Heart Biomarker Evaluation in Apnea Treatment

This is a Phase II randomized controlled trial that will evaluate the effects of supplemental nocturnal oxygen or Positive Airway Pressure (PAP) therapy, compared to optimal medical preventive therapy for Cardiovascular Disease (CVD) risk, on biomarkers of CVD risk in Obstructive Sleep Apnea (OSA) patients at high risk for CVD events. The study will focus on patients with moderate to severe OSA but only mild OSA symptoms. Eligible participants have a history or symptoms of heart disease AND have symptoms of sleep apnea or snoring. Participants will be contributing to medical knowledge about different options that can be used to improve heart disease in people with sleep apnea.