Obstructive Sleep Apnea Is Associated with Worsened Oxidative Stress and Treatment Resistance in Atrial Fibrillation

Introduction: The epidemiology of obstructive sleep apnea (OSA) in the US is increasing. OSA is a known risk factor for cardiac disease. However, the relationship between OSA and the pathophysiology of atrial fibrillation (AF) is less clear. Recent data has shown that OSA is associated with increased oxidative stress. Previously, we documented the association between oxidative stress and AF. Hypothesis: Patients with OSA and AF will have a worsened oxidative stress profile compared to patients with AF and no OSA. Methods: In a case control study we compared redox potentials of glutathione (EhGSH) and cysteine (EhCyS) among consecutive AF patients with and without OSA who were referred for sleep study. Groups were matched for HTN, CAD, DM and smoking status, known confounders of oxidative stress. OSA in the case group was diagnosed by sleep study and Berlin questionnaire was used in control group to rule out OSA. A single non fasting blood sample was measured for redox potentials at Emory core laboratory. AF history, number and type of interventions were collected retrospectively for 5 years. Exclusion criteria: Severe lung disease requiring home oxygen or oral steroid therapy, MI or CABG within last 6 months, LA diameter more than 5 cm, severe valvular disease, uncontrolled hypertension, CHF and chronic diseases. Results: 10 patients were enrolled in each group. The case group all had a positive sleep study for OSA and all control group patients had a Berlin score of 0. When compared, afib in OSA tend be permanent (mean duration 5 yrs vs. 1 yr; p < 0.05), resistant to intervention (number of patients with 2 or more interventions; 9 vs. 1; p < 0.05) and worsened oxidative stress profile. (mean EhGSH -118 ± 6mV vs. -139 ± 16mV; p = 0.0038.) Mean values for EhCyS were not different. The number of patients on B blockers, ACE inhibitors and statins (known to alter oxidative stress) were not different. Conclusion: Our data suggest, OSA is associated with worsened oxidative stress and treatment resistance in AF. A significant proportion of elderly population have AF, aggressive evaluation for OSA in new onset afib population is paramount, as it is often under attended by both physicians and patients. Further studies are needed to evaluate the efficacy of treating OSA in afib and the possible role of oxidative stress treatment in this population.