Endovascular ultrasound renal denervation to treat hypertension (RADIANCE-HTN SOLO): a multicentre, international, single-blind, randomised, sham-controlled trial

Renal nerve stimulation identifies renal innervation and optimizes the strategy for renal denervation in canine

BACKGROUND

Renal denervation (RDN) was still performed without any intra-procedural method for nerve mapping. Whether renal nerve stimulation (RNS) is an efficient way to identify renal autonomic innervation and optimize the strategy for RDN remain to be worthy for further exploration.

METHODS

The characteristics of renal autonomic innervation at the sites with different blood pressure (BP) responses to RNS were explored. Then, dogs anatomically eligible for RDN were randomly assigned into elevated BP response ablation group, reduced BP response ablation group, and RNS-control group. The postoperative outcomes were measured at baseline and after 4 weeks follow-up.

RESULTS

The proportion of afferent sensory nerve was higher at elevated BP response sites (ERS) than reduced BP response sites (RRS) and non-response sites (NRS) (P = 0.012 and P = 0.004). Conversely, the proportion of parasympathetic nerve at RRS was the highest (RRS vs. ERS, P = 0.017; RRS vs. NRS, P = 0.023). More importantly, there was a significant correlation between systolic blood pressure changes and the area ratios of afferent sensory and parasympathetic nerve (R = 0.859; P < 0.001). In addition, ablation at BP-elevation sites can result in a significant decrease in BP and plasma norepinephrine (NE) after 4 weeks (P = 0.002; P = 0.008), while ablation at BP-reduction sites can lead to significant increases in BP and plasma NE (P = 0.016; P = 0.033).

CONCLUSIONS

RNS is an effective method to identify renal autonomic innervation. It could not only help to identify optimal target sites, but also avoid ablation of sympathetic-inhibitory areas during RDN.

2022 Renal denervation therapy for the treatment of hypertension: a statement from the Thai Hypertension Society

Hypertension remains a significant risk factor for major cardiovascular events worldwide. Poor adherence to treatment is extremely common in clinical practice, leading to uncontrolled hypertension. However, some patients with resistant hypertension still have uncontrolled blood pressure despite good medical compliance. A specific group of patients also develop adverse reactions to many blood pressure-lowering medications. These scenarios indicate that innovative strategies to lower blood pressure in challenging cases of hypertension are needed. The blood pressure-lowering efficacy of catheter-based renal denervation therapy to decrease sympathetic tone has been confirmed in many publications in recent years. Apart from both the invasiveness and the expensiveness of this technology, appropriate case selection to undergo this procedure is still developing. The utilization of renal denervation therapy for hypertension treatment in Thailand has lasted for 10 years with a good response in most cases. Currently, only certain interventionists at a few medical schools in Thailand can perform this procedure. However, more physicians are now interested in applying this technology to their patients. The Thai Hypertension Society Committee has reviewed updated information to provide principles for the appropriate utilization of renal denervation therapy. The blood pressure-lowering mechanism, efficacy, suitable patient selection, pre- and postprocedural assessment and procedural safety of renal denervation are included in this statement.

Translational value of preclinical models for renal denervation: a histological comparison of human versus porcine renal nerve anatomy

BACKGROUND

Preclinical models have provided key insights into the response of local tissues to radiofrequency (RF) renal denervation (RDN) that is unobtainable from human studies. However, the anatomic translatability of these models to the procedure in humans is incompletely understood.  Aims: We aimed to compare the renal arterial anatomy in normotensive pigs treated with RF-RDN to that of human cadavers to evaluate the suitability of normotensive pigs for determining the safety of RF-RDN.

METHODS

Histopathologic analyses were performed on RF-treated renal arteries in a porcine model and untreated control renal arteries. Similar analyses were performed on untreated renal arteries from human cadavers.  Results: In both human and porcine renal arteries, the median number of nerves was lower in the more distal sections (the numbers in the proximal, middle, distal, 1st bifurcation, and 2nd bifurcation sections were 65, 58, 47, 22.5, and 14.7 in humans, respectively, and 39, 26, 29, 16.5, and 9.3 in the porcine models, respectively). Renal nerves were common in the regions between arteries and adjacent veins, but only 3% and 13% of the renal nerves in humans and pigs, respectively, were located behind the renal vein. The semiquantitative score of RF-induced renal arterial nerve necrosis was significantly greater at 7 days than 28 days (0.98 vs 0.75; p=0.01), and injury to surrounding organs was rarely observed.

CONCLUSIONS

The distribution of nerve tissue and the relative distribution of extravascular anatomic structures along the renal artery was similar between humans and pigs, which validates the translational value of the normotensive porcine model for RDN.

Newer alternatives for resistant hypertension: Beyond 2022 paradigms

Given the increased incidence of resistant hypertension and no novel agents to manage hypertension for more than 15 years, there has been an increase in the development of newer agents with unique mechanisms that will hopefully aid in getting this subset of patients under control. More recent classes of agents include nonsteroidal mineralocorticoid receptor blockers, aminopeptidase A inhibitors, dual endothelin A and B antagonists and aldosterone synthetase inhibitors, and novel agents affecting angiotensinogen mRNA in the liver. All these agents are under different levels of development and, if all goes well, should be available to the public within the next 2-5 years. In addition to these agents, renal denervation is anticipated to be approved in the United States within the next 6-9 months, whereas it has already been authorized in certain European countries. Thus, by 2025 and later, we will have a more extensive armamentarium to help quell the rise in resistant hypertension. From early actuarial data associating elevated blood pressure with mortality to the first trials of blood pressure-lowering medications to contemporary American and European hypertension guidelines, the beneficial impact of blood pressure lowering in individuals with hypertension is well established^1,2-4. Population-level decreases in incident cardiovascular disease and mortality over the past 50 years reflect this well-established impact. Yet, the year-over-year decline in the incidence of cardiovascular disease has now plateaued, and concomitantly rates of uncontrolled hypertension have increased^5,6. Additionally, how the global COVID-19 pandemic impacts cardiovascular disease and hypertension-related outcomes is yet to be determined, but early data suggests population-level increases in blood pressure⁷.

The intrarenal blood pressure modulation system is differentially altered after renal denervation guided by different intensities of blood pressure responses

The aim of this study was to investigate alterations in the intrarenal blood pressure (BP) regulation system after renal denervation (RDN) guided by renal nerve stimulation (RNS). Twenty-one dogs were randomized to receive RDN at strong (SRA group, n = 7) or weak (WRA group, n = 7) BP-elevation response sites identified by RNS or underwent RNS only (RNS-control, RSC, n = 7). After 4 weeks of follow-up, renal sympathetic components, the main components of renin-angiotensin system (RAS) and the major transporters involved in sodium and water reabsorption were assessed by immunohistochemical analysis. Compared with RSC treatment, RDN therapy significantly reduced renal norepinephrine and tyrosine hydroxylase levels, decreased the renin content and inhibited the onsite generation of angiotensinogen. Moreover, the expression of exciting axis components, including angiotensin-converting enzyme (ACE), angiotensin II and angiotensin II type-1 receptor, was downregulated, while protective axis components for the cardiovascular system, including ACE2 and Mas receptors, were upregulated in both WRA and SRA groups. Moreover, RDN reduced the abundance of aquaporin-1 and aquaporin-2 in kidneys. Although RDN had a minimal effect on overall NKCC2 expression, its activation (p-NKCC2) and directional enrichment in the apical membrane (mNKCC2) were dramatically blunted. All these changes were more obvious in the SRA group than WRA group. Selective RDN guided by RNS effectively reduced systemic BP by affecting the renal neurohormone system, as well as the sodium and water transporter system, and these effects at sites with a strong BP response were more superior.

Patient Preferences for Pharmaceutical and Device-Based Treatments for Uncontrolled Hypertension: Discrete Choice Experiment

BACKGROUND

Discrete choice experiment is a survey method used to understand how individuals make decisions and to quantify the relative importance of features. Using discrete choice experiment methods, we quantified patient benefit-risk preferences for hypertension treatments, including pharmaceutical and interventional treatments, like renal denervation.

METHODS

Respondents from the United States with physician-confirmed uncontrolled hypertension selected between treatments involving a procedure or pills, using a structured survey. Treatment features included interventional, noninterventional, or no hypertension treatment; number of daily blood pressure (BP) pills; expected reduction in office systolic BP; duration of effect; and risks of drug side effects, access site pain, or vascular injury. The results of a random-parameters logit model were used to estimate the importance of each treatment attribute.

RESULTS

Among 400 patients completing the survey between 2020 and 2021, demographics included: 52% women, mean age 59.2±13.0 years, systolic BP 155.1±12.3 mm Hg, and 1.8±0.9 prescribed antihypertensive medications. Reduction in office systolic BP was the most important treatment attribute. The remaining attributes, in decreasing order, were duration of effect, whether treatment was interventional, number of daily pills, risk of vascular injury, and risk of drug side effects. Risk of access site pain did not influence choice. In general, respondents preferred noninterventional over interventional treatments, yet only a 2.3 mm Hg reduction in office systolic BP was required to offset this preference. Small reductions in office systolic BP would offset risks of vascular injury or drug side effects. At least a 20% risk of vascular injury or drug side effects would be tolerated in exchange for improved BP.

CONCLUSIONS

Reduction in systolic BP was identified as the most important driver of patient treatment preference, while treatment-related risks had less influence. The results indicate that respondents would accept interventional treatments in exchange for modest reductions in systolic BP compared with those observed in renal denervation trials.

The position of renal denervation in treatment of hypertension: an expert consensus statement

Hypertension is an important risk factor for cardiovascular disease. In the Netherlands, there are approximately 2.8 million people with hypertension. Despite treatment recommendations including lifestyle changes and antihypertensive drugs, most patients do not meet guideline-recommended blood pressure (BP) targets. In order to improve BP control and lower the risk of subsequent cardiovascular events, renal sympathetic denervation (RDN) has been introduced and studied as a non-pharmacological approach. While early data on the efficacy of RDN showed conflicting results, improvements in treatment protocols and study design resulted in robust new evidence supporting the potential of the technology to improve patient care in hypertensive subjects. Recently, 5 randomised sham-controlled trials demonstrated the safety and efficacy of the technology. Modelling studies have further shown that RDN is cost-effective in the Dutch healthcare setting. Given the undisputable disease burden along with the shortcomings of current therapeutic options, we postulate a new, clearly framed indication for RDN as an adjunct in the treatment of hypertension. The present consensus statement summarises current guideline-recommended BP targets, proposed workup and treatment for hypertension, and position of RDN for those patients with primary hypertension who do not meet guideline-recommended BP targets (see central illustration).

Effect of concomitant Renal DeNervation and cardiac ablation on Atrial Fibrillation recurrence - RDN+AF study

BACKGROUND

Renal denervation (RDN) can reduce cardiac sympathetic activity maintained by arterial hypertension (aHT). Its potential antiarrhythmic effect on rhythm outcome in patients with multi-drug resistant aHT undergoing catheter ablation for atrial fibrillation (AF) is unclear.

METHODS

The RDN+AF study was a prospective, randomized, two-center trial. Patients with paroxysmal or persistent AF and uncontrolled aHT (mean systolic 24-h ambulatory BP > 135 mmHg) despite taking at least three antihypertensive drugs were enrolled. Patients were 1:2 randomized to either RDN+AF ablation or AF-only ablation. Primary endpoint was freedom from any AF episode > 2 min at 12 months assessed by implantable loop recorder (ILR) or 7d-holter electrocardiogram. Secondary endpoints included rhythm outcome at 24 months, blood pressure control, periprocedural complications, and renovascular safety.

RESULTS

The study randomized 61 patients (mean age 65 ± 9 years, 53% men). At 12 months, RDN+AF patients tended to have a greater decrease in ambulatory BPs but did not reach statistical significance. No differences in rhythm outcome were observed. Freedom from AF recurrence in the RDN+AF and AF-only group measured 61% versus 53% p = .622 at 12 months and 39% versus 47% p = .927 at 24 months, respectively. Periprocedural complications occurred in 9/61 patients (15%). No patient died.

CONCLUSION

Among patients with multidrug-resistant aHT and paroxysmal or persistent AF, concomitant RDN+AF ablation was not associated with better blood pressure control or rhythm outcome in comparison to AF-only ablation and medical therapy.

Novel Invasive Methods as the Third Pillar for the Treatment of Essential Uncontrolled Hypertension

Pharmacologic therapies remain the treatment of choice for patients with essential hypertension, as endorsed by international guidelines. However, several cases warrant additional modalities, such as invasive antihypertensive therapeutics. The major target of these interventions is the modulation of the sympathetic nervous system, which is a common pathophysiologic mechanism in essential hypertension. In this narrative review, we elaborate on the role of invasive antihypertensive treatments with a focus on renal denervation, stressing their potential as well as the drawbacks that prevent their widespread implementation in everyday clinical practice. In the field of renal denervation, several trials have shown significant and sustained reductions in the level of office and ambulatory blood pressure, regardless of the type of energy that was used (radiofrequency or ultrasound). Critically, renal denervation is considered a safe intervention, as evidenced by follow-up data from large clinical trials. Baroreflex activation therapy may result in enhanced parasympathetic nervous system activation, thus lowering blood pressure levels. Along the same lines, carotid body ablation could also produce a significant antihypertensive effect, which has not been tested in appropriately designed randomized trials. Moreover, cardiac neuromodulation therapy could prove efficacious by altering the duration of the atrioventricular interval in order to regulate the preload of the left ventricle and, therefore, lower blood pressure.

Hypertension and cardiomyopathy associated with chronic kidney disease: epidemiology, pathogenesis and treatment considerations

Chronic kidney disease (CKD) is a complex condition with a prevalence of 10-15% worldwide. An inverse-graded relationship exists between cardiovascular events and mortality with kidney function which is independent of age, sex, and other risk factors. The proportion of deaths due to heart failure and sudden cardiac death increase with progression of chronic kidney disease with relatively fewer deaths from atheromatous, vasculo-occlusive processes. This phenomenon can largely be explained by the increased prevalence of CKD-associated cardiomyopathy with worsening kidney function. The key features of CKD-associated cardiomyopathy are increased left ventricular mass and left ventricular hypertrophy, diastolic and systolic left ventricular dysfunction, and profound cardiac fibrosis on histology. While these features have predominantly been described in patients with advanced kidney disease on dialysis treatment, patients with only mild to moderate renal impairment already exhibit structural and functional changes consistent with CKD-associated cardiomyopathy. In this review we discuss the key drivers of CKD-associated cardiomyopathy and the key role of hypertension in its pathogenesis. We also evaluate existing, as well as developing therapies in the treatment of CKD-associated cardiomyopathy.

Consensus and inconsistency between different consensus documents on renal denervation worldwide: the way forward

ABSTRACT

Given the unsatisfactory hypertension control rates and high rates of non-adherence to antihypertensive medications worldwide, device therapy which can safely provide durable blood pressure-lowering effects can fulfill the unmet need. A series of second-generation randomized sham-controlled renal denervation (RDN) trials have demonstrated the efficacy and safety of RDN in a wide range of hypertensive patients. The four representative consensus documents on RDN (from the Chinese Taiwan Hypertension Society and Taiwan Society of Cardiology [THS/TSOC 2019], Asia Renal Denervation Consortium 2019, European Society of Hypertension [ESH 2021], and Society for Cardiovascular Angiography & Intervention and National Kidney Foundation [SCAI/NKF 2021]) consistently recommend RDN as an alternative or complementary treatment strategy for patients with uncontrolled hypertension. In addition, both documents from Asia further recommend that RDN can be considered as an initial treatment strategy for drug-naïve hypertensive patients. There is still inconsistency regarding whether ambulatory blood pressure monitoring should be used routinely both before and after RDN, and whether patients with a secondary cause of hypertension could be treated with RDN if their blood pressure remains uncontrolled after definitive treatment (treatment-resistant secondary hypertension). The THS/TSOC consensus provides acronyms to summarize key aspects of patient selection (RDNi2) and pre-RDN assessments (RAS). The ESH and SCAI/NKF documents recommend establishing structured pathways for clinical practice and issues regarding reimbursement. All documents identify knowledge gaps in RDN, from identifying predictors of super-responders to demonstrating effects on cardiovascular events. These gaps should be urgently filled to facilitate the wider application of this device therapy for patients with hypertension.

A nanofiber hydrogel derived entirely from ocean biomass for wound healing

Crustaceans and fish scales in the marine food industry are basically thrown away as waste. This not only wastes resources but also causes environmental pollution. While reducing pollution and waste, biological activity and storage of materials are urgent issues to be solved. In this study, by first preparing dry fibers and then making hydrogels, we prepared a fish scale/sodium alginate/chitosan nanofiber hydrogel (FS-P) by cross-linking the nanofibers in situ. From fish and other organisms, fish gelatin (FG), collagen and CaCO₃ were extracted. Fish scale (FS)/sodium alginate/chitosan nanofibers were cross-linked with copper sulfide nanoparticles prepared by a one-step green method to obtain FS-P nanofiber hydrogels under mild conditions without catalyst and additional procedures. These fiber hydrogels not only have good tissue adhesion and tensile properties, but also have the antibacterial effect of natural antibacterial and CuS photothermal synergism, which can achieve 51.32% and 49.96% of the antibacterial effect against Staphylococcus aureus and Escherichia coli respectively, avoiding the generation of superbacteria. The nanofiber hydrogels have 87.56% voidage and 52.68% degradability after 14 days. The combined strategy of using marine bio-based fibers to prepare gels promoted angiogenesis and tissue repair.

Quality of life following renal sympathetic denervation in treatment-resistant hypertensive patients: a two-year follow-up study

Objective. Hypertension is a significant health burden. In the last 10 years, renal sympathetic denervation has been tested as a potential treatment option for a select group of patients with treatment-resistant hypertension. The aim of this study was to broadly assess the quality of life in patients undergoing renal sympathetic denervation with two years' follow-up. Materials and methods. Patients with treatment-resistant hypertension being treated by hypertension specialists were eligible for inclusion in this study. Bilateral renal sympathetic denervation was performed with the Symplicity Catheter System. Quality of life was measured using standardised questionnaires (Short Form 36, 15 D and a single-item question) and an open question before denervation, after six months and after two years. Results. A total of 23 patients were included. The typical participant was male, 53 years, had a mean office blood pressure of 162/108 mmHg, body mass index of 32 kg/m², and was prescribed 4.8 blood pressure lowering drug classes. At baseline, both physical and mental aspects of quality of life were affected negatively by the treatment-resistant hypertension. Over time, there were modest improvements in quality of life. The largest improvements were seen at six months. Simultaneously, the mean number of blood pressure lowering drug classes was reduced to 4.2. Conclusion. Following renal sympathetic denervation treatment, some aspects of health related quality of life showed an improved trend during follow-up. The observed improvement may reflect the impact of a reduced number of blood pressure lowering drug classes. Clinical Trial Number registered: NCT01630928.

Effects of catheter-based renal denervation on renin-aldosterone system, catecholamines, and electrolytes: A systematic review and meta-analysis

In recent years, catheter-based renal denervation (RDN) has emerged as a promising instrumental therapy for hypertension. The interruption of sympathetic nervous system was regarded as a possible mechanism for RDN regulating blood pressure. While the results reflected by renin-angiotensin-aldosterone system (RAAS), catecholamines and electrolytes remained inconsistent and was never systematically assessed. Pubmed, Embase, and Web of Science were comprehensively searched from inception to September 5, 2021. Studies that evaluated the effects of RDN on RAAS, catecholamines, and electrolytes were identified. Primary outcomes were changes in RAAS hormones after RDN, and secondary outcomes involved changes in plasma norepinephrine, serum, and urinary sodium and potassium. Out of 6391 retrieved studies, 20 studies (two randomized controlled studies and 18 observational studies) involving 771 persons were eventually included. Plasma renin activity had a statistically significant reduction after RDN (0.24 ng/mL/h, 95% CI 0.04 to 0.44, P = .02). While no significant change was found regarding plasma aldosterone (1.53 ng/dL, 95% CI -0.61 to 3.67, P = .16), norepinephrine (0.42 nmol/L, 95% -0.51 to 1.35, P = 0.38), serum sodium and potassium (0.16 mmol/L, 95% CI -0.17 to 0.49, P = .34; -0.02 mmol/L, 95% CI -0.09 to 0.04, P = .48, respectively), and urinary sodium and potassium (3.95 mmol/24 h, 95% CI -29.36 to 37.26, P = .82; 10.22 mmol/24 h, 95% CI -12.11 to 32.54, P = .37, respectively). In conclusion, plasma renin activity significantly decreased after RDN, while no significant change was observed in plasma aldosterone, plasma norepinephrine, and serum and urinary electrolytes.

The impact of renal denervation procedure on use of antihypertensive drugs in the real-life setting

Purpose. Randomised controlled trials have shown that renal denervation lowers office and ambulatory blood pressure. The aim of the present study was to evaluate whether patients undergoing renal denervation procedure in a real-life setting have a reduction in antihypertensive drug prescription over the subsequent years.Material and methods. Using the healthcare utilisation database of the Lombardy Region (Italy), the 136 patients who, during the period 2011-2016, were prescribed four or more antihypertensive drugs and underwent renal denervation were included in the study cohort. The number and type of antihypertensive drugs were assessed over the year before and during the three-year period after renal denervation.Results. The median age of the patients was 67 years and 68% of them were men. Based on a multisource comorbidity score, about 40% of patients showed a poor or very poor clinical status. Before renal denervation, the majority of the patients were prescribed four or five antihypertensive drugs. The number of drugs decreased after the denervation and reached 55% after three years. Over the same period, patients prescribed six drugs decreased from 18% to 2%. All antihypertensive drugs were less prescribed throughout the post denervation period. Compared to the year before the denervation, after three years prescription of diuretics was reduced by 15%, calcium channel blockers by 21%, ACE-inhibitors by 32%, angiotensin receptor blockers by 22%, beta-blockers by 20%, and alfa-blockers by 30%. Use of antihypertensive drugs exhibited a reduction also in an age, sex, and clinically matched control group with no renal denervation to an extent, however, much lower than in denervated patients (p-value = 0.013).Conclusion. In the real-life setting, patients who underwent renal denervation had a clearcut reduction in antihypertensive drug prescription over the following years.Plain Language SummaryPatients exhibited a reduction in the prescription of antihypertensive drugs during the three years that followed the denervation procedureThe decrease in the number of antihypertensive drugs was marked, started after a relatively short time (six months), and involved all drugs prescribed before the denervationThe number of hospitalisations for a cardiovascular event was similar before and after renal denervationAlbeit blood pressure values were not recorded in our database, all these findings taken together suggest the renal denervation procedure has a favourable influence on blood pressure control and is not associated with an increase in the risk of major cardiovascular complications.

The enigma of resistant hypertension: from lifestyle changes and pharmacological treatment to renal denervation

Resistant hypertension consists in the failure to achieve effective control of blood pressure despite the use of at least three drugs, including a diuretic, at the maximum tolerated dosage. Despite the progress made in terms of improving awareness and effectiveness of the available therapeutic strategies, the percentage of patients with resistant hypertension represents up to 18% of the entire hypertensive population. The management of resistant hypertension includes the combination of different strategies from lifestyle changes to complex interventional procedures. Lifestyle interventions include reducing salt intake, weight loss, quitting smoking and alcohol consumption, and performing aerobic physical activity. With regard to drug therapy, international guidelines recommend the introduction of a mineralocorticoid receptor antagonist or, if not tolerated, of a loop diuretic, or of the beta-blocker bisoprolol, or of the alpha-blocker doxazosin. In the last few years, promising results have been obtained from studies that have evaluated the efficacy and safety of the denervation of the renal arteries by ablation. This procedure may constitute an increasingly widespread option for those patients suffering from resistant hypertension despite the use of different drug classes, or who are intolerant or poorly adherent to medical therapy.

Effects of Renal Denervation vs Sham in Resistant Hypertension After Medication Escalation: Prespecified Analysis at 6 Months of the RADIANCE-HTN TRIO Randomized Clinical Trial

Importance

Although early trials of endovascular renal denervation (RDN) for patients with resistant hypertension (RHTN) reported inconsistent results, ultrasound RDN (uRDN) was found to decrease blood pressure (BP) vs sham at 2 months in patients with RHTN taking stable background medications in the Study of the ReCor Medical Paradise System in Clinical Hypertension (RADIANCE-HTN TRIO) trial.

Objectives

To report the prespecified analysis of the persistence of the BP effects and safety of uRDN vs sham at 6 months in conjunction with escalating antihypertensive medications.

Design, Setting, and Participants

This randomized, sham-controlled, clinical trial with outcome assessors and patients blinded to treatment assignment, enrolled patients from March 11, 2016, to March 13, 2020. This was an international, multicenter study conducted in the US and Europe. Participants with daytime ambulatory BP of 135/85 mm Hg or higher after 4 weeks of single-pill triple-combination treatment (angiotensin-receptor blocker, calcium channel blocker, and thiazide diuretic) with estimated glomerular filtration rate (eGFR) of 40 mL/min/1.73 m2 or greater were randomly assigned to uRDN or sham with medications unchanged through 2 months. From 2 to 5 months, if monthly home BP was 135/85 mm Hg or higher, standardized stepped-care antihypertensive treatment starting with aldosterone antagonists was initiated under blinding to treatment assignment.

Interventions

uRDN vs sham procedure in conjunction with added medications to target BP control.

Main Outcomes and Measures

Six-month change in medications, change in daytime ambulatory systolic BP, change in home systolic BP adjusted for baseline BP and medications, and safety.

Results

A total of 65 of 69 participants in the uRDN group and 64 of 67 participants in the sham group (mean [SD] age, 52.4 [8.3] years; 104 male [80.6%]) with a mean (SD) eGFR of 81.5 (22.8) mL/min/1.73 m2 had 6-month daytime ambulatory BP measurements. Fewer medications were added in the uRDN group (mean [SD], 0.7 [1.0] medications) vs sham (mean [SD], 1.1 [1.1] medications; P = .045) and fewer patients in the uRDN group received aldosterone antagonists at 6 months (26 of 65 [40.0%] vs 39 of 64 [60.9%]; P = .02). Despite less intensive standardized stepped-care antihypertensive treatment, mean (SD) daytime ambulatory BP at 6 months was 138.3 (15.1) mm Hg with uRDN vs 139.0 (14.3) mm Hg with sham (additional decreases of -2.4 [16.6] vs -7.0 [16.7] mm Hg from month 2, respectively), whereas home SBP was lowered to a greater extent with uRDN by 4.3 mm Hg (95% CI, 0.5-8.1 mm Hg; P = .03) in a mixed model adjusting for baseline and number of medications. Adverse events were infrequent and similar between groups.

Conclusions and Relevance

In this study, in patients with RHTN initially randomly assigned to uRDN or a sham procedure and who had persistent elevation of BP at 2 months after the procedure, standardized stepped-care antihypertensive treatment escalation resulted in similar BP reduction in both groups at 6 months, with fewer additional medications required in the uRDN group.

Trial Registration

ClinicalTrials.gov Identifier: NCT02649426.

Hypertension management in patients with cardiovascular comorbidities

Arterial hypertension is a leading cause of death globally. Due to ageing, the rising incidence of obesity, and socioeconomic and environmental changes, its incidence increases worldwide. Hypertension commonly coexists with Type 2 diabetes, obesity, dyslipidaemia, sedentary lifestyle, and smoking leading to risk amplification. Blood pressure lowering by lifestyle modifications and antihypertensive drugs reduce cardiovascular (CV) morbidity and mortality. Guidelines recommend dual- and triple-combination therapies using renin–angiotensin system blockers, calcium channel blockers, and/or a diuretic. Comorbidities often complicate management. New drugs such as angiotensin receptor-neprilysin inhibitors, sodium–glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and non-steroidal mineralocorticoid receptor antagonists improve CV and renal outcomes. Catheter-based renal denervation could offer an alternative treatment option in comorbid hypertension associated with increased sympathetic nerve activity. This review summarises the latest clinical evidence for managing hypertension with CV comorbidities.

Long-term follow-up of patients undergoing renal sympathetic denervation

OBJECTIVES

Renal denervation (RDN) proved to significantly lower blood pressure (BP) at 2-6 months in patients on and off antihypertensive drugs. Given a lack of longer-term follow-up data, our aim was to assess the safety and efficacy of RDN up to five years taking into account antihypertensive drug regimen changes over time.

METHODS

In the present single-center study, patients underwent RDN for (therapy resistant) hypertension. Patients underwent protocolized yearly follow-up out to five years. Data were collected on 24-h ambulatory BP and office BP monitoring, renal function, antihypertensive drug regimen, and safety events, including non-invasive renal artery imaging at 6/12 months. Efficacy analyses were performed using linear mixed-effects models.

RESULTS

Seventy-two patients with mean age 63.3 ± 9.5 (SD) years (51% female) were included. Median follow-up time was 3.5 years and Clark's Completeness Index was 72%. Baseline ambulatory daytime BP was 146.1/83.7 ± 17.4/12.2 mmHg under a mean number of 4.9 ± 2.7 defined daily doses (DDD). At five years, ambulatory daytime systolic BP as calculated from the mixed model was 120.8 (95% CI 114.2-127.5) mmHg and diastolic BP was 73.3 (95% CI 69.4-77.3) mmHg, implying a reduction of -20.9/-8.3 mmHg as compared to baseline estimates (p < 0.0001). The number of DDDs remained stable over time (p = 0.87). No procedure-related major adverse events resulting in long-term consequences were observed.

CONCLUSIONS

The BP-lowering effect of RDN was safely maintained at least five years post-procedure as reflected by a significant decrease in ambulatory daytime BP in the absence of escalating antihypertensive drug therapy over time.

Device-Based Therapy for Resistant Hypertension: An Up-to-Date Review

Hypertension is the major risk factor for cardiovascular morbidity and mortality. Matter of fact, untreated hypertension can worsen the overall health, whereas pharmacotherapy can play an important role in lowering the risk of high blood pressure in hypertensive patients. However, persistent uncontrolled hypertension remains an unsolved condition characterized by non-adherence to medication and increased sympathetic activity. This paper will review the non-pharmacological treatments for resistant hypertension (RH) that have emerged in recent years. In addition, the technologies developed in device-based RH therapy, as well as the clinical trials that support their use, will be discussed. Indeed, the novel device-based approaches that target RH present a promising therapy which has been supported by several studies and clinical trials, whereas drug non-adherence and high sympathetic activity are known to be the main causes of RH. Nevertheless, some additional aspects of these RH systems need to be tested in the near future, with a particular focus on the device's design and availability of randomized controlled trials.

Hypertension urgencies in the SPYRAL HTN-OFF MED Pivotal trial

The SPYRAL HTN-OFF MED Pivotal trial ( https://clinicaltrials.gov/ct2/show/NCT02439749 ) demonstrated significant reductions in blood pressure (BP) after renal denervation (RDN) compared to sham control in the absence of anti-hypertensive medications. Prior to the 3-month primary endpoint, medications were immediately reinstated for patients who met escape criteria defined as office systolic BP (SBP) ≥ 180 mmHg or other safety concerns. Our objective was to compare the rate of hypertensive urgencies in RDN vs. sham control patients. Patients were enrolled with office SBP ≥ 150 and < 180 mmHg, office diastolic BP (DBP) ≥ 90 mmHg and mean 24 h SBP ≥ 140 and < 170 mmHg. Patients had been required to discontinue any anti-hypertensive medications and were randomized 1:1 to RDN or sham control. In this post-hoc analysis, cumulative incidence curves with Kaplan-Meier estimates of rate of patients meeting escape criteria were generated for RDN and sham control patients. There were 16 RDN (9.6%) and 28 sham control patients (17.0%) who met escape criteria between baseline and 3 months. There was a significantly higher rate of sham control patients meeting escape criteria compared to RDN for all escape patients (p = 0.032), as well as for patients with a hypertensive urgency with office SBP ≥ 180 mmHg (p = 0.046). Rate of escape was similar between RDN and sham control for patients without a measured BP exceeding 180 mmHg (p = 0.32). In the SPYRAL HTN-OFF MED Pivotal trial, RDN patients were less likely to experience hypertensive urgencies that required immediate use of anti-hypertensive medications compared to sham control.

Renal denervation prevents subclinical atrial fibrillation in patients with hypertensive heart disease: Randomized, sham-controlled trial

BACKGROUND

Catheter-based renal denervation (RD), in addition to pulmonary vein isolation (PVI), reduces atrial fibrillation (AF) recurrence in hypertensive patients. Whether RD, without additional PVI, can prevent subclinical atrial fibrillation (SAF) in patients with hypertensive heart disease (HHD) is unknown.

OBJECTIVE

The purpose of this study was to assess the efficacy of RD in preventing SAF in patients with HHD.

METHODS

A single-center, randomized, sham-controlled pilot trial, including patients >55 years in sinus rhythm, but with a high risk of developing SAF was conducted. Patients had uncontrolled hypertension despite taking 3 antihypertensive drugs, including a diuretic. The primary endpoint was the first SAF episode lasting ≥6 minutes recorded via an implantable cardiac monitor scanned every 6 months for 24 months. A blinded independent monitoring committee assessed electrocardiographic rhythm recordings. Change in SAF burden (SAFB), and office and 24-hour ambulatory blood pressure (BP) at 6-month follow-up were secondary endpoints.

RESULTS

Eighty patients were randomly assigned to RD (n = 42) or sham groups (n = 38). After 24 months of follow-up, SAF occurred in 8 RD patients (19%) and 15 sham patients (39.5%) (hazard ratio 0.40; 95% confidence interval 0.17-0.96; P = .031). Median [interquartile range] SAFB was low in both groups but was significantly lower in the RD vs sham group (0% [0-0] vs 0% [0-0.3]; P = .043). Fast AF (>100 bpm) occurred less frequently in the RD than sham group (2% vs 26%; P = .002). After adjusting for baseline values, there were no significant differences in office or 24-hour BP changes between treatment groups.

CONCLUSION

RD reduced incident SAF events, SAFB, and fast AF in patients with HHD. The observed effects may occur independent of BP lowering.

Long-term outcomes after catheter-based renal artery denervation for resistant hypertension: final follow-up of the randomised SYMPLICITY HTN-3 Trial

BACKGROUND

The SYMPLICITY HTN-3 (Renal Denervation in Patients With Uncontrolled Hypertension) trial showed the safety but not efficacy of the Symplicity system (Medtronic, Santa Rosa, CA, USA) at 6 months follow-up in patients with treatment-resistant hypertension. This final report presents the 36-month follow-up results.

METHODS

SYMPLICITY HTN-3 was a single-blind, multicentre, sham-controlled, randomised clinical trial, done in 88 centres in the USA. Adults aged 18-80 years, with treatment-resistant hypertension on stable, maximally tolerated doses of three or more drugs including a diuretic, who had a seated office systolic blood pressure of 160 mm Hg or more and 24 h ambulatory systolic blood pressure of 135 mm Hg or more were randomly assigned (2:1) to receive renal artery denervation using the single electrode (Flex) catheter or a sham control. The original primary endpoint was the change in office systolic blood pressure from baseline to 6 months for the renal artery denervation group compared with the sham control group. Patients were unmasked after the primary endpoint assessment at 6 months, at which point eligible patients in the sham control group who met the inclusion criteria (office blood pressure ≥160 mm Hg, 24 h ambulatory systolic blood pressure ≥135 mm Hg, and still prescribed three or more antihypertensive medications) could cross over to receive renal artery denervation. Changes in blood pressure up to 36 months were analysed in patients in the original renal artery denervation group and sham control group, including those who underwent renal artery denervation after 6 months (crossover group) and those who did not (non-crossover group). For comparisons between the renal artery denervation and sham control groups, follow-up blood pressure values were imputed for patients in the crossover group using their most recent pre-crossover masked blood pressure value. We report long-term blood pressure changes in renal artery denervation and sham control groups, and investigate blood pressure control in both groups using time in therapeutic blood pressure range analysis. The primary safety endpoint was the incidence of all-cause mortality, end stage renal disease, significant embolic event, renal artery perforation or dissection requiring intervention, vascular complications, hospitalisation for hypertensive crisis unrelated to non-adherence to medications, or new renal artery stenosis of more than 70% within 6 months. The trial is registered with ClinicalTrials.gov, NCT01418261.

FINDINGS

From Sep 29, 2011, to May 6, 2013, 1442 patients were screened, of whom 535 (37%; 210 [39%] women and 325 [61%] men; mean age 57·9 years [SD 10·7]) were randomly assigned: 364 (68%) patients received renal artery denervation (mean age 57·9 years [10·4]) and 171 (32%) received the sham control (mean age 56·2 years [11·2]). 36-month follow-up data were available for 219 patients (original renal artery denervation group), 63 patients (crossover group), and 33 patients (non-crossover group). At 36 months, the change in office systolic blood pressure was -26·4 mm Hg (SD 25·9) in the renal artery denervation group and -5·7 mm Hg (24·4) in the sham control group (adjusted treatment difference -22·1 mm Hg [95% CI -27·2 to -17·0]; p≤0·0001). The change in 24 h ambulatory systolic blood pressure at 36 months was -15·6 mm Hg (SD 20·8) in the renal artery denervation group and -0·3 mm Hg (15·1) in the sham control group (adjusted treatment difference -16·5 mm Hg [95% CI -20·5 to -12·5]; p≤0·0001). Without imputation, the renal artery denervation group spent a significantly longer time in therapeutic blood pressure range (ie, better blood pressure control) than patients in the sham control group (18% [SD 25·0] for the renal artery denervation group vs 9% [SD 18·8] for the sham control group; p≤0·0001) despite a similar medication burden, with consistent and significant results with imputation. Rates of adverse events were similar across treatment groups, with no evidence of late-emerging complications from renal artery denervation. The rate of the composite safety endpoint to 48 months, including all-cause death, new-onset end-stage renal disease, significant embolic event resulting in end-organ damage, vascular complication, renal artery re-intervention, and hypertensive emergency was 15% (54 of 352 patients) for the renal artery denervation group, 14% (13 of 96 patients) for the crossover group, and 14% (10 of 69 patients) for the non-crossover group.

INTERPRETATION

This final report of the SYMPLICITY HTN-3 trial adds to the totality of evidence supporting the safety of renal artery denervation to 36 months after the procedure. From 12 months to 36 months after the procedure, patients who were originally randomly assigned to receive renal artery denervation had larger reductions in blood pressure and better blood pressure control compared with patients who received sham control.

FUNDING

Medtronic.

Durability of blood pressure reduction after ultrasound renal denervation: three-year follow-up of the treatment arm of the randomised RADIANCE-HTN SOLO trial

BACKGROUND

While the blood pressure (BP)-lowering effect of renal denervation (RDN) has been established, long-term durability is a key prerequisite for a broader clinical implementation.

AIMS

Our aims were to assess the long-term durability of the office BP (OBP)-lowering efficacy, antihypertensive medication (AHM) use, and safety of ultrasound RDN (uRDN).

METHODS

Four weeks after withdrawal of AHM, patients with untreated daytime ambulatory BP ≥135/85 mmHg and <170/105 mmHg were randomised to uRDN (n=74) or sham (n=72) in the RADIANCE-HTN SOLO trial. Initiation of AHM was encouraged for home BP >135/85 mmHg following primary endpoint ascertainment at 2 months. Patients and physicians were unblinded at 6 months.  Results: Fifty-one of 74 patients (age: 53.9±11 years; 67% men) originally randomised to uRDN completed the 36-month follow-up. Initial screening OBP upon study entry was 145/92±14/10 mmHg on a mean of 1.2 AHM (range: 0-2.0). Baseline OBP after AHM washout was 154/99±13/8 mmHg. At 36 months, patients were on an average of 1.3 AHM (range: 0-3.0) with 8 patients on no AHM. OBP decreased by 18/11±15/9 mmHg from baseline to 36 months (p<0.001 for both). Overall, OBP control (<140/90 mmHg) improved from 29.4% at screening to 45.1% at 36 months (p=0.059). For patients uncontrolled at screening (n=36), systolic OBP decreased by 10.8 mmHg (p<0.001) at 36 months on similar AHM (p=0.158).

CONCLUSIONS

The safety and effectiveness of uRDN was durable to 36 months, with reduced OBP and improved OBP control despite a similar starting medication burden. No new uRDN-related long-term safety concerns were identified.

Assessment of arterial stiffness to predict blood pressure response to renal sympathetic denervation

BACKGROUND

Recent trials support the efficacy of renal sympathetic denervation (RDN) to reduce blood pressure (BP). Nevertheless, about one third of patients are considered non-responders to RDN. Previous retrospective analyses suggest arterial stiffness could predict BP response to RDN.

AIMS

We prospectively assessed the potential of invasive pulse wave velocity (iPWV) to predict BP response to RDN. Additionally, we aimed to establish non-invasive models based on arterial stiffness to predict BP response to RDN.

METHODS

 iPWV, magnetic resonance imaging-based markers of arterial stiffness and the carotid-femoral pulse wave velocity were recorded prior to RDN in patients with treatment resistant hypertension. Changes in daytime BP after 3 months were analysed according to the prespecified iPWV cut-off (14.4 m/s). Regression analyses were used to establish models for non-invasive prediction of BP response. Results were compared to iPWV as reference and were then validated in an external patient cohort.

RESULTS

Eighty patients underwent stiffness assessment before RDN. After 3 months, systolic 24h and daytime BP were reduced by 13.6±9.8 mmHg and 14.7±10.6 mmHg in patients with low iPWV, versus 6.2±13.3 mmHg and 6.3±12.8 mmHg in those with high iPWV (p<0.001 for both). Upon regression analysis, logarithmic ascending aortic distensibility and systolic baseline BP independently predicted BP change at follow-up. Both were confirmed in the validation cohort.

CONCLUSIONS

 iPWV is an independent predictor for BP response after RDN. In addition, BP change prediction following RDN using non-invasive measures is feasible. This could facilitate patient selection for RDN treatment.

Renal Denervation: A Review

Uncontrolled hypertension persists as an important health issue despite the availability of many medications and nondrug therapies that lower blood pressure. Increasingly, nonadherence to medication is found in approximately 2 of every 5 patients with uncontrolled hypertension. In the search for interventions that lower blood pressure that do not rely on adherence to a regimen requiring daily ingestion of medication or repeated physical activity, device-based methods that denervate the renal arteries have emerged as a potential complement to standard antihypertensive treatments. At least 3 different approaches to renal artery denervation are under active investigation, including the use of radiofrequency energy, ultrasound, or the injection of neurolytic agents into the renal perivascular tissue. In this review, we cover what is currently known about the mechanisms of antihypertensive effects of renal denervation, summarize the efficacy and safety of renal denervation using recent controlled trial publications in a number of hypertensive populations, and conclude with some thoughts about challenges in the field, including the optimization of patient selection for the procedure and what the reader can expect in the near future in this rapidly developing field.

Renal denervation in the antihypertensive arsenal - knowns and known unknowns

Even though it has been more than a decade since renal denervation (RDN) was first used to treat hypertension and an intense effort on researching this therapy has been made, it is still not clear how RDN fits into the antihypertensive arsenal. There is no question that RDN lowers blood pressure (BP), it does so to an extent at best corresponding to one antihypertensive drug. The procedure has an excellent safety record. However, it remains clinically impossible to predict whose BP responds to RDN and whose does not. Long-term efficacy data on BP reduction are still unconvincing despite the recent results in the SPYRAL HTN-ON MED trial; experimental studies indicate that reinnervation is occurring after RDN. Although BP is an acceptable surrogate endpoint, there is complete lack of outcome data with RDN. Clear indications for RDN are lacking although patients with resistant hypertension, those with documented increase in activity of the sympathetic system and perhaps those who desire to take fewest medication may be considered.

The role of blood pressure management in stroke prevention: current status and future prospects

INTRODUCTION

Stroke is the second-leading cause of death worldwide and the second-leading cause of disability-adjusted life-years. It is well known that hypertension is a significant risk factor for cardiovascular events, including stroke.

AREAS COVERED

Recent interventional trials have demonstrated the superiority of intensive blood pressure (BP) control for prevention of cardiovascular events compared to standard BP control. Notably, in the Strategy of Blood Pressure Intervention in Elderly Hypertensive Patients (STEP) trial, intensive BP control showed superiority in the prevention of stroke events in elderly hypertensive patients. Novel medications such as angiotensin receptor-neprilysin inhibitors and sodium glucose cotransporter 2 inhibitors have the potential to suppress various CVD events including stroke. Non-pharmacological antihypertensive therapies such as renal denervation have demonstrated BP-lowering effects and may be useful for stroke prevention. Additionally, new methods and systems of BP monitoring including various kinds of nighttime BP measurement devices, wearable devices, and methods using information and communication technology can be used to assess the pathophysiology of BP variability as a risk factor and an event trigger of stroke incidence.

EXPERT OPINION

Novel therapies and new technologies for BP evaluation strongly support the development of individualized anticipatory medicine, which should be useful for the prevention of stroke.

Renal Sympathetic Denervation for Hypertension

Arterial hypertension is the most prevalent global modifiable risk factor for cardiovascular morbidity and mortality. Despite the availability of numerous pharmacologic treatments, many patients do not achieve guideline-recommended blood pressure targets. Therefore, renal sympathetic denervation (RDN), a process in which catheter-directed techniques are used to ablate portions of the renal artery to reduce sympathetic activity, has been extensively investigated as a complementary and nonpharmacologic approach for the treatment of arterial hypertension. This review seeks to discuss the pathophysiological rationale of this strategy, to survey its history and development, and to highlight the current clinical evidence and possible future directions of its employment. In sum, RDN has demonstrated itself to be a safe and well-tolerated endovascular intervention that can reliably contribute to improved blood pressure control and, perhaps ultimately, significant cardiovascular prognosis.

Renal denervation for atrial fibrillation: a comprehensive updated systematic review and meta-analysis

The study aims to compare clinical outcomes following renal denervation (RDN) in hypertensive patients with atrial fibrillation (AF). Three online databases were searched (MEDLINE, EMBASE and PubMed) for literature related to outcomes of RDN on hypertension and AF, between January 1, 2010, and June 1, 2021. Where possible, risk ratios (RR) and mean differences (MD) were combined using a random effects model. Significance was set at p ≤ 0.05. Seven trials were included that assessed the effect of adding RDN to pulmonary vein isolation (PVI) in patients with hypertension and AF. A total of 711 patients (329 undergoing PVI + RDN and 382 undergoing PVI alone), with an age range of 56 ± 6 to 68 ± 9 years, were included. Pooled analysis showed a significant lowering of AF recurrence in the PVI + RDN (31.3%) group compared to the PVI-only (52.9%) group (p < 0.00001). Pooled analysis of patients with resistant hypertension showed a significant mean reduction of systolic blood pressure (SBP) (-9.42 mm Hg, p = 0.05), but not diastolic blood pressure (DBP) (-4.11 mm Hg, p = 0.16) in favor of PVI + RDN. Additionally, the pooled analysis showed that PVI + RDN significantly improved estimated glomerular filtration rate (eGFR) (+10.2 mL/min per 1.73 m2, p < 0.001) compared to PVI alone. RDN procedures in these trials have proven to be both safe and efficacious with an overall complication rate of 6.32%. Combined PVI and RDN is beneficial for patients with hypertension and AF. Combined therapy showed improvement in SBP and eGFR, reducing the risk of AF recurrence. RDN may serve as an innovative intervention in the treatment of AF.

Insight on Efficacy of Renal Artery Denervation for Refractory Hypertension with Chronic Kidney Diseases: A Long-Term Follow-Up of 24-Hour Ambulatory Blood Pressure

Aims

To explore the long-term efficacy and safety of renal denervation in patients with RHT and CKD, a post hoc analysis of eGFR subgroups was completed.

Methods

Fifty-four patients with refractory hypertension with chronic kidney disease were treated with RDN and enrolled in the study. Patients were divided into three groups according to eGFR: eGFR 46–90 ml/min group, eGFR 15–45 ml/min group, and eGFR <15 ml/min group. The planned follow-up period was 48 months to assess 24 h ambulatory blood pressure, renal function, type of antihypertensive medication, and RDN complications.

Results

The ablation sites of the GFR 46–90 ml/min group and GFR 15–45 ml/min group were 32.57 ± 2.99 and 29.53 ± 5.47, respectively. No complications occurred in the GFR 46–90 ml/min group. The GFR<15 ml/min group was treated with 27.07 ± 5.59  ablation. Renal artery dissection occurred in each group of GFR 15–45 ml/min and GFR <15 ml/min. And renal stent implantation artery was performed on these two patients. No severe renal artery stenosis occurred. There were no significant differences in Scr and eGFR between the three groups at each follow-up point. Compared with baseline, SBP was significantly of each group decreased to varying degrees at each follow-up time point. SBP decreased most in the GFR 46–90 ml/min group. Compared with baseline, the type of antihypertensive drugs used in the GFR46-90 ml/min group decreased significantly except for 36 and 48 months. At 48 months' postadmission, there was a significant decrease in the type of antihypertensive medication used in the GFR15-45 ml/min group, and there was no significant decrease in the type of antihypertensive medication used in the GFR<15 ml/min group.

Conclusions

RDN can safely reduce SBP in CKD patients combined with RHT for 48 months, with the most pronounced reduction in the GFR15-45 ml/min group. The variety of antihypertensive drugs was significantly reduced after RDN. This was particularly evident in patients with GFR 15–45 ml/min.

Predicting Renal Denervation Response in Resistant High Blood Pressure by Arterial Stiffness Assessment: A Systematic Review

Background: Accurately selecting hypertensive candidates for renal denervation (RDN) therapy is required, as one-third of patients who undergo RDN are non-responders. We aimed to systematically review the literature on RDN response prediction using arterial stiffness assessment, optimizing the selection of patients referred for interventional blood pressure lowering procedures. Methods: A literature search was performed in MEDLINE, Embase, Scopus, and Cochrane databases to retrieve potential eligible studies from the inception to 30 June 2022. Results: Ten studies were finally included in this systematic review. Studies consistently documented that invasive pulse wave velocity (PWV) was correlated with RDN’s significant success. Nevertheless, non-invasive ambulatory arterial stiffness index and PWV derived from ambulatory blood pressure monitoring were independent predictors of blood pressure response (p = 0.04 and p < 0.0001). In some studies, magnetic resonance imaging parameters of arterial stiffness (ascending aortic distensibility, total arterial compliance) were correlated with blood pressure reduction (AUC = 0.828, p = 0.006). Conclusions: Assessing arterial stiffness prior to RDN predicted procedural success, since stiffness parameters were strongly correlated with a significant blood pressure response. Our endeavor should be tackled as a step forward in selecting appropriate hypertensive patients scheduled for RDN therapy. Non-invasive measurements could be an alternative to invasive parameters for response prediction.

Present Evidence of Determinants to Predict the Efficacy of Renal Denervation

Sympathetic overactivation is one of the main contributors to development and progress of hypertension. Renal denervation (RDN) has been evidenced by series of clinical trials for its efficacy and safety to treat overactivated sympathetic nervous system induced diseases. However, the results were inconsistent and not all patients benefited from RDN. Appropriate patient selection and intraoperative factors to improve the efficacy of RDN need to be solved urgently. Over the decade, research studies on the correlations between indicators and the antihypertensive effects have been conducted and made a fairly well progress. Herein, we comprehensively reviewed the research studies on how to make RDN more predictable or improve the efficacy of RDN and summarized these potential indicators or devices which might be applied in clinical settings.

Renal Denervation for Resistant Hypertension: A Concise Update on Treatment Options and the Latest Clinical Evidence

Evidence from recent sham-controlled trials supports the use of endovascular renal denervation (RDN) to lower blood pressure in general as well as in treatment-resistant hypertension. According to recent studies, the effects of RDN are long lasting. Newer technologies using multipolar radiofrequency catheters and an additional ablation of the renal side branches as well as ultrasound with improved circumferential tissue penetration have made these advances possible. This has initiated a change of the perspective on RDN in clinical guidelines and has thereby set a cornerstone for a broader clinical application of RDN in the future.

Update on Hypertension Research in 2021

In 2021, 217 excellent manuscripts were published in Hypertension Research. Editorial teams greatly appreciate the authors' contribution to hypertension research progress. Here, our editorial members have summarized twelve topics from published work and discussed current topics in depth. We hope you enjoy our special feature, "Update on Hypertension Research in 2021".

Update on Renal Sympathetic Denervation for the Treatment of Hypertension

PURPOSE OF REVIEW

Hypertension is a leading risk factor for all-cause mortality in adults; however, medication non-adherence and intolerance present an enormous treatment challenge. Given the critical role of renal sympathetic nerves in neurogenic control of blood pressure and pathophysiology of hypertension, renal sympathetic denervation (RDN) has been explored as a therapeutic strategy in hypertension treatment over the last 15 years. In this review, we will discuss the role of renal sympathetic nerves in the pathophysiology of hypertension, provide an update on the available evidence regarding the short- and long-term safety and effectiveness of RDN in the treatment of hypertension, and consider its future perspectives.

RECENT FINDINGS

RDN is a percutaneous endovascular catheter-based neuromodulation approach that enables ablation of renal sympathetic nerve fibers within the adventitial layer of the renal arteries using radiofrequency (most extensively studied), ultrasound energy, or neurolytics (e.g., alcohol). In the last decade, advancements in procedural techniques and well-designed sham-controlled trials utilizing 24-h ambulatory blood pressure measurements have demonstrated that RDN has an excellent safety profile and results in a modest reduction of blood pressure, in a wide range of hypertensive phenotypes (mild to resistant), irrespective of antihypertensive drug use and this effect is sustained over a 3-year period. Superiority of a particular RDN modality has not been yet established. Despite strong evidence demonstrating efficacy and safety of RDN, current data does not support its use as a primary approach in the treatment of hypertension due to its modest treatment effect and concerns around long-term sustainability. Perhaps the best utility of RDN is in hypertensives intolerant to antihypertensive medications or as an adjunct to aldosterone antagonists in the management of resistant hypertension. Patient selection will be critical to demonstrate a meaningful benefit of RDN. Future well-designed studies are necessary to determine predictors and measures of response to RDN, long-term efficacy given question of renal nerve regeneration, comparison of available technologies, safety in patients with advanced kidney disease, and improvement in patient quality of life measures.

The Potential Role of Renal Denervation in the Management of Heart Failure

Sympathetic nervous system activation in patients with heart failure is one of the main pathophysiologic mechanisms associated with the worse outcomes. Pharmacotherapies targeting neurohormonal activation have been at the center of heart failure management. Despite the advancement of therapies and the available treatments, heart failure continues to have an overall poor prognosis. Renal denervation was originally developed to lower systemic blood pressure in patients with poorly controlled hypertension, by modulating sympathetic outflow. However, more recently, multiple studies have investigated the effect of renal denervation in heart failure patients with both preserved (HFpEF) and reduced ejection fractions (HFrEF). This paper provides an overview of the potential effect of renal denervation in altering the various pathophysiologic, sympathetically mediated pathways that contribute to heart failure, and reviews the literature that supports its future use in those patients.

Microglia-derived PDGFB promotes neuronal potassium currents to suppress basal sympathetic tonicity and limit hypertension

Although many studies have addressed the regulatory circuits affecting neuronal activities, local non-synaptic mechanisms that determine neuronal excitability remain unclear. Here, we found that microglia prevented overactivation of pre-sympathetic neurons in the hypothalamic paraventricular nucleus (PVN) at steady state. Microglia constitutively released platelet-derived growth factor (PDGF) B, which signaled via PDGFRα on neuronal cells and promoted their expression of Kv4.3, a key subunit that conducts potassium currents. Ablation of microglia, conditional deletion of microglial PDGFB, or suppression of neuronal PDGFRα expression in the PVN elevated the excitability of pre-sympathetic neurons and sympathetic outflow, resulting in a profound autonomic dysfunction. Disruption of the PDGFB^MG-Kv4.3^Neuron pathway predisposed mice to develop hypertension, whereas central supplementation of exogenous PDGFB suppressed pressor response when mice were under hypertensive insult. Our results point to a non-immune action of resident microglia in maintaining the balance of sympathetic outflow, which is important in preventing cardiovascular diseases.

Twenty-Four-Hour Pulsatile Hemodynamics Predict Brachial Blood Pressure Response to Renal Denervation in the SPYRAL HTN-OFF MED Trial

Renal denervation (RDN) lowers blood pressure (BP), but BP response is variable in individual patients. We investigated whether measures of pulsatile hemodynamics, obtained during 24-hour ambulatory BP monitoring, predict BP drop following RDN.

Intravascular Renal Denervation Reduces Ambulatory and Office Blood Pressure in Patients with Essential Hypertension: A Meta-Analysis of Randomized Sham-Controlled Trials

BACKGROUND

This meta-analysis was designed to evaluate the antihypertensive efficacy of intravascular renal denervation (RDN) in patients with essential hypertension, especially to determine the magnitude of blood pressure (BP) reduction with RDN therapy using second-generation catheters.

METHODS

PubMed was searched to identify randomized sham-controlled trials from inception through August 2021. The endpoints were changes in 24-h ambulatory BP or office BP. This meta-analysis was performed by calculating the weighted mean difference (WMD) with 95% confidence interval (CI) using the random-effects model when the I2 index was <50%. A fixed-effects model was used when the I2 index was ≥50%.

RESULTS

A total of 1,297 patients were included in 8 randomized, sham-controlled trials in this meta-analysis. Intravascular RDN reduced 24-h ambulatory systolic BP (SBP) -3.02 (WMD, 95% CI: -4.95, -1.10, p < 0.01) and diastolic BP (DBP) -1.66 (WMD, 95% CI: -2.44, -0.88, p < 0.001) mm Hg, respectively. In the studies using first-generation catheters, the WMDs of 24-h ambulatory SBP and DBP changes between intravascular RDN and sham control were -2.67 (95% CI: -5.08, -0.27; p < 0.05; I2 = 0%, p = 0.53) and -0.82 (95% CI: -2.19, 0.56; p > 0.05; I2 = 0%, p = 0.64) mm Hg. In the studies using second-generation catheters, the WMDs of 24-h ambulatory SBP and DBP changes between intravascular RDN and sham control were -3.14 (95% CI: -5.94, -0.33, p < 0.05; I2 = 71%, p = 0.008) and -2.06 (95% CI: -3.02, -1.11, p < 0.001; I2 = 50%, p = 0.09) mm Hg. Intravascular RDN using second-generation catheters reduced office SBP -6.30 (WMD, 95% CI: -7.67, -4.93, p < 0.001; I2 = 43%, p = 0.14) and DBP -3.88 (WMD, 95% CI: -4.44, -3.33, p < 0.001; I2 = 42%, p = 0.14) mm Hg, respectively.

CONCLUSIONS

Intravascular RDN using second-generation catheters reduces ambulatory and office BP in patients with essential hypertension. The selection of appropriate hypertensive patients may be the major challenge for the performance of intravascular RDN in routine clinical practice.

Renal denervation in patients with chronic kidney disease: current evidence and future perspectives

Supported by several high-quality randomised clinical trials and registry analyses, catheter-based renal denervation is becoming an important adjunctive treatment modality for the safe and efficacious treatment of hypertension besides lifestyle modifications and antihypertensive medication. Renal denervation is of particular interest to nephrologists as the intervention may provide additional benefits to hypertensive people with chronic kidney disease (CKD), a condition typically characterised by sympathetic hyperactivity. A growing body of clinical evidence supports the safety and efficacy of renal denervation in this difficult-to-control population. In addition, preclinical and clinical research indicate potential nephroprotective effects in CKD patients. The current review examines recent research on renal denervation with focus on renal disease and assesses the latest findings and their implications from a nephrologist's perspective.

Impact of drug adherence on blood pressure response to alcohol-mediated renal denervation

PURPOSE

While poor drug adherence is frequent in patients with resistant hypertension, detailed analyses of the impact of drug adherence on the success of renal denervation are scarce. We report drug adherence at baseline, changes in drug adherence, and the influence of these parameters on blood pressure changes at 6 and 12 months in patients treated with alcohol-mediated renal denervation as part of the Peregrine study.

MATERIALS AND METHODS

Urinary detection of antihypertensive drugs was performed using high-performance liquid chromatography-tandem mass spectrometry. Full adherence, partial adherence, and complete non-adherence were defined as 0, 1, or ≥2 drugs not detected, respectively.

RESULTS

Renal denervation was performed in 45 patients with uncontrolled hypertension on ≥3 antihypertensive medications (62% men, age 55 ± 10 years). At baseline, the proportion of fully, partially, and non-adherent patients was 62% (n = 28), 16% (n = 7), and 22% (n = 10), respectively. At 6 months, adherence improved by 21% (n = 9), remained unchanged at 49% (n = 21), and worsened by 30% (n = 13). Mean 24-h systolic blood pressure decreased by 10 ± 13, 10 ± 4, and 14 ± 19 mmHg in fully, partially, and non-adherent patients (p = 0.77), and by 14 ± 14, 8 ± 11, and 14 ± 18 mmHg in patients who improved, maintained, or decreased adherence, respectively (p = 0.35). The results at 12 months were similar.

CONCLUSION

About 40% of patients with apparently treatment-resistant hypertension were not fully adherent at baseline, and adherence decreased further in 30%. Nevertheless, mean blood pressure changes after renal denervation were similar irrespective of drug adherence. Our results suggest that such patients may benefit from alcohol-mediated renal denervation, irrespective of drug adherence. These findings are hypothesis-generating and need to be confirmed in ongoing sham-controlled trials.

Effect of Yiqi Huayu Pinggan Zishen Formula Combined with Valsartan in the Treatment of Hypertension and Its Effect on MMP-9, Ang II, and MCP-1

Objective

To explore the effect of Yiqi Huayu Pinggan Zishen recipe combined with valsartan in the treatment of hypertension and its effect on MMP-9, Ang II, and MCP-1.

Methods

About 100 patients with hypertension treated in our hospital from March 2020 to April 2021 were enrolled. All patients were arbitrarily assigned to the control group and the study group. The former group was cured with valsartan, and the latter group was cured with Yiqi Huayu Pinggan Zishen recipe combined with valsartan. The curative effect, blood pressure level, renal function index, serum matrix metalloproteinase-9 (MMP-9), monocyte chemoattractant protein-1 (MCP-1), angiotensin II (Ang II) level, traditional Chinese medicine (TCM) syndrome score, and the incidence of adverse reactions were compared.

Results

First of all, we compared the curative effects; the study group exhibited remarkably effective in 44 cases and effective in 6 cases, and the effective rate was 100.00%, while in the control group, 24 cases were markedly effective, 16 cases were effective, and 5 cases were ineffective; the effective rate was 90.00%. The curative effect in the study group was higher (P < 0.05). Secondly, we compared the blood pressure level. Before treatment, there was no remarkable difference (P > 0.05). After treatment, the blood pressure of the two groups decreased. The systolic blood pressure and diastolic blood pressure of the study group were lower (P < 0.05). In terms of renal function indexes, the levels of blood urine nitrogen (BUN), Cr, and β 2-MG in the study group were lower, while the level of eGFR in the study group was higher (P < 0.05). The serum levels of MMP-9, MCP-1, and Ang II decreased. Of note, the levels of serum MMP-9, MCP-1, and Ang II in the study group were lower (P < 0.05). After treatment, the TCM syndrome scores decreased, and the study group was lower (P < 0.05). Finally, we compared the incidence of adverse reactions. The incidence of adverse reactions in the study group was lower (P < 0.05).

Conclusion

Yiqi Huayu Pinggan Zishen recipe combined with valsartan in the treatment of hypertension can remarkably reduce the clinical symptoms, enhance the renal function, strengthen the therapeutic effect, promote the ability of independent movement, and reduce the levels of serum MMP-9, MCP-1, and Ang II with high safety, which has the value of clinical application.