Efficacy of catheter-based renal denervation in the absence of antihypertensive medications (SPYRAL HTN-OFF MED Pivotal): a multicentre, randomised, sham-controlled trial

Renale Denervation – Phoenix aus der Asche

Die arterielle Hypertonie ist eine häufige und meistens unzureichend behandelte Erkrankung, die für eine Vielzahl von kardiovaskulären Komplikationen verantwortlich ist. Aufgrund der schlechten Therapieadhärenz resultieren Lebensstiländerungen und die medikamentöse Dauertherapie häufig nicht in einer ausreichenden Blutdrucksenkung. Die renale Denervation (RDN) hat damit das Potenzial, die bisherigen Strategien zur Therapie der arteriellen Hypertonie sinnvoll zu ergänzen. Unlängst haben mehrere randomisierte, unabhängige Studien das biologische Konzept der RDN eindeutig nachgewiesen. Dabei entspricht die erreichte Blutdrucksenkung im Mittel etwa dem eines Antihypertonikums. Unabhängig von der Therapietreue des Patienten ist die Wirkung anhaltend. Weitere klinische Untersuchung werden derzeit durchgeführt, um die bisherigen Ergebnisse zu festigen und bislang ungeklärte Fragen zu beantworten.

Long-term efficacy and safety of renal denervation in the presence of antihypertensive drugs (SPYRAL HTN-ON MED): a randomised, sham-controlled trial

BACKGROUND

Renal denervation has been shown to lower blood pressure in the presence of antihypertensive medications; however, long-term safety and efficacy data from randomised trials of renal denervation are lacking. In this pre-specified analysis of the SPYRAL HTN-ON MED study, we compared changes in blood pressure, antihypertensive drug use, and safety up to 36 months in renal denervation versus a sham control group.

METHODS

This randomised, single-blind, sham-controlled trial enrolled patients from 25 clinical centres in the USA, Germany, Japan, the UK, Australia, Austria, and Greece, with uncontrolled hypertension and office systolic blood pressure between 150 mm Hg and 180 mm Hg and diastolic blood pressure of 90 mm Hg or higher. Eligible patients had to have 24-h ambulatory systolic blood pressure between 140 mm Hg and less than 170 mm Hg, while taking one to three antihypertensive drugs with stable doses for at least 6 weeks. Patients underwent renal angiography and were randomly assigned (1:1) to radiofrequency renal denervation or a sham control procedure. Patients and physicians were unmasked after 12-month follow-up and sham control patients could cross over after 12-month follow-up completion. The primary endpoint was the treatment difference in mean 24-h systolic blood pressure at 6 months between the renal denervation group and the sham control group. Statistical analyses were done on the intention-to-treat population. Long-term efficacy was assessed using ambulatory and office blood pressure measurements up to 36 months. Drug surveillance was used to assess medication use. Safety events were assessed up to 36 months. This trial is registered with ClinicalTrials.gov, NCT02439775; prospectively, an additional 260 patients are currently being randomly assigned as part of the SPYRAL HTN-ON MED Expansion trial.

FINDINGS

Between July 22, 2015, and June 14, 2017, among 467 enrolled patients, 80 patients fulfilled the qualifying criteria and were randomly assigned to undergo renal denervation (n=38) or a sham control procedure (n=42). Mean ambulatory systolic and diastolic blood pressure were significantly reduced from baseline in the renal denervation group, and were significantly lower than the sham control group at 24 and 36 months, despite a similar treatment intensity of antihypertensive drugs. The medication burden at 36 months was 2·13 medications (SD 1·15) in the renal denervation group and 2·55 medications (2·19) in the sham control group (p=0·26). 24 (77%) of 31 patients in the renal denervation group and 25 (93%) of 27 patients in the sham control group adhered to medication at 36 months. At 36 months, the ambulatory systolic blood pressure reduction was -18·7 mm Hg (SD 12·4) for the renal denervation group (n=30) and -8·6 mm Hg (14·6) for the sham control group (n=32; adjusted treatment difference -10·0 mm Hg, 95% CI -16·6 to -3·3; p=0·0039). Treatment differences between the renal denervation group and sham control group at 36 months were -5·9 mm Hg (95% CI -10·1 to -1·8; p=0·0055) for mean ambulatory diastolic blood pressure, -11·0 mm Hg (-19·8 to -2·1; p=0·016) for morning systolic blood pressure, and -11·8 mm Hg (-19·0 to -4·7; p=0·0017) for night-time systolic blood pressure. There were no short-term or long-term safety issues associated with renal denervation.

INTERPRETATION

Radiofrequency renal denervation compared with sham control produced a clinically meaningful and lasting blood pressure reduction up to 36 months of follow-up, independent of concomitant antihypertensive medications and without major safety events. Renal denervation could provide an adjunctive treatment modality in the management of patients with hypertension.

FUNDING

Medtronic.

Long-term outcome of renal nerve denervation (RDN) for resistant hypertension

We aimed to determine the long-term outcome of renal denervation (RDN). All patients with resistant hypertension who underwent RDN between 2012 and 2018 at Siriraj Hospital were included in the study. Patients were followed up at 3, 6, and 12 months and then annually up to 9 years. Effectiveness of the RDN outcome was defined by either (1) a reduction in office systolic BP ≥ 10 mmHg, (2) a reduction in the number of antihypertensive drugs taken, or (3) both outcomes being achieved. In total, 18 RDN procedures were performed during the study period. The mean and longest follow-up periods were 52 months and 104 months, respectively. Heterogeneous BP responses after RDN for resistant hypertension were observed. Effectiveness of the RDN outcome was achieved in 88% of the patients at 1 year and in >80% of the patients during the entire follow-up at each time point up to 9 years.

Patient preference for renal denervation therapy in hypertension: A cross-sectional survey in Chengdu, China

This study investigated patient preferences for renal denervation (RDN) therapy in hypertension patients in Chengdu, China. A questionnaire-based cross-sectional study was conducted between August and December 2020. First, we collected and analyzed information on demographics, the duration of hypertension, the presence or absence of medication, the medication regimen, the duration of medication, maximal and minimal blood pressure levels, self-reported comorbidities, the willingness of patients to choose RDN as a blood pressure control strategy, choice determinants and expectations for RDN. In total, 485 patients were interviewed, and 402 questionnaires were eligible for analysis. The mean age of the participants was 61 years, 53.9% of the participants were male, and 32.6% of the patients demonstrated a willingness to choose RDN as a blood pressure control strategy. The proportion of patients who were already on medication was 34.7%, whereas the proportion of those who were not on medication was 23.3%. Furthermore, 47.3% of the patients would choose RDN treatment if the procedure could decrease their blood pressure by over 20 mmHg, while no patient would choose the device treatment if their blood pressure would decrease by less than 5 mmHg. In addition, 56.5% of the patients expected that they could take one less medication after RDN. Approximately 70% of the patients expected that RDN could consistently decrease their blood pressure for at least 15 years. In summary, among hypertensive patients in Chengdu, an estimated one-third were willing to choose RDN therapy as a blood pressure control approach; these patients were younger, more likely to be male, took more antihypertensive drugs, and had concomitant metabolic disorders. The perspectives of patients on RDN were not dependent on their education levels; also, their expectations for RDN were high.

[Arterial Hypertension]

Arterial hypertension affects about one third of the German population with a prevalence increasing with age up to 60 %. Globally, more than a quarter gedoppelt of the population are considered hypertensive, resulting in a total of more than one billion people. Not only due to such high prevalence, but also because of its multiple cardiovascular, renal, ocular, and cognitive complications, arterial hypertension is a leading contributor to the global burden of disease and responsible for up to 10 million deaths worldwide. Contrary to the great importance of arterial hypertension resulting from such high prevalence and immense impact on health worldwide, awareness of disease is low in affected people. Less than every second patient knows about his or her disease status and less than 40 % of patients in Europe show adequate blood pressure control with a treatment target of < 140/90 mmHg despite antihypertensive treatment. This overview of arterial hypertension, its etiology, diagnostic tools, and therapeutic options aims to improve the understanding of arterial hypertension and to facilitate the diagnostic and therapeutic approach, eventually resulting in a better and more successful handling of patients with arterial hypertension.

Clinical Trial Design Principles and Outcomes Definitions for Device-Based Therapies for Hypertension: A Consensus Document From the Hypertension Academic Research Consortium

The clinical implications of hypertension in addition to a high prevalence of both uncontrolled blood pressure and medication nonadherence promote interest in developing device-based approaches to hypertension treatment. The expansion of device-based therapies and ongoing clinical trials underscores the need for consistency in trial design, conduct, and definitions of clinical study elements to permit trial comparability and data poolability. Standardizing methods of blood pressure assessment, effectiveness measures beyond blood pressure alone, and safety outcomes are paramount. The Hypertension Academic Research Consortium (HARC) document represents an integration of evolving evidence and consensus opinion among leading experts in cardiovascular medicine and hypertension research with regulatory perspectives on clinical trial design and methodology. The HARC document integrates the collective information among device-based therapies for hypertension to better address existing challenges and identify unmet needs for technologies proposed to treat the world’s leading cause of death and disability. Consistent with the Academic Research Consortium charter, this document proposes pragmatic consensus clinical design principles and outcomes definitions for studies aimed at evaluating device-based hypertension therapies.

Advances in the Treatment Strategies in Hypertension: Present and Future

Hypertension is the most frequent chronic and non-communicable disease all over the world, with about 1.5 billion affected individuals worldwide. Its impact is currently growing, particularly in low-income countries. Even in high-income countries, hypertension remains largely underdiagnosed and undertreated, with consequent low rates of blood pressure (BP) control. Notwithstanding the large number of clinical observational studies and randomized trials over the past four decades, it is sad to note that in the last few years there has been an impressive paucity of innovative studies. Research focused on BP mechanisms and novel antihypertensive drugs is slowing dramatically. The present review discusses some advances in the management of hypertensive patients, and could play a clinical role in the years to come. First, digital/health technology is expected to be increasingly used, although some crucial points remain (development of non-intrusive and clinically validated devices for ambulatory BP measurement, robust storing systems enabling rapid analysis of accrued data, physician-patient interactions, etc.). Second, several areas should be better outlined with regard to BP diagnosis and treatment targets. Third, from a therapeutic standpoint, existing antihypertensive drugs, which are generally effective and well tolerated, should be better used by exploiting available and novel free and fixed combinations. In particular, spironolactone and other mineral-corticoid receptor antagonists should be used more frequently to improve BP control. In particular, some drugs initially developed for conditions different from hypertension including heart failure and diabetes have demonstrated to lower BP significantly and should therefore be considered. Finally, renal artery denervation is another procedure that has proven effective in the management of hypertension.

Dynamics of Soluble Factors and Double-Negative T Cells Associated with Response to Renal Denervation in Resistant Hypertension Patients

The role of the immune system, and hence inflammation, in the pathophysiology of hypertensive patients is not clear. Until now, most clinical and biochemical parameters have failed to predict a positive response to renal denervation (RDN). Our aim was to evaluate the immune response in a cohort of patients treated by RDN, through the analysis of cytokine, chemokine, and growth factor behavior. A population of 21 resistant hypertension patients, treated by RDN, was evaluated at six months and one year. Response was defined as a drop of ≥5 mmHg in ambulatory blood pressure monitoring. Sixty-seven percent and 81% of patients clinically responded after six months and one year, respectively. There were no complications or safety issues. Plasmatic levels of 45 cytokine, chemokine, and growth factors were quantified at four different times, pre- and post-procedure. Baseline characteristics were similar between groups, except that active smoking was more frequent in non-responders at one year. Regulated on activation, normal T cell expressed, and secreted (RANTES/CCL5) levels were significantly lower in responders, both at baseline and at 30 days (p = 0.037), and a level ≤15,496 pg/mL was the optimal cutoff, for prediction of a response. IL-15, IL-17A, IL-27, and leukemia inhibitory factor varied significantly in time, with an acute rise being observed 24 h after RDN. Our group has previously showed that HLA-DR+ double-negative (DN) T cells were significantly lower in responders. There was a positive correlation between IL-13, -27, and -4, and DN T cells, and a negative correlation between the latter and SDF-1α and TNF-α, at baseline. Low plasmatic levels of the chemokine RANTES/CCL5 was the most significant result associated with RDN response and may help to identify the best candidates among patients with true resistant hypertension. Pro-inflammatory cytokines correlated negatively with DN T cells in responders, a finding compatible with an enhanced inflammatory milieu present in this extremely high cardiovascular risk cohort.

Renal Denervation Prevents Atrial Arrhythmogenic Substrate Development in CKD

BACKGROUND

In patients with chronic kidney disease (CKD), atrial fibrillation (AF) is highly prevalent and represents a major risk factor for stroke and death. CKD is associated with atrial proarrhythmic remodeling and activation of the sympathetic nervous system. Whether reduction of the sympathetic nerve activity by renal denervation (RDN) inhibits AF vulnerability in CKD is unknown.

METHODS

Left atrial (LA) fibrosis was analyzed in samples from patients with AF and concomitant CKD (estimated GFR, <60 mL/min per 1.73 m²) using picrosirius red and compared with AF patients without CKD and patients with sinus rhythm with and without CKD. In a translational approach, male Sprague Dawley rats were fed with 0.25% adenine (AD)-containing chow for 16 weeks to induce CKD. At week 5, AD-fed rats underwent RDN or sham operation (AD). Rats on normal chow served as control. After 16 weeks, cardiac function and AF susceptibility were assessed by echocardiography, radiotelemetry, electrophysiological mapping, and burst stimulation, respectively. LA tissue was histologically analyzed for sympathetic innervation using tyrosine hydroxylase staining, and LA fibrosis was determined using picrosirius red.

RESULTS

Sirius red staining demonstrated significantly increased LA fibrosis in patients with AF+CKD compared with AF without CKD or sinus rhythm. In rats, AD demonstrated LA structural changes with enhanced sympathetic innervation compared with control. In AD, LA enlargement was associated with prolonged duration of induced AF episodes, impaired LA conduction latency, and increased absolute conduction inhomogeneity. RDN treatment improved LA remodeling and reduced LA diameter compared with sham-operated AD. Furthermore, RDN decreased AF susceptibility and ameliorated LA conduction latency and absolute conduction inhomogeneity, independent of blood pressure reduction and renal function.

CONCLUSIONS

In an experimental rat model of CKD, RDN inhibited progression of atrial structural and electrophysiological remodeling. Therefore, RDN represents a potential therapeutic tool to reduce the risk of AF in CKD, independent of changes in renal function and blood pressure.

Plasma renin and aldosterone concentrations related to endovascular ultrasound renal denervation in the RADIANCE-HTN SOLO trial

OBJECTIVE

The RADIANCE-HTN SOLO trial demonstrated a greater reduction in daytime ambulatory SBP at 2 months by endovascular ultrasound renal denervation than sham procedure. We hypothesized that plasma renin and aldosterone concentrations would be associated with the SBP response to renal denervation.

METHODS

Hypertensive patients were randomized to renal denervation (n = 74) or sham (n = 72) after a 4-week washout of antihypertensive medications. In a 53-patient subset, 2-month and 6-month plasma renin and aldosterone concentration were measured. Dietary sodium was not controlled.

RESULTS

Mean age of the 29 treatment and 24 sham patients was 54 years; 62% were men; 17% black. Daytime ambulatory SBP fell in the denervation but not the sham group at 2 months (-7.8 ± 10.7 vs. -0.1 ± 10.1 mmHg; P = 0.048). Baseline plasma renin and aldosterone concentrations were in the low-normal range, did not change significantly at 2 months in either group and did not predict response to renal denervation. At 6 months, after the addition of antihypertensive medications, there was a significant rise in renin in the sham but not the denervation group.

CONCLUSION

Although renal denervation but not sham resulted in a decrease in daytime ambulatory SBP at 2 months, renin and aldosterone concentrations did neither predict the BP response to renal denervation; nor did they fall after denervation. A rise in renin at 6 months in the sham group likely represents confounding from antihypertensive medications. Whether the BP-lowering effect of renal denervation depends on reducing local intrarenal renin release requires further study.

Catheter-based ultrasound renal denervation in patients with resistant hypertension: the randomized, controlled REQUIRE trial

Renal denervation is a promising new non-pharmacological treatment for resistant hypertension. However, there is a lack of data from Asian patients. The REQUIRE trial investigated the blood pressure-lowering efficacy of renal denervation in treated patients with resistant hypertension from Japan and South Korea. Adults with resistant hypertension (seated office blood pressure ≥150/90 mmHg and 24-hour ambulatory systolic blood pressure ≥140 mmHg) with suitable renal artery anatomy were randomized to ultrasound renal denervation or a sham procedure. The primary endpoint was change from baseline in 24-hour ambulatory systolic blood pressure at 3 months. A total of 143 patients were included (72 renal denervation, 71 sham control). Reduction from baseline in 24-hour ambulatory systolic blood pressure at 3 months was not significantly different between the renal denervation (-6.6 mmHg) and sham control (-6.5 mmHg) groups (difference: -0.1, 95% confidence interval -5.5, 5.3; p = 0.971). Reductions from baseline in home and office systolic blood pressure (differences: -1.8 mmHg [p = 0.488] and -2.0 mmHg [p = 0.511], respectively), and medication load, did not differ significantly between the two groups. The procedure-/device-related major adverse events was not seen. This study did not show a significant difference in ambulatory blood pressure reductions between renal denervation and a sham procedure in treated patients with resistant hypertension. Although blood pressure reduction after renal denervation was similar to other sham-controlled studies, the sham group in this study showed much greater reduction. This unexpected blood pressure reduction in the sham control group highlights study design issues that will be addressed in a new trial. CLINICAL TRIAL REGISTRATION: NCT02918305 ( http://www.clinicaltrials.gov ).

Validation of a Novel Renal Denervation System With Cryoablation: A Preclinical Study and Case Series

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With the concept of cryoablation, we innovatively applied liquid nitrogen in RDN and designed a dedicated balloon catheter and system for Cryo-RDN.

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In a swine model, this Cryo-RDN system demonstrated device-related safety and efficacy. The extent and depth of nerve ablation were efficient and stable. Sustained decreases in renal and serum norepinephrine also suggested effective ablation in the long term.

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Cryo-RDN also met safety endpoints in 6 patients with resistant hypertension. The 24-hour ambulatory blood pressure and office blood pressure of all 6 patients were reduced after 6 months compared with their baseline values, providing clinical support for further large-scale clinical studies.

Recently, we designed a renal denervation with cryoablation (Cryo-RDN) system using liquid nitrogen and proved its short-term safety and effectiveness. In this study, we first conducted a 6-month follow-up in a swine model. Renal sympathetic nerve activity remained at a significantly lower level than that of the control group after 6 months. In patients with resistant hypertension, Cryo-RDN demonstrated preliminary safety. Renal function fluctuations and vascular-related complications were not detected. In addition, the average 24-hour systolic and diastolic blood pressure decreased by 12.17 ± 8.35 mm Hg and 8.50 ± 3.83 mm Hg at the 6-month follow-up, respectively, compared with their baseline values.

Renal denervation: basic and clinical evidence

Renal nerves have critical roles in regulating blood pressure and fluid volume, and their dysfunction is closely related with cardiovascular diseases. Renal nerves are composed of sympathetic efferent and sensory afferent nerves. Activation of the efferent renal sympathetic nerves induces renin secretion, sodium absorption, and increased renal vascular resistance, which lead to increased blood pressure and fluid retention. Afferent renal sensory nerves, which are densely innervated in the renal pelvic wall, project to the hypothalamic paraventricular nucleus in the brain to modulate sympathetic outflow to the periphery, including the heart, kidneys, and arterioles. The effects of renal denervation on the cardiovascular system are mediated by both efferent denervation and afferent denervation. The first half of this review focuses on basic research using animal models of hypertension and heart failure, and addresses the therapeutic effects of renal denervation for hypertension and heart failure, including underlying mechanisms. The second half of this review focuses on clinical research related to catheter-based renal denervation in patients with hypertension. Randomized sham-controlled trials using second-generation devices, endovascular radiofrequency-based devices and ultrasound-based devices are reviewed and their results are assessed. This review summarizes the basic and clinical evidence of renal denervation to date, and discusses future prospects and potential developments in renal denervation therapy for cardiovascular diseases.

A Japan nationwide web-based survey of patient preference for renal denervation for hypertension treatment

Renal denervation is a potential alternative to antihypertensive drug therapy. However, data on patient preference for this treatment option are limited and there are no data specifically from Asian patients. This study evaluated patient preference for renal denervation in patients with hypertension from Japan. Patients were a subset of those who participated in a March 2020 online electronic survey of patients with hypertension who had regularly visited medical institutions for treatment, were receiving antihypertensive drug therapy and had home blood pressure recordings available. The survey included a question about patient preference for treatment with renal denervation. A total of 2,392 patients were included (66% male, mean age 59.8 ± 11.6 years, mean duration of hypertension 11.4 ± 9.5 years). Preference for renal denervation was expressed by 755 patients (31.6%), and was higher in males than in females, in younger compared with older patients, in those with higher versus lower blood pressure, in patients who were less adherent versus more adherent to antihypertensive drug therapy, and in those who did rather than did not have antihypertensive drug-related side effects. Significant predictors of preference for renal denervation on logistic regression analysis were younger patient age, male sex, higher home or office systolic blood pressure, poor antihypertensive drug adherence, the presence of heart failure, and the presence of side effects during treatment with antihypertensive drugs. Overall, a relevant proportion of Japanese patients with hypertension expressed a preference for renal denervation. This should be taken into account when making shared decisions about antihypertensive drug therapy.

Morphometric analysis of the human common hepatic artery reveals a rich and accessible target for sympathetic liver denervation

This study quantified the distribution of nerves and adjacent anatomies surrounding human common hepatic artery (CHA) as guidance for catheter based denervation. CHA collected from cadaveric human donors (n = 20) were histologically evaluated and periarterial dimensions and distributions of nerves, lymph nodes, pancreas and blood vessels quantified by digital morphometry. Nerve abundance decreased significantly with distance from the aortic ostium (P < 0.0001) and was higher in the Superior/Inferior compared to the Anterior/Posterior quadrants (P = 0.014). In each locational group, nerves were absent from the artery wall, and starting 0.5–1.0 mm from the lumen exhibited a first order dependence on radial distance, fully defined by the median distance. Median subject-averaged nerve distance to the lumen was 2.75 mm, ranging from 2.1–3.1 mm in different arterial segments and quadrants and 2.0–3.5 mm in individuals. Inter-individual variance was high, with certain individuals exhibiting 50th and 75th nerve distances of, respectively, 3.5 and 6.5 mm The pancreas rarely approached within 4 mm of the lumen proximally and 2.5 mm more distally. The data indicate that the CHA is a rich and accessible target for sympathetic denervation regardless of sex and diabetes, with efficacy and safety most optimally balanced proximally.

Effect of Renal Denervation for the Management of Heart Rate in Patients With Hypertension: A Systematic Review and Meta-Analysis

Objective:

The effect of renal denervation (RDN) on heart rate (HR) in patients with hypertension had been investigated in many studies, but the results were inconsistent. This meta-analysis was performed to evaluate the efficacy of RDN on HR control.

Methods:

Databases, such as PubMed, EMBASE, Cochrane, and ClinicalTrials.gov, were searched until September 2021. Randomized controlled trials (RCTs) or non-RCTs of RDN in hypertensive patients with outcome indicators, such as HR, were selected. Weighted mean difference (WMD) was calculated for evaluating the changes in HR from baseline using fixed-effects or random-effects models. The Spearman's correlation coefficients were used to identify the relationship between the changes of HR and systolic blood pressure (SBP).

Results:

In the current meta-analysis, 681 subjects from 16 individual studies were included. This study showed that RDN could reduce office HR in patients with hypertension [WMD = −1.93 (95% CI: −3.00 to −0.85, p < 0.001)]. In addition, 24-h HR and daytime HR were decreased after RDN [WMD = −1.73 (95% CI: −3.51 to −0.31, p = 0.017) and −2.67 (95% CI: −5.02 to −0.32, p = 0.026) respectively], but nighttime HR was not significantly influenced by RDN (WMD = −2.08, 95% CI: −4.57 to 0.42, p = 0.103). We found that the reduction of HR was highly related to the decrease of SBP (r = 0.658, p < 0.05).

Conclusion:

Renal denervation could reduce office, 24-h, and daytime HR, but does not affect nighttime HR. And the effect is highly associated with blood pressure (BP) control.

Systematic Review Registration:

https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42021283065.

[Renal denervation : Really an alternative to reducing blood pressure?]

Since the current guidelines were published in 2018, a total of 5 sham-controlled high-quality studies evaluating renal denervation have been conducted and the results were published. These five studies clearly confirmed the efficacy and safety of renal denervation, which correspond to the knowledge of the Clinical Consensus Conference. Thus, an update of the guidelines for the treatment of arterial hypertension regarding the clinical significance of renal denervation is urgently necessary. For this reason, the position paper of the working group of the European Society of Hypertension on the current state of renal denervation was reviewed. An approval of this procedure can soon be expected. In Germany there is a diagnosis-related group (DRG) for the reimbursement of renal denervation, which was suspended due to the erroneous Symplicity 3 study. This DRG should be revived in practice by a structured process of the implementation of renal denervation. It will then be a joint task of treating physicians and specialists in certified centers to identify eligible patients. In the future, antihypertensive treatment will consist of three pillars: lifestyle measures, pharmacotherapy and interventional treatment. These three treatment options should not be regarded as competitive (which is better) but alternative (patient preference) and additive (the aim is blood pressure control). It is the task of the treating physician to provide the patient with the ideal treatment concept. Clearly, renal denervation will not replace antihypertensive pharmacotherapy; however, it can lead to a reduction of the drug burden and increase of patient adherence to medication. It represents an option of modern antihypertensive treatment and will also become increasingly more important in special patient groups.

Effectiveness of radiofrequency renal denervation in diseases with increased sympathetic nervous system activity

The article discusses the role of sympathetic nervous system hyperactivity in the pathogenesis of various pathologies (hypertension, heart failure, atrial fibrillation, metabolic syndrome, diabetes and systemic inflammatory response syndrome). On the example of large randomized clinical trials using catheter-based radiofrequency ablation, the antihypertensive effect in patients with uncontrolled hypertension has been proven. The first experimental and clinical studies on the effectiveness of renal denervation in reducing the activity of inflammatory markers, the incidence of atrial fibrillation and ventricular arrhythmia episodes, and improving the left ventricular contractility. The first clinical results of the favorable effect of renal denervation on carbohydrate metabolism (insulin resistance and glycemic level) in patients with metabolic syndrome and diabetes have been studied in detail.

Durable strong efficacy and favorable long-term renal safety of the anatomically optimized distal renal denervation according to the 3 year follow-up extension of the double-blind randomized controlled trial

Background

Historical reports on surgical renal denervation consistently describe renal plexus as a triangle or fan-like structure converging at the kidney gate. Following that anatomy, we developed a distal mode of radiofrequency renal denervation (RDN) mainly in segmental branches of the renal artery and confirmed its superior efficacy over the conventional main trunk procedure in a 6-months double-blind randomized controlled trial (NCT02667912). To assess the long-term effects of distal RDN we extended the follow-up of our study to three years.

Methods

BP, serum creatinine, eGFR were measured one and three years after randomization; major adverse renal events were assessed over the entire study period. The blinding was maintained over the entire three-year study period.

Findings

Of 55 randomized patients, 47 (23/24, distal/main trunk RDN, respectively) were assessed at one year and 39 (21/18) at three years post-procedure. Twenty-four-hour ambulatory systolic BP remained powerfully lowered after distal RDN both at one- and three-years assessments(mean change from baseline: -18.0, 95% CI -27.6 to -8.5; p<0.05 and -16·9, 95% CI -27·3 to -6·5; p<0·05, mmHg, respectively. This was accompanied by a moderate drop in eGFR at one year: -8·9 ml/min/m2, 95% CI -14·8 to -3·1; p<0·05, which, however, subsequently decreased in size at three years: -6·5, 95% CI -13·2 to 0·3; p>0·05. After main trunk RDN, the decrease of 24h systolic BP was quite moderate at one year: -12·1, 95% CI -19·2 to -5·0; p<0·05, and further weakened at three-year assessment: -8·5, 95% CI -19·7 to 2·2; p>0.05. eGFR was almost unchanged at one year: -1·3, 95% CI -6·6 to 4·0; p>0·05, but significantly decreased at three years: -5·0, 95% CI -9·6 to -0·3; p<0·05.

Interpretation

Our data demonstrate the durable strong BP-lowering efficacy and favorable long-term renal safety of distal RDN.

Arterial hypertension - Clinical trials update 2021

AIM

This review aims to summarize and discuss some of the most relevant clinical trials in epidemiology, diagnostics, and treatment of hypertension published in 2020 and 2021.

DATA SYNTHESIS

The trials included in this review are related to hypertension onset age and risk for future cardiovascular disease, reliability of different blood pressure monitoring methods, role of exercise-induced hypertension, treatment of hypertension in patients with SARS-CoV-2 infection, management of hypertension high-risk patient groups, e.g., in the elderly (≥80 years) and patients with atrial fibrillation, and the interplay between nutrition and hypertension, as well as recent insights into renal denervation for treatment of hypertension.

CONCLUSIONS

Hypertension onset age, nighttime blood pressure levels and a riser pattern are relevant for the prognosis of future cardiovascular diseases. The risk of coronary heart disease appears to increase linearly with increasing exercise systolic blood pressure. Renin-angiotensin system blockers are not associated with an increased risk for a severe course of COVID-19. In elderly patients, a risk-benefit assessment of intensified blood pressure control should be individually evaluated. A J-shaped association between cardiovascular disease and achieved blood pressure could also be demonstrated in patients with atrial fibrillation on anticoagulation. Salt restriction and lifestyle modification remain effective options in treating hypertensive patients at low cardiovascular risk. Sodium glucose co-transporter 2 inhibitors and Glucagon-like peptide-1 receptor agonists show BP-lowering effects. Renal denervation should be considered as an additional or alternative treatment option in selected patients with uncontrolled hypertension.

Randomized Blinded Placebo-Controlled Trials of Renal Sympathetic Denervation for Hypertension: A Meta-Analysis

BACKGROUND

The efficacy of renal denervation has been controversial, but the procedure has now undergone several placebo-controlled trials. New placebo-controlled trial data has recently emerged, with longer follow-up of one trial and the full report of another trial (which constitutes 27% of the total placebo-controlled trial data). We therefore sought to evaluate the effect of renal denervation on ambulatory and office blood pressures in patients with hypertension.

METHODS

We systematically identified all blinded placebo-controlled randomized trials of catheter-based renal denervation for hypertension. The primary efficacy outcome was ambulatory systolic blood pressure change relative to placebo. A random-effects meta-analysis was performed.

RESULTS

6 studies randomizing 1232 patients were eligible. 713 patients were randomized to renal denervation and 519 to placebo. Renal denervation significantly reduced ambulatory systolic blood pressure (-3.52 mmHg; 95% CI -4.94 to -2.09; p < 0.0001), ambulatory diastolic blood pressure (-1.93 mmHg; 95% CI -3.04 to -0.83, p = 0.0006), office systolic blood pressure size (-5.10 mmHg; 95% CI -7.31 to -2.90, p < 0.0001) and office diastolic pressure (effect size -3.11 mmHg; 95% CI -4.43 to -1.78, p < 0.0001). Adverse events were rare and not more common with denervation.

CONCLUSIONS

The totality of blinded, randomized placebo-controlled data shows that renal denervation is safe and provides genuine reduction in blood pressure for at least 6 months post-procedure. If this effect continues in the long term, renal denervation might provide a life-long 10% relative risk reduction in major adverse cardiac events and 7.5% relative risk reduction in all-cause mortality.

New Aspects in the Management of Hypertension in Patients with Chronic Kidney Disease not on Renal Replacement Therapy

With chronic kidney disease (CKD) being a global arising health problem, strategies for delaying kidney disease progression and reducing the high cardiovascular risk inherent to CKD, are the main objectives of the actual management of patients with kidney diseases. In these patients, the control of arterial hypertension is essential, as high blood pressure (BP) is a strong determinant of worst cardiovascular and renal outcomes. Achieving target blood pressures recommended by international guidelines is mandatory and often demands a multiple levels management, including several pharmacological and lifestyle measures. Even in the presence of adequate BP control, the residual cardiovascular risk remains high. In this respect, the recent demonstration that novel agents such as sodium glucose transporter 2 (SGLT2) inhibitors or the new non-steroidal mineralocorticoid antagonist finerenone can retard the progression of kidney diseases and reduce cardiovascular mortality on top of standard of care treatment with renin-angiotensin system inhibitors represent enormous progresses. These studies also demonstrate that cardiovascular and renal protection can be obtained beyond blood pressure control. Other promising novelties are still to come such as renal denervation and endothelin receptor antagonists in the setting of diabetic and non-diabetic kidney diseases. In the present review, we shall discuss the classic and the new aspects for the management of hypertension in CKD, integrating the new data from recent clinical studies.

Catheter-Based Renal Denervation Therapy: Evolution of Evidence and Future Directions

Motivated by the persistence of uncontrolled blood pressure and its public health impact, the development and evaluation of device-based therapies for hypertension has advanced at an accelerated pace to complement pharmaceutical and lifestyle intervention strategies. Countering widespread interest from early studies, the lack of demonstrable efficacy for renal denervation (RDN) in a large, sham-controlled randomized trial motivated revision of trial design and conduct to account for confounding variables of procedural technique, medication variability, and selection of both patients and end points. Now amidst varied trial design and methods, several sham-controlled, randomized trials have demonstrated clinically meaningful reductions in blood pressure with RDN. With this momentum, additional studies are underway to position RDN as a potential part of standard therapy for the world's leading cause of death and disability. In parallel, further studies will address unresolved issues including durability of blood pressure lowering and reduction in antihypertensive medications, late-term safety, and impact on clinical outcomes. Identifying predictors of treatment effect and surveys of patient-reported outcomes and treatment preferences are also evolving areas of investigation. Aside from confirmatory studies of safety and effectiveness, these additional studies will further inform patient selection, expand experience with RDN in broader populations with hypertension, and provide guidance to how RDN may be incorporated into treatment pathways.

Device-Based Sympathetic Nerve Regulation for Cardiovascular Diseases

Sympathetic overactivation plays an important role in promoting a variety of pathophysiological processes in cardiovascular diseases (CVDs), including ventricular remodeling, vascular endothelial injury and atherosclerotic plaque progression. Device-based sympathetic nerve (SN) regulation offers a new therapeutic option for some CVDs. Renal denervation (RDN) is the most well-documented method of device-based SN regulation in clinical studies, and several large-scale randomized controlled trials have confirmed its value in patients with resistant hypertension, and some studies have also found RDN to be effective in the control of heart failure and arrhythmias. Pulmonary artery denervation (PADN) has been clinically shown to be effective in controlling pulmonary hypertension. Hepatic artery denervation (HADN) and splenic artery denervation (SADN) are relatively novel approaches that hold promise for a role in cardiovascular metabolic and inflammatory-immune related diseases, and their first-in-man studies are ongoing. In addition, baroreflex activation, spinal cord stimulation and other device-based therapies also show favorable outcomes. This review summarizes the pathophysiological rationale and the latest clinical evidence for device-based therapies for some CVDs.

Main Renal Artery Plus Branch Ablation in the Treatment of Resistant Hypertension with Renal Denervation

Objective: To study the safety and efficacy of denervation of renal artery branches in the treatment of resistant hypertension.Methods: Sixty patients with resistant hypertension were enrolled. The patients were randomly assigned to the main renal artery plus branch ablation group or the main renal artery ablation group. The clinical data and operation-related parameters, including number of ablation points, temperature, and average energy, were recorded. Ambulatory blood pressure was taken for all patients at the baseline and at 6 months after treatment. Office blood pressure was recorded before treatment and after treatment every 3 months for 2 years.Results: Sixty patients with resistant hypertension were enrolled in this study. There were 30 patients in each group. Angiography was performed after ablation. No renal artery complications, such as stenosis and dissection, occurred in the two groups. There was no significant difference in age, sex, BMI, comorbid disease, and medication between the two groups (P>0.05). The number of ablation points for the main renal artery plus branch ablation group was greater than that for the main renal artery ablation group. The office blood pressure and 24-hour blood pressure were significantly lower 6 months after treatment than before treatment in both groups (P<0.05). Office blood pressure in the main renal artery plus branch ablation group was lower than that in the main renal artery ablation group during the 3‐12-month follow-up period, with a statistical difference. However, as the follow-up time increased, the difference disappeared.Conclusion: The results of this study show that main renal artery plus branch ablation is a safe interventional method, but there was no obvious advantage on long-term follow-up compared with only main renal artery ablation.

Endovascular denervation (EDN): From Hypertension to Non-Hypertension Diseases

Recently, the use of endovascular denervation (EDN) to treat resistant hypertension has gained significant attention. In addition to reducing sympathetic activity, EDN might also have beneficial effects on pulmonary arterial hypertension, insulin resistance, chronic kidney disease, atrial fibrillation, heart failure, obstructive sleep apnea syndrome, loin pain hematuria syndrome, cancer pain and so on. In this article we will summarize the progress of EDN in clinical research.

Renal denervation for resistant hypertension

BACKGROUND

Resistant hypertension is highly prevalent among the general hypertensive population and the clinical management of this condition remains problematic. Different approaches, including a more intensified antihypertensive therapy, lifestyle modifications or both, have largely failed to improve patients' outcomes and to reduce cardiovascular and renal risk. As renal sympathetic hyperactivity is a major driver of resistant hypertension, in the last decade renal sympathetic ablation (renal denervation) has been proposed as a possible therapeutic alternative to treat this condition.

OBJECTIVES

We sought to evaluate the short- and long-term effects of renal denervation in individuals with resistant hypertension on clinical end points, including fatal and non-fatal cardiovascular events, all-cause mortality, hospital admissions, quality of life, blood pressure control, left ventricular hypertrophy, cardiovascular and metabolic profile and kidney function, as well as the potential adverse events related to the procedure.

SEARCH METHODS

For this updated review, the Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to 3 November 2020: Cochrane Hypertension's Specialised Register, CENTRAL (2020, Issue 11), Ovid MEDLINE, and Ovid Embase. The World Health Organization International Clinical Trials Registry Platform (via CENTRAL) and the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov were searched for ongoing trials. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that compared renal denervation to standard therapy or sham procedure to treat resistant hypertension, without language restriction.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed study risk of bias. We summarised treatment effects on available clinical outcomes and adverse events using random-effects meta-analyses. We assessed heterogeneity in estimated treatment effects using Chi² and I² statistics. We calculated summary treatment estimates as a mean difference (MD) or standardised mean difference (SMD) for continuous outcomes, and a risk ratio (RR) for dichotomous outcomes, together with their 95% confidence intervals (CI). Certainty of evidence has been assessed using the GRADE approach.

MAIN RESULTS

We found 15 eligible studies (1416 participants). In four studies, renal denervation was compared to sham procedure; in the remaining studies, renal denervation was tested against standard or intensified antihypertensive therapy. Most studies had unclear or high risk of bias for allocation concealment and blinding.  When compared to control, there was low-certainty evidence that renal denervation had little or no effect on the risk of myocardial infarction (4 studies, 742 participants; RR 1.31, 95% CI 0.45 to 3.84), ischaemic stroke (5 studies, 892 participants; RR 0.98, 95% CI 0.33 to 2.95), unstable angina (3 studies, 270 participants; RR 0.51, 95% CI 0.09 to 2.89) or hospitalisation (3 studies, 743 participants; RR 1.24, 95% CI 0.50 to 3.11). Based on moderate-certainty evidence, renal denervation may reduce 24-hour ambulatory blood pressure monitoring (ABPM) systolic BP (9 studies, 1045 participants; MD -5.29 mmHg, 95% CI -10.46 to -0.13), ABPM diastolic BP (8 studies, 1004 participants; MD -3.75 mmHg, 95% CI -7.10 to -0.39) and office diastolic BP (8 studies, 1049 participants; MD -4.61 mmHg, 95% CI -8.23 to -0.99). Conversely, this procedure had little or no effect on office systolic BP (10 studies, 1090 participants; MD -5.92 mmHg, 95% CI -12.94 to 1.10). Moderate-certainty evidence suggested that renal denervation may not reduce serum creatinine (5 studies, 721 participants, MD 0.03 mg/dL, 95% CI -0.06 to 0.13) and may not increase the estimated glomerular filtration rate (eGFR) or creatinine clearance (6 studies, 822 participants; MD -2.56 mL/min, 95% CI -7.53 to 2.42).  AUTHORS' CONCLUSIONS: In patients with resistant hypertension, there is low-certainty evidence that renal denervation does not improve major cardiovascular outomes and renal function. Conversely, moderate-certainty evidence exists that it may improve 24h ABPM and diastolic office-measured BP. Future trials measuring patient-centred instead of surrogate outcomes, with longer follow-up periods, larger sample size and more standardised procedural methods are necessary to clarify the utility of this procedure in this population.

[Renal sympathetic denervation can significantly reduce blood pressure and improve arterial stiffness in hypertensive beagles]

OBJECTIVE

To investigate the effect of renal sympathetic denervation (RDN) on blood pressure and arterial stiffness in hypertensive beagles and explore the underlying mechanism.

METHODS

Sixteen beagles were randomly divided into RDN group (n=8, fed with a high-salt high-fat diet to establish models of hypertension and treated with RDN), sham-operated group (n=4, fed with a high-salt high-fat diet to induce hypertension but only examined with renal arteriography) and control group (n=4, fed with formula dog food). The changes in blood pressure, arterial stiffness, endothelial function, and sympathetic activity were compared among the 3 groups and correlation analysis was performed.

RESULTS

All the animal models of hypertension were established successfully in the beagles. At 3 months after the RDN, the changes in systolic blood pressure (SBP) differed significantly among the 3 groups (P=0.006), and the reduction in SBP was significantly greater in RDN group than in the other two groups (P < 0.05). The variations of diastolic blood pressure (DBP) also differed significantly among the 3 groups (P=0.016), and DBP reduction was more obvious in RDN group than in the control group (P=0.007), but similar to that in the sham-operated group (P=0.052). The changes of resistance index (RI) after the procedure were significantly different among the 3 groups (P=0.043), and the RDN group showed a greater reduction of RI than the control group (P=0.032) and sham group (P=0.043). Serum levels of eNOS, NO and Ang Ⅱ did not differ significantly among the groups either before or after RDN (P>0.05), but serum NE level was significantly higher in RDN group than in the control groupafter successful modeling (P=0.014), but similar to that in the sham group (P=0.560). Compared with the sham operation, RDN in the hypertensive beagles resulted in a significantly greater decrease of serum NE level (P=0.032) to almost the control level (P= 0.080). The changes of RI following RDN were significantly correlated with the changes of SBP, DBP and serum levels of NO and NE (P < 0.05).

CONCLUSION

RDN can significantly reduce blood pressure and improve arterial stiffness in hypertensive beagles possibly by reducing sympathetic activity and blood pressure and promoting NO synthesis.

Pulmonary and Systemic Hemodynamics following Multielectrode Radiofrequency Catheter Renal Denervation in Acutely Induced Pulmonary Arterial Hypertension in Swine

Objective

We aimed to assess the effects of renal denervation (RDN) on systemic and pulmonary hemodynamics in a swine model of thromboxane A2- (TXA2-) induced pulmonary arterial hypertension (PAH).

Methods

The study protocol comprised two PAH inductions with a target mean pulmonary artery pressure (PAP) of 40 mmHg at baseline and following either the RDN or sham procedure. Ten Landrace pigs underwent the first PAH induction; then, nine animals were randomly allocated in 1 : 1 ratio to RDN or sham procedure; the second PAH induction was performed in eight animals (one animal died of pulmonary embolism during the first PAH induction, and one animal died after RDN). In the RDN group, ablation was performed in all available renal arteries, and balloon inflation within artery branches was performed in controls. An autopsy study of the renal arteries was performed.

Results

At baseline, the target mean PAP was achieved in all animals with 25.0 [20.1; 25.2] mcg of TXA2. The second PAH induction required the same mean TXA2 dose and infusion time. There was no statistically significant difference in the mean PAP at second PAH induction between the groups (39.0 ± 5.3 vs. 39.75 ± 0.5 mmHg, P > 0.05). In the RDN group, the second PAH induction resulted in a numerical but insignificant trend toward a decrease in the mean systemic blood pressure and systemic vascular resistance, when compared with the baseline induction (74 ± 18.7 vs. 90.25 ± 28.1 mmHg and 1995.3 ± 494.3 vs. 2433.7 ± 1176.7 dyn∗sec∗cm⁻⁵, P > 0.05, respectively). No difference in hemodynamic parameters was noted in the sham group between the first and second PAH induction. Autopsy demonstrated artery damage in both groups, but RDN resulted in more severe lesions.

Conclusions

According to our results, RDN does not result in significant acute pulmonary or systemic hemodynamic changes in the TXA2-induced PAH model. The potential chronic effects of RDN on PAH require further research.

Renal Denervation in Combination With Angiotensin Receptor Blockade Prolongs Blood Pressure Trough During Hemorrhage

Majority of patients with hypertension and chronic kidney disease (CKD) undergoing renal denervation (RDN) are maintained on antihypertensive medication. However, RDN may impair compensatory responses to hypotension induced by blood loss. Therefore, continuation of antihypertensive medications in denervated patients may exacerbate hypotensive episodes. This study examined whether antihypertensive medication compromised hemodynamic responses to blood loss in normotensive (control) sheep and in sheep with hypertensive CKD at 30 months after RDN (control-RDN, CKD-RDN) or sham (control-intact, CKD-intact) procedure. CKD-RDN sheep had lower basal blood pressure (BP; ≈9 mm Hg) and higher basal renal blood flow (≈38%) than CKD-intact. Candesartan lowered BP and increased renal blood flow in all groups. 10% loss of blood volume alone caused a modest fall in BP (≈6-8 mm Hg) in all groups but did not affect the recovery of BP. 10% loss of blood volume in the presence of candesartan prolonged the time at trough BP by 9 minutes and attenuated the fall in renal blood flow in the CKD-RDN group compared with CKD-intact. Candesartan in combination with RDN prolonged trough BP and attenuated renal hemodynamic responses to blood loss. To minimize the risk of hypotension-mediated organ damage, patients with RDN maintained on antihypertensive medications may require closer monitoring when undergoing surgery or experiencing traumatic blood loss.

Comparison of Long-Term Outcomes for Responders Versus Non-Responders Following Renal Denervation in Resistant Hypertension

Background

Recent trial results support the efficacy of renal sympathetic denervation in lowering blood pressure (BP). While BP reduction in general is associated with a clinically meaningful reduction in cardiovascular events and mortality, such a relationship has not been described for patients undergoing renal sympathetic denervation.

Methods and Results

Clinical events were assessed in patients who underwent renal sympathetic denervation at our center using telephone‐ and clinical follow‐up, interviews with general practitioners, as well as review of hospital databases. Event rates were compared between BP responders (≥5 mm Hg 24‐hour ambulatory BP reduction) and non‐responders; 296 patients were included. Compared with baseline, 24‐hour systolic ambulatory BP was reduced by 8.3±12.2 mm Hg and diastolic BP by 4.8±7.0 mm Hg (P<0.001 for both) after 3 months. One hundred eighty patients were classified as BP responders and 116 as non‐responders. During a median follow‐up time of 48 months, significantly less major adverse cardiovascular events (cardiovascular death, stroke, myocardial infarction, critical limb ischemia, renal failure) occurred in responders than in non‐responders (22 versus 23 events, hazard ratio [HR], 0.53 [95% CI, 0.28 to 0.97], P=0.041). This was consistent after adjustment for potential confounders as well as confirmed by propensity‐score matching. A proportional relationship was found between BP reduction after 3 months and frequency of major adverse cardiovascular events (HR, 0.75 [95% CI, 0.58 to 0.97] per 10 mm Hg 24‐hour systolic ambulatory BP reduction).

Conclusions

Based on these observational data, blood pressure response to renal sympathetic denervation is associated with improved long‐term clinical outcome.

Renal denervation based on experimental rationale

Excessive activation of the sympathetic nervous system is one of the pathophysiological hallmarks of hypertension and heart failure. Within the central nervous system, the paraventricular nucleus (PVN) of the hypothalamus and the rostral ventrolateral medulla in the brain stem play critical roles in the regulation of sympathetic outflow to peripheral organs. Information from the peripheral circulation, including serum concentrations of sodium and angiotensin II, is conveyed to the PVN via adjacent structures with a weak blood-brain barrier. In addition, signals from baroreceptors, chemoreceptors and cardiopulmonary receptors as well as afferent input via the renal nerves are all integrated at the level of the PVN. The brain renin-angiotensin system and the balance between nitric oxide and reactive oxygen species in these brain areas also determine the final sympathetic outflow. Additionally, brain inflammatory responses have been shown to modulate these processes. Renal denervation interrupts both the afferent inputs from the kidney to the PVN and the efferent outputs from the PVN to the kidney, resulting in the suppression of sympathetic outflow and eliciting beneficial effects on both hypertension and heart failure.

Diagnosis and treatment of arterial hypertension 2021

In the last 4 years, several evidence-based, national, and international guidelines on the management of arterial hypertension have been published, mostly with concordant recommendations, but in some aspects with discordant opinions. This in-depth review takes these guidelines into account but also addresses several new data of interest. Although being somewhat obvious and simple, accurate blood pressure (BP) measurement with validated devices is the cornerstone of the diagnosis of hypertension, but out-of-office BP measurements are of crucial importance as well. Simplified antihypertensive drug treatment such as single-pill combinations enhances the adherence to medication and speeds up the process of getting into the BP target range, a goal not so far adequately respected. Recommended (single-pill) combination therapy includes diuretics as part of the first step of antihypertensive therapy, and updated analysis does not provide evidence to exclude diuretics from this first step because of the recently discussed potential risk of increasing cancer incidence. Target BP goals need to be individualized, according to comorbidities, hypertension-mediated organ damage, coexistence of cardiovascular risk factors (including age), frailty in the elderly, and individual tolerability. There are also concordant recommendations in the guidelines that an office BP between 120 and 140 mm Hg systolic and between 70 and 80 mm Hg diastolic should be achieved. The BP target of Kidney Disease: Improving Global Outcomes for hypertensive patients with chronic kidney disease are not applicable for clinical practice because they heavily rely on 1 study that used a study-specific, nontransferable BP measurement technique and excluded the most common cause of chronic kidney disease, namely, diabetic nephropathy. Actual data even from a prospective trial on chronotherapy have to be disregarded, and antihypertensive medication should not be routinely dosed at bedtime. Rigorously conducted trials justify the revival of renal denervation for treatment of (at least, but not only) uncontrolled and treatment-resistant hypertension.

Renal Denervation for Hypertension: A Systematic Review and Meta-Analysis of Randomized, Blinded, Placebo-Controlled Trials

OBJECTIVES

The authors performed an updated meta-analysis of randomized placebo-controlled trials of renal denervation and specifically compared the effect of renal denervation in patients taking medications and in those not taking medications.

BACKGROUND

Renal denervation has now undergone several blinded placebo-controlled trials, covering the spectrum from patients with drug-resistant hypertension to those not yet taking antihypertensive medications.

METHODS

All blinded placebo-controlled randomized trials of catheter-based renal sympathetic denervation for hypertension were systematically identified, and a random-effects meta-analysis was performed. The primary efficacy outcome was the change in ambulatory systolic blood pressure beyond the effect of the placebo procedure. Analysis was stratified by whether there was background antihypertensive medication use.

RESULTS

There were 7 eligible trials, totaling 1,368 patients. Denervation significantly reduced ambulatory systolic (mean difference -3.61 mm Hg; 95% confidence interval [CI]: -4.89 to -2.33 mm Hg; P < 0.0001), ambulatory diastolic (-1.85 mm Hg; 95% CI: -2.78 to -0.92 mm Hg; P < 0.0001), office systolic (-5.86 mm Hg; 95% CI: -7.77 to -3.94 mm Hg; P < 0.0001), and office diastolic (-3.63 mm Hg; 95% CI: -4.77 to -2.50; P < 0.0001) blood pressure. There was no evidence that the use of concomitant antihypertensive medication had a significant impact on the effect of denervation on any of these endpoints (P_interaction = NS for each comparison).

CONCLUSIONS

The randomized placebo-controlled trials show consistently that renal denervation provides significant reduction in ambulatory and office blood pressure. Although the magnitude of benefit, about 4/2 mm Hg, is modest, it is similar between patients on background antihypertensive medications and those who are not. Denervation could therefore be a useful strategy at various points for patients who are not willing to add antihypertensive agents. Whether the effect changes with time is currently unknown.

Effects of renal denervation on blood pressures in patients with hypertension: a systematic review and meta-analysis of randomized sham-controlled trials

The efficacy of renal denervation has been controversial, but recent randomized sham-controlled trials demonstrated significant blood pressure reductions after renal denervation in patients with hypertension. We conducted a systematic review and updated meta-analysis to evaluate the effects of renal denervation on ambulatory and office blood pressures in patients with hypertension. Databases were searched up to 25 May 2021 to identify randomized, sham-controlled trials of renal denervation. The primary endpoint was change in 24 h ambulatory systolic blood pressure with renal denervation versus sham control. The secondary endpoints were daytime and nighttime systolic blood pressure, and office systolic blood pressure. A sub-analysis determined outcomes by medication, procedure, and device. From nine trials, 1555 patients with hypertension were randomized to undergo renal denervation (n = 885) or a sham procedure (n = 670). At 2-6 months after treatment, renal denervation significantly reduced 24 h ambulatory systolic blood pressure by 3.31 mmHg (95% confidence interval: -4.69, -1.94) compared with the sham procedure (p < 0.001). Renal denervation also reduced daytime SBP by 3.53 mmHg (-5.28, -1.78; p < 0.001), nighttime SBP by 3.20 mmHg (-5.46, -0.94; p = 0.006), and office SBP by 5.25 mmHg (-7.09, -3.40; p < 0.001) versus the sham control group. There were no significant differences in the magnitude of blood pressure reduction between first- and second-generation trials, between devices, or with or without medication. These data from randomized sham-controlled trials showed that renal denervation significantly reduced all blood pressure metrics in medicated or unmedicated patients with hypertension, including resistant/uncontrolled hypertension. Future trials should investigate the long-term efficacy and safety of renal denervation.

Renal arteries denervation: from the treatment of resistant hypertension to the treatment of atrial fibrillation

Renal denervation (RDN) is a therapeutic strategy for patients with uncontrolled arterial hypertension characterized by considerable fluctuations during its progression. After initial strong enthusiasm, the procedure came to an abrupt halt following the publication of the Symplicity HTN-3 study results. The results of recently published studies highlight the reduction in blood pressure values after RDN and justify the inclusion in the Guidelines of new recommendations for the use of RDN in clinical practice, in selected patients. Additionally, RDN findings are summarized in view of other potential indications such as atrial fibrillation. Six prospective, randomized studies are presented that evaluated RDN as an adjunct therapy to pulmonary vein isolation for the treatment of atrial fibrillation. In five studies, patients had uncontrolled hypertension despite therapy with three antihypertensive drugs. The analysis of these studies showed that RDN reduced the recurrence of atrial fibrillation (AF) by 57% compared to patients with pulmonary vein isolation (PVI) only. Modulation of the autonomic nervous system by RDN has been shown not only to reduce blood pressure but also to have an antiarrhythmic effect in symptomatic AF patients when the strategy is combined with PVI, thus opening up new therapeutic scenarios.

Renal nerve stimulation: complete versus incomplete renal sympathetic denervation

PURPOSE

Blood pressure (BP) reduction after renal sympathetic denervation (RDN) is highly variable. Renal nerve stimulation (RNS) can localize sympathetic nerves. The RNS trial aimed to investigate the medium-term BP-lowering effects of the use of RNS during RDN, and explore if RNS can check the completeness of the denervation.

MATERIAL AND METHODS

Forty-four treatment-resistant hypertensive patients were included in the prospective, single-center RNS trial. The primary study endpoint was change in 24-h BP at 6- to 12-month follow-up after RDN. The secondary study endpoints were the acute procedural RNS-induced BP response before and after RDN; number of antihypertensive drugs at follow-up; and the correlation between the RNS-induced BP increase before versus after RDN (delta [Δ] RNS-induced BP).

RESULTS

Before RDN, the RNS-induced systolic BP rise was 43(±21) mmHg, and decreased to 9(±12) mmHg after RDN (p < 0.001). Mean 24-h systolic/diastolic BP decreased from 147(±12)/82(±11) mmHg at baseline to 135(±11)/76(±10) mmHg (p < 0.001/<0.001) at follow-up (10 [6-12] months), with 1 antihypertensive drug less compared to baseline. The Δ RNS-induced BP and the 24-h BP decrease at follow-up were correlated for systolic (R = 0.44, p = 0.004) and diastolic (R = 0.48, p = 0.003) BP. Patients with ≤0 mmHg residual RNS-induced BP response after RDN had a significant lower mean 24-h systolic BP at follow-up compared to the patients with >0 mmHg residual RNS-induced BP response (126 ± 4 mmHg versus 135 ± 10 mmHg, p = 0.04). 83% of the patients with ≤0 mmHg residual RNS-induced BP response had normal 24-h BP at follow-up, compared to 33% in the patients with >0 mmHg residual RNS-induced BP response (p = 0.023).

CONCLUSION

The use of RNS during RDN leads to clinically significant and sustained lowering of 24-h BP with fewer antihypertensive drugs at follow-up. RNS-induced BP changes were correlated with 24-h BP changes at follow-up. Moreover, patients with complete denervation had significant lower BP compared to the patients with incomplete denervation.

Targeting mitochondria-inflammation circle by renal denervation reduces atheroprone endothelial phenotypes and atherosclerosis

OBJECTIVE

The disruption of mitochondrial redox homeostasis in endothelial cells (ECs) can cause chronic inflammation, a substantial contributor to the development of atherosclerosis. Chronic sympathetic hyperactivity can enhance oxidative stress to induce endothelial dysfunction. We determined if renal denervation (RDN), the strategy reducing sympathetic tone, can protect ECs by ameliorating mitochondrial reactive oxygen species (ROS)-induced inflammation to reduce atherosclerosis.

METHODS AND RESULTS

ApoE deficient (ApoE^-/-) mice were conducted RDN or sham operation before 20-week high-fat diet feeding. Atherosclerosis, EC phenotype and mitochondrial morphology were determined. In vitro, human arterial ECs were treated with norepinephrine to determine the mechanisms for RDN-inhibited endothelial inflammation. RDN reduced atherosclerosis, EC mitochondrial oxidative stress and inflammation. Mechanistically, the chronic sympathetic hyperactivity increased circulating norepinephrine and mitochondrial monoamine oxidase A (MAO-A) activity. MAO-A activation-impaired mitochondrial homeostasis resulted in ROS accumulation and NF-κB activation, thereby enhancing expression of atherogenic and proinflammatory molecules in ECs. It also suppressed mitochondrial function regulator PGC-1α, with involvement of NF-κB and oxidative stress. Inactivation of MAO-A by RDN disrupted the positive-feedback regulation between mitochondrial dysfunction and inflammation, thereby inhibiting EC atheroprone phenotypic alterations and atherosclerosis.

CONCLUSIONS

The interplay between MAO-A-induced mitochondrial oxidative stress and inflammation in ECs is a key driver in atherogenesis, and it can be reduced by RDN.

Renal Denervation Exacerbates LPS- and Antibody-induced Acute Kidney Injury, but Protects from Pyelonephritis in Mice

BACKGROUND

Renal denervation (RDN) is an invasive intervention to treat drug-resistant arterial hypertension. Its therapeutic value is contentious. Here we examined the effects of RDN on inflammatory and infectious kidney disease models in mice.

METHODS

Mice were unilaterally or bilaterally denervated, or sham operated, then three disease models were induced: nephrotoxic nephritis (NTN, a model for crescentic GN), pyelonephritis, and acute endotoxemic kidney injury (as a model for septic kidney injury). Analytical methods included measurement of renal glomerular filtration, proteinuria, flow cytometry of renal immune cells, immunofluorescence microscopy, and three-dimensional imaging of optically cleared kidney tissue by light-sheet fluorescence microscopy followed by algorithmic analysis.

RESULTS

Unilateral RDN increased glomerular filtration in denervated kidneys, but decreased it in the contralateral kidneys. In the NTN model, more nephritogenic antibodies were deposited in glomeruli of denervated kidneys, resulting in stronger inflammation and injury in denervated compared with contralateral nondenervated kidneys. Also, intravenously injected LPS increased neutrophil influx and inflammation in the denervated kidneys, both after unilateral and bilateral RDN. When we induced pyelonephritis in bilaterally denervated mice, both kidneys contained less bacteria and neutrophils. In unilaterally denervated mice, pyelonephritis was attenuated and intrarenal neutrophil numbers were lower in the denervated kidneys. The nondenervated contralateral kidneys harbored more bacteria, even compared with sham-operated mice, and showed the strongest influx of neutrophils.

CONCLUSIONS

Our data suggest that the increased perfusion and filtration in denervated kidneys can profoundly influence concomitant inflammatory diseases. Renal deposition of circulating nephritic material is higher, and hence antibody- and endotoxin-induced kidney injury was aggravated in mice. Pyelonephritis was attenuated in denervated murine kidneys, because the higher glomerular filtration facilitated better flushing of bacteria with the urine, at the expense of contralateral, nondenervated kidneys after unilateral denervation.