BACKGROUND Central sleep apnea is associated with poor prognosis and death in patients with heart failure. Adaptive servo-ventilation is a therapy that uses a noninvasive ventilator to treat central sleep apnea by delivering servo-controlled inspiratory pressure support on top of expiratory positive airway pressure. We investigated the effects of adaptive servo-ventilation in patients who had heart failure with reduced ejection fraction and predominantly central sleep apnea. METHODS We randomly assigned 1325 patients with a left ventricular ejection fraction of 45% or less, an apnea–hypopnea index (AHI) of 15 or more events (occurrences of apnea or hypopnea) per hour, and a predominance of central events to receive guideline-based medical treatment with adaptive servo-ventilation or guideline-based medical treatment alone (control). The primary end point in the time-to-event analysis was the first event of death from any cause, lifesaving cardiovascular intervention (cardiac transplantation, implantation of a ventricular assist device, resuscitation after sudden cardiac arrest, or appropriate lifesaving shock), or unplanned hospitalization for worsening heart failure. RESULTS In the adaptive servo-ventilation group, the mean AHI at 12 months was 6.6 events per hour. The incidence of the primary end point did not differ significantly between the adaptive servo-ventilation group and the control group (54.1% and 50.8%, respectively; hazard ratio, 1.13; 95% confidence interval [CI], 0.97 to 1.31; P = 0.10). All-cause mortality and cardiovascular mortality were significantly higher in the adaptive servo-ventilation group than in the control group (hazard ratio for death from any cause, 1.28; 95% CI, 1.06 to 1.55; P = 0.01; and hazard ratio for cardiovascular death, 1.34; 95% CI, 1.09 to 1.65; P = 0.006). CONCLUSIONS Adaptive servo-ventilation had no significant effect on the primary end point in patients who had heart failure with reduced ejection fraction and predominantly central sleep apnea, but all-cause and cardiovascular mortality were both increased with this therapy.

Endpoint selection is a critically important step in clinical trial design. It poses major challenges for investigators, regulators, and study sponsors, and it also has important clinical and practical implications for physicians and patients. Clinical outcomes of interest in heart failure trials include all‐cause mortality, cause‐specific mortality, relevant non‐fatal morbidity (e.g. all‐cause and cause‐specific hospitalization), composites capturing both morbidity and mortality, safety, symptoms, functional capacity, and patient‐reported outcomes. Each of these endpoints has strengths and weaknesses that create controversies regarding which is most appropriate in terms of clinical importance, sensitivity, reliability, and consistency. Not surprisingly, a lack of consensus exists within the scientific community regarding the optimal endpoint(s) for both acute and chronic heart failure trials. In an effort to address these issues, the Heart Failure Association of the European Society of Cardiology (HFA‐ESC) convened a group of expert heart failure clinical investigators, biostatisticians, regulators, and pharmaceutical industry scientists (Nice, France, 12–13 February 2012) to evaluate the challenges of defining heart failure endpoints in clinical trials and to develop a consensus framework. This report summarizes the group's recommendations for achieving common views on heart failure endpoints in clinical trials.

SchlaHF registry data demonstrate a high prevalence of SDB in a representative population of stable patients with chronic HF receiving contemporary medical management. Male sex, age, body mass index, and the severity of both symptoms and left ventricular dysfunction were clinical predictors for prevalent SDB. (Prevalence, Clinical Characteristics and Type of Sleep-disordered Breathing in Patients With Chronic, Symptomatic, Systolic Heart Failure; NCT01500759).

Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnoea (OSA), but treatment compliance is often unsatisfactory. This study investigated the efficacy and cost-effectiveness of telemonitoring for improving CPAP compliance.100 newly diagnosed OSA patients requiring CPAP (apnoea-hypopnoea index >15 events·h) were randomised to standard management or a telemonitoring programme that collected daily information about compliance, air leaks and residual respiratory events, and initiated patient contact to resolve issues. Clinical/anthropometric variables, daytime sleepiness and quality of life were recorded at baseline and after 3 months. Patient satisfaction, additional visits/calls, side-effects and total costs were assessed.There were no significant differences between the standard and telemedicine groups in terms of CPAP compliance (4.9±2.2 5.1±2.1 h·night), symptoms, clinical variables, quality of life and unwanted effects. Telemedicine was less expensive than standard management (EUR123.65 EUR170.97; p=0.022) and was cost-effective (incremental cost-effectiveness ratio EUR17 358.65 per quality-adjusted life-year gained). Overall patient satisfaction was high, but significantly more patients rated satisfaction as high/very high in the standard management telemedicine group (96% 74%; p=0.034).Telemonitoring did not improve CPAP treatment compliance and was associated with lower patient satisfaction. However, it was more cost-effective than traditional follow-up.