Sleep apnoea in heart failure: To treat or not to treat?

<jats:title>ABSTRACT</jats:title><jats:p>Heart failure (<jats:styled-content style="fixed-case">HF</jats:styled-content>) and sleep apnoea are common disorders which frequently coexist. Two main types of apnoea occur: one is obstructive which, through recurring episodes of snoring, hypoxaemia, large negative intra‐thoracic pressures and arousals from sleep leading to downstream inflammatory and autonomic nervous system changes, is thought to be a causative factor to the development of systemic hypertension and <jats:styled-content style="fixed-case">HF</jats:styled-content>. The other type of apnoea, Cheyne–Stokes respiration with central sleep apnoea (<jats:styled-content style="fixed-case">CSR‐CSA</jats:styled-content>), is characterized by an oscillatory pattern of ventilation with a prevailing hyperventilation‐induced hypocapnia, often in the absence of significant hypoxaemia and snoring, and is thought to be a consequence of advanced <jats:styled-content style="fixed-case">HF</jats:styled-content>‐related low cardiac output, high sympathetic nervous system activation and pulmonary congestion. <jats:styled-content style="fixed-case">CSR‐CSA</jats:styled-content> may be a compensatory response to advanced <jats:styled-content style="fixed-case">HF</jats:styled-content>. Rostral fluid shift during sleep may play an important role in the pathogenesis of both obstructive sleep apnoea (<jats:styled-content style="fixed-case">OSA</jats:styled-content>) and <jats:styled-content style="fixed-case">CSA</jats:styled-content>. Studies of positive airway pressure (<jats:styled-content style="fixed-case">PAP</jats:styled-content>) treatment of <jats:styled-content style="fixed-case">OSA</jats:styled-content> and <jats:styled-content style="fixed-case">CSA</jats:styled-content> in <jats:styled-content style="fixed-case">HF</jats:styled-content> have shown short‐term improvements in cardiac and autonomic function; however, there is no evidence of improved survival. Loop gain may provide useful marker of continuous <jats:styled-content style="fixed-case">PAP</jats:styled-content> (<jats:styled-content style="fixed-case">CPAP</jats:styled-content>) responsiveness in patients with central apnoea. A greater understanding of the pathophysiology of the interaction between obstructive and central apnoea and the various types of <jats:styled-content style="fixed-case">HF</jats:styled-content>, and the mechanisms of therapies, such as <jats:styled-content style="fixed-case">PAP</jats:styled-content>, is required to develop new strategies to overcome the disabling symptoms, and perhaps improve the mortality, that accompany <jats:styled-content style="fixed-case">HF</jats:styled-content> with sleep apnoea.</jats:p>