005 Impact of Continuous Positive Airway Pressure on the Atrial Substrate in Patients With Obstructive Sleep Apnoea and Atrial Fibrillation: The SLEEP-AF Substrate Sub-Study

Abstract

Obstructive sleep apnoea (OSA) is associated with an increasingly remodeled atrial substrate in atrial fibrillation (AF). Management of OSA has also been linked with improved management outcomes of AF. However, the impact of OSA management on the electrophysiologic atrial substrate has not been evaluated. To determine the impact of OSA management on the atrial substrate in AF. We recruited 24 consecutive patients having catheter ablation for AF with at least moderate OSA (AHI ≥15). Participants were randomised in a 1:1 ratio to receive continuous positive airway pressure (CPAP) or no therapy. At baseline, all participants underwent invasive electrophysiologic study comprising high density right atrial mapping and evaluation of effective refractory periods (ERP). After minimum of 6 months, the electrophysiologic protocol was repeated. Data was blinded and analysed offline. Outcome variables were atrial voltage (mV), conduction velocity (m/s), atrial surface area <1.5mV (%), atrial surface area <0.5mV (%), complex points (%) and atrial ERP (ms). There were no differences in baseline characteristics between groups and electrophysiologic parameters were comparable at baseline. Participants having CPAP were highly compliant (device usage: 79±19%, usage time: 268±91mins) resulting in significant AHI reduction (mean reduction: 31±23). There were no differences in blood pressure or body mass index between groups over time. The table presents data showing that CPAP results in marked reverse atrial remodelling. CPAP therapy results in reversal of atrial remodelling, providing mechanistic evidence advocating for management of OSA in AF.