Obstructive sleep apnea in coronary artery disease: Impact of CPAP treatment

Obstructive Sleep Apnea in Coronary Artery Disease: Impact of CPAP treatment Helena Glantz Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden ABSTRACT Background: Obstructive sleep apnea (OSA) is common in patients with coronary artery disease (CAD). Earlier research has not investigated whether CAD patients should be screened for OSA and subsequently treated with continuous positive airway pressure (CPAP) even if they have no symptoms. This thesis investigated the prevalence and predictors of OSA in a newly revascularized CAD cohort, and further addressed the relationship between OSA and diastolic dysfunction among patients with left ventricular ejection fraction (LVEF) ≥50%. Moreover, the impact of CPAP treatment on diastolic function as well as on long-term cardiovascular outcomes was evaluated in patients with CAD and non-sleepy OSA. Methods: Patients who underwent a mechanical revascularization in Skaraborg, Sweden, between September 2005 and November 2010 (n=1,291) were invited to participate. Anthropometrics and medical history were obtained, ambulatory sleep recording was performed, and all subjects completed the Epworth Sleepiness Scale (ESS) questionnaire. OSA diagnosis was based on an apnea–hypopnea index (AHI) ≥15/h, and no OSA was defined as an AHI <5/h. Left atrial diameter, myocardial relaxation velocity (é), and the ratio of early diastolic mitral flow to myocardial relaxation velocity (E/é) were evaluated as echocardiographic diastolic function parameters at baseline, three months, and one year. The long-term primary endpoint was the first event of new revascularization, myocardial infarction, stroke or cardiovascular death. Intention-to-treat (ITT) and on-treatment analyses were performed for evaluation of the impact of CPAP in the randomized controlled arm of the CAD patients with non-sleepy OSA (ESS score