Positional OSA Prevalent in Those With and Without Atrial Fibrillation, Study Finds

A study published in Sleep and Breathing found that positional obstructive sleep apnea (POSA) was common regardless of atrial fibrillation (AF) diagnosis. The researchers also found that obesity and severe OSA were associated with lower odds of POSA.

The researchers recruited patients with AF who were referred to an academic sleep medicine center and underwent diagnostic polysomnography (PSG) from January 2011 through January 2019. Patients without AF with a PSG test were identified and included retrospectively from July 2017 to December 2017.

Patients needed to be 18 years or older; those with incomplete PSG data, split-night sleep studies, continuous positive airway pressure (CPAP) titration studies, insufficient total sleep time, insufficient lateral sleep time, insufficient supine sleep time, apnea-hypopnea index (AHI) less than 5 per hour, or a supine AHI that was not recorded were all excluded from this study.

A more strict definition of POSA, “exclusive POSA (ePOSA),” was included if a patient had a nonsupine AHI less than 5/h.

The study included a total of 215 patients with OSA, with 51% also having a diagnosis of AF. The mean (SD) age of the population was 62.3 (14.4) years and 56% of the patients were male; paroxysmal AF was the most common subtype of AF, with 81% of participants.

Patients with AF had a trend of more severe OSA compared with those without AF (number of patients: mild, 40 vs 53; moderate, 35 vs 32; severe, 35 vs 20, respectively). Overall average severity of OSA was moderate (mean AHI, 26/h). AHI in both groups was lower in the nonsupine vs supine position. The overall difference in AHI between supine and nonsupine was comparable between AF and no AF groups (–13.1 vs ­­­–16.4).

POSA was present in 57% of the entire cohort whereas ePOSA was present in 24%. POSA was more common in patients with mild OSA compared with moderate OSA or severe OSA (28% vs 20% vs 17%, respectively). ePOSA prevalence was lower in the group with AF vs the no AF group (10% vs 14%). ePOSA was also more common in mild OSA compared with moderate and severe OSA (17% vs 5% vs 1%).

The researchers also found that obesity and severe OSA were associated with low odds of POSA. Men were more likely to have POSA compared with women (odds ratio [OR], 3.16; 95% CI, 1.06-10.43). Obesity and severe OSA were associated with lower odds of ePOSA and older age was linked with higher odds of ePOSA.

There were some limitations to this study. Selection bias is likely due to the inclusion of only patients referred for a diagnostic PSG. Patients with split night studies were excluded, which may have introduced bias. Patients with and without AF had PSG tests in different time periods. The diagnosis and burden of AF is difficult to assess without repeated or continuous monitoring. The heterogeneity of the AF population may have influenced the results.

The researchers concluded that POSA is common in patients with and without AF and in those with mild OSA; OSA severity was also associated with POSA. A nonsupine sleep position should be considered in patients with AF who exhibit POSA.

Reference

Stafford PL, Harmon E, Patel P, et al. Positional obstructive sleep apnea in patients with atrial fibrillation. Sleep Breath. Published online May 10, 2022. doi:10.1007/s11325-022-02625-y