Abumuamar AM, et al. - Researchers sought to determine the prevalence and clinical predictors of obstructive sleep apnea (OSA) in patients with atrial fibrillation (AF), presuming that OSA is underdiagnosed in a large number of patients with AF and may not be predicted by conventional clinical indices. A common prevalence of OSA, which often remained undetected, was reported in AF patients, particularly in nonobese and/or female patients. Patients may have a normal overall Apnea-Hypopnea Index (AHI) but an abnormal AHI during rapid eye movement sleep. OSA in these subjects was not reliably predicted by the clinical features of OSA. Only age and male sex were identified as independent predictors of the presence of OSA. A low threshold for detection of OSA, with sleep studies, in these patients may be merited.