In the general population, the prevalence of CSA is less than 1% (Bixler et al., 1998), but it has been reported in 2–37% of patients with heart failure and in 3–72% of patients who have had a stroke (Randerath et al., 2017). Treatment-emergent central sleep apnea (TE-CSA) can also be observed in patients treated with opioids and in patients treated with continuous positive airway pressure (CPAP) (Baillieul et al., 2019).
As with OSA, CSA is more likely in men than women but there are specific subpopulations in which CSA is over-represented.
Patients with heart failure: CSA is highly prevalent in patients with stable congestive heart failure with reduced ejection fraction (HFrEF) and in those with preserved ejection fraction (HFpEF) (Randerath et al., 2017). Data from a large, long-term, observational study showed increased mortality in hospitalised HFrEF patients with CSA (Cowie et al., 2015; Khayat et al., 2015).
Patients who have suffered a stroke: Evidence shows that CSA is often present in patients following stroke (Randerath et al., 2017). OSA is more prevalent than CSA following stroke and it is likely that CSA is a sequel to extensive cerebrovascular events. Brainstem stroke (comprising at least 10% of all ischaemic strokes) has been shown to predispose CSA (Baillieul et al., 2019).
Patients treated with opioids: While literature in this area is limited, there is solid evidence that CSA and irregular breathing may be induced and maintained by opioids (Randerath et al., 2017). In a study of patients on opioid therapy for chronic pain, CSA was reported in 24% and there was a direct relationship between the central apnea index and the daily dosage of methadone (Webster et al., 2008).
Patients treated with CPAP: CSA may emerge or persist in some patients with OSA treated using CPAP. CSA following CPAP initiation may spontaneously resolve within a few weeks or be persistent (Baillieul et al., 2019).
Like OSA, CSA is associated with snoring and important complications which include frequent night-time awakenings, excessive daytime fatigue and increased risk of adverse cardiovascular events and mortality (Eckert et al., 2007).