Background:  The clinical yield of cavo-tricuspid isthmus (CTI) radiofrequency ablation of atrial flutter (AF) is limited by a high incidence of atrial fibrillation (AFib) in the long term. Among other acknowledged variables, the association of obstructive sleep apnea (OSA) could favor incomplete arrhythmia control in this setting. We assessed the impact of continuous positive airway pressure (CPAP) in reducing the occurrence of AFib after CTI ablation.
Methods:  Consecutive AF patients undergoing CTI ablation were screened for OSA. Relationship of the following variables with the occurrence of AFib during follow-up (12 months) was investigated: CPAP initiation, hypertension, body mass index, underlying structural heart disease, left atrial diameter and AFib documentation prior to ablation.
Results:  We prospectively included 56 patients [age 66 (11) years, 12 female], 46 of whom (82%) had OSA and 25 (45%) had severe OSA. Twenty-one patients (38%) had AFib during follow-up after CTI ablation. Both freedom from AFib prior to ablation and CPAP initiation in those patients without previously documented AFib at inclusion were associated with a reduction of AFib episodes during follow-up (p = 0.019 and p = 0.025, respectively). Inversely, CPAP was not protective from AFib recurrence when this arrhythmia was documented prior to ablation (p = 0.25).
Conclusions:  Obstructive sleep apnea is a prevalent condition in patients with AF. Treatment with CPAP is associated with a lower incidence of newly diagnosed AFib after CTI ablation. Screening for OSA in AF patients appears to be a reasonable clinical strategy.