Impact of Obstructive Sleep Apnea Treatment on Cardiovascular Disease Associated Mortality and Morbidity: A Systematic Review

The association between untreated obstructive sleep apnea (OSA) and cardiovascular disease (CVD) is well known. In this literature review, we aim to review the existing literature on treatment effects of OSA and its impact on CVD morbidity and mortality, stratified by gender. We systematically reviewed PubMed, Medline, and Scopus per PRISMA guidelines and included 25 studies in the final review. Primary outcomes were CVD-associated morbidity and mortality. Out of 25 studies, 10 were meta-analysis, 8 observational, and 7 randomized controlled trials. The treatment modality was continuous positive airway pressure (CPAP) in 23 studies, noninvasive positive pressure ventilation, and oral appliance therapy in 2. Secondary prevention of CVD was the endpoint in 23 studies. A total of 165,775 participants between 45 and 75 years of age, 60%-90% males, and the average Epworth Sleepiness Scale (ESS) score was 5-9. CV outcomes included myocardial infarction, angina, heart failure (HF), acute coronary syndrome (ACS), coronary artery disease (CAD), ischemic heart disease, cardiomyopathy, atrial fibrillation (AF), and hypertension. In 4 studies, CPAP was associated with a reduction in CVD mortality, and 10 studies showed improvement in morbidity. Our review of literature did not show consistent benefits in CV outcomes in OSA patients. We identified many potential research areas, especially the lack of studies demonstrating dose-dependent effect of OSA treatment on CV outcomes, especially when stratified by severity of OSA and gender. Larger prospective studies with longer follow-up will be helpful to study these parameters.