Coronary flow reserve is impaired in patients with obstructive sleep apnea

Study Objectives: Obstructive sleep apnea (OSA) is common in adult populations. Accumulating data indicate that it is independently associated with a variety of cardiovascular diseases and has prognostic importance in affected cases. In this study, we aimed to evaluate coronary flow reserve (CFR) in patients with OSA and controls. Methods: Sixty-one patients undergoing an overnight polysomnography were enrolled in this study. Patients with an apnea–hypopnea index (AHI) >5 were accepted as OSA group (n = 45) and those with an AHI <5 were taken as controls (n = 16). Using Doppler echocardiography at baseline and following dipyridamole infusion, coronary peak flow velocities were obtained. CFR was calculated as the ratio of peak diastolic flow to baseline diastolic flow. A CFR value