SERVE-HF identified a specific at-risk patient population. The harmful effects of ASV correlate with pre-existing LV systolic impairment and the mortality risk is in patients with LVEF<45%. ASV therapy is contraindicated in patients with chronic, symptomatic heart failure with reduced left ventricular ejection fraction (LVEF ≤ 45%) and moderate to severe predominant central sleep apnoea.
Reduced LVEF should be excluded before using ASV.1 It is therefore important to ensure that LVEF is >45% and echocardiography is recommended for this purpose.
Some patients – especially if referred by a cardiologist – may already have undergone echocardiography so it is worthwhile checking their medical notes. If not, a cardiology referral may be worth considering, as a high proportion of patients with SDB have some form of underlying cardiac disease.
The mortality risk observed in SERVE-HF was seen in a high-risk group of patients with systolic heart failure and predominantly central sleep apnoea. This group is not representative of all patients who may be eligible for ASV therapy.
Informed by these findings, experts1,2,3,4 in the field agree that patients with LVEF≥45% remain eligible for ASV whenever there is a clinical rationale for using it.
Since May 2015, the French and German healthcare authorities have agreed to limit the contra-indication to heart failure with reduced EF ≤45%.5
Experts’ statements confirm that ASV is eligible in these different situations1,2,3,4
French Langage Pneumology Society. It was essential to [ensure] that these results, obtained in a very precise and very fragile population which is not representative of the majority of current indications of ASV, [would not be extrapolated to] pathologies with different mechanisms and for which the use of ASV remains fully effective. This is of course the case of the treatment of central sleep apnoea secondary to stroke or related to a complex sleep apnoea syndrome for example. But this is also the case of heart failure with preserved ejection fraction.
French Society of Sleep Research and Medicine. Data from the literature advocate the continued use of ASV in different indications, including heart failure with preserved LVEF, complex sleep apnoea syndrome, opioid-induced central sleep apnoea syndrome, idiopathic central SAS, and central SAS due to a stroke.
German Society of Sleep Research and German Society of Sleep Medicine Pneumology. It should be stressed that all statements relate exclusively to patients with heart failure New York Heart Association Functional Classification II-IV (NYHA II-IV) and an ejection fraction ≤45%. That is that the therapy can be continued unchanged in patients:
American Academy of Sleep Medicine. Adaptive servo-ventilation (ASV) targeted to normalize the apnoea-hypopnea index (AHI) can be used for the treatment of CSAS related to CHF in adults with an ejection fraction >45% or mild CHF-related CSAS.