Obstructive Sleep Apnea in Patients With Typical Atrial Flutter: Prevalence and Impact on Arrhythmia Control Outcome
What is the impact of continuous positive airway pressure (CPAP) in reducing atrial fibrillation after cavotricuspid isthmus (CTI) ablation of atrial flutter?
Consecutive patients during 2009 with atrial flutter (AF) from one hospital in Spain, undergoing CTI ablation, were screened for obstructive sleep apnea (OSA). Inclusion was not based on any suspicion of sleep apnea. All patients underwent overnight polysomnography within 1 week of successful ablation. Treatment with CPAP was indicated for patients with severe OSA and for those with mild or moderate sleep apnea plus significant daytime sleepiness or cardiovascular morbidity. During the third and sixth month after CTI, 24-hour Holter monitoring was performed in search of paroxysmal atrial arrhythmias. Compliance with CPAP was defined as a minimum of 4 hours per night. Relationship of the following variables with the occurrence of atrial fibrillation during follow-up (12 months) was investigated: CPAP initiation, hypertension, body mass index, underlying structural heart disease, left atrial diameter, and atrial fibrillation documentation prior to ablation.
Of the 59 patients in this cohort, 56 patients had successful CTI ablation (mean age: 66 ± 11 years; 12 female patients), of whom 46 (82%) had OSA and 25 (45%) had severe OSA. Only 10 patients had a normal sleep study. A total of 27 patients met criteria for CPAP therapy. Twenty-one patients (38%) had atrial fibrillation during follow-up after CTI ablation. Both freedom from atrial fibrillation prior to ablation and CPAP initiation in those patients without previously documented atrial fibrillation at inclusion were associated with a reduction of atrial fibrillation episodes during follow-up (p = 0.019 and p = 0.025, respectively). Inversely, CPAP was not protective from atrial fibrillation recurrence when atrial fibrillation was documented prior to ablation (p = 0.25).
The authors concluded that OSA is a prevalent condition in patients with atrial flutter. Treatment with CPAP is associated with a lower incidence of newly diagnosed atrial fibrillation after ablation of atrial flutter. Screening for OSA in patients with atrial flutter appears to be a reasonable clinical strategy.
Historically, atrial fibrillation develops about one third of the time after successful ablation of atrial flutter as long as atrial fibrillation is absent at baseline and is concordant with study results. The impact of CPAP on adequate rhythm control is attenuated in patients with baseline atrial fibrillation. Further identification of clinical characteristics of patients with mild to moderate OSA not treated with CPAP who remain free of atrial fibrillation is needed. Validation of these results will require multivariate analysis with a larger sample size.
Keywords: Multivariate Analysis, Body Mass Index, Continuous Positive Airway Pressure, Spain, Catheter Ablation, Hypertension, Sleep Apnea, Obstructive, Sleep Apnea Syndromes, Atrial Flutter
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