From the Journals

OSA raises risk of atrial fibrillation and stroke



Undiagnosed atrial fibrillation (AFib) was significantly more common among adults with obstructive sleep apnea (OSA), compared with controls, based on data from 303 individuals.

OSA has become a common chronic disease, and cardiovascular diseases including AFib also are known independent risk factors associated with OSA, Anna Hojager, MD, of Zealand University Hospital, Roskilde, Denmark, and colleagues wrote. Previous studies have shown a significant increase in AFib risk in OSA patients with severe disease, but the prevalence of undiagnosed AFib in OSA patients has not been explored.

In a study published in Sleep Medicine, the researchers enrolled 238 adults with severe OSA (based on apnea-hypopnea index of 15 or higher) and 65 with mild or no OSA (based on an AHI of less than 15). The mean AHI across all participants was 34.2, and ranged from 0.2 to 115.8.

Participants underwent heart rhythm monitoring using a home system or standard ECG for 7 days; they were instructed to carry the device at all times except when showering or sweating heavily. The primary outcome was the detection of AFib, defined as at least one period of 30 seconds or longer with an irregular heart rhythm but without detectable evidence of another diagnosis. Sleep was assessed for one night using a portable sleep monitoring device. All participants were examined at baseline and measured for blood pressure, body mass index, waist-to-hip ratio, and ECG.

Overall, AFib occurred in 21 patients with moderate to severe OSA and 1 patient with mild/no OSA (8.8% vs. 1.5%, P = .045). The majority of patients across both groups had hypertension (66%) and dyslipidemia (77.6%), but the severe OSA group was more likely to be dysregulated and to have unknown prediabetes. Participants who were deemed candidates for anticoagulation therapy were referred for additional treatment. None of the 22 total patients with AFib had heart failure with reduced ejection fraction, and 68.2% had normal ejection fraction and ventricle function.

The researchers noted that no guidelines currently exist for systematic opportunistic screening for comorbidities in OSA patients, although the American Academy of Sleep Medicine recommends patient education as part of a multidisciplinary chronic disease management strategy. The high prevalence of AFib in OSA patients, as seen in the current study, “might warrant a recommendation of screening for paroxysmal [AFib] and could be valuable in the management of modifiable cardiovascular risk factors in patients with OSA,” they wrote.

The study findings were limited by several factors including the observational design and absence of polysomnography to assess OSA, the researchers noted. However, the study has the highest known prevalence of silent AFib in patients with moderate to severe OSA, and supports the value of screening and management for known comorbidities of OSA.

The study received no outside funding. The researchers had no financial conflicts to disclose.

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