Sleep Apnea and Incident Unprovoked Venous Thromboembolism: Data from the French Pays de la Loire Sleep Cohort

Trzepizur W, Gervès-Pinquié C, Heude B, et al. ERS 2022 Congress. Presented Sept. 5, 2022. Abstract available at: https://k4.ersnet.org/prod/v2/Front/Program/Session?e=377&session=14833

Medscape is reporting that you can add unprovoked venous thromboembolic events to the list of potential consequences of severe obstructive sleep apnea (1). That conclusion comes from a study showing that patients with obstructive sleep apnea (OSA) who had the longest nocturnal hypoxemia episodes had a twofold risk for venous thromboembolic events. The association between nocturnal hypoxemia and VTE was strongest among patients who did not use continuous positive airway pressure (CPAP) systems, reported Wojciech Trzepizur, MD, from Angers University Hospital in Angers, France. "We found that those who spent more than 6% of their nighttime with levels of oxygen in their blood below 90% of normal had an almost twofold risk of developing VTEs as compared to patients without oxygen deprivation," he said. Trzepizur and colleagues conducted a retrospective study linking cohort data to an administrative health database. They identified unprovoked VTE in patients with a suspicion for OSA and no previous VTE. They created Cox proportional hazard models to assess the association of unprovoked VTE with apnea hypopnea index (AHI) measures and nocturnal hypoxemia markers, including the time patients spent below 90% oxygen saturation (T90), oxygen desaturation index (ODI), and hypoxic burden, defined as the total area under the respiratory event-related desaturation curve. They found that after a median follow-up of 6.3 years, 104 out of 7355 patients had an unprovoked VTE. In an unadjusted hazard model, there were significant associations between VTE and T90, as well as with hypoxic burden, but not with either AHI or ODI. However, in an analysis adjusted for age, gender, body mass index, alcohol intake,  hypertension, depression, history of cardiovascular disease, statin use, type of sleep study, study site and CPAP adherence, the investigators found that only T90 remained a significant independent predictor of VTE, with a hazard ratio (HR) of 1.06, P = .02. The association between T90 and VTE strengthened as the time spent below 90% saturation increased. Patients in the highest tercile, who spent more than 6% of the time undersaturated, had an HR for VTE of 1.95 (P = .02) compared with patients with a T90 less than 1%. There were no significant differences in VTE risk between patients who used CPAP for more than 4 hours per night compared with those who either used the devices for less than 4 hours or refused CPAP.

Reference

1. Osterweil N. Obstructive Sleep Apnea Linked to Unprovoked VTE. Medscape. September 8, 2022. Available at: https://www.medscape.com/viewarticle/980453 (accessed 9/13/2022).