Introduction on Sleep-disordered Breathing in Heart Failure
Despite advances in therapy, heart failure (HF) continues to be a leading cause of hospitalisation in those over 65.1 Around 2 % of people in Europe live with HF and as many as 10 % of those over 75 years are affected.2 Prognosis continues to be poor, with approximately half of patients dying within 5 years of first hospitalisation,3 a more severe prognosis than many malignancies.4
Sleep-disordered breathing (SDB) may comprise obstructive sleep apnoea (OSA) or central sleep apnoea (CSA), although many patients have a mixed pattern that may change during the course of a night.5 SDB is common in HF with either reduced or preserved ejection fraction (EF) – around 50 % of patients are affected compared with less than 10 % of the general population.6,7
SDB is associated with an increased morbidity and mortality in patients with HF and there is some evidence that it is not merely a marker of poor prognosis, but may be a process with independent pathophysiological consequences that may accelerate the natural history of HF. It remains under-diagnosed and may be a therapeutic target in some patients.
This article reviews the aetiology and mechanisms of SDB and the current evidence for the investigation and management of this condition in patients with HF. The SERVE-HF randomised outcome trial8 has recently reported some unexpected results that have changed our view of CSA and this will be discussed.