Renal denervation in patients with versus without chronic kidney disease: results from the global SYMPLICITY Registry with follow-up data of 3 years

Patient-Specific Factors Predicting Renal Denervation Response in Patients With Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

The accurate selection of patients likely to respond to renal denervation (RDN) is crucial for optimizing treatment outcomes in patients with hypertension. This systematic review was designed to evaluate patient-specific factors predicting the RDN response.

METHODS AND RESULTS

We focused on individuals with hypertension who underwent RDN. Patients were categorized based on their baseline characteristics. The primary outcome was blood pressure (BP) reduction after RDN. Both randomized controlled trials and nonrandomized studies were included. We assessed the risk of bias using corresponding tools and further employed the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the overall quality of evidence. A total of 50 studies were ultimately included in this systematic review, among which 17 studies were for meta-analysis. Higher baseline heart rate and lower pulse wave velocity were shown to be associated with significant antihypertensive efficacy of RDN on 24-hour systolic BP reduction (weighted mean difference, -4.05 [95% CI, -7.33 to -0.77]; weighted mean difference, -7.20 [95% CI, -9.79 to -4.62], respectively). In addition, based on qualitative analysis, higher baseline BP, orthostatic hypertension, impaired baroreflex sensitivity, and several biomarkers are also reported to be associated with significant BP reduction after RDN.

CONCLUSIONS

In patients with hypertension treated with the RDN, higher heart rate, and lower pulse wave velocity were associated with significant BP reduction after RDN. Other factors, including higher baseline BP, hypertensive patients with orthostatic hypertension, BP variability, impaired cardiac baroreflex sensitivity, and some biomarkers are also reported to be associated with a better BP response to RDN.

Diagnosis and management of resistant hypertension

Resistant hypertension is defined as blood pressure that remains above the therapeutic goal despite concurrent use of at least three antihypertensive agents of different classes, including a diuretic, with all agents administered at maximum or maximally tolerated doses. Resistant hypertension is also diagnosed if blood pressure control requires four or more antihypertensive drugs. Assessment requires the exclusion of apparent treatment resistant hypertension, which is most often the result of non-adherence to treatment. Resistant hypertension is associated with major cardiovascular events in the short and long term, including heart failure, ischemic heart disease, stroke, and renal failure. Guidelines from several professional organizations recommend lifestyle modification and antihypertensive drugs. Medications typically include an angiotensin converting enzyme inhibitor or angiotensin receptor blocker, a calcium channel blocker, and a long acting thiazide-type/like diuretic; if a fourth drug is needed, evidence supports addition of a mineralocorticoid receptor antagonist. After a long pause since 2007 when the last antihypertensive class was approved, several novel agents are now under active development. Some of these may provide potent blood pressure lowering in broad groups of patients, such as aldosterone synthase inhibitors and dual endothelin receptor antagonists, whereas others may provide benefit by allowing treatment of resistant hypertension in special populations, such as non-steroidal mineralocorticoid receptor antagonists in patients with chronic kidney disease. Several device based approaches have been tested, with renal denervation being the best supported and only approved interventional device treatment for resistant hypertension.

Effects of renal denervation on the kidney: albuminuria, proteinuria, and renal function

Renal denervation has attracted attention as a novel antihypertensive treatment for hypertensive patients who are poorly controlled by medicine. Clinical studies have shown the antihypertensive effects of renal denervation in patients with treatment-resistant hypertension. However, renal denervation potentially has other beneficial effects, such as improving glucose metabolism and cardioprotection beyond its antihypertensive effects. In this mini-review article, we summarize and discuss the effects of renal denervation on proteinuria, albuminuria, and renal function based on the recent findings of clinical studies, and review the renoprotective effects of renal denervation.

CT-guided ozone-mediated lumbar-renal sympathetic denervation for resistant hypertension treatment: A pilot single-arm clinical trial

BACKGROUND

Renal sympathetic denervation (RDN) reduces blood pressure (BP).

METHODS

This single-arm open-label study enrolled patients with resistant hypertension (RH) and treat them by CT-guided ozone mediated lumbar-renal sympathetic denervation (L-RDN). The primary endpoint was to assess the changes of BP over 24-h ambulatory BP monitoring (ABPM) and to evaluate the anti-hypertensive medication burden (AHMB) at 3-month follow-up. This study was registered in Chictr.org.cn (ChiCTR2300071375).

RESULTS

17 patients (mean age 65.12 ± 10.77 years) with AHMB of 4.12 ± 1.11 were enrolled. After the procedure, 7 patients (46.7 %) matched the criteria for antihypertensive medication reduction. The AHMB decreased to 3.87 ± 0.96 for the whole objectives and from 3.87 ± 0.96 to 3.55 ± 0.78 for patients with normal baseline renal function. On top of the lessened AHMB, L-RDN further reduced morning systolic BP (SBP) by -8.6 ± 4.0 mmHg (p = 0.034) and diastolic BP (DBP) by -4.6 ± 2.1 mmHg (p = 0.032) for all participants and morning SBP by -13.2 ± 3.6 mmHg (p < 0.001), morning DBP by -6.2 ± 2.4 mmHg (p = 0.011) and daytime SBP by -4.1 ± 1.6 mmHg (p = 0.009) for those with normal baseline renal function at 3-month of follow-up. No adverse events were reported intra- and post operation.

CONCLUSIONS

CT-guided ozone-mediated L-RDN might be an innovative approach of RDN for treating RH. Confirmatory studies are warranted.

Renal denervation in the management of hypertension

Arterial hypertension is a global leading cause of cardiovascular, cerebrovascular, and renal disease, as well as mortality. Although pharmacotherapy is safe and effective in lowering blood pressure (BP) and cardiovascular disease risk, BP control remains poor, and the mortality rates associated with high BP have been steadily increasing. Device-based therapies have been investigated to overcome barriers to pharmacotherapy, including non-adherence and low rates of persistence to daily medications. Among these device-based therapies, catheter-based renal denervation (RDN) has been most extensively examined over the past 15 years. In this state-of-the-art article, we summarise the rationale for RDN, review the available evidence, provide recommendations for a safe procedure, and discuss the role of RDN in current guidelines and clinical practice.

The feasibility, efficacy, and safety of RDN procedure using CO2 angiography through radial artery in severe chronic kidney disease patients

The recent evidence regarding the effectiveness of renal denervation (RDN) in blood pressure control is becoming increasingly substantial. However, many studies have excluded populations with severely impaired kidney function, even though these individuals have a higher prevalence of hypertension compared to the general population, and controlling their blood pressure is more challenging. The effectiveness and safety of RDN in patients with severe chronic kidney disease (CKD) lack strong evidence support. Concerns about worsening kidney function still exist, particularly in patients with CKD stage 5. We conducted an observational study involving 10 patients who were using at least 3 different antihypertensive medications and had an estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m2 but had not undergone dialysis. For these patients, we performed RDN via the radial artery approach, with the assistance of carbon dioxide (CO2) angiography. Utilizing this approach, the systolic 24-hour ambulatory blood pressure monitoring did not exhibit a significant decrease at 3 months; however, a significant reduction was observed at 6 months after RDN. We also minimized contrast agent usage, observed no kidney function decline 3 months post-RDN, and experienced no vascular-related complications. Using the radial artery approach and CO2 angiography assistance for RDN may be an effective and safe blood pressure control method for patients with severe kidney impairment.

Blood pressure reduction after renal denervation in patients with or without chronic kidney disease

Background

Renal denervation (RDN) has emerged as an adjacent option for the treatment of hypertension. This analysis of the Erlanger registry aimed to compare the blood pressure (BP)-lowering effects and safety of RDN in patients with and without chronic kidney disease (CKD).

Methods

In this single-center retrospective analysis, 47 patients with and 127 without CKD underwent radiofrequency-, ultrasound- or alcohol-infusion-based RDN. Office and 24-h ambulatory BP and estimated glomerular filtration rate (eGFR) were measured at baseline, and after 6 and 12 months.

Results

A total of 174 patients with a mean age of 59.0 ± 10 years were followed up for 12 months. At baseline, mean eGFR was 55.8 ± 21 mL/min/1.73 m2 in patients with CKD and 87.3 ± 13 mL/min/1.73 m2 in patients without CKD. There was no significant eGFR decline in either of the groups during 12 months of follow-up. In patients without CKD, office systolic and diastolic BP were reduced by -15.3 ± 17.5/-7.9 ± 10.8 mmHg 6 months after RDN and by -16.1 ± 18.2/-7.7 ± 9.6 mmHg 12 months after RDN. In patients with CKD, office systolic and diastolic BP were reduced by -10.7 ± 24.0/-5.8 ± 13.2 mmHg 6 months after RDN and by -15.1 ± 24.9/-5.9 ± 12.9 mmHg 12 months after RDN. Accordingly, in patients without CKD, 24-h ambulatory systolic and diastolic BP were reduced by -7.2 ± 15.8/-4.9 ± 8.8 mmHg 6 months after RDN and by -9.0 ± 17.0/-6.2 ± 9.8 mmHg 12 months after RDN. In patients with CKD, 24-h systolic and diastolic BP were reduced by -7.4 ± 12.9/-4.2 ± 9.9 mmHg 6 months after RDN and by -8.0 ± 14.0/-3.6 ± 9.6 mmHg 12 months after RDN. There was no difference in the reduction of office and 24-h ambulatory BP between the two groups at any time point (all P > .2). Similar results have been found for the 6 months data. With exception of rare local adverse events, we did not observe any safety signals.

Conclusion

According to our single-center experience, we observed a similar reduction in 24-h, day and night-time ambulatory BP as well as in-office BP in patients with and without CKD at any time point up to 12 months. We conclude that RDN is an effective and safe treatment option for patients with hypertension and CKD.

Renal Denervation in the Treatment of Resistant Hypertension and Difficult-to-Control Hypertension - Consensus Document of the Croatian Hypertension League - Croatian Society of Hypertension, Croatian Cardiac Society, Croatian Endovascular Initiative, Croatian Society for Diabetes and Metabolic Diseases, Croatian Renal Association, and Croatian Society of Family Physicians of the Croatian Medical Association

Renal denervation (RDN) as a method of treating arterial hypertension (AH) was introduced in Croatia in 2012. A multidisciplinary team and a network of hospitals that diagnose and treat patients with severe forms of AH were established, and a very strict diagnostic-treatment algorithm was prepared. At monthly meetings patients with truly resistant hypertension who were candidates for RDN were discussed. According to the 2021 ESH position statement and 2023 ESH guidelines, RDN is considered an alternative and additional, not a competitive method of treating patients with various forms of AH which must be performed by following a structured procedure and the patient's preference should be considered. In view of the changes in the global scientific community, the Croatian Hypertension League brings this consensus document on RDN conducted with radiofrequency-based catheter, the only currently available method in Croatia. In this document, exclusion and inclusion criteria are shown, as well as three groups of patients in whom RDN could be considered. The new diagnostic-treatment algorithm is prepared and follow-up procedure is explained. In Croatia, RDN is reimbursed by the national insurance company, thus pharmacoeconomic analyses is also shown. Criteria required by an individual centre to be approved of RDN are listed, and plans for prospective research on RDN in Croatia, including the Croatian registry for RDN, are discussed.

Does Renal Denervation a Reasonable Treatment Option in Hemodialysis-Dependent Patient with Resistant Hypertension? A Narrative Review

PURPOSE OF REVIEW

This narrative review aims to assess the pathophysiology, diagnosis, and treatment of resistant hypertension (RH) in end-stage kidney disease (ESKD) patients on dialysis, with a specific focus on the effect of renal denervation (RDN) on short-term and long-term blood pressure (BP) control. Additionally, we share our experience with the use of RDN in an amyloidotic patient undergoing hemodialysis with RH.

RECENT FINDINGS

High BP, an important modifiable cardiovascular risk factor, is often observed in patients in ESKD, despite the administration of multiple antihypertensive medications. However, in clinical practice, it remains challenging to identify RH patients on dialysis treatment because of the absence of specific definition for RH in this context. Moreover, the use of invasive approaches, such as RDN, to treat RH is limited by the exclusion of patients with reduced renal function (eGFR < 45 mL/min/1.73 m3) in the clinical trials. Nevertheless, recent studies have reported encouraging results regarding the effectiveness of RDN in stage 3 and 4 chronic kidney disease (CKD) and ESKD patients on dialysis, with reductions in BP of nearly up to 10 mmhg. Although multiple underlying pathophysiological mechanisms contribute to RH, the overactivation of the sympathetic nervous system in ESKD patients on dialysis plays a crucial role. The diagnosis of RH requires both confirmation of adherence to antihypertensive therapy and the presence of uncontrolled BP values by ambulatory BP monitoring or home BP monitoring. Treatment involves a combination of nonpharmacological approaches (such as dry weight reduction, sodium restriction, dialysate sodium concentration reduction, and exercise) and pharmacological treatments. A promising approach for managing of RH is based on catheter-based RDN, through radiofrequency, ultrasound, or alcohol infusion, directly targeting on sympathetic overactivity.

Radio frequency-based renal denervation: a story of simplicity?

Radio frequency-based renal denervation is a safe and effective way of lowering blood pressure, a common condition associated with high cardiovascular risk. Several catheters have been developed to administer energy to the renal arteries and their side branches, thereby modulating sympathetic renal activity. The Symplicity Flex™ and Symplicity Spyral™ are first- and second-generation devices, respectively, for radio frequency-based renal denervation. There is a continuous need to further improve and adjust interventional antihypertensive therapies. Several randomized controlled trials have been conducted to investigate the safety and efficacy of these catheters and most were able to show radio frequency-based renal denervation to be feasible, safe and effective in lowering blood pressure in hypertensive patients with and without concomitant antihypertensive medication. Herein, the authors discuss the pathophysiologic concepts of renal denervation and its procedural approaches, report catheter designs, summarize clinical trials outcomes and, finally, discuss real-world evidence.

Advances in Renal Denervation in the Treatment of Hypertension

Hypertension significantly increases the risk of cardiovascular events and it is associated with high rates of disability and mortality. Hypertension is a common cause of cardiovascular and cerebrovascular accidents, which severely affect patients’ quality of life and lifespan. Current treatment strategies for hypertension are based primarily on medication and lifestyle interventions. The renal sympathetic nervous system plays an important role in the pathogenesis of hypertension, and catheter-based renal denervation (RDN) has provided a new concept for the treatment of hypertension. In recent years, studies on RDN have been performed worldwide. This article reviews the latest preclinical research and clinical evidence for RDN.

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.

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.

Catheter-based renal denervation in Chinese patients with chronic kidney disease and uncontrolled hypertension

Sympathetic activation contributes to the progression of hypertension and chronic kidney disease (CKD). Ablation of renal sympathetic nerves lowers blood pressure (BP) and preserves renal function in patients with CKD and uncontrolled hypertension by reducing sympathetic nerve activity. But whether this approach is safe and effective in Chinese patients with CKD is unknown. We performed an observational study of eight patients with CKD stages from 1 to 5, office BP ≥150/90 mmHg, while on at least three antihypertensive drug classes including a diuretic, and diagnosis confirmed by 24 h ambulatory systolic BP measurement ≥135 mmHg. All patients underwent catheter-based renal denervation (RDN) using a newly designed RDN System (Golden Leaf Medtech, Shanghai, China). For up to 6 months after RDN, BP was monitored and renal function was assessed. Mean baseline office BP was 165.0 ± 13.9/97.8 ± 5.5 mmHg, despite treatment with three antihypertensive drugs. Six months after RDN, office BP was reduced by 22.1 ± 12.0 (P = .002)/11.0 ± 8.8 mmHg (P = .012) and average 24 h ambulatory BP by 18 ± 13.7 (P = .01)/9.3 ± 7.7 mmHg (P = .016). After RDN, heart rate and estimated glomerular filtration rate (GFR) had no significant change compared with before RDN. In Chinese patients with CKD, our observational pilot study found that treating hypertension with RDN lowers BP while not affecting renal function. Brief Abstract: We performed RDN in eight Chinese patients with hypertension and CKD. The results showed that RDN lowered blood pressure of these patients significantly and eGFR was stable. No obvious adverse event was observed.

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.

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.

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.

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.

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.

[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.

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.