Substudy on the Mechanistic Plausibility of the Clinical Benefits of Adaptive Servo-ventilation

The purpose of this study is to assess changes in left ventricular performance using echocardiography as well as ventricular remodelling, changes in sleep and changes in mood, anxiety and cognitive functions occurring as a result of treatment of predominant central sleep apnoea by adaptive servoventilation (ASV) in chronic heart failure in addition to optimal medical therapy in chronic heart failure. This will be a substudy of the SERVE-HF study.

This substudy is performed within the SERVE-HF Study, a randomised, multi-centre,international trial with parallel group design, with patients randomised to either control (optimal medical management) or active treatment (optimal medical treatment plus use of adaptive servoventilation) in a 1:1 ratio. The randomization will be the same as in the parent study. For this purpose, the randomization of the parent study will be stratified as to whether a patient is included in the substudy or not. 300 patients will be recruited for the substudy overall.

For the purpose of this substudy, patients will be followed up for a period of 12 months.

The following extra tests will be performed at the baseline visit, the 3 months follow up and the 12 months follow up:

* Echocardiogram (for both groups)
* cMRI (for both groups)
* PSG (at the baseline visit only for patients in the treatment group and at 3 months follow up and the 12 months follow up for all patients)
* 4 questionnaires (for both groups)
* Additional blood testing (for both groups)

Eligibility Criteria:
The inclusion and exclusion criteria are mainly those applicable for the parent study; SERVE-HF. The inclusion and exclusion criteria are listed here.

INCLUSION CRITERIA FOR SERVE-HF STUDY:

* Over 22 years of age
* Severe Chronic Heart Failure (CHF) with NYHA class III-IV or NYHA class II with at least one hospitalisation for HF within the last 24 months
* Left ventricular ejection fraction (LVEF) less than or equal to 45% by means of echocardiography, radionucleotide angiography, left ventriculography or cardiac MRI documented less than 12 weeks before randomisation
* Diagnosis of sleep disordered breathing (SDB) with an apnoea-hypopnoea-index (AHI) of \>15/hr with at least 50% central events and a central AHI of at least 10/hr
* Clinically stable with no change in medication and no unplanned hospitalisation for heart failure in preceding month
* Optimised medical treatment according to the applicable guidelines
* Able to provide informed consent

ADDITIONAL INCLUSION CRITERIA FOR THE SUBSTUDY

• Predominant central sleep apnoea (apnoea hypopnoea index \> 15/hour with ≥ 50% central events and a central AHI ≥10/hour, derived from full polysomnography (based on total sleep time), documented less than 4 weeks before randomization. Flow measurements have to be performed with nasal cannula

EXCLUSION CRITERIA FOR THE SERVE-HF STUDY:

* Significant chronic obstructive pulmonary disease (COPD) with Forced Expiratory Volume within one second (FEV1)\<50% predicted
* Oxygen saturation at rest during the day 90% at the time of inclusion
* Current use of Positive Airway Pressure (PAP) therapy
* Life expectancy \< 1 year for diseases unrelated to chronic heart failure
* Cardiac surgery, Percutaneous coronary intervention (PCI), Myocardial Infarction (MI) or unstable angina within 6 months prior to randomisation
* Implantation of ICD (implanted cardiodefibrillator) or CRT (cardiac resynchronisation therapy) scheduled or within 6 months prior to randomisation
* Transient ischemic attack (TIA) or Stroke within 3 months prior to randomisation
* Primary hemodynamically significant uncorrected valvular heart disease, obstructive or regurgitant, or any valvular disease expected to lead to surgery during the trial
* Acute myocarditis/pericarditis within 6 months prior to randomisation
* Untreated or therapy refractory Restless legs Syndrome (RLS)
* Pregnancy

ADDITIONAL EXCLUSION CRITERIA FOR THE SUBSTUDY

* Amyloidosis, hypertrophic obstructive cardiomyopathy or arteriovenous fistulas
* Dosage changes of diuretics more than doubled within the last 4 weeks prior to randomisation