Abstract 12619: Positional Obstructive Sleep Apnea and Risk of Atrial Fibrillation

Introduction: Obstructive sleep apnea (OSA), a common sleep disorder, has been associated with the risk of atrial fibrillation (AF). OSA is a heterogenous condition but is heavily position-dependent. Positional OSA (POSA) is a common form of OSA in which OSA is predominantly manifested in a supine position. The implication of POSA in cardiovascular risks is unclear. This study aimed to examine whether the risk of AF is different between individuals with POSA and those with non-positional OSA (nPOSA).

Methods: We identified individuals with OSA (AHI ≥ 5/h) from the Sleep Heart Health Study (SHHS) cohort. POSA was defined if overall AHI ≥ 5/h, supine AHI ≥ 5/h, and supine AHI greater than twice the non-supine AHI based on the SHHS visit 1 sleep study. Incident AF was deemed present if detected on a 12-lead ECG during the SHHS visit 2 or confirmed by the parent cohorts at any time between the baseline PSG and the final follow-up date for AF assessment. Multiple logistic regression analysis was conducted with covariates including age, race, gender, body mass index, smoking status, systolic blood pressure, use of hyperlipidemia medication, use of diabetes medication (oral or insulin), use of hypertension medication, cholesterol, triglyceride, and high-density-lipoprotein, and other sleep characteristics (total sleep duration, sleep efficiency, and sleep onset latency).

Results: The study included a total of 1712 participants (females, 45%; mean age, 65 years old) with OSA. Compared with individuals with nPOSA, those with POSA were more likely to be white (p=.002), older (p<.043), have lower AHI (p<.001), lower BMI (p<.001), lower systolic blood pressure (p<.001), and lower triglyceride (p=.029), longer sleep duration (p=.002), and less likely to take hypertension medication (p<.001). After accounting for these differences, the odds of incident AF were about 30% lower in the individuals with POSA compared with those with nPOSA (OR=0.7, p=.037).

Conclusions: Individuals with OSA exhibit a lower risk of AF when they have POSA. While it is possible that residual confounding could account for this finding, we conclude that POSA might represent a unique phenotype with distinct cardiovascular implications.