Abstract 13027: Reduced Left Atrial Strain is More Common in Embolic Stroke of Undetermined Source Compared to Non-Cardioembolic Stroke and Can Predict Atrial Fibrillation on Outpatient Cardiac Monitoring

Abstract

Embolic stroke of undetermined source (ESUS) accounts for 20% of all ischemic strokes with at least 30% having biomarkers of atrial cardiopathy. Traditional parameters of left atrial (LA) structure and function (particularly Left Atrial Volume Index) are similar in ESUS and non-cardioembolic (NCE) stroke subtypes. LA strain measured by speckle tracking echocardiography (STE) is an emerging non-invasive technique to assess LA structure, function, and biomechanics. Our study evaluates whether LA strain differs between patients with ESUS and NCE and whether LA strain magnitude predicts diagnosis of atrial fibrillation (AF) in ESUS. Hospitalized patients with ESUS and NCE stroke subtypes who underwent in-hospital echocardiography were included. STE was performed, and three phases of LA strain (reservoir, conduit, and contractile) were measured. Binary logistic regression analyses were performed to determine the association between different phases of LA strain and stroke subtypes (ESUS vs NCE) as well as AF detection in ESUS patients. A total of 685 patients met the inclusion criteria. Mean age was 65 years; 55% were men; 49% of strokes were NCE; and 51% were ESUS. In patients with ESUS, 57% (189/330) underwent cardiac monitoring. AF was detected in 17.4% (33/189). In fully adjusted binary logistic regression analysis, patients with ESUS had lower LA reservoir strain (adjusted OR 0.99, 95% CI 0.98-0.99, p = 0.039) and LA contractile strain (adjusted OR 0.98, 95% CI 0.97-1.00, p = 0.089). Furthermore, lower LA reservoir strain was associated with AF detection in ESUS patients (OR 0.96, 95% CI 0.93-0.99, p = 0.028). In conclusion, all phases of LA strain were reduced in ESUS compared to NCE. This suggests the presence of atrial cardiopathy in ESUS stroke patients. Furthermore, atrial strain was significantly reduced in ESUS patients found to have AF. These findings may carry mechanistic significance in stroke development and AF detection in ESUS patients.