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≥II, LV‐EF≤40%) for SDB using cardiorespiratory polygraphy (Embletta™). 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%, β‐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 (VO 2 ) was lowest in CSA patients: predicted peak VO 2 57±16% vs. 64±18% in OSA and 63±17% in no SDB, p <0.05. 6‐min walking distances were 331±111m in CSA, 373±108m in OSA and 377±118m 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.