What is Barostim (Baroreflex Activation Therapy) and what are its indications?

Barostim: What It Is and Why It's Used

Barostim (Baroreflex Activation Therapy) is a device-based treatment for resistant hypertension and heart failure that electronically activates baroreceptors in the carotid sinus to reduce sympathetic nervous system activity and enhance vagal activity, leading to improved blood pressure control and cardiac function in patients who don't respond adequately to conventional medical therapy. 1

How Barostim Works

• The system consists of baroreflex activation leads placed adjacent to the carotid sinus, an implantable pulse generator, and an external programming system 1
• It electronically activates baroreceptors that signal the brain to orchestrate a multisystemic response for disorders associated with sympathetic overactivity 1
• The stimulation reduces sympathetic nervous system activity and enhances vagal activity, resulting in several beneficial physiological effects 1
• The degree of stimulation can be titrated in approximately 4-minute periods to meet individual patient hemodynamic requirements 1

Physiological Effects

• Heart rate slowing, allowing greater left ventricular filling time and reducing cardiac workload and energy demands 1
• Arterial dilation, reducing cardiac afterload 1
• Improved renal blood flow, which augments natriuresis 1
• Decreased levels of angiotensin II, vasopressin, and atrial natriuretic peptide 1
• Improved baroreflex sensitivity 1

Indications for Barostim

Resistant Hypertension

• Indicated for patients with resistant hypertension who remain uncontrolled on a combination of three antihypertensive medications, including a diuretic 2
• Should be considered after other treatment options have been exhausted, including:
  • Intensifying lifestyle measures, particularly sodium restriction 2
  • Adding low-dose spironolactone to existing treatment 2
  • Adding other diuretics if spironolactone is not tolerated 2
  • Adding bisoprolol or doxazosin 2

Heart Failure

• May benefit patients with heart failure with reduced ejection fraction (HFrEF) 1, 3
• Studies have shown improvements in:
  • Muscle sympathetic nerve activity (31-33% reduction) 3
  • Ejection fraction 3
  • NYHA functional class 3
  • Quality of life 3
  • 6-minute hall walk distance 3
  • Reduced hospitalizations and emergency department visits for worsening heart failure (observational data) 3

Evolution of Barostim Technology

• First-generation system (Rheos) used bilateral carotid stimulation 4
• Second-generation system (Barostim neo) operates by unilateral baroreflex activation, using a completely different carotid electrode 4
• The newer unilateral system achieves similar efficacy with a simpler implantation procedure 4

Clinical Efficacy

For Resistant Hypertension

• Long-term studies show sustained blood pressure reductions:
  • Average decreases in systolic blood pressure of 38,36,40, and 53 mmHg at 1,2,3, and 4 years, respectively 5
  • Significant reduction in office mean arterial blood pressure from 169 ± 27 to 148 ± 29 mmHg systolic within 6 months 6
  • Continued reduction to 145 ± 24 mmHg after 1 year 6
• Allows reduction in antihypertensive medications from 6.6 ± 1.5 to 5.6 ± 1.8 classes 6

For Heart Failure

• Improves cardiac remodeling with reduced left ventricular mass and posterior wall thickness 5
• Reduces muscle sympathetic nerve activity 3
• Improves quality of life and functional capacities 3

Safety Considerations

• Not recommended for patients with moderate to severe renal impairment (eGFR <40 mL/min/1.73 m²) 2
• Not recommended for patients with secondary hypertension 2
• Common adverse events (mild, occurring in 97.6% of patients) include local discomfort, typically resolving with device parameter optimization 6
• Moderate adverse events (occurring in 28.6% of patients) may include hypertensive crisis, syncope, or arrhythmias 6
• Most procedure-related adverse events are directly related to the incision or anesthetic procedure 6
• Regular follow-up visits are necessary to monitor and adjust device parameters to minimize side effects 6

Patient Selection

• Suitable candidates should have true resistant hypertension, confirmed after excluding pseudo-resistance and medication non-adherence 2
• Multidisciplinary assessment and shared risk-benefit discussion are required 2
• The procedure should be performed in medium to high-volume centers to ensure quality and safety 2

Current Status

• Barostim neo is currently available in several European countries 5
• Device therapy for resistant hypertension is still considered investigational in many regions 1
• Large randomized trials showing reduction of blood pressure and cardiovascular events are still needed to conclusively assess efficacy and safety 7