Impact of CPAP Therapy Adherence on Time to First Recurrence of Paroxysmal Atrial Fibrillation in Patients with Severe Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) is a major modifiable risk factor for atrial fibrillation (AF), promoting arrhythmogenesis through intermittent hypoxia, autonomic activation, and atrial remodeling. Although continuous positive airway pressure (CPAP) effectively treats OSA, real-world evidence linking objectively measured CPAP exposure to clinically relevant AF recurrence remains limited. Aims: We aimed to evaluate the association between CPAP adherence and risk of recurrent paroxysmal AF, and to compare time to first recurrence between patients with mean nightly CPAP use ≥4 h/night versus 30 events/h) and documented paroxysmal atrial fibrillation (AF) were enrolled. Persistent and long-standing persistent AF were excluded to ensure a homogeneous population with respect to atrial substrate. OSA was assessed using home sleep apnea testing (ResMed ApneaLink), and all patients initiated continuous positive airway pressure (CPAP) therapy (ResMed AirSense 10). Objective adherence data were obtained via the ResMed AirView telemonitoring platform. Exclusion criteria included permanent AF, prior pulmonary vein isolation, central sleep apnea, left ventricular ejection fraction < 50%, end-stage chronic kidney disease (eGFR < 15 mL/min/1.73 m2 or dialysis), or inability to initiate or maintain CPAP therapy. Patients were followed for 12 months. The primary endpoint was time to first documented recurrence of paroxysmal AF (≥30 s on 12-lead electrocardiography or 24-h Holter monitoring). Progression to permanent AF, defined after unsuccessful rhythm control attempts and subsequent transition to a rate control strategy, was assessed as a secondary endpoint. Time-to-event analyses used Kaplan–Meier estimates with log-rank testing, and Cox proportional hazards regression adjusted for age, body mass index, apnea–hypopnea index, heart failure, left atrial volume index, and antiarrhythmic drug therapy. Results: The final analysis included 91 patients (mean age 62.15 ± 8.29 years; 68.13% men). Mean nightly CPAP use was ≥4 h/night in 49 patients and