BACKGROUND: Obstructive sleep apnea represents an arrhythmia recurrence risk following catheter ablation of atrial fibrillation (AF). Continuous positive airway pressure (CPAP) therapy may reduce recurrence, but individual adherence to CPAP varies, potentially leading to inconsistent results across studies. METHODS AND RESULTS: We analyzed the impact of CPAP adherence on AF recurrence after catheter ablation in patients with severe obstructive sleep apnea (apnea-hypopnea index ≥30). Of 1864 consecutive patients undergoing an index catheter ablation of AF, those with severe obstructive sleep apnea were enrolled in this study. Recurrence rates were compared between patients with and without long-term CPAP adherence (>
1-year use). CPAP use was monitored via telemonitoring and outpatient follow-ups. Among 466 patients, 157 (33.7%) adhered to CPAP long-term, reducing apnea-hypopnea index from 37.7±15.3 to 3.9±3.1 ( CONCLUSIONS: In patients with severe obstructive sleep apnea at baseline, AF recurrence rates within 1-year postablation were similar regardless of CPAP adherence. However, long-term CPAP therapy was associated with a reduced AF recurrence rate in the subsequent period.