Abstract 23: Detection of Atrial Fibrillation by Implantable Cardiac Monitoring After Acute Central Retinal Artery Occlusion

Introduction: Central retinal artery occlusion (CRAO) is a form of ischemic stroke and necessitates a comprehensive workup, including for cardioembolic sources such as atrial fibrillation (AF). However, the incidence of new AF diagnosed after CRAO is unknown. We aimed to examine the incidence of new, cardiac device-detected AF after CRAO in a large population-based cohort. Methods: Using patient-level data from the Optum® de-identified EHR dataset (2007-2017) linked with Medtronic implantable cardiac device data, we identified patients that had a diagnosis-code corresponding to CRAO and no known history of AF, and who also had either a device in-situ at the time of CRAO or implanted ≤1 year post-CRAO with continuous AF monitoring data available. AF incidence was defined as ≥2 minutes of device-detected AF in a day. Results: Of 467,167 patients screened, 246/433 (56.8%) with CRAO had no history of AF, of whom 39 had an eligible implantable cardiac device (mean age 66.7±14.8, 41.0% female). Prevalence of vascular risk factors was high (hypertension, 71.8%; hyperlipidemia, 61.5%; coronary artery disease, 46.2%). Within 3 months, 7.7% of these patients (n=3) had device-detected AF. At 36 months, 33.3% of patients (n=13). The maximum daily AF burden post CRAO ranged from 2 minutes to 24 hours with a mean of 390±530 minutes. Of the patients with device-detected AF, 9 were found by an implantable cardiac monitor and 4 by pacemaker or defibrillator. Discussion: The rate of long-term AF detection after CRAO was high in patients with implanted cardiac devices, and appears comparable with rates seen after cryptogenic ischemic stroke and in other high-risk populations. Our findings warrant future prospective studies not limited by selection bias.