Coronary Artery Endothelial Dysfunction Associated With Sleep Apnea

Abstract

There is little information about coronary artery endothelial dysfunction in patients with sleep apnea. We evaluated relation between severity of sleep apnea and coronary artery endothelial dysfunction. In all, 26 patients without significant coronary stenoses were enrolled. Endothelial function was estimated by measuring coronary vasoreactivity in response to acetylcholine infusion (10-7 mol/L) into coronary arteries. Vasoconstriction rate was defined as ([lumen diameter after isosorbide dinitrate injection - lumen diameter after acetylcholine injection]/lumen diameter after isosorbide dinitrate injection × 100). Vasoconstriction rate was calculated at each major coronary artery and the highest value was used for that patient. Overnight sleep study was performed and the apnea-hypopnea index (AHI) was calculated as the mean number of apneas and hypopneas per hour of sleep. There was significant correlation between AHI and vasoconstriction rate (P = .04). There is significant correlation between severity of sleep apnea and endothelial function of coronary arteries.