Obstructive sleep apnea could lead to atrial fibrillation

Patients with obstructive sleep apnea may be at greater risk for atrial fibrillation, according to findings recently presented at the American Thoracic Society International Conference.

“Evidence for a causal relationship between obstructive sleep apnea (OSA) and atrial fibrillation (AF) is limited and conflicting,” Tetyana Kendzerska, MD, MSc, PhD, Institute of Health Policy, Management and Evaluation, University of Toronto, and colleagues wrote.

To gather more data on the subject, researchers analyzed connections between OSA severity and incident AF in 8,256 patients, controlling for known risk factors such as pulmonary embolism/infarction, COPD, prior congestive heart failure, alcohol dependency/intoxication, smoking status, age and sex. The mean age of the participants was 47 years and 62% of the participants were men. Participants were excluded if they had arrhythmias at baseline. The median Apnea–Hypopnea Index of the participants was 15 events per hour, and 28% had Apnea-Hypopnea Indexes of more than 30 events per hour.

Hypertension was not included in the primary analysis.

“Hypertension may be the causal pathway between OSA and AF, so including it might have diminished the association between OSA and AF,” Kendzerska explained in a press release, adding that in a secondary analysis, researchers did control for hypertension. The study’s primary outcome was incident hospitalization with AF, and Cox regressions were used to investigate the longitudinal association between OSA and hospitalized AF.

Kendzerska and colleagues found that during a median follow-up of 10 years (interquartile range, 7-13 years), 173 participants (2.1%) were hospitalized with AF. Those hospitalized due to AF were more likely to be older, men, current or ex-smokers, had a higher level of comorbidities, and more severe OSA as measured by the Apnea-Hypopnea Index or degree of nocturnal oxygen desaturation.

In addition, univariate analysis showed an Apnea-Hypopnea Index of more than 30 events per hour vs. 30 or fewer events per hour (HR = 1.92; 95% CI, 1.41-2.62), and 10 minutes or more of sleep time vs. 10 minutes or less of sleep time with oxygen desaturation of less than 90% (HR = 2.81; 95% CI, 2.07-3.81) were significant predictors of being hospitalized for AF. After controlling for known risk factors, sleep time spent with oxygen desaturation of less than 90% remained significantly associated with hospitalized AF (HR = 1.64; 95% CI, 1.18-2.28) and that this association was significantly stronger in women compared to men. Researchers also noted that in the secondary analysis, which controlled for hypertension, the association between oxygen desaturation and AF remained significant, suggesting that OSA can directly cause AF without the intermediate step of developing hypertension.

Kendzerska said that she and the other researchers are now analyzing data that connects OSA to ED visits for AF.– by Janel Miller

Reference: Kendzerska T, et al. Abstract 3913. Presented at: American Thoracic Society 2017 International Congress; May 19-24, 2017; Washington, D.C.

Disclosure: Healio Family Medicine was unable to determine researchers’ relevant financial disclosures prior to publication.