Implant-Mediated Therapy of Arterial Hypertension

Alleviating Hypertension by Selectively Targeting Angiotensin Receptor-Expressing Vagal Sensory Neurons

Cardiovascular homeostasis is maintained, in part, by neural signals arising from arterial baroreceptors that apprise the brain of blood volume and pressure. Here, we test whether neurons within the nodose ganglia that express angiotensin type-1a receptors (referred to as NGAT1aR) serve as baroreceptors that differentially influence blood pressure (BP) in male and female mice. Using Agtr1a-Cre mice and Cre-dependent AAVs to direct tdTomato to NGAT1aR, neuroanatomical studies revealed that NGAT1aR receive input from the aortic arch, project to the caudal nucleus of the solitary tract (NTS), and synthesize mechanosensitive ion channels, Piezo1/2 To evaluate the functionality of NGAT1aR, we directed the fluorescent calcium indicator (GCaMP6s) or the light-sensitive channelrhodopsin-2 (ChR2) to Agtr1a-containing neurons. Two-photon intravital imaging in Agtr1a-GCaMP6s mice revealed that NGAT1aR couple their firing to elevated BP, induced by phenylephrine (i.v.). Furthermore, optical excitation of NGAT1aR at their soma or axon terminals within the caudal NTS of Agtr1a-ChR2 mice elicited robust frequency-dependent decreases in BP and heart rate, indicating that NGAT1aR are sufficient to elicit appropriate compensatory responses to vascular mechanosensation. Optical excitation also elicited hypotensive and bradycardic responses in ChR2-expressing mice that were subjected to deoxycorticosterone acetate (DOCA)-salt hypertension; however, the duration of these effects was altered, suggestive of hypertension-induced impairment of the baroreflex. Similarly, increased GCaMP6s fluorescence observed after administration of phenylephrine was delayed in mice subjected to DOCA-salt or chronic delivery of angiotensin II. Collectively, these results reveal the structure and function of NGAT1aR and suggest that such neurons may be exploited to discern and relieve hypertension.

Integrated Analysis of miRNA and mRNA Regulation Network in Hypertension

Hypertension is the most common chronic disease. Early diagnosis is helpful for early medical intervention. The miRNAs and the messenger RNAs (mRNAs) network may be valuable disease diagnosis markers. We aimed to explore the diagnostic value of the miRNA-mRNA network for hypertension patients. Data of miRNAs and mRNAs expression were obtained from the Gene Expression Omnibus database. The weighted gene co-expression network analysis was performed to screen hypertension-related gene modules, and these genes undergone functional enrichment analysis using "clusterProfiler" package. Differential expression analysis was applied on miRNAs expression profiles using "limma" package. TargetScanHuman and miRDB databases were used to select target mRNAs. Cytoscape software was used to visualize the miRNA-mRNA regulation network. P value < 0.05 was considered statistically significant after t test. There were 123 screened mRNAs which were enriched in 161 Gene ontology (GO) terms and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Thirty-five differentially expressed miRNAs (DEMs) are found in the GSE75670. Totally 36 miRNA-mRNA pairs were obtained after the integrated analysis, and three mRNAs and the hsa-miRNA-5589-5p were identified as key joints. Hub genes, KIAA0513, ARID3A and LRPAP1, and key hsa-miRNA-5589-5p are potential diagnostic biomarkers for hypertension. Our findings are promising in the clinical application, conducive to early detection and prompt intervention of hypertension.

Single-interface bioelectronic medicines - concept, clinical applications and preclinical data

Presently, large groups of patients with various diseases are either intolerant, or irresponsive to drug therapies and also intractable by surgery. For several diseases, one option which is available for such patients is the implantable neurostimulation therapy. However, lacking closed-loop control and selective stimulation capabilities, the present neurostimulation therapies are not optimal and are therefore used as only "third" therapeutic options when a disease cannot be treated by drugs or surgery. Addressing those limitations, a next generation class of closed-loop controlled and selective neurostimulators generically named bioelectronic medicines seems within reach. A sub-class of such devices is meant to monitor and treat impaired functions by intercepting, analyzing and modulating neural signals involved in the regulation of such functions using just one neural interface for those purposes. The primary objective of this review is to provide a first broad perspective on this type of single-interface devices for bioelectronic therapies. For this purpose, the concept, clinical applications and preclinical studies for further developments with such devices are here analyzed in a narrative manner.

Effect of Exercise Training on Ambulatory Blood Pressure Among Patients With Resistant Hypertension: A Randomized Clinical Trial

Importance

Limited evidence suggests exercise reduces blood pressure (BP) in individuals with resistant hypertension, a clinical population with low responsiveness to drug therapy.

Objective

To determine whether an aerobic exercise training intervention reduces ambulatory BP among patients with resistant hypertension.

Design, Settings, and Participants

The Exercise Training in the Treatment of Resistant Hypertension (EnRicH) trial is a prospective, 2-center, single-blinded randomized clinical trial performed at 2 hospital centers in Portugal from March 2017 to December 2019. A total of 60 patients with a diagnosis of resistant hypertension aged 40 to 75 years were prospectively enrolled and observed at the hospitals' hypertension outpatient clinic.

Interventions

Patients were randomly assigned in a 1:1 ratio to a 12-week moderate-intensity aerobic exercise training program (exercise group) or a usual care control group. The exercise group performed three 40-minute supervised sessions per week in addition to usual care.

Main Outcomes and Measures

The powered primary efficacy measure was 24-hour ambulatory systolic BP change from baseline. Secondary outcomes included daytime and nighttime ambulatory BP, office BP, and cardiorespiratory fitness.

Results

A total of 53 patients completed the study, including 26 in the exercise group and 27 in the control group. Of these, 24 (45%) were women, and the mean (SD) age was 60.1 (8.7) years. Compared with the control group, among those in the exercise group, 24-hour ambulatory systolic BP was reduced by 7.1 mm Hg (95% CI, -12.8 to -1.4; P = .02). Additionally, 24-hour ambulatory diastolic BP (-5.1 mm Hg; 95% CI, -7.9 to -2.3; P = .001), daytime systolic BP (-8.4 mm Hg; 95% CI, -14.3 to -2.5; P = .006), and daytime diastolic BP (-5.7 mm Hg; 95% CI, -9.0 to -2.4; P = .001) were reduced in the exercise group compared with the control group. Office systolic BP (-10.0 mm Hg; 95% CI, -17.6 to -2.5; P = .01) and cardiorespiratory fitness (5.05 mL/kg per minute of oxygen consumption; 95% CI, 3.5 to 6.6; P < .001) also improved in the exercise group compared with the control group.

Conclusions and Relevance

A 12-week aerobic exercise program reduced 24-hour and daytime ambulatory BP as well as office systolic BP in patients with resistant hypertension. These findings provide clinicians with evidence to embrace moderate-intensity aerobic exercise as a standard coadjutant therapy targeting this patient population.

Trial Registration

ClinicalTrials.gov Identifier: NCT03090529.

Benefits of pharmacological and electrical cholinergic stimulation in hypertension and heart failure

Systemic arterial hypertension and heart failure are cardiovascular diseases that affect millions of individuals worldwide. They are characterized by a change in the autonomic nervous system balance, highlighted by an increase in sympathetic activity associated with a decrease in parasympathetic activity. Most therapeutic approaches seek to treat these diseases by medications that attenuate sympathetic activity. However, there is a growing number of studies demonstrating that the improvement of parasympathetic function, by means of pharmacological or electrical stimulation, can be an effective tool for the treatment of these cardiovascular diseases. Therefore, this review aims to describe the advances reported by experimental and clinical studies that addressed the potential of cholinergic stimulation to prevent autonomic and cardiovascular imbalance in hypertension and heart failure. Overall, the published data reviewed demonstrate that the use of central or peripheral acetylcholinesterase inhibitors is efficient to improve the autonomic imbalance and hemodynamic changes observed in heart failure and hypertension. Of note, the baroreflex and the vagus nerve activation have been shown to be safe and effective approaches to be used as an alternative treatment for these cardiovascular diseases. In conclusion, pharmacological and electrical stimulation of the parasympathetic nervous system has the potential to be used as a therapeutic tool for the treatment of hypertension and heart failure, deserving to be more explored in the clinical setting.

Device profile of the MobiusHD EVBA system for the treatment of resistant hypertension: overview of its mechanism of action, safety and efficacy

INTRODUCTION

Early promising results of renal nerve denervation awakened interest in developing medical device alternatives for patients with resistant hypertension. The subsequent sham-controlled renal nerve denervation randomized trials were disappointing leading researchers and innovators to explore alternative device and trial designs to address this significant unmet need. We describe the innovation process leading to the first endovascular carotid baroreflex amplification device currently undergoing clinical trials in the United States and Europe.

AREAS COVERED

We provide a brief overview of carotid baroreceptor physiology and then couple this knowledge with the fundamental principles of strain pattern changes that led to the proposed innovation. The mechanism of blood pressure reduction via enhancing innate physiologic carotid sinus baroreceptor signaling through changes in pulsatile focal carotid bulb strain is described alongside preclinical testing and early clinical results.

EXPERT OPINION

The collective data to date suggest endovascular carotid baroreflex amplification may be an innovative alternative for resistant hypertension patients. However, well-controlled studies will be needed to assess efficacy, safety, durability, and risk: benefit of this permanent intravascular carotid implant.

SUBJECT CODES

high blood pressure, hypertension, treatment, physiology.