P3705Impact of subclinical atrial fibrillation detected by cardiac implantable electronic devices on the risk of future embolic stroke events from Far East

Abstract

Abstract Background Atrial fibrillation (AF) is the most common type of arrhythmia. AF-related stroke tends to be more severe, and the mortality rate is higher compared with stroke without AF. The definition of AF in patients with cardiac implantable electronic devices (CIEDs) is not clear and the appropriate treatment guideline for patients with AF episode has not established yet. Recent CIEDs have led to an improvement in the early detection of AF episodes, especially in patients who are asymptomatic. Previous studies showed that atrial high-rate episodes (AHREs) detected by CIEDs are associated with embolic stroke events. However, little is known about the incidence of AF and stroke events in Japanese patients with CIEDs who have no prior AF and take no anticoagulant. Objective The purpose of this study was to identify the incidence of embolic stroke events in patients with and without AF events detected by CIEDs and examine the risk factors of embolic stroke events. Methods We retrospectively analyzed the database of our hospital. Every 6 months, AF events were checked by CIEDs. AF30 was defined as AF episodes lasting for ≥30 seconds detected by CIEDs. We examined the characteristics and incidence of embolic stroke events and investigated the relationship between AF30 and the incidence of embolic stroke events. Results We enrolled 348 consecutive patients who had no prior AF and took no anticoagulant in this study (follow-up period, 65±58 months; age, 70±16 years; male sex; 64%; defibrillator, 55%). The mean CHADS2 score and CHA2DS2-VASc score were 1.8±1.1 points and 2.8±1.5 points, respectively. The mean HAS-BLED score was 1.7±1.2 points. During the follow-up, 23 of 348 patients (6.6%) had embolic stroke events. Thirteen patients (4.1%/year) and 10 patients (0.63%/year) had embolic stroke events with and without AF30, respectively. The comparison of characteristics among patients with and without embolic stroke events was shown in Table. In multivariate logistic regression analysis, independent predictors for embolic stroke events were new-onset episode of AF30 (odd ratio [OR] 5.3, 95% confidence interval [CI] 2.2–13, P=0.0003) and an enlarged left atrium ≥40mm (OR 3.1, 95% CI 1.2–7.9, P=0.016). Conclusions Embolic stroke events were common in Japanese patients with CIEDs. AF30 and enlarged left atrium were risk factors of embolic stroke events in this population. Therefore, when physicians detect new-onset AF in patients with CIEDs, they should consider a comprehensive assessment of the risk and benefit of prescribing an anticoagulant.