Sleep apnoea may increase risk of developing AF
Obstructive sleep apnoea (OSA) is associated with an increased risk of new-onset atrial fibrillation (AF), particularly in women, according to a study presented at the American Thoracic Society (ATS) Conference 2017 held in Washington, DC, US.
The longitudinal study involved 8,256 adults (median age, 47 years, 62 percent men) with suspected OSA and who did not have any arrhythmias at baseline. [ATS 2017, abstract 3913]
Over a median follow-up duration of 10 years, 173 individuals (2.1 percent) developed AF requiring hospitalization. Those who were hospitalized for AF had more severe OSA, as indicated by the degree of oxygen desaturation during sleep and the apnoea-hyponoea index (AHI), which measures the number of pauses in breathing or shallow breathing per hour of sleep, compared with those who did not develop AF.
Compared with participants with AHI ≤30, those with AHI >30 were almost twice as likely to be hospitalized for AF (hazard ratio [HR], 1.92, 95 percent confidence interval [CI], 1.41–2.62) during the 10 years of follow-up.
The duration of sleep time spent with <90 percent oxygen desaturation also significantly predicted AF hospitalization, with those who spent ≥10 minutes with abnormal oxygen desaturation during sleep having more than twofold risk of hospitalization for AF than those with <10 minutes of sleep time in such condition (HR, 2.81, 95 percent CI, 2.07–3.81).
Additionally, participants who were hospitalized for AF were more likely to be male, older, current or previous smokers, and have more comorbidities. After controlling for these and other known risk factors including hypertension, sleep time with abnormal oxygen desaturation remained a significant predictor of hospitalized AF (HR, 1.64; p=0.02), while AHI was not. The association was particularly evident in women than in men (p=0.02).
“Other studies have shown that women with sleep apnoea are at greater risk of cardiovascular consequences, including mortality,” said senior investigator Dr Richard Leung of the University of Toronto in Canada. “Greater endothelial dysfunction, higher propensity to develop pulmonary, and systemic hypertension and impaired heart rate responses to autonomic challenges in women with OSA may explain these findings, but further studies are needed to confirm this finding and understand the potential mechanisms.”
According to lead author Dr Tetyana Kendzerska, assistant professor of medicine at the University of Ottawa in Canada, there are several mechanisms through which OSA may increase AF risk.
“There is emerging evidence from animals and smaller studies in humans that OSA may increase the chances of developing AF through oxidative stress, increased sympathetic activity, metabolic abnormalities, endothelial dysfunction, and cardiac stretch from intrathoracic pressure swings,” proposed Kendzerska.
Current study is ongoing to explore the association between OSA and emergency department visits for AF, according to the authors.