Baroreflex activation therapy for resistant hypertension: results from mid-term prospective ambulatory blood pressure registry
Authors: Sindt M , Madej T , Grimm S , Knaut M 
Published: November 2020

Abstract

Objectives
First generation baroreflex activation therapy (BAT) devices showed clinical efficacy in patients with drug-resistant arterial hypertension (AHT), but the safety profile was insufficient. Data regarding efficacy of second-generation devices were generated mostly from office blood pressure (BP) measurements or short-term 24-hour ambulatory blood pressure measurements (ABPM). We present a mid-term prospective registry to evaluate the efficacy and safety of recent BAT devices.

Purpose
The purpose of our study was to find a method that helps patients with drug-resistant arterial hypertension to control their blood pressure. Further we sought to reduce the overall amount of antihypertensive drugs to lessen side effects, as well as the effects of polypharmacy.

Methods
All patients receiving Barostim neo between November 2013 and June 2019 for resistant AHT were prospectively included into this observational study. ABPM was performed at baseline, in 3-month intervals in the first year after BAT implantation and in 6-month intervals afterwards for up to 42 months. Patients were assigned into two groups of responders and non-responders. Non-responders had a mean blood pressure drop (BPD) below 5mmHg. Responders in turn were categorized into 3 sub-groups (low-BPD between 5–9 mmHg, medium-BPD between 10–19 mmHg and high-BPD ≥20 mmHg). The primary efficacy end-points were changes in systolic and diastolic BP and number of antihypertensive medications. The primary safety end point was BAT-related major adverse events (MAE).

Results
64 patients (mean age 63 years, 67% males) were included. Only patients who completed a 24-hour ABPM during a follow up were counted in the statistical analysis. We had an overall responder rate of 67.8%. Out of those 15.4% had low-BPD, 38.4% medium-BPD and 46.2% had a high-BPD. Systolic BP decreased over the 3.5-years period from 168±17 mmHg to 149±19 mmHg (n=19, mean change −18.8 mmHg; 95% confidence interval [CI]: −29.32 to −8.36; p&lt;0.0007). Diastolic BP decreased from 97±16 to 85±12 mmHg (n=19, mean change −11.7 mmHg; 95% CI: −19.2 to −4.2; p&lt;0.0021). The mean number of antihypertensive drugs was reduced from 6.9±1.3 to 5.2±1.5 (n=19, mean change −1.7; 95% CI: −0.8 to −0.27; p&lt;0.0009). The time course of primary end-points is shown in Fig.1. Freedom from BAT-related MAE was 93.5%. 4 perioperative complications (1 pocket bleeding, 1 pocket infection, 1 N. hypoglossus palsy, 1 hoarseness) resolved without residual side effects. There were five non BAT related deaths (7,8%) in the follow up period.

Conclusion
Systolic and diastolic ABP, as well as number and dosage of antihypertensive drugs decreased significantly during 3.5-years follow-up after Barostim neo implantation in 64 consecutive patients (of whom 62 completed at least one follow-up). No MAE associated with BAT were observed after the perioperative period. However, further controlled trials are needed to confirm the long-term efficacy of BAT.
Figure 1. Mean blood pressure drop

Funding Acknowledgement
Type of funding source: None