The objective of this single center prospective clinical trial is to evaluate the safety and efficacy of carotid Baroreflex Activation Therapy (BAT) in advanced heart failure (HFrEF). Beyond that, the primary aim of this study is to identify patients of the whole HFrEF population that are most likely to benefit from this new promising therapy.

Baroreflex activation therapy (BAT) is a new treatment option for patients (pts) suffering from heart failure with reduced left ventricular ejection fraction (HFrEF) to improve functional status and quality of life. Yet it is unknown which pts of the whole HFrEF population are most likely to benefit from this new promising therapy. As this invasive technique should definitely not be proposed for all HFrEF pts with left ventricular ejection fraction of 35 % or less the aim of this single center prospective clinical trial is to evaluate to which extent possible factors (e.g. cardiac resynchronization therapy (CRT), atrial fibrillation) may influence the response to BAT. To analyze any possible differences concerning the modulation of the autonomic nervous system caused by BAT in the presence of atrial fibrillation or cardiac resynchronization therapy, heart rate variability (HRV) analyses will be performed additionally. As autonomic nervous activity plays a pivotal role in the genesis and termination of atrial fibrillation any possible impact of baroreflex activation therapy on atrial fibrillation will be examined.

Inclusion Criteria:

• chronic heart failure (NYHA functional class III)
• LVEF of 35% or less
• chronic stable Guideline-directed medical therapy (diuretic agent, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker and a beta blocker, if tolerated)
• resting heart rate between 60 and 100 beats/min
• systolic blood pressure of at least 100 mmHg

Exclusion Criteria:

• estimated glomerular filtration rate < 30 ml/min/1.73 m²
• Plaque and atherosclerosis reducing the linear diameter of the internal or distal common carotid arteries by 50% or more
• acute pulmonary edema within the last six weeks
• implantation of Pacemakers, ICDs or CRTs within the last 3 months or planned for the next three months
• life expectancy < 1 year
• body mass index > 40 kg/m²
• symptomatic uncontrolled bradyarrhythmias
• severe asthma, chronic obstructive pulmonary disease or restrictive lung disease
• active malignancy
• pregnancy

All patients suffering from advanced heart failure with left ventricular ejection fraction of 35 % or less are eligible for this study.