Abstract
BACKGROUND: Risk stratification in patients with atrial fibrillation (AF) is critically important because this group is at high risk of mortality and morbidity. One of the comorbidities potentially affecting thromboembolic and total cardiovascular risk is obstructive sleep apnea (OSA). The aim of this study was to determine whether or not patients with atrial fibrillation and concomitant obstructive sleep apnea have a higher predicted cardiovascular risk than those without sleep-disordered breathing. METHODS: The study was designed to be a cross-sectional observational study. Consecutive patients with primary diagnosis of AF who qualified for first-ever catheter ablation between 2011 and 2013 were enrolled. All patients had an overnight polysomnography performed for the diagnosis of OSA and calculation of a 2MACE score-a cardiovascular risk assessment score for AF. RESULTS: We studied 211 AF patients (mean age 57.1 ± 10.2 years, 62.6% males). OSA with apnea-hypopnea index (AHI) ≥15/h was found in 48 patients (22.7%). Cardiovascular disease and risk factors were as follows: 8 (3.8%) patients had congestive heart failure, 27 (12.8%) diabetes, 16 (7.6%) history of stroke or thromboembolic disease, 194 (91.9%) arterial hypertension, 24 (11.4%) vascular disease, and 31 (14.7%) were current smokers. A significantly higher percentage of patients with OSA was at high risk of cardiovascular disease (29.2 vs. 8.1%; p < 0.0001). The trend remained significant in different categories of obstructive sleep apnea when categorized by AHI into non-OSA, and mild, moderate, and severe OSA. Similarly, the mean 2MACE score was statistically significantly higher in OSA than non-OSA patients (2.1 ± 1.1 vs. 1.4 ± 1.0; p < 0.0001). CONCLUSION: OSA prevalence is increased in AF patients and is associated with an increase 2MACE score-an indicator of major cardiovascular events. There is a linear relationship between severity of OSA and increasing 2MACE scores, indicating increasing cardiovascular risk related to OSA severity.