P6569Additive value of evaluating patients with syncope by an implantable loop recorder: diagnosis of subclinical atrial fibrillation

Abstract

Background Few information exists about the additive value of implantable loop recorders (ILR) for the diagnosis of subclinical atrial fibrillation or flutter (AF) in patients (p) studied for syncope and its therapeutic and prognostic implications. Purpose To evaluate the burden of new onset AF diagnosed by ILR in patients studied for syncope and its therapeutic and prognostic implications. Methods We conducted an observational cohort study in a tertiary center. From April 2014 to January 2019, 355 ILR were implanted in patients with syncope according the ESC syncope guidelines. We excluded the ones with previous known AF and younger than 18 years old (yo), with a final cohort of 197 patients. All of them were therefore followed in outpatient clinic and treated according to current clinical guidelines. New AF diagnosis and consequent therapeutic changes and related clinical events were recorded. Results Of 197p, 38 had a first episode of AF (19.29%), with a mean AF burden of 4.19%, and a median of 0.15%. The incidence rate of AF detection was 10.67patients/year (p-y), with higher incidence among patients older than 65 yo (14.17p-y vs 5.27p-y, p<0.05). Only 1 patient out of 38 had a symptomatic episode that triggered consultation to the emergency room (2.63%). Oral anticoagulants (OAC) were started in 30 of 38 patients with new onset AF (78.94%). Only one stroke was reported secondary to new onset AF before OAC were started. 2 mayor bleedings were reported (1.01%), both of them related to OAC start for new AF diagnosis. 4 patients died (2.03%), all of them from non-cardiovascular causes. Kaplan Meier survival from AF Conclusions New onset AF is frequent in patients with ILR implanted for syncope, especially among those older of 65 yo, with the vast majority consisting in short paroxysms. Following AF detection, generally OAC are initiated.