Sleep apnoea in patients with heart failure: part II: therapy.

Nasal continuous positive airway pressure (CPAP) is generally recommended for the treatment of obstructive sleep apnoea. CPAP lowers the cardiovascular morbidity and mortality associated with severe obstructive sleep apnoea. At least 50% of patients presenting with chronic heart failure (HF) have sleep apnoea; a subset of these patients may have obstructive sleep apnoea and may derive a survival benefit from CPAP. However, this population is also prone to developing central sleep apnoea, Cheyne-Stokes respiration or both (CSA/CSR), for which CPAP lowers the apnoea-hypopnoea index only partially and for which the overall effect of CPAP on survival remains to be determined, particularly as it has been observed to increase the mortality rate in subsets of patients. Other treatments may prove effective in patients with chronic HF and CSA/CSR, although none, thus far, has been found to confer a survival benefit. New ventilatory modes include bi-level positive airway pressure and automated adaptive servoventilation, the latter being most effective against CSA/CSR. Measures that can alleviate CSA/CSR indirectly include beta-adrenergic blockers and renin-angiotensin-aldosterone system inhibitors, nocturnal supplemental oxygen and cardiac resynchronization therapy (CRT). The effects of theophylline, acetazolamide and nocturnal CO(2) have also been studied. The second part of this review describes the applications and effects of therapies that are available for sleep apnoea in patients with chronic HF.