This article is more than 5 years old. Information may no longer be current.
Central sleep apnea device increases mortality in patients with HF
LONDON — Adaptive servo-ventilation had no significant impact on the primary composite endpoint of all-cause mortality, lifesaving CV intervention or unplanned hospitalization for worsening HF compared with medical management alone in certain patients with HF, according to results of the SERVE-HF trial.
However, adaptive servo-ventilation was associated with increased mortality in patients with central sleep apnea and HF with reduced ejection fraction, according to the findings, which were presented at European Society of Cardiology Congress.
The study included 1,325 patients (left ventricular EF < 45%; mean apnea-hypopnea index, ≥ 15 events per hour; mean age, 69 years; 90% men) with chronic HF with reduced ejection fraction (HFrEF) who were randomly assigned to receive guideline-based medical management alone or with the addition of adaptive servo-ventilation (ASV). The trial was conducted at 91 centers in 11 countries.
Median follow-up was 31 months. During follow-up, the incidence of the primary endpoint was 54.1% in the ASV group vs. 50.8% in the control group (HR = 1.13; 95% CI, 0.97-1.31; P = .1), researchers found. However, all-cause mortality (HR = 1.28; 95% CI, 1.06-1.55; P = .01) and CV mortality (HR = 1.34; 95% CI, 1.09-1.65; P = .006) were significantly increased in the ASV group.
At a press conference, Martin R. Cowie, MD, professor of cardiology, National Heart and Lung Institute, Imperial College London, said these results are a “game changer” for management of central sleep apnea this population.
Quality of life measures, NYHA functional class and symptoms were similar between the ASV and control groups. Six-minute walk test distance declined in both groups, but to a greater extent among patients assigned ASV (P = .04).
ASV effectively controlled sleep-disordered breathing, Cowie said. Mean apnea-hypopnea index improved from 31.2/h at baseline to 6.2-6.8/h during 48 months of treatment and mean central apnea-hypopnea index improved from 25.2/h to 3.2-4/h (P < .001 for both).
Rates of ASV use were constant during the study period, about 4 hours per night. The recommended treatment duration was 5 hours per night, 7 days per week.
ASV is a noninvasive ventilator therapy that supports inspiration when breathing amplitude is reduced and ensures sufficient respiration when respiratory effort is absent. Upper airway patency is ensured by provision of end-expiratory pressure. Although algorithms employed by different ASV devices vary, the principle of treatment is the same: back-up rate ventilation with adaptive pressure support, Cowie said during a press conference.
“The addition of ASV to guideline-based medical management does not improve outcomes in patients with HFrEF and predominant central sleep apnea, despite effective control of sleep apnea,” Cowie said. He noted that the findings of the SERVE-HF trial are inconsistent with results from previous smaller and observational studies.
A possible explanation for the results is that central sleep apnea may be a compensatory mechanism in this patient population. Another hypothesis is that positive airway pressure may impair cardiac function in specific patients with HF, according to the researchers.
“The pathophysiology of the increased mortality with ASV remains to be elucidated,” Cowie said.
The researchers noted that these findings apply only to the population of HFrEF patients studied and, at this time, cannot be generalized. – by Katie Kalvaitis
References:
Cowie MR, et al. Hot Line V: Heart Failure. Presented at: European Society of Cardiology Congress; Aug. 29-Sept. 2, 2015; London.
Cowie MR, et al. N Engl J Med. 2015;doi:10.1056/NEJMoa1506459.
Disclosure: The SERVE-HF study was funded by ResMed Ltd. Cowie reports receiving research funding and consultant fees from ResMed Ltd.
Perspective
Back to Top
There are two different types of sleep apnea: central and obstructive. We know that sleep apnea in general is a risk factor for the development of HF, but also if a patient has HF and sleep apnea, it creates a comorbid disease state that can make HF worse in multiple ways. The setting of this trial was to see if treatment of central sleep apnea would improve outcomes in HF.
An important takeaway is that all-cause and CV mortality were higher in patients treated with ASV. This is a somewhat surprising and concerning finding. We need to be cautious about the use and interpretation of these findings. The results cannot be generalizable to all patients [with HF and with sleep apnea]. Patients should talk to their physicians, but not assume that the type of sleep apnea therapy they have is the one that was studied in this trial. Also, this was a patient population with HFrEF — not all patients with HF. Another important point is that 90% of all patients in this trial were men. Although the data are important, we cannot extrapolate the findings to all of our HF patients and all of our female patients.