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-disordered breathing in consecutive patients referred for angina evaluation, and analyzed the parameters influencing the severity of sleep-disordered breathing. Methods: In all, 68 consecutive patients (53 men, 15 women, aged 63.4 +/- 10.0 years) referred for angina evaluation were studied. Coronary angiography, selective left ventriculography. and a polygraphic study with a validated six-channel monitoring device were performed. Full-night polysomnography was used to reevaluate patients with an apnea/hypopnea index greater than or equal to 10/h. Results: Sleep-disordered breathing as defined by an apnea/hypopnea index greater 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 the severity of sleep-disordered breathing was significantly and independently associated with left ventricular ejection fraction (r = -0.38; p = 0.002). but not with age, body mass index, gender, diabetes mellitus, hypertension, hyperuricemia, hypercholesterolemia, smoking habits, or coronary artery disease. In this group of patients, multiple logistic regression analysis could not demonstrate sleep-disordered breathing to be an independent predictor of coronary artery disease. Conclusions: Sleep-disordered breathing is common in patients referred for angina evaluation. The degree of sleep-disordered breathing is mainly determined by the extent of left ventricular dysfunction.