Sleep-disordered breathing in patients with symptomatic heart failure -: A contemporary study of prevalence in and characteristics of 700 patients

Aim: Evaluation of the prevalence and nature of sleep-disordered breathing (SDB) in patients with symptomatic chronic heart failure (CHF) receiving therapy according to current guidelines. Methods and results: We prospectively screened 700 patients with CHF (NYHA class >= 11, LV-EF <= 40%) for SDB using cardiorespiratory polygraphy (Embletta (TM)). Furthermore, echocardiography, cardiopulmonary exercise and 6-min walk testing were performed. Medication included ACE-inhibitors and/or AT1-receptor blockers in at least 94%, diuretics in 87%, beta-blockers in 85%, digitalis in 61% and spironolactone in 62% of patients. SDB was present in 76% of patients (40% central (CSA), 36% obstructive sleep apnoea (OSA)). CSA patients were more symptomatic (NYHA class 2.9 +/- 0.5 vs. no SDB 2.57 +/- 0.5 or OSA 2.57 +/- 0.5; p < 0.05) and had a lower LV-EF (27.4 +/- 6.6% vs. 29.3 +/- 2.6%, p < 0.05) than OSA patients. Oxygen uptake (VO2) was lowest in CSA patients: predicted peak VO2 57 +/- 16% vs. 64 +/- 18% in OSA and 63 +/- 17% in no SDB, p < 0.05. 6-min walking distances were 331 Ill m in CSA, 373 108 m in OSA and 377 118 m in no SDB (p < 0.05). Conclusions: This study confirms the high prevalence of SDB, particularly CSA in CHF patients. CSA seems to be a marker of heart failure severity. (c) 2006 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.