Snoring and the risk of obstructive sleep apnea in patients with pulmonary embolism.

THE ANNUAL INCIDENCE OF PULMONARY EMBOLISM (PE) EXCEEDS 1 PER 1000 IN THE UNITED STATES, WITH AN ASSOCIATED MORTALITY OF UP TO 40%.1 PE is thought to account for 5% to 10% of deaths in hospitalized patients.2,3 If untreated, approximately one third of those who survive an initial PE die of a future embolic episode. Although risk factors for the development of PE are well established, up to 30% of cases have no identifiable cause.4 Moreover, risk-factor assessment may have important implications for both prevention and treatment of PE.5 Obstructive sleep apnea (OSA) is characterized by episodes of recurrent upper airway obstruction during sleep, leading to repetitive sleep disruption, with or without concomitant oxygen desaturation.6 Recent studies estimate that OSA affects up to 25% of the adult population in the United States.7,8 OSA is increasingly recognized as a risk factor for cardiovascular disease.9–12 Some of the proposed mechanisms whereby OSA contributes to cardiovascular complications include hemodynamic alterations,13 sympathetic nervous system activation,14 oxidative stress,15 systemic inflammation,16 hypercoagulability,10 and vascular endothelial dysfunction.17 These same pathophysiologic derangements are prothrombotic and could promote the development of venous thromboembolic disease. Several previous case reports and uncontrolled cohort studies have suggested a possible association between OSA and PE.18–23 We hypothesized that patients with PE might have an increased prevalence of OSA. We performed a prospective cross-sectional study to determine the prevalence of snoring and the risk of having OSA in patients suspected of having an acute PE.