CE-452778-1 LEFT ATRIAL MECHANICAL DYSFUNCTION AND THE INCIDENCE OF ATRIAL FIBRILLATION WITHIN 1 YEAR OF EMBOLIC STROKE OF UNKNOWN SOURCE

Abstract

Atrial fibrillation (AF) is detected in a significant proportion of patients with embolic stroke of unkown source (ESUS) on subsequent cardiac monitoring and represents an indication for anticoagulation to prevent future stroke in these patients. Left atrial mechanical dysfunction often precedes development of atrial fibrillation and may represent an upstream marker which can readily be assessed at the point of care to inform decisions about future stroke prevention in people with ESUS. To evaluate the association between left atrial mechanical dysfunction, measured by left atrial emptying fraction (LAEF) and reservoir strain (LARS), and incident atrial fibrillation in patients with ESUS. Patients with interpretable echocardiograms who received an implantable loop recorder for ESUS at a tertiary care medical center between 2015 and 2022 were included and followed for 1 year. LAEF and LARS were calculated from two-dimensional transthoracic echocardiograms. Covariates including congestive heart failure, hypertension, age, diabetes, sex, stroke/transient ischemic attack, and vascular disease were ascertained by review of hospital medical records. Incident AF post ESUS was obtained from review of loop recorder data. Odds ratios were calculated using logistic regression models. Two-sided student's T-test was used to compare means of continuous variables. 167 patients (mean age 74.4 years, 52.1% female) were followed for 1 year after ESUS. AF was detected in 49 (20.3%) patients. Patients who developed AF had lower LAEF (46.78% vs 57.50%, P<0.01) and LARS (24.33% vs 31.60%, P<0.01) compared to those who did not develop AF. LAEF and LARS were independently associated with AF within 1 year of ESUS (Table). Left atrial mechanical dysfunction, detected by meeasurement of left atrial reseervoir strain and emptying fraction, is independently associated with the incidence of atrial fibrillation within 1 year of ESUS.