Abstract 12591: Atrial Fibrillation Detection (Incidence And Accuracy) By Implantable Loop Recorders For The Indications: Cryptogenic Stroke, Syncope, Or Palpitations: A Real World Cohort Study

Abstract

Introduction: Cryptogenic Stroke (CS), syncope, and palpitations are common indications for implantable loop recorder (ILR) insertion, however the incidence of new-onset atrial fibrillation (AF) in these groups in a real world clinical setting is not well characterized. Methods: At a single US center, we evaluated 273 consecutive patients who had a Medtronic Reveal LINQ™ LNQ11 implanted for the indications of CS, syncope, or palpitations from 2016-2021. All patients were followed remotely by Carelink. Patients with known AF were excluded. For each patient with an AF episode ≥ 2 minutes, the longest AF electrogram was adjudicated by an electrophysiologist and a cardiology fellow to confirm or refute the AF diagnosis. Results: Mean follow-up time was 21 months. There was no difference in mean age between the 3 groups. True, adjudicated AF was diagnosed more often in patients with palpitations and syncope than in patients with CS (table) [p < 0.001]. The ILR reported AF in 92 patients (all groups), of which only 56 (61%) were adjudicated to be true AF. Of the 20 patients with a longest detected AF episode <6 minutes, only 5 (25%) were true AF . Of the 72 patients with a longest detected AF of ≥ 6 minutes, 51 (71%) were true AF (p < 0.001). Conclusions: True, adjudicated AF ≥ 6 minutes was detected in 11% of patients with CS, consistent with prior studies. However, in this real world cohort study, AF ≥ 6 minutes was more likely to be detected in patients with palpitations, followed by patients with syncope. The accuracy of ILR detected AF was significantly improved when the AF episode was ≥ 6 minutes duration.