Nocturnal desaturation is associated with atrial fibrillation in patients with ischemic stroke and obstructive sleep apnea

Study Objectives: Both atrial fbrillation (AF) and obstructive sleep apnea (OSA) are risk factors for ischemic stroke. Previous studies suggested that OSA is associated with AF in individuals who have not had a stroke. For better secondary prevention of stroke, this study determined the association between OSA and AF among patients with ischemic stroke. Methods: This cross-sectional study recruited consecutive patients with subacute ischemic stroke admitted for neurorehabilitation. The baseline and clinical data were collected, and standard polysomnography was performed in a sleep center. Results: The 47 women and 111 men enrolled in this study were divided into two groups according to the presence of AF. The AF group (n = 26) had a signifcantly older age (72.2 versus 60.1 years, P = .016), signifcantly more disability (Barthel index: 35 versus 45, P = .045), and marginally higher mean oxygen desaturation (6.7% versus 5.6%, P = .079) compared to the non-AF group. The two groups did not signifcantly differ in sex, body mass index, prevalence of hyperthyroidism, and other parameters of OSA. The multivariate logistic regression analysis revealed that mean desaturation was signifcantly associated with AF after adjusting for age, neck circumference, Barthel index and high-density lipoprotein level (odds ratio = 1.19 (95% confdence interval 1.05-1.35), P = .008). Conclusions: Nocturnal hypoxia due to OSA is an independent predictor of AF in patients with subacute ischemic stroke. The use of overnight pulse oximeter to assess nocturnal hypoxia and predict paroxysmal AF in patients with cryptogenic stroke needs further evaluation. Commentary: A commentary on this article appears in this issue on page 667.