Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice, significantly increasing the risks of death, stroke, heart failure, cognitive impairment, and dementia, thus severely impacting patients' quality of life. However, for AF patients with concomitant cardiovascular risk factors, particularly those with obstructive sleep apnea (OSA), the success rate of catheter ablation is significantly reduced. Continuous positive airway pressure (CPAP) is currently an effective treatment for OSA, effectively correcting nocturnal intermittent hypoxia and fragmented sleep caused by OSA. However, the effect of CPAP therapy on AF recurrence in patients with OSA undergoing catheter ablation remains controversial. Faced with conflicting research findings, our team recently conducted a meta-analysis (registration number CRD42023398588) to assess the impact of CPAP on AF recurrence post catheter ablation in patients with AF and OSA, suggesting that CPAP significantly reduces AF recurrence post catheter ablation (RR = 0.58, P < 0.01). However, considering the limited number of included studies, potential bias risks, and confounding factors, our meta-analysis results await further confirmation through real-world studies by our team. Therefore, our team plans to conduct further research on the impact of CPAP on AF recurrence post catheter ablation in patients with moderate to severe OSA, aiming to provide clinical guidance for the treatment of AF in patients with moderate to severe OSA.

Inclusion Criteria:

1. Clinical diagnosis of AF combined with moderate to severe OSA (OSA diagnostic criteria: apnea hypopnea index (AHI) greater than 15/hour, and at least 80% of all events are respiratory sleep obstructive events; AF includes persistent atrial fibrillation and paroxysmal atrial fibrillation)
2. Age ≥ 18 years old
3. The patient voluntarily participates in the project and signs informed consent
4. All patients undergo overnight sleep pressure titration at the sleep center to determine the minimum pressure value for continuous positive airway pressure ventilation at home. All patients are required to undergo CPAP treatment at home at least 5 days a week, with each session lasting at least 4 hours

Exclusion Criteria:

1. Patients with neuromuscular disorders, pulmonary hypopnea, and severe lung diseases
2. Preoperative confirmation of thrombus in the left atrium
3. The patient has no desire for conversion
4. Secondary atrial fibrillation (hyperthyroidism, tumors, etc.)
5. Individuals with contraindications to anticoagulants
6. Left atrial diameter (LAD) exceeding 60mm (2D echocardiography long axis section data)
7. Pregnant women
8. History of myocardial infarction, percutaneous coronary intervention, and cardiac surgery in the past three months
9. Stroke or transient ischemic attack in the past six months
10. After artificial valve implantation surgery
11. Severe renal insufficiency (creatinine Cr>2.5mg/dl or>221umol/L, or glomerular filtration rate eGFR<30ml/min/1.73m2)
12. Acute diseases or active infections that occur before surgery, recorded as pain, fever, positive blood culture, and/or leukocytosis, or have been treated with antibiotics.
13. Expected survival period<1 year

Clinical diagnosis of AF combined with moderate to severe OSA (OSA diagnostic criteria: apnea hypopnea index (AHI) greater than 15/hour, and at least 80% of all events are respiratory sleep obstructive events; AF includes persistent atrial fibrillation and paroxysmal atrial fibrillation)