Data included demographics, clinical baseline variables, laboratory tests (including admission troponin level), and transthoracic echocardiographic variables (regional wall motion abnormalities, ejection fraction, and left atrial volume index), and stroke subtype. Multivariable logistic regression models were built to determine associations between AF, and cardiac biomarkers and insular infarcts. Results: We identified 1224 patients who met the inclusion criteria; 397 (32.4%) had insular involvement of the infarct. In multivariable models, insular infarcts were associated with AF (adjusted OR 1.73, 95% CI 1.23-2.43, p = 0.001) and left atrial volume index (adjusted OR per standard deviation increase 1.30, 95% CI 1.13-1.49, p = 0.001). There was a trend for association between insular involvement and positive troponin level (adjusted OR 1.45 95% CI 0.91-2.33, p = 0.122) but not with regional wall motion abnormalities (adjusted OR 1.13, 95% CI 0.69-1.84, p = 0.627). Insular involvement was associated with cardioembolic stroke subtype (45.8% vs. 26.7%, p<0.001) but not other stroke subtypes. Conclusion: The insular cortex is commonly involved in patients with atrial fibrillation and/or atrial dilation and maybe a neuroimaging biomarker of cardioembolic stroke. Larger studies are needed to confirm this association and test anticoagulation therapy in patients with insular infarcts.