Abstract 206: Incidence and Duration of Atrial Fibrillation Among a Large, Real-World Population of Cryptogenic Stroke Patients with Insertable Cardiac Monitors

Abstract

Introduction: The characteristics of atrial fibrillation (AF) episodes in cryptogenic stroke patients have recently been explored in carefully selected patient populations. However, the incidence and duration of AF episodes among a large, real-world population of unselected patients with an insertable cardiac monitor (ICM) placed for the detection of AF following a cryptogenic stroke have not been investigated. Methods: All patients in the de-identified Medtronic Discovery™ Link database who received an ICM (Reveal LINQ™) for the purpose of AF detection following a cryptogenic stroke and who had at least 30 days of device data were included. AF episodes underwent expert adjudication and were at least 2 minutes in duration. We quantified the AF detection rate using Kaplan-Meier survival estimates and compared this to the results from the CRYSTAL AF study, which rigorously excluded patients with evidence of AF prior to enrollment and ICM insertion. The maximum duration of AF episodes was also analyzed. Results: A total of 1247 patients were included and followed for 84±34 days. The mean age at the time of device insertion was 65.3±13.0 years. AF episodes (n=657) were detected in 91 patients, resulting in an AF detection rate of 9.22% at 120 days (Figure) which was 15% higher than CRYSTAL AF at the same time-point. The median duration of the longest detected AF episode was 3.9 [IQR 1.0-11.5] hours. Conclusions: AF episodes of clinically important durations were detected via continuous monitoring with ICMs in a significant proportion of cryptogenic stroke patients, despite relatively brief follow-up thus far. The real-world incidence of AF among patients being monitored with an ICM after a cryptogenic stroke appears to validate a recent randomized controlled trial and may be slightly higher when adjusted for the duration of follow-up, possibly due to differences in the rigor of the stroke work-up or inclusion/exclusion criteria.