Research in context
Evidence before this study
The primary intention-to-treat analysis of the Treatment of Sleep-Disordered Breathing With Predominant Central Sleep Apnea by Adaptive Servo-Ventilation in Patients With Heart Failure (SERVE-HF) was neutral for the primary endpoint (time to first event of death from any cause, life-saving cardiovascular intervention [cardiac transplantation, implantation of a ventricular assist device, resuscitation after sudden cardiac arrest, or appropriate life-saving shock], or unplanned hospital admission for worsening heart failure) but showed a significant increase in all-cause, and cardiovascular, mortality in the adaptive servoventilation group versus the control group. However, mechanisms underlying this increase in mortality risk and outcomes in specific patient subgroups remain unclear.
Added value of this study
This multistate modelling analysis of SERVE-HF data allows the effects of adaptive servoventilation treatment on different elements of the study's composite endpoint to be determined, providing insight into potential mechanisms underlying the increased risk of cardiovascular death in patients receiving adaptive servoventilation, and defining a subgroup of heart failure patients with more severely reduced ejection fraction with predominant central sleep apnoea who do particularly badly when adaptive servoventilation is added to optimum medical treatment.
Implications of all the available evidence
Adaptive servoventilation treatment should not be used in patients with systolic heart failure with predominant central sleep apnoea due to the increased mortality risk. This risk is for sudden death, presumably due to arrhythmia, and is particularly marked in patients with the lowest ejection fraction; however, the pathophysiological mechanism of this effect remains to be elucidated.