Abstract 14663: The Impact of Continuous Positive Airway Pressure for Sleep Apnea on Left Atrial Dilatation in Patients Receiving Catheter Ablation of Atrial Fibrillation

Background Sleep apnea (SA) and left atrial dilatation (LA) are both risk factors for an arrhythmia recurrence after catheter ablation (CA) of atrial fibrillation (AF). Negative intrathoracic pressure fluctuations during an obstructive apnea episode may cause the left atrium to distend and stretch its wall. However, the impact of continuous positive airway pressure (CPAP) for SA on the reverse LA remodeling has not been elucidated. Methods This study was conducted under a retrospective, single-center, observational design. Data was derived from screening tests for sleep apnea, which were routinely performed in patients scheduled to receive CA of AF in our institution. The severity of the sleep apnea was evaluated by the apnea-hypopnea index (AHI). After excluding patients who were already diagnosed with sleep apnea, we enrolled 1232 consecutive patients who underwent multidetector computed tomography (MDCT) both before and 3-months after the CA of AF. The left atrial dilatation and volume reduction were evaluated by the left atrial minimum volume (LA min V) using 256-slice MDCT. Results The age was 65±11 years, 27.8% were females, and 46.0% had non-paroxysmal AF. The mean AHI was 20.2±15.2 and LA min V 79.1± 37.8ml (r=0.31, p<0.0001) before CA. LA dilatation was defined as an LA min V≥79.1ml. After an adjustment by an advanced age (≥65 years), non-paroxysmal AF, male sex, obesity, hypertension, diabetes, and congestive heart failure, SA (AHI≥5) was a significant predictor of LA dilatation before CA (odds ratio 2.83, 95% confidence interval 1.55-5.16, p=0.0007). After CA, 206 out of 1092 patients (18.9%) with SA started CPAP. SA patients with CPAPs had a greater LA min V reduction rate on the postprocedural CT than those without CPAP (26.2% vs. 20.5%, p=0.013). Conclusion Among the patients scheduled to receive catheter ablation of AF, SA was independently associated with left atrial dilatation. Patients who started CPAP treatment for SA had greater LA reverse remodeling at 3 months after the CA.