Abstract 15388: Atrial Fibrillation Burden Reduction From Antiarrhythmic Drugs in Patients With Cardiac Implantable Electronic Devices

Abstract

Introduction: Efficacy of rhythm control treatments for atrial fibrillation (AF) is usually measured by time to recurrent AF, however reduction in AF burden is a more clinically relevant endpoint. Cardiac implantable electronic devices (CIEDs) provide continuous rhythm monitoring that allows for highly accurate measures of AF burden. Ablation has been shown to reduce AF burden by > 99% in CIED patients, but there are limited data on the impact of antiarrhythmic drug (AAD) therapy on AF burden. Methods: A single-center retrospective study of all CIED patients with new AAD initiation for AF between 4/2018-3/2022 was conducted. Patients with CIED-detected AF burden within 6 months pre- and 12 months post-AAD initiation were eligible for inclusion. CIED-detected AF burden was compared pre- and post-AAD initiation. Results: Of the 214 patients included in analysis (73.6 ± 11.8 yrs, 63% male, CHA 2 DS 2 -VASc 3.8 ± 1.6), there was a statistically significant reduction in AF burden following AAD initiation (pre-AAD 4.5% [IQR: 1.0%, 27.9%]; post-AAD 0.1% [IQR: 0%, 3.2%], p<0.001). Of patients prescribed amiodarone (n=148, 69%), the median AF burden decreased from 3.6% [IQR: 1.0%, 28.0%] to 0.1% [IQR: 0.0%, 2.5%] (p<0.001). Among patients on other AADs (flecainide n=22, 10%; sotolol n=21, 10%; dronedarone n=12, 6%; dofetilide n=8, 4%; propafenone n=3, 1%) the median AF burden decreased from 6.6% [IQR: 1.7%, 25.5%] to 0.2% [IQR: 0%, 3.5%] (p=0.028) (Figure). There was no significant difference in AF burden reduction between amiodarone and non-amiodarone AADs (amiodarone 90.9% [IQR: 0.0%, 100.0%], non-amiodarone AADs 74.0% [IQR: 0.0%, 99.9%], p=0.686). Conclusions: AADs significantly reduce CIED-measured AF burden, but this burden reduction is less than what is reported with ablation. There was no significant difference in AF burden reduction between cohorts of patients on amiodarone and non-amiodarone AADs.