Nasal CPAP in cardiac failure: Case not proven

Cheyne-Stokes Respiration (CSR) has long been recognized to be associated with congestive cardiac failure. It is present in al least 45% of such patients with stable disease and is a predictor of future mortality. Nasal continuous positive airway pressure (CPAP) reduces the work of breathing in congestive cardiac failure (CCF) during short-term application, and chronic therapy has been reported to improve left ventricular function and sleep quality. However, some groups report little benefit for nasal CPAP in patients with little or no sleep-disordered breathing, whether assessed during short-term or longer (up to 1 month) treatment periods. Iri studies of patients with atrial fibrillation, CPAP depressed the left ventricular ejection fraction, especially when the systemic vascular resistance was low. Differences in CPAP acclimatization and patient selection may explain these results. Treatment with oxygen or ACE inhibitors can improve sleep quality, but data showing improved cardiac function with chronic treatment are lacking. To date no study has reported a mortality benefit but all consist of small and relatively shortterm observations. Substantial questions remain to be answered before the role of CPAP in the maintenance treatment of CCF can be considered established.