Abstract 18826: Atrial Fibrillation, Atrial Myopathy, and the Risk of Recurrent Stroke or Transient Ischemic Attack After Cryptogenic Stroke

Abstract

Background: The annual risk of recurrent stroke after cryptogenic stroke (CS) is estimated at 3-6%. Atrial myopathy, characterized by left atrial structural and electrophysiological remodeling, is associated with atrial fibrillation (AF) and stroke. Hypothesis: Atrial myopathy is associated with an increased risk of recurrent stroke or transient ischemic attack (rCVA) within one year. Methods: Patients with interpretable echocardiograms who received an implantable loop recorder for CS at a tertiary care medical center (2015-22) were included and followed for at least 1 year. Left atrial emptying fraction (LAEF) and reservoir strain (LARS) were calculated from two-dimensional transthoracic echocardiograms. Covariates including congestive heart failure, hypertension, age, diabetes, sex, stroke/transient ischemic attack, vascular disease, carotid artery stenosis, and rCVA were ascertained by review of hospital medical records. Incident AF post CS 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. Results: 159 patients (mean age 74.4 years, 52.1% female) were followed for at least one-year post CS. Patients with rCVA had significantly lower LAEF (p=0.012) and near-significantly lower LARS (p=0.088) compared to those who did not. The odds of rCVA were 4.82 (2.22, 7.11)-fold greater in those found to have new AF independent of LAEF, LARS, and remaining covariates including carotid artery stenosis. Patients on anticoagulation at time of rCVA had trends towards reduced stroke severity (p=0.184). Conclusions: Atrial myopathy characterized by AF or reduced LA function is associated with rCVA post CS.