Late Breaking Abstract - Prevalence and incident subclinical atherosclerosis in obstructive sleep apnea. The EPIOSA study

<bold>Background:</bold> Obstructive sleep apnea (OSA) is associated with cardiovascular diseases (CVD). If this may reflect differential vulnerability to early atherosclerosis is unknown. <bold>Aim</bold>. To study the impact of OSA on prevalent and incident subclinical atherosclerosis (SA) in patients without cardiovascular risk factors. <bold>Methods:</bold> 442 patients aged 20 to 70 who consecutively attended the Sleep Unit of the Hospital Miguel Servet in Zaragoza-Spain, were selected for lacking concomitant CVD or CVD risk factors and included in the EPIOSA study (GovTrials, NCT01457542111). The 10-year SCORE2 CVD risk was calculated. Bilateral carotid ultrasound were performed at baseline and every 18 to 24 months. SA was defined if ≥1 atheroma plaque was present. The relationship between OSA and SA was analyzed with multivariable regression logistic models. Development of at least ³ 1 new atheroma plaques rates were compared between those OSA patients treated and non-treated with positive airway pressure (PAP) using Cox proportional hazard models. <bold>Results:</bold> Prevalence of SA was significantly higher in OSA (AHI ³ 15 events/h) than in non-OSA group (30% vs 13% respectively). After adjusting for SCORE2, BMI, physical activity and education level, OSA patients were more likely than non-OSA to have SA (OR: 1.97; 95% CI: 1.10-3.54; P = 0.023). During a mean follow-up of 7.5 years, 26% of subjects treated with PAP develop new atheroma plaques vs 33% in patients non-treated with PAP (adjusted HR: 0.75; 95%CI, 0.37-1.58). <bold>Conclusions:</bold> OSA patients seem more vulnerable to early subclinical atherosclerosis than non-OSA. Treatment with PAP seem to slow the progression of SA in the medium-large term.