Measuring therapeutic efficacy in the treatment of central sleep apnoea in patients with heart failure.

The goal of treating sleep disordered breathing (SDB) has traditionally focused on improving daytime sleepiness and fatigue. In heart failure (HF) patients with SDB, this is not as easy to ascertain as their symptoms overlap with HF. Thus, improvement in treating SDB in HF patients must focus more on overall quality of life. Over the past 5 years, there has been a shift in sleep medicine from only improving symptoms in SDB, to preventing the long term consequences. The specialist Heart Failure community is, however, desirous of also seeing benefit in reduction of major clinical events for their patients with interventions, such as effects on mortality or re-hospitalisation rates and so may wish to see other benefits beyond a reduction in sleep apnea events before either commencing therapy or referring their patients for sleep study evaluation and further management. To expect lower mortality as well may be asking for too much. Consequently, success in the treatment in SDB should focus on three items: 1) proof that the underlying disease is treated, 2) symptomatic benefit and 3) demonstration that the pathological consequences are prevented. These benefits must then be balanced with a strong safety profile. Here we evaluate a variety of end-points of value to our CSA patients, in an effort to see what may reasonably be required for treating physicians to recommend an intervention for their CHF patients with CSA by looking at candidate measures of treatment success in CSA within a heart failure population.