Sleep-disordered breathing in patients referred for angina evaluation - Association with left ventricular dysfunction

Background: Clinical observations have linked sleep-disordered breathing to cardiovascular morbidity and mortality, and especially to coronary artery disease. Hypothesis: The study was undertaken to determine the prevalence of sleep-d isordered breathing in consecutive patients referred for angina evaluation, and analyzed the parameters influencing the severity of sleep-disordered b reathing. Methods: In all, 68 consecutive patients (53 men, 15 women, aged 63.4 +/- 1 0.0 years) referred for angina evaluation were studied. Coronary angiograph y, selective left ventriculography. and a polygraphic study with a validate d six-channel monitoring device were performed. Full-night polysomnography was used to reevaluate patients with an apnea/hypopnea index greater than o r equal to 10/h. Results: Sleep-disordered breathing as defined by an apnea/hypopnea index g reater than or equal to 10/h was found in 30.9% of patients; its prevalence was not increased in patients with and without coronary artery disease (26 .5 vs. 42.1). Multiple stepwise Linear regression analysis revealed that th e severity of sleep-disordered breathing was significantly and independentl y associated with left ventricular ejection fraction (r = -0.38; p = 0.002) . but not with age, body mass index, gender, diabetes mellitus, hypertensio n, hyperuricemia, hypercholesterolemia, smoking habits, or coronary artery disease. In this group of patients, multiple logistic regression analysis c ould not demonstrate sleep-disordered breathing to be an independent predic tor of coronary artery disease. Conclusions: Sleep-disordered breathing is common in patients referred for angina evaluation. The degree of sleep-disordered breathing is mainly deter mined by the extent of left ventricular dysfunction.