What is the Barostim Device?
The Barostim device is an implantable neuromodulation system that electronically activates carotid sinus baroreceptors to reduce sympathetic nervous system activity and enhance vagal tone, primarily used as adjunctive therapy for resistant hypertension and heart failure with reduced ejection fraction when conventional medical therapy fails. 1, 2
Device Components and Mechanism
The Barostim system consists of three key components that work together to modulate the autonomic nervous system 1:
- Baroreflex activation leads placed adjacent to the carotid sinus (unilateral placement in the current-generation Barostim Neo system) 3, 4
- Implantable pulse generator that delivers electrical stimulation
- External programming system that allows titration of stimulation parameters in approximately 4-minute intervals to meet individual hemodynamic requirements 1
Physiological Effects
The device works by electrically stimulating baroreceptors in the carotid sinus, which signal the brainstem to orchestrate a multisystemic cardiovascular response 1:
- Reduces sympathetic nervous system activity and enhances vagal activity, addressing the autonomic imbalance seen in resistant hypertension and heart failure 1, 2
- Slows heart rate, allowing greater left ventricular filling time and reducing cardiac workload and energy demands 1
- Causes arterial dilation, reducing cardiac afterload 1
- Improves renal blood flow, which augments natriuresis (sodium excretion) 1
- Decreases levels of angiotensin II, vasopressin, and atrial natriuretic peptide while improving baroreflex sensitivity 2
Clinical Indications
According to the American College of Cardiology and American Heart Association, Barostim therapy is indicated for 2:
- Resistant hypertension: Patients who remain uncontrolled on three antihypertensive medications (including a diuretic) after confirming true resistance and excluding pseudo-resistance and medication non-adherence 2
- Heart failure with reduced ejection fraction (HFrEF): Patients with severe symptoms despite optimal medical therapy 2, 5
Clinical Evidence and Current Status
The evidence base for Barostim has evolved through multiple generations of the device 1:
- First-generation Rheos system: A large randomized trial in 322 participants with resistant hypertension failed to meet its primary composite endpoint, though the device was considered safe and efficacious long-term 1
- Second-generation Barostim Neo system: This unilateral system has shown promising results in smaller studies with improved safety profile compared to the bilateral first-generation device 3, 4
- Blood pressure reductions: Studies have reported average decreases in systolic blood pressure of 38,36,40, and 53 mmHg at 1,2,3, and 4 years respectively in patients with resistant hypertension 6
- Heart failure benefits: Limited randomized studies show the device can improve heart failure symptoms, decrease neuroendocrine activation, and improve quality of life 3, 5
Important caveat: Despite these results, large randomized controlled trials demonstrating reduction in cardiovascular events are still lacking, so the device's efficacy and safety cannot be conclusively assessed 3. The American Heart Association notes that device therapy for resistant hypertension remains investigational 1.
Safety Profile and Contraindications
The European Society of Cardiology specifies that Barostim therapy is not recommended for 2, 7:
- Patients with moderate to severe renal impairment (eGFR <40 mL/min/1.73 m²) 2, 7
- Patients with secondary hypertension 2, 7
The implantation procedure carries risks comparable to other active implantable devices, with the second-generation unilateral system having a better safety profile than the first-generation bilateral system 6, 4.
Implementation Requirements
For appropriate use of Barostim therapy 2:
- Multidisciplinary assessment and shared risk-benefit discussion are required before implantation 2
- Regular follow-up visits are necessary to monitor and adjust device parameters to minimize side effects 2
- Procedures should be performed in medium to high-volume centers to ensure quality and safety 2
- True resistant hypertension must be confirmed after excluding pseudo-resistance, medication non-adherence, and secondary causes 2, 7