Abstract TP489: Atrial Fibrillation Detection Following Implanted Cardiac Monitor Placement in Patients with Embolic Stroke of Undetermined Source

Abstract

Objective: Determine atrial fibrillation detection rates in patients with ischemic stroke and TIA following implanted cardiac monitor placement. Introduction: Annually an estimated 795,000 Americans suffer a stroke. Embolic stroke of undetermined source (ESUS) is estimated to account for 25-30% of all ischemic strokes. While atrial fibrillation is associated with an increased risk of ischemic stroke, AF is often asymptomatic. Current guidelines recommend antiplatelet therapy for secondary stroke prevention in ESUS. Unfortunately the prevalence of atrial fibrillation in ESUS is unknown. Thus detection of asymptomatic AF in ESUS has potential therapeutic implications. Methods: To determine the frequency of asymptomatic AF, a retrospective chart review was conducted of patients admitted to a single center 627 bed quaternary referral hospital and certified comprehensive stroke center in Hennepin County, Minnesota. Between June of 2015 and June of 2018, 237 implanted cardiac monitors (ICM) were placed in patients with a primary diagnosis of stroke or TIA. Inclusion criteria was admission to the stroke center or evaluation in the TIA clinic, primary diagnosis of ischemic stroke or TIA, diagnosis of ESUS, and placement of ICM. Diagnosis of ESUS was confirmed by the stroke medical director. Patients were monitored remotely for a minimum of six and a maximum of eighteen months post ICM insertion. Remote monitoring was discontinued at time of AF detection confirmed by an electrophysiologist. Medication adjustments were directed by the stroke service. Results: Multivariable analysis will be reported to compare patients with positive and negative AF detection, age, sex, ethnicity/race, and CHA 2 DS 2 -VASC score. Hazard ratios will be calculated for AF detection at 6 and 12 months post ICM insertion. Conclusion: Since AF is often asymptomatic, cardiac monitoring plays an important role in evaluation of ESUS. Detection of AF often results in initiation of anticoagulation which is superior to antiplatelet agents for stroke prevention in AF. Identifying asymptomatic AF may reduce recurrent stroke rates in ESUS.