What is the effectiveness of Barostim in treating heart failure and resistant hypertension?

Barostim Effectiveness in Heart Failure and Resistant Hypertension

Barostim (baroreflex activation therapy) shows meaningful improvements in heart failure symptoms, quality of life, and exercise capacity in HFrEF patients, but is not recommended as standard therapy for resistant hypertension due to lack of large randomized outcome trials demonstrating cardiovascular event reduction.

Current Guideline Position

The most recent 2024 ESC Guidelines do not include Barostim as a recommended treatment option for resistant hypertension 1. The 2018 AHA Scientific Statement on resistant hypertension notes that device-based sympatholytic treatments, including baroreceptor stimulation, "await clarification" and that "validation of true benefit has not been confirmed in rigorous, double-blind comparisons with sham intervention" 1. The role of baroreceptor activation therapy remains investigational pending results from ongoing studies 1.

For heart failure, current guidelines focus on proven pharmacologic therapies (ACE inhibitors/ARBs, beta-blockers, MRAs, SGLT2 inhibitors) without mentioning device-based neuromodulation like Barostim 1.

Evidence for Heart Failure with Reduced Ejection Fraction

Symptomatic and Functional Improvements

The strongest evidence comes from a 2022 patient-level meta-analysis of randomized controlled trials in HFrEF patients 2:

• 6-minute walk distance improved by 49 meters (95% CI 33-64 meters) at 6 months 2
• Minnesota Living With Heart Failure quality of life score improved by 13 points (95% CI -17 to -10) 2
• 3.4-fold higher odds of improving at least one NYHA class (95% CI 2.3-4.9) 2
• These improvements were consistent across 554 randomized patients 2

Cardiac Function Effects

A 2023 single-center registry of 30 HFrEF patients showed 3:

• LVEF improved from 25.5% to 30.0% at 12 months (P=0.014) 3
• NYHA class improved in 19 of 24 evaluable patients (P<0.001) 3
• NT-proBNP showed numerical but non-significant decrease 3

The meta-analysis found NT-proBNP improvements were most evident in patients with baseline NT-proBNP <1600 pg/mL 2.

Evidence for Resistant Hypertension

Blood Pressure Reduction

The first-generation Rheos device demonstrated blood pressure lowering in the double-blind, randomized Rheos Pivotal Trial 4. However, for the currently used unilateral Barostim Neo system, no data from large randomized trials exist 4.

A 2014 cost-effectiveness analysis based on the Rheos trial and DEBuT-HT follow-up estimated that Barostim reduced lifetime rates of 5:

• Myocardial infarction by 19%
• Stroke by 35%
• Heart failure by 12%
• End-stage renal disease by 23%

Critical limitation: These are modeled projections, not actual clinical outcomes from randomized trials 5.

Safety Profile

Barostim appears safe with successful implantation in all reported cases 3. A 2021 review noted "preliminary clinical investigations have given promising results with an encouraging safety profile" 6.

Patient Selection Considerations

Optimal Candidates for HFrEF

Based on the meta-analysis, improvements were similar or better in patients with baseline NT-proBNP <1600 pg/mL, regardless of cardiac resynchronization therapy indication 2.

High-Risk Patients

The single-center registry identified poor outcomes despite BAT in patients with 3:

• NYHA Class IV at baseline
• NT-proBNP >1600 pg/mL
• eGFR <30 mL/min

Mortality remained high (20% at 1 year, 33% at 3 years) in this advanced heart failure population despite BAT 3. NYHA class and eGFR were independent predictors of mortality 3.

Clinical Algorithm for Consideration

For Heart Failure:

1. Optimize guideline-directed medical therapy first (ACE inhibitors/ARBs/ARNi, beta-blockers, MRAs, SGLT2 inhibitors) 1
2. Consider BAT only in patients with:
   • NYHA Class III (not IV) 3
   • LVEF <35% despite optimal therapy 3
   • NT-proBNP <1600 pg/mL for best response 2
   • eGFR ≥30 mL/min 3
3. Patient selection is crucial—BAT appears most beneficial in earlier disease stages, not advanced heart failure 3

For Resistant Hypertension:

1. Follow standard guideline-recommended approach first 1:
   • Confirm true resistance (exclude white-coat effect, nonadherence)
   • Optimize lifestyle (sodium restriction <2400 mg/day)
   • Ensure appropriate 3-drug regimen (RAS blocker, CCB, long-acting thiazide/thiazide-like diuretic)
   • Add spironolactone as fourth-line agent 1
2. Do not routinely consider Barostim until large randomized outcome trials demonstrate cardiovascular event reduction 1, 4

Key Limitations and Caveats

The fundamental problem is the absence of large randomized trials showing reduction in hard cardiovascular outcomes (death, myocardial infarction, stroke) 4. The 2018 German review concluded: "BAT's efficacy and safety cannot be conclusively assessed" due to this evidence gap 4.

For heart failure, while symptomatic improvements are encouraging, the impact on heart failure hospitalization and death is not yet established 3. Experience in clinical routine remains limited 3.

Barostim remains investigational and should not replace proven pharmacologic therapies that have demonstrated mortality benefit in large randomized trials 1, 4.