Association of device detected atrial high rate episodes with embolic events

Abstract

Abstract Background Subclinical atrial fibrillation (AFib) is a common etiology of embolic events such as embolic strokes of undetermined source. With the advent of cardiac implantable electronic devices (CIED), there has been increased detection of subclinical AFib, or atrial high rate episodes (AHRE) in asymptomatic patients without a known diagnosis of AFib. The clinical significance of AHRE detected with CIED remains poorly characterized with studies reporting conflicting results. The purpose of this meta-analysis is to evaluate the association of AHRE with cerebrovascular accidents (CVA), transient ischemic attacks (TIA), and systemic embolic events. Methods A literature search was conducted for studies reporting on the association of subclinical AFib or AHRE with CVA, TIA, and systemic embolic events. The search included the following databases: Ovid MEDLINE, EMBASE, Google Scholar, and Web of Science. The search was not restricted to time or publication status. Results A total of 19 studies and 50,968 patients (12,879 with AHRE vs 38,089 without AHRE) were included. Mean follow-up was 32 months, mean age was 72 years old, 53.3% were male. Patients with device detected AHRE had increased risk of composite endpoint of CVA, TIA, and systemic embolic events (OR 2.98, 95% CI 2.03-4.39; P<0.01). Subgroup analysis by maximum AHRE burden demonstrated that both maximum AHRE burden >24 hours and burden <24 hours are associated with increased risk of CVA, TIA, and systemic embolic events (OR 4.82, 95% CI 2.07-11.24; p<0.01; OR 1.55, 95% CI 1.11-2.15; p<0.01). The overall effect size is larger for maximum AHRE burden >24 hours compared to <24 hours (Z=3.64 vs Z=2.61). Conclusions Our results suggest that AHRE detected with CIED is associated with increased risk of CVA, TIA, and systemic embolic events regardless of maximum AHRE burden >24 hours or <24 hours. Additional studies are required to determine the utility anticoagulation therapy for treatment of asymptomatic patients with device detected AHRE.