Barostim Neo Research Articles

Old problem surfaces with new technology: Twiddler’s syndrome in Barostim NEO

Old problem surfaces with new technology: Twiddler’s syndrome in Barostim NEO

Abstract 13319: The Barostim Baroreflex Activation Therapy System: Safety Insights From FDA MAUDE Database

Introduction: BAROSTIM NEO® is a Baroreflex activation therapy (BAT) system which has been approved recently by FDA for patients with refractory heart failure. Post market experience of BAT related complications and performance issues have not been reported. Objective: To analyze the post-approval device failures and patient related adverse events (AE) associated with Barostim NEO® system using Manufacturer and User Facility Device Experience (MAUDE) database. Methods: A MAUDE database search was conducted on December 7, 2022, for reports received between Jan 1, 2019, to November 30, 2022. Manual search of the MAUDE database conducted using the term “Barostim” in the brand name section. The AE were adjudicated to various categories based on the review of the event description for each medical device report (MDR). Results: A total of 22 events were reported which included MDRs reported by physicians or manufacturer or both. Device related malfunction was reported in 45.5% (n=10) whereas patient related AE reported in 77.3% (n=17) cases. Of total device related AE, material split, cut or torn was most commonly reported problem (32%, n=7), followed by high impedance (13.6%, n=3) and low impedance (9.1%, n=2). Of the patient related AE, 32% (n=7) were related to clinical or subclinical infection, 18.2% (n=4) hematoma, 13.6% (n=3) heart failure or myocardial injury, 9.1% (n=2) stroke/CVA, 9.1% and 9.1% (n=2) twiddler’s syndrome. No carotid artery or jugular injury and procedure related death reported in the study period. The report is limited by the lack of information on the total number of BAT devices implanted across the country. Conclusions: This study provides a wide range of device malfunction and patient related post-approval adverse events for Barostim device which have not been reported in any clinical trial/study before. The reported complications seem to be in line with other cardiac implantable electronic devices and no BAT specific complications were noted.

EFFECT OF BAROREFLEX ACTIVATION THERAPY ON BLOOD PRESSURE: THE BAT-STUDY – A RANDOMIZED SHAM CLINICAL PILOT TRIAL

Objective: To explore the effects of baroreflex activation therapy (BAT) on blood pressure in individuals with refractory hypertension. Design and method: This investigator-initiated randomized, double-blinded sham-controlled pilot trial included five Finnish patients with refractory hypertension. Participants were found eligible if they were 18 - 70 years old with a daytime systolic ambulatory blood pressure (ABP) of 145 mmHg or higher, and/or a daytime diastolic ABP of 95 mm Hg or higher. Patients were on 3 or more antihypertensive drugs including a diuretic. A witnessed drug intake prior to ABPM was implemented. The Barostim Neo System was implanted for modulation of the autonomic nervous system by direct electrical stimulation of the carotid baroreceptors. After 1 month following implantation, all participants were randomized to either 8 months of baroreflex activation therapy (BAT-system on) or continuous pharmacotherapy (BAT-system off) followed by continuous BAT-therapy for all participants for 8 months. The complete design is outlined in the Figure. 24-hour ABP-measurements were performed per protocol. The primary outcome was defined as a change in ambulatory systolic blood pressure after 8 months of BAT, compared to pharmacotherapy. Results and conclusions: After 8 months of follow-up BAT decreased mean systolic daytime blood pressure by 11.8 mmHg in three participants randomized to BAT, while in the two remaining participants randomized to continuous pharmacotherapy mean systolic daytime blood pressure increased by 8.7 mmHg. When pooling all daytime systolic 24-hour ABP-measurements across the entire follow-up, BAT-therapy was associated with a 9.2 mmHg lower mean blood pressure as compared to continuous pharmacotherapy (143.5 mmHg [95% CI:142.2 - 144.9] vs 152.7 mmHg [151.1 - 154.2], P < 0.0001). In linear mixed models with the BAT-system's status as a fixed effect, day-time systolic blood pressure recordings from 24-hour ABP-measurements at baseline and after 8 months of follow-up were compared between individuals on BAT and continuous pharmacotherapy. Here, BAT-therapy was associated with a reduction in mean systolic day-time blood pressure of -11.7 mmHg (P < 0.0001). In conclusion, BAT-therapy may be a promising tool in lowering systolic blood pressure in individuals with refractory hypertension. Figure. Study design. ABPM = ambulatory blood pressure measurement. Device = Control of Device.

The Year in Electrophysiology: Selected Highlights From 2020

This article is the third in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the Editor-in-Chief Dr. Kaplan, the Associate Editor-in-Chief Dr. Augoustides, and the editorial board for the opportunity to continue this series; namely, the highlights of the year that pertain to electrophysiology in relation to cardiothoracic and vascular anesthesia. This third article focuses on the convergent procedure, His-bundle pacing, a comparison of subcutaneous and transvenous defibrillator therapies, the 2020 practice advisory update for the perioperative management of patients with cardiac implantable electronic devices, and a technology update regarding the Micra AV (Medtronic, Moundsview, MN), the EMPOWER leadless pacemaker (Boston Scientific, Marlborough, MA), WiSE-CRT (EBR Systems, Sunnyvale, CA), the Extravascular Implantable Cardioverter Defibrillator (Medtronic, Moundsview, MN), and the BAROSTIM NEO (CVRx Inc, Minneapolis, MN).

Baroreflex activation therapy for resistant hypertension: results from mid-term prospective ambulatory blood pressure registry

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<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<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<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

Nonpharmacologic Treatment for Heart Failure: A Review of Implantable Carotid Baroreceptor Stimulators As a Therapeutic Option.

There has been significant interest in research for the development of device-based therapy as a treatment option of heart failure (HF), whether it is with reduced or preserved ejection fraction. This is due to the high morbidity and mortality rate in patients with HF despite recent advances in pharmacologic treatment. Following the success of cardiac resynchronization therapy, baroreceptor activation therapy has emerged as another novel device-based treatment for HF. The Barostim neo was developed by CVRx Minneapolis, MN for the treatment of mild to severe HF. The device works by electrically activating the baroreceptor reflex with the goal to restore the maladaptive autonomic imbalance that is seen in patients with HF. Preliminary clinical investigations have given promising results with an encouraging safety profile. Baroreceptor activation therapy as a treatment option is still investigational at this time; however, several trials in different patient populations have already shown benefit with a very good safety profile. In this review, we will summarize the current state of technology and the available literature of the use of baroreceptor activation therapy in patients with different comorbidities, with a focus on this device-based therapy in patients with HF.

Baroreflex activation therapy : Indication and evidence in resistant hypertension and heart failure

Baroreflex activation therapy (BAT) is asympathoinhibitory procedure for treatment of therapy-resistant hypertension (rsHTN) and severe heart failure with reduced ejection fraction (HFrEF) that been available for several years. The double-blind, randomized Rheos Pivotal Trial demonstrated ablood pressure lowering effect in patients with rsHTN for the first-generation BAT device. Asmaller randomized study in heart failure showed that the Barostim Neo system is safe and can improve heart failure symptoms and decrease neuroendocrine activation. However, for this unilateral system, which is currently in clinical use, no data from large randomized trials exist. Despite existing data for BAT in rsHTN and HFrEF, large randomized trials, showing reduction of blood pressure and cardiovascular events are still lacking. Therefore, BAT's efficacy and safety cannot be conclusively assessed.

An early analysis of cost-utility of baroreflex activation therapy in advanced chronic heart failure in Germany

BackgroundThis study aimed to evaluate cost-utility of baroreflex activation therapy (BAT) using the Barostim neo™ device (CVRx Inc., Minneapolis, MN, USA) compared with optimized medical management in patients with advanced chronic heart failure (NYHA class III) who were not eligible for treatment with cardiac resynchronization therapy, from a statutory health insurance perspective in Germany over a lifetime horizon.MethodsA decision analytic model was developed using the combination of a decision tree and the Markov process. The model included transitions between New York Heart Association (NYHA) health states, each of which is associated with a risk of mortality, hospitalization, cost, and quality of life. The effectiveness of BAT was projected through relative risks for mortality (obtained by application of patient-level data to the Meta-analysis Global Group in Chronic Heart Failure risk prediction model) and hospitalization owing to worsening of heart failure (obtained from BAT Randomized Clinical Trial). All patients were in NYHA class III at baseline.ResultsBAT led to an incremental cost of €33,185 (95% credible interval [CI] €24,561–38,637) and incremental benefits of 1.78 [95% CI 0.45–2.71] life-years and 1.19 [95% CI 0.30–1.81] quality-adjusted life-years (QALYs). This resulted in an incremental cost-effectiveness ratio of €27,951/QALY (95% CI €21,357–82,970). BAT had a 59% probability of being cost-effective at a willingness-to-pay threshold of €35,000/QALY (but 84% at a threshold of €52,000/QALY).ConclusionsBAT can be cost-effective in European settings in those not eligible for cardiac resynchronization therapy among patients with advanced heart failure.

Safety profile of baroreflex activation therapy (NEO) in patients with resistant hypertension.

Unlike safety data of baroreflex activation therapy device (Rheos), only few data of the currently used second device (Barostim neo) are available and little is reported about common side effects. We prospectively analyzed patients with resistant hypertension treated with Barostim neo. A standardized interview regarding side effects of the therapy was performed in routine follow-up visits after device implantation in 42 patients to determine adverse events staged into three degrees. Within 6 months of baroreflex activation therapy, the office mean arterial blood pressure decreased from 169 ± 27 to 148 ± 29 mmHg systolic (P < 0.001), respectively, to 145 ± 24 mmHg after 1 year (P < 0.001), whereas the number of prescribed antihypertensive classes decreased from 6.6 ± 1.5 to 5.6 ± 1.8 (P < 0.001). Adverse events were combination of the following field depending on the severity (I° mild: local discomfort, clinical observation only, no intervention indicated; II° moderate: medically significant such as occurrence of hypertensive crisis, syncope, arrhythmias; III° severe: life-threatening events or urgent medical intervention indicated). Adverse events I° were present in almost all patients (97.6%), and occurred mainly within first 6 months after device activation. Device-related events were most frequently and could be resolved by optimization of device parameters. Most procedure-related adverse events were directly related to the incision or anesthetic procedure. Adverse events II° occurred in 28.6% patients treated with Barostim neo, whereas patients' elevated individual risks might be potential triggers. Because of individual diversity of blood pressure response and the occurrence of adverse events, no standardization of parameters of implantable pulse generator could be found. By adapting the pulse generator settings individually, most of adverse events I° resolved without sequel. Though there are common side effects, Barostim neo significantly lowers blood pressure in resistant hypertension and provides an adequate safety profile. Regular patient visits are necessary to register side effects.

Non-clinical and Pre-clinical Testing to Demonstrate Safety of the Barostim Neo Electrode for Activation of Carotid Baroreceptors in Chronic Human Implants.

The Barostim neo™ electrode was developed by CVRx, Inc.to deliver baroreflex activation therapy (BAT)™ to treat hypertension and heart failure. The neo electrode concept was designed to deliver electrical stimulation to the baroreceptors within the carotid sinus bulb, while minimizing invasiveness of the implant procedure. This device is currently CE marked in Europe, and in a Pivotal (akin to Phase III) Trial in the United States. Here we present the in vitro and in vivo safety testing that was completed in order to obtain necessary regulatory approval prior to conducting human studies in Europe, as well as an FDA Investigational Device Exemption (IDE) to conduct a Pivotal Trial in the United States. Stimulated electrodes (10 mA, 500 μs, 100 Hz) were compared to unstimulated electrodes using optical microscopy and several electrochemical techniques over the course of 27 weeks. Electrode dissolution was evaluated by analyzing trace metal content of solutions in which electrodes were stimulated. Lastly, safety testing under Good Laboratory Practice guidelines was conducted in an ovine animal model over a 12 and 24 week time period, with results processed and evaluated by an independent histopathologist. Long-term stimulation testing indicated that the neo electrode with a sputtered iridium oxide coating can be stimulated at maximal levels for the lifetime of the implant without clinically significant dissolution of platinum or iridium, and without increasing the potential at the electrode interface to cause hydrolysis or significant tissue damage. Histological examination of tissue that was adjacent to the neo electrodes indicated no clinically significant signs of increased inflammation and no arterial stenosis as a result of 6 months of continuous stimulation. The work presented here involved rigorous characterization and evaluation testing of the neo electrode, which was used to support its safety for chronic implantation. The testing strategies discussed provide a starting point and proven framework for testing new neuromodulation electrode concepts to support regulatory approval for clinical studies.

The effects of baroreflex activation therapy on blood pressure and sympathetic function in patients with refractory hypertension: the rationale and design of the Nordic BAT study*

Objective: To explore the effects of baroreflex activation therapy (BAT) on hypertension in patients with treatment resistant or refractory hypertension.Methods: This investigator-initiated randomized, double-blind, 1:1 parallel-design clinical trial will include 100 patients with refractory hypertension from 6 tertiary referral hypertension centers in the Nordic countries. A Barostim Neo System will be implanted and after 1 month patients will be randomized to either BAT for 16 months or continuous pharmacotherapy (BAT off) for 8 months followed by BAT for 8 months. A second randomization will take place after 16 months to BAT or BAT off for 3 months. Eligible patients have a daytime systolic ambulatory blood pressure (ABPM) of ≥145 mm Hg, and/or a daytime diastolic ABPM of ≥95 mm Hg after witnessed drug intake (including ≥3 antihypertensive drugs, preferably including a diuretic).Results: The primary end point is the reduction in 24-hour systolic ABPM by BAT at 8 months, as compared to pharmacotherapy. Secondary and tertiary endpoints are effects of BAT on home and office blood pressures, measures of indices of cardiac and vascular structure and function during follow-up, and safety.Conclusions: This academic initiative will increase the understanding of mechanisms and role of BAT in the refractory hypertension.

PP.13.09] THE EFFECTS OF BAROREFLEX ACTIVATION THERAPY ON BLOOD PRESSURE AND SYMPATHETIC FUNCTION IN PATIENTS WITH REFRACTORY HYPERTENSION – THE RATIONALE AND DESIGN OF THE NORDIC BAT STUDY

Objective: Baroreflex activation therapy (BAT) modulates the autonomic nervous system to restore sympathovagal balance. The aim of this study is to explore the effects of BAT on hypertension in patients with refractory (true resistant) hypertension (RH). Design and method: This academic (independent of industry support) randomized, double-blind, 1:1 parallel-design clinical trial will include 100 patients with RH from six hypertension centers in the Nordic countries. A Barostim Neo® System will be implanted and after 1 month of stabilization patients will be randomized to either BAT for 16 months or continuous pharmacotherapy (BAT off) for 8 months followed by the BAT for 8 months (Figure). Blood and urine samples will be drawn and measures of arterial and cardiac function and structure, and of autonomic function will be performed at randomization, and after 8 and 16 months. Eligible patients will be 18–70 years and have a daytime systolic ambulatory blood pressure (ABMP) of 145 mmHg or more, and/or a daytime diastolic ABMP of 95 mmHg or more, after witnessed intake of antihypertensive treatment (including at least 3 antihypertensive drugs, preferably a diuretic), with no changes in medication for a minimum of 4 weeks prior to enrolment. Patients with secondary causes of hypertension, severe renal insufficiency, untreated sleep apnea, pregnancy, type 1 diabetes, alcohol/drug abuse, or psychiatric illnesses, other than sinus rhythm (controlled atrial fibrillation is not a contraindication), uncontrolled systolic heart failure, aortic stenosis, and a cardiovascular event 3 within months before enrolment will be excluded. Results: The primary end point is to test whether BAT reduces 24-hour systolic ABMP at 8 months of follow-up compared to pharmacotherapy. Secondary/tertiary endpoints are the effects of BAT on home and office blood pressure, measures of autonomic function, arterial and cardiac structure and function during follow-up, and extended long-term follow-up. Two patients have been included in the study so far. An interim analysis will be done after 50 patients. Conclusions: This initiative will increase the understanding of the mechanisms and role of BAT in the treatment of RH.

OP-051 Baroreceptor Activation Therapy with Barostim Neo for Treatment of Resistant Hypertension and/or Heart Failure: First Reported 2 Cases in Turkey

OP-051 Baroreceptor Activation Therapy with Barostim Neo for Treatment of Resistant Hypertension and/or Heart Failure: First Reported 2 Cases in Turkey

Clinical Implications

Clinical Implications

Baroreflex Activation Therapy for the Treatment of Heart Failure With a Reduced Ejection Fraction

ObjectivesThe objective of this clinical trial was to assess the safety and efficacy of carotid BAT in advanced HF. BackgroundIncreased sympathetic and decreased parasympathetic activity contribute to heart failure (HF) symptoms and disease progression. Baroreflex activation therapy (BAT) results in centrally mediated reduction of sympathetic outflow and increased parasympathetic activity. MethodsPatients with New York Heart Association (NYHA) functional class III HF and ejection fractions ≤35% on chronic stable guideline-directed medical therapy (GDMT) were enrolled at 45 centers in the United States, Canada, and Europe. They were randomly assigned to receive ongoing GDMT alone (control group) or ongoing GDMT plus BAT (treatment group) for 6 months. The primary safety end point was system- and procedure-related major adverse neurological and cardiovascular events. The primary efficacy end points were changes in NYHA functional class, quality-of-life score, and 6-minute hall walk distance. ResultsOne hundred forty-six patients were randomized, 70 to control and 76 to treatment. The major adverse neurological and cardiovascular event–free rate was 97.2% (lower 95% confidence bound 91.4%). Patients assigned to BAT, compared with control group patients, experienced improvements in the distance walked in 6 min (59.6 ± 14 m vs. 1.5 ± 13.2 m; p = 0.004), quality-of-life score (–17.4 ± 2.8 points vs. 2.1 ± 3.1 points; p < 0.001), and NYHA functional class ranking (p = 0.002 for change in distribution). BAT significantly reduced N-terminal pro–brain natriuretic peptide (p = 0.02) and was associated with a trend toward fewer days hospitalized for HF (p = 0.08). ConclusionsBAT is safe and improves functional status, quality of life, exercise capacity, N-terminal pro–brain natriuretic peptide, and possibly the burden of heart failure hospitalizations in patients with GDMT-treated NYHA functional class III HF. (Barostim Neo System in the Treatment of Heart Failure; NCT01471860; Barostim HOPE4HF [Hope for Heart Failure] Study; NCT01720160)

Electrical carotid baroreceptor stimulation.

The Barostim neo ™ system is a novel implantable device that activates the carotid baroreflex. It decreases the sympathetic activity and inhibits the renin system, which results in reduced blood pressure and heart rate. In patients with resistant hypertension, electrically activation of the baroreflex leads to an average decrease in systolic blood pressure of 38, 36, 40 and 53 mmHg at 1, 2, 3 and 4 years, respectively. Additionally, cardiac remodelling with reduced left ventricular mass and posterior wall thickness has been observed in long-term studies. In a limited number of patients with heart failure, baroreflex activation therapy leads to a decrease in muscle sympathetic nerve activity and to improved quality of life and functional capacities. The implantation procedure is safe and associated with risks comparable with those of other active implantable devices. Barostim neo is currently available in several European countries.

Cost-effectiveness of Barostim therapy for the treatment of resistant hypertension in European settings

The purpose of this study is to simulate the cost-effectiveness and the long-term clinical performance of the Barostim neo System for the treatment of resistant hypertension when compared to optimal medical treatment. A decision analytic model with a combination of a decision tree and Markov process was used to evaluate the cost-effectiveness of Barostim. The clinical effectiveness of Barostim was based on the results of the randomized, placebo-controlled Rheos trial and the follow-up substudy of the DEBuT-HT trial. The cost-effectiveness was modelled from a German societal perspective over a lifetime horizon. Patients with high SBP levels have an increased risk of myocardial infarction, stroke, heart failure and end-stage renal disease. In a simulated cohort of 50-year-old patients at high risk of end-organ damage, Barostim therapy generated 1.66 additional life-years and 2.17 additional quality-adjusted life years with an incremental cost of &OV0556;16 891 when compared with continuation of medical management. Barostim was estimated to be cost-effective compared with optimal medical treatment with an incremental cost-effectiveness ratio of &OV0556;7 797/QALY. In the model, Barostim reduced over a lifetime the rates of myocardial infarction by 19%, stroke by 35%, heart failure by 12% and end-stage renal disease by 23%. The cost-effectiveness of Barostim can be greater in younger patients with resistant hypertension and in patients with significant risk factors for end-organ damage. Barostim may be a cost-effective treatment when compared with optimal medical management in patients with resistant hypertension.

Baroreflex activation therapy for treating resistant hypertension and heart failure

Chronic baroreflex activation therapy (BAT) has demonstrated long-term blood pressure reductions in a resistant hypertensive population using a first generation system. A second generation system, the Barostim neo, has recently shown comparable chronic blood pressure reductions at 6 months while advancing the safety profile of the therapy. Furthermore, data from studies in heart failure patients suggest BAT may be a promising therapy for heart failure. These early successes have led to the initiation of larger-scale, randomized, controlled trials in both disease populations. I. INTRODUCTION Baroreflex activation therapy (BAT), a unique treatment for cardiovascular dysfunction, delivers electrical stimulation to the carotid sinus to elicit the intrinsic baroreflex depressor response, thereby normalizing sympatho-vagal balance. Chronic BAT with a first generation system produced significant and durable reductions in blood pressure (BP) in a resistant hypertension (HTN) population.(1) BAT has also been proposed as a therapy for heart failure (HF) because of its multiple cardiovascular benefits.(2) This overview summarizes results from studies with an advanced second generation system for BAT that demonstrate the promise of BAT for both resistant HTN and HF. II. THE BAROSTIM NEO SYSTEM The second generation Barostim neo system employs a unilaterally-implanted miniaturized electrode to facilitate a minimally invasive procedure. The disk-shaped electrode is sutured to the right carotid sinus adventitia and the pulse generator is implanted subcutaneously in the ipsilateral pectoral region. The intensity of stimulation is controlled via radiofrequency telemetry from an external, laptop computer- based programming system. III. RESISTANT HYPERTENSION

Chronic baroreflex activation persistently lowers blood pressure in resistant hypertension: single-center experience with the barostim neo system

Background: Hypertension (HTN) continues to pose a significant healthcare challenge. Medical therapies are useful for improving outcomes but have significant limitations such as side effects, inconsistent patient compliance and incomplete control of blood pressure (BP). Nonpharmacologic therapies have recently become commercially available that lower BP adjunctive to medical therapy and are promising to reduce the HTN-related morbidity and mortality. Chronic activation of the baroreflex has been shown to reduce BP for >4 years using the first-generation device (Rheos) and 6 months using the next-generation system (Barostim neo), which requires only unilateral stimulation and therefore allows considerably less invasive implantation. Here, we report our long-term, single-center results for 7 patients over 12 months with the Barostim neo device. Methods: Resistant HTN patients were enrolled in an open-label, single-arm evaluation of Barostim neo. Eligibility criteria required systolic BP ≥ 140 mmHg despite stable (≥4 weeks) medical therapy consisting of ≥3 medications including at least one diuretic. Patients with secondary HTN, severe chronic kidney disease, advanced carotid atherosclerosis or baroreflex failure were excluded. Results: Seven patients were enrolled including 3 women and 2 with previous renal nerve ablation. The mean office cuff blood pressure at enrollment was 183.4±28.3mmHg (systolic blood pressure;SBP) over 97.4±19.1mmHg (diastolic blood pressure;DBP) with an average of 4.7±1.4 antihypertensive drugs. 6 months after activation of the Barostim neo device the blood pressure was reduced to 150.7±50.9mmHg (SBP; p=0.06) over 85.0±35.7mmHg (DBP; p=0.28) with an average of 5.4±1.0 (p=0.22) antihypertensive drugs. After 12 months blood pressure remained lowered at 157.1±55.5mmHg (SBP; p=0.12) over 84.0±30.5mmHg (DBP; p=0.11) with an average of 4.6±1.9 (p=0.86) antihypertensive drugs. At screening 1 patient had a SBP between 140 and 160mmHg, two patients had SBPs 180mmHg. After 6 months 4 patients (=57%) reached a SBP below 140mmHg, which proved to be consistent on the twelve-month evaluation. During the 12 months of follow-up only one serious adverse event, a device pocket haematoma, occurred and resolved completely. Conclusions: Throughout 12 months of follow-up unilateral baroreflex activation therapy reduces BP consistently in patients with resistant HTN without exposing patients to excessive risks. Therefore baroreflex activation therapy should be considered as a treatment option for patients with resistant HTN after exclusion of secondary HTN.

Minimally invasive system for baroreflex activation therapy chronically lowers blood pressure with pacemaker-like safety profile: results from the Barostim neo trial

BackgroundPrevious trials have demonstrated clinically significant and durable reductions in arterial pressure from baroreflex activation therapy (BAT), resulting from electrical stimulation of the carotid sinus using a novel implantable device. A second-generation system for delivering BAT, the Barostim neo™ system, has been designed to deliver BAT with a simpler device and implant procedure. MethodsBAT, delivered with the advanced system, was evaluated in a single-arm, open-label study of patients with resistant hypertension, defined as resting systolic blood pressure (SBP) ≥140 mm Hg despite treatment with ≥3 medications, including ≥1 diuretic. Stable medical therapy was required for ≥4 weeks before establishing pretreatment baseline by averaging two SBP readings taken ≥24 hours apart. ResultsThirty patients enrolled from seven centers in Europe and Canada. From a baseline of 171.7 ± 20.2/99.5 ± 13.9 mm Hg, arterial pressure decreased by 26.0 ± 4.4/12.4 ± 2.5 mm Hg at 6 months. In a subset (n = 6) of patients with prior renal nerve ablation, arterial pressure decreased by 22.3 ± 9.8 mm Hg. Background medical therapy for hypertension was unchanged during follow-up. Three minor procedure-related complications occurred within 30 days of implant. All complications resolved without sequelae. ConclusionBAT delivered with the second-generation system significantly lowers blood pressure in resistant hypertension with stable, intensive background medical therapy, consistent with studies of the first-generation system for electrical activation of the baroreflex, and provides a safety profile comparable to a pacemaker.