Abstract Body (Do not enter title and authors here): Background:
Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice and is associated with significant morbidity, mortality, and health system costs. Obstructive sleep apnea (OSA) is a highly prevalent condition affecting more than one third of the global adult population and, among patients with comorbid AF, contributes to poor AF related quality of life. However, the prevalence of undiagnosed OSA in the general AF population is unknown.
Methods:
In this pragmatic, phase IV prospective cohort study, we performed sleep testing on consecutively enrolled ambulatory AF patients for OSA using a cloud-based disposable home sleep test (the WatchPAT system). The primary outcome of our study was the prevalence of undiagnosed mild (5≤AHI<15) or moderate/severe (AHI≥15) OSA in the general AF population. A prespecified power analysis supports 80% power to detect a <5% difference in OSA prevalence compared to the general population (defined by AHI cut-offs of ≥5 or ≥15).
Results:
We performed sleep testing in 180 AF patients. Enrollment concluded early after a prespecified interim power analysis showed a larger than predicted difference of OSA prevalence between AF patients and the general population. Among the patients tested, 126 (70.4%) had paroxysmal AF, and 53 (29.6%) had persistent/long standing persistent AF. None had previous sleep testing. Our results show that the prevalence of OSA was 83.3% by AHI≥5 and 47.2% had moderate/severe OSA (AHI≥15). Patients with persistent or long standing persistent AF demonstrated even higher rates of OSA with 51 (96.3%) testing positive for OSA (AHI≥5) and 35 (64.2%) with moderate/severe OSA (AHI≥15). Conversely, standardized OSA screening instruments (Stop-BANG questionnaire or Epworth Sleepiness Scale) were poorly predictive of OSA in AF patients (AUC 0.66 and AUC 0.44, respectively).
Conclusions:
Undiagnosed OSA is highly prevalent in the general AF population. Our results demonstrate that OSA prevalence in AF patients exceeds that in the general population with a high degree of confidence. Widely used clinical prediction instruments cannot effectively be used to guide sleep testing decisions in AF patients. Our results suggest routine OSA testing should be performed in the comprehensive evaluation of all AF patients.