Catheter-based renal denervation in patients with uncontrolled hypertension in the absence of antihypertensive medications (SPYRAL HTN-OFF MED): a randomised, sham-controlled, proof-of-concept trial

Renal Sympathetic Denervation for Hypertension

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

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

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

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

Aims

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

Methods

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

Results

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

Conclusions

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

The role of renal nerve stimulation in percutaneous renal denervation for hypertension: A mini-review

Recent trials have demonstrated the efficacy and safety of percutaneous renal sympathetic denervation (RDN) for blood pressure (BP)-lowering in patients with uncontrolled hypertension. Nevertheless, major challenges exist, such as the wide variation of BP-lowering responses following RDN (from strong response to no response) and lack of feasible and reproducible peri-procedural predictors for patient response. Both animal and human studies have demonstrated different patterns of BP responses following renal nerve stimulation (RNS), possibly related to varied regional proportions of sympathetic and parasympathetic nerve tissues along the renal arteries. Animal studies of RNS have shown that rapid electrical stimulation of the renal arteries caused renal artery vasoconstriction and increased norepinephrine secretion with a concomitant increase in BP, and the responses were attenuated after RDN. Moreover, selective RDN at sites with strong RNS-induced BP increases led to a more efficient BP-lowering effect. In human, when RNS was performed before and after RDN, blunted changes in RNS-induced BP responses were noted after RDN. The systolic BP response induced by RNS before RDN and blunted systolic BP response to RNS after RDN, at the site with maximal RNS-induced systolic BP response before RDN, both correlated with the 24-h ambulatory BP reductions 3-12 months following RDN. In summary, RNS-induced BP changes, before and after RDN, could be used to assess the immediate effect of RDN and predict BP reductions months following RDN. More comprehensive, large-scale and long term trials are needed to verify these findings.

Regions of the human renal artery: histomorphometric analysis

The renal artery is frequently involved in the pathogenesis of vasculorenal diseases, and it is a target in kidney surgery and therapeutic techniques for refractory hypertension. However, few detailed structural studies on the human renal artery have been conducted. Using histocytochemistry, immunohistochemistry, and quantitative image analysis, the wall thickness, structure, smooth muscle cells, extracellular matrix, and proportion of elastic tissue in the tunica media of main human renal arteries were used estimated. Ninety-six tissue samples were collected from sections of the right and left main renal arteries. The results showed that the renal artery changed from an elastic vessel in its proximal segment to a muscular artery in its distal part. A critical characteristic of the renal artery was the presence of longitudinal smooth muscle cell formations in the tunica adventitia of middle and distal segments but not in the proximal part of the artery. In addition, the tunica adventitia of the renal artery showed a rich vascularization and the presence of numerous nerves profiles. The artery's regional structural and morphometric features explain that a particular arterial pathology is more frequent in a specific vessel sector than in others. In addition, those characteristics could determine a different therapeutic response attending to the arterial sector.

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

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

Update on 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.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

2022 Malaysian Working Group Consensus Statement on Renal Denervation for management of arterial hypertension

Hypertension is highly prevalent and a major contributor to cardiovascular mortality and morbidity. In spite of the availability of efficacious, safe and affordable anti-hypertensive drugs, hypertension remains poorly controlled in the majority of hypertensive patients. Various reasons including non-adherence to the anti-hypertensive drugs, account for the poor control. Resistant hypertension is also one of the reasons for poor control of blood pressure (BP). The sympathetic nervous system (SNS) has long been recognized as one of the determinants in the pathophysiology of a raised BP. Overactivity of the SNS is a contributor to sustained arterial hypertension. Renal denervation (RDN) is increasingly recognized as a safe and effective adjunctive therapy to control BP with or without pharmacotherapy. Hence for patients who remain uncontrolled despite all efforts, renal denervation (RDN) is a novel treatment that can potentially improve BP control, hence reducing the major adverse cardiovascular events (MACE). More recent randomized, sham control trials of RDN have shown that RDN produces a sustained lowering of BP. To date, this lowering of BP through RDN is maintained for at least 3 years. Furthermore, this procedure has been found to be safe. Hence this consensus summarises the science behind RDN and the available clinical data to support the use of this therapy. It is hoped that this consensus will offer guidance on the importance of identifying patients who will benefit most from this therapy. A multidisciplinary team approach in the management of the patient undergoing RDN is recommended.

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

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

Renal denervation in resistant hypertension: a review of clinical trials and future perspectives

A previous report using the National Health and Nutrition Examination Survey demonstrated an increase in the prevalence of resistant hypertension, which does not respond to traditional therapy and medication. Studies using various animal hypertensive models have demonstrated significant blood pressure (BP) reduction following renal artery denervation (RDN). Catheter-based RDN became available in clinical trials as a possible treatment option for resistant hypertension. Although first clinical trials of RDN have demonstrated the efficacy and safety of this treatment mortality for lowering BP in patients with resistant hypertension, the role of RDN has been questioned since the results of the Symplicity HTN-3 trial. Considering the ethnic differences demonstrated in the Symplicity HTN-Japan and Global Symplicity registry, by contrast, RDN might be an effective for resistant hypertension in Asian population. Here, we discuss RDN applications and technology, the old and new clinical evidence of RDN, patients' selection of RDN responder, and optimization of RDN procedure in this review. The available evidence demonstrates that RDN could be effective in carefully selected patients with resistant hypertension, paving the way for future research in this area.

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.

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.

Acute and Short-Term Autonomic and Hemodynamic Responses to Transcranial Direct Current Stimulation in Patients With Resistant Hypertension

Previously, we demonstrated that acute transcranial direct current stimulation (tDCS) reduced blood pressure (BP) and improved autonomic modulation in hypertensives. We hypothesized that acute and short-term tDCS intervention can promote similar benefits in resistant hypertensive patients (RHT). We assessed the impact of one (acute intervention) and ten (short-term intervention) tDCS or SHAM (20 min, each) sessions on BP, pulse interval (PI) and systolic blood pressure variabilities, humoral mechanisms associated with BP regulation, and cytokines levels. True RHT subjects (n = 13) were randomly submitted to one and ten SHAM and tDCS crossing sessions (1 week of “washout”). Hemodynamic (Finometer^®, Beatscope), office BP, and autonomic variables (accessed through spectral analysis of the pulse-to-pulse BP signal, in the time and frequency domain – Fast Fourrier Transform) were measured at baseline and after the short-term intervention. 24 h-ambulatory BP monitoring was measured after acute and short-term protocols. Acute intervention: tDCS reduced BP, cardiac output, and increase high-frequency band of PI (vagal modulation to the heart). Short-term protocol: tDCS did not change BP and cardiac output parameters. In contrast, central systolic BP (−12%), augmentation index (−31%), and pulse wave velocity (34%) were decreased by the short-term tDCS when compared to SHAM. These positive results were accompanied by a reduction in the low-frequency band (−37%) and an increase of the high-frequency band of PI (+62%) compared to SHAM. These findings collectively indicate that short-term tDCS concomitantly improves resting cardiac autonomic control and pulse wave behavior and reduces central BP in RHT patients, https://ensaiosclinicos.gov.br/rg/RBR-8n7c9p.

Rethinking Resistant Hypertension

Resistant hypertension is common and known to be a risk factor for cardiovascular events, including stroke, myocardial infarction, heart failure, and cardiovascular mortality, as well as adverse renal events, including chronic kidney disease and end-stage kidney disease. This review will discuss the definition of resistant hypertension as well as the most recent evidence regarding its diagnosis, evaluation, and management. The issue of medication non-adherence and its association with apparent treatment-resistant hypertension will be addressed. Non-pharmacological interventions for the treatment of resistant hypertension will be reviewed. Particular emphasis will be placed on pharmacological interventions, highlighting the role of mineralocorticoid receptor antagonists and sodium-glucose cotransporter-2 inhibitors and device therapy, including renal denervation, baroreceptor activation or modulation, and central arteriovenous fistula creation.

Adequacy of blood pressure control in high-risk hypertensive patients: The DEGREE study

INTRODUCTION

Hypertension is a modifiable risk factor in patients at the highest risk for cardiovascular events. New invasive treatment options are becoming available that might be particularly appealing for high-risk patients. Therefore, the aim of this study was to determine the prevalence of high-risk patients on routine therapy that do not meet guideline recommended ambulatory blood pressure (ABP) targets.

METHODS

This single-center, cross-sectional study was conducted at the Erasmus University Medical Center (Rotterdam, The Netherlands). Inclusion criteria were: (1) age 18-80 years, (2) drugs prescribed for hypertension or history of hypertension and (3) high cardiovascular risk as defined according to the European Society of Cardiology/European Society of Hypertension (ESC/ESH) guidelines. Patients underwent standardized office blood pressure (OBP) and same-day 24-h ABP measurements. Blood pressure (BP) control was defined according to the 2018 ESC/ESH and 2017 American College of Cardiology/American Heart Association (ACC/AHA) guidelines.

RESULTS

A total of 100 patients were enrolled (median age 71 years, 35% female). Mean OBP was 142.2/81.9 ± 18.6/12.6 mmHg and mean 24-h ABP was 126.1/70.1 ± 14.3/9.2 mmHg. Patients were on 2.0 [25th-75th percentile: 1.0-3.3] Defined Daily Doses of antihypertensive drugs. ESC/ESH guideline 24-h ABP and OBP targets were not met in 41.8% (95%CI: 31.5-52.6%) and 52.7% (95%CI: 42.0-63.3%), respectively. ACC/AHA guideline 24-h ABP and OBP targets were not met in 59.3% (95%CI: 48.5-69.5%) and 79.1% (95%CI: 69.3-86.9%), respectively.

CONCLUSIONS

BP remains uncontrolled in 40-60% of high-risk hypertensive patients despite routine use of guideline-recommended therapy. Our findings support the search towards novel invasive BP lowering treatment options.

Treatment of Resistant Hypertension With Endovascular Baroreflex Amplification: 3-Year Results From the CALM-FIM Study

OBJECTIVES

The aim of this study was to evaluate the long-term (3-year) safety and effectiveness of endovascular baroreflex amplification (EVBA) from both the European and American CALM-FIM cohorts.

BACKGROUND

The CALM-FIM study demonstrated that EVBA in patients with resistant hypertension significantly lowered blood pressure (BP) with an acceptable safety profile during 6-month follow-up.

METHODS

The CALM-FIM studies were prospective, nonrandomized, first-in-human studies that enrolled patients with resistant hypertension (office systolic BP ≥160 mm Hg and mean 24-hour ambulatory BP ≥130/80 mm Hg despite a stable regimen of ≥3 antihypertensive medications, including a diuretic agent). The incidence of (serious) adverse events and changes in BP, heart rate, and prescribed antihypertensive medication up to 3 years after implantation were determined.

RESULTS

The Mobius device was implanted in 47 patients (30 in Europe, 17 in the United States; mean age 54 years, 23 women). Five serious adverse events (hypotension, n = 2; hypertension, n = 1; vascular access complications, n = 2) and 2 transient ischemic attacks occurred within 30 days postprocedure. Two strokes and 1 transient ischemic attack occurred more than 2 years postimplantation. Mean office BP at baseline was 181 ± 17/107 ± 16 mm Hg and decreased by 25/12 mm Hg (95% CI: 17-33/8-17 mm Hg) at 6 months and 30/12 mm Hg (95% CI: 21-38/8-17 mm Hg) at 3 years. Mean 24-hour ambulatory BP at baseline was 166 ± 16/98 ± 15 mm Hg and decreased by 20/11 mm Hg (95% CI: 14-25/8-15 mm Hg) at 6 months.

CONCLUSIONS

EVBA with the MobiusHD was effective in reducing BP at 3-year follow-up and appears to have an acceptable safety profile in patients with uncomplicated implantation, although data from randomized sham-controlled trials are needed to further evaluate the risk-benefit profile. (Controlling and Lowering Blood Pressure With the MobiusHD™ [CALM-FIM_EUR], NCT01911897; Controlling and Lowering Blood Pressure With the MobiusHD™ [CALM-FIM_US], NCT01831895).

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 ).

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.

Estimating the sample size of sham-controlled randomized controlled trials using existing evidence

Background: In randomized controlled trials (RCTs), the power is often 'reverse engineered' based on the number of participants that can realistically be achieved. An attractive alternative is planning a new trial conditional on the available evidence; a design of particular interest in RCTs that use a sham control arm (sham-RCTs). Methods: We explore the design of sham-RCTs, the role of sequential meta-analysis and  conditional planning in a systematic review of renal sympathetic denervation for patients with arterial hypertension. The main efficacy endpoint was mean change in 24-hour systolic blood pressure. We performed sequential meta-analysis to identify the time point where the null hypothesis would be rejected in a prospective scenario. Evidence-based conditional sample size calculations were performed based on fixed-effect meta-analysis. Results: In total, six sham-RCTs (981 participants) were identified. The first RCT was considerably larger (535 participants) than those subsequently published (median sample size of 80). All trial sample sizes were calculated assuming an unrealistically large intervention effect which resulted in low power when each study is considered as a stand-alone experiment. Sequential meta-analysis provided firm evidence against the null hypothesis with the synthesis of the first four trials (755 patients, cumulative mean difference -2.75 (95%CI -4.93 to -0.58) favoring the active intervention)). Conditional planning resulted in much larger sample sizes compared to those in the original trials, due to overoptimistic expected effects made by the investigators in individual trials, and potentially a time-effect association. Conclusions: Sequential meta-analysis of sham-RCTs can reach conclusive findings earlier and hence avoid exposing patients to sham-related risks. Conditional planning of new sham-RCTs poses important challenges as many surgical/minimally invasive procedures improve over time, the intervention effect is expected to increase in new studies and this violates the underlying assumptions. Unless this is accounted for, conditional planning will not improve the design of sham-RCTs.

Estimating the sample size of sham-controlled randomized controlled trials using existing evidence

Background: In randomized controlled trials (RCTs), the power is often 'reverse engineered' based on the number of participants that can realistically be achieved. An attractive alternative is planning a new trial conditional on the available evidence; a design of particular interest in RCTs that use a sham control arm (sham-RCTs). Methods: We explore the design of sham-RCTs, the role of sequential meta-analysis and  conditional planning in a systematic review of renal sympathetic denervation for patients with arterial hypertension. The main efficacy endpoint was mean change in 24-hour systolic blood pressure. We performed sequential meta-analysis to identify the time point where the null hypothesis would be rejected in a prospective scenario. Evidence-based conditional sample size calculations were performed based on fixed-effect meta-analysis. Results: In total, six sham-RCTs (981 participants) were identified. The first RCT was considerably larger (535 participants) than those subsequently published (median sample size of 80). All trial sample sizes were calculated assuming an unrealistically large intervention effect which resulted in low power when each study is considered as a stand-alone experiment. Sequential meta-analysis provided firm evidence against the null hypothesis with the synthesis of the first four trials (755 patients, cumulative mean difference -2.75 (95%CI -4.93 to -0.58) favoring the active intervention)). Conditional planning resulted in much larger sample sizes compared to those in the original trials, due to overoptimistic expected effects made by the investigators in individual trials, and potentially a time-effect association. Conclusions: Sequential meta-analysis of sham-RCTs can reach conclusive findings earlier and hence avoid exposing patients to sham-related risks. Conditional planning of new sham-RCTs poses important challenges as many surgical/minimally invasive procedures improve over time, the intervention effect is expected to increase in new studies and this violates the underlying assumptions. Unless this is accounted for, conditional planning will not improve the design of sham-RCTs.

Intravascular Ultrasound Can Be Used to Locate Nerves, but not Confirm Ablation, During Renal Sympathetic Denervation

Background

No methods exist for confirming nerve ablation in catheter-based renal sympathetic denervation (RDN).

Methods

We investigated the feasibility of using intravascular ultrasound (IVUS) to locate nerves and observe nerve integrity changes during RDN in a pig. To confirm our observations, we used post-RDN histological sections matched anatomically to the IVUS images.

Results

IVUS revealed multiple hypoechoic structures along the renal artery, whose locations matched those of nerves in the histological sections. Nerves clustered near the junction between the renal artery and vein. Histology confirmed necrosis of nerve bundles at RDN ablation sites, but no changes in echogenicity were observed using IVUS.

Conclusions

Although IVUS cannot currently be used to confirm ablation during RDN, it clearly reveals some clusters of renal sympathetic nerves. It remains to be demonstrated how IVUS can guide RDN devices and potentially improve ablation success.

[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.

Linear and non-linear analyses of autonomic modulation in uncontrolled and controlled elderly resistant hypertensives

Resistant hypertension (RHT) is associated with worse outcomes among patients, and sympathetic overactivity is a challenge in treating this clinical condition. Here, we evaluated the autonomic modulation (by linear and non-linear analyses), central blood pressure, and pulse wave velocity in controlled and uncontrolled RHT patients, as well as those in use of beta-blockers. We observed that uncontrolled RHT patients display, in addition to an increase in peripheral blood pressure, presented higher central blood pressure values concerning controlled RHT. Furthermore, despite the use of beta-blockers, both patients in the RHT + beta-blockers and uncontrolled RHT groups had negative changes in autonomic balance as compared with controlled RHT. These results reinforce the importance of autonomic nervous system interventions in managing arterial hypertension.

Safety and efficacy of renal denervation in patients with heart failure with reduced ejection fraction (HFrEF): A systematic review and meta-analysis

INTRODUCTION

A systematic analysis of clinical trials was performed in order to assess the effectiveness and risks of bilateral renal denervation (RDN) in patients with chronic heart failure with reduced ejection fraction (HFrEF).

METHODS

A systematic review was conducted of all clinical trials exploring the effectiveness of RDN in patients with HF who had reduced (<50%) EF. Primary outcomes were NYHA class, 6-min walk test, N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, left ventricular ejection fraction (LVEF) and other cardiac parameters including left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD), and left atrium diameter (LAD). Secondary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), glomerular filtration rate (GFR), and creatinine.

RESULTS

Seven studies were included in this analysis. From baseline to 6 months after RDN, the pooled mean NYHA class was decreased (mean difference [MD], -0.9; 95% confidence interval [CI], -1.6 to -0.2; P = 0.018), the mean 6-min walk test was increased (MD, 79.5 m; 95% CI, 26.9 to 132.1; P = 0.003), and the average NT-proBNP level was decreased (MD, -520.6 pg/mL; 95% CI, -1128.4 to 87.2; P = 0.093). Bilateral RDN increased the LVEF (MD, 5.7%; 95% CI, 1.6 to 9.6; P = 0.004), decreased the LVESD (MD, -0.4 cm; 95% CI, -0.5 to -0.2; P < 0.001), decreased the LVEDD (MD, -0.5 cm; 95% CI, -0.6 to -0.3; P < 0.001), and decreased the LAD (MD, -0.4 cm; 95% CI, -0.8 to 0; P = 0.045). In addition, RDN significantly decreased systolic BP (MD, -9.4 mmHg; 95% CI, -16.3 to -2.4; P = 0.008) and diastolic BP (MD, -4.9 mmHg; 95% CI, -9.5 to -0.4; P = 0.033), and decreased HR (MD, -4.5 bpm; 95% CI, -8.2to -0.9; P = 0.015). RDN did not significantly change GFR (MD, 7.9; 95% CI, -5.0 to 20.8; P = 0.230), or serum creatinine levels (MD, -7.2; 95% CI, -23.7 to 9.4; P = 0.397).

CONCLUSION

Bilateral RDN appears safe and well-tolerated in patients with HF. RDN improved the signs and symptoms of HF and slightly decreased systolic and diastolic BP without affecting renal function in the clinical trials performed to date.

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.

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.

Comparison of a 5 F Microtube-Irrigated Ablation Catheter and a General Ablation Catheter in the Treatment of Resistant Hypertension with Renal Denervation

Objective: To assess the effectiveness of catheter-based renal denervation for reducing blood pressure in patients with resistant hypertension using a 5 F microtube-irrigated ablation catheter.Methods: Sixty patients with resistant hypertension were divided into two groups: a microtube-irrigated ablation catheter group and a general ablation catheter group. We conducted 12-month follow-up of all patients and recorded clinical blood pressure, ambulatory blood pressure, medication use, and biochemistry test results in both groups at the baseline and at the 12-month follow-up.Results: All patients underwent renal denervation. At the 6-month follow-up, ambulatory blood pressure in the microtube-irrigated ablation catheter group was significantly lower than in the general ablation catheter group (systolic blood pressure 142.0 ± 14.4 mmHg vs. 150.8 ± 17.9 mmHg, P=0.04; diastolic blood pressure 81.2 ± 7.0 mmHg vs. 87.6 ± 8.0 mmHg, P=0.002). At the 12-month follow-up, the between-group difference in ambulatory blood pressure was not statistically significant. At the 12-month follow-up, the number of antihypertensive drugs and diuretics used in the microtube-irrigated ablation catheter group was less than in the general ablation catheter group (P=0.043). There was no statistical difference between the two groups in the results of biochemistry tests and echocardiography.Conclusion: The microtube-irrigated ablation catheter is more effective in treating hypertension than the general ablation catheter at the 6-month follow up and thus fewer antihypertensive drugs were used in the microtube-irrigated ablation catheter group than in the general ablation catheter group.

Renal denervation inhibits the renin-angiotensin-aldosterone system in spontaneously hypertensive rats

This study was conducted to explore the effect of renal denervation (RDN) on the renin-angiotensin-aldosterone system (RAAS) in spontaneously hypertensive rats (SHRs). Our experimental rats were randomly divided into the RDN group conducted by painting 10% phenol on the bilateral renal nerves (RDNX), the shamoperation group simply painting with saline (Sham), and the normotension control group (WKY) following all the animal blood and tissues of kidney, hypothalamus, and adrenal gland collected and examined 2 weeks after RDN operation. We found that the aldosterone (ALD) levels in serum and tissues all decreased in the RDNX group compared with the Sham group (p < .05). Meantime, the expression of angiotensin II type1 receptor (AT1R) mRNA also exhibited significantly reduced by 2.22-fold in the RDNX group compared to the Sham group identical to the expression of AT1R protein in the renal cortex and outer stripe of the outer medulla (OSOM) subjected to denervation surgery, which manifested the lower ATIR protein expression than the Sham group (p < .05). Besides, the expression of angiotensin II (Ang II) protein in the cortex , OSOM, and inner stripe of the outer medulla were all attenuated by RDN in comparison with the Sham group (p < .05). RDN reduced intrarenal RAAS and circulating RAAS to lower blood pressure and repair renal function.

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.

Systematic review of renal denervation for the management of cardiac arrhythmias

Background

In the wake of the controversy surrounding the SYMPLICITY HTN-3 trial and data from subsequent trials, this review aims to perform an updated and more comprehensive review of the impact of renal sympathetic denervation on cardiac arrhythmias.

Methods and results

A systematic search was performed using the Medline, Scopus and Embase databases using the terms “Renal Denervation” AND “Arrhythmias or Atrial or Ventricular”, limited to Human and English language studies within the last 10 years. This search yielded 19 relevant studies (n = 6 randomised controlled trials, n = 13 non-randomised cohort studies) which comprised 783 patients. The studies show RSD is a safe procedure, not associated with increases in complications or mortality post-procedure. Importantly, there is no evidence RSD is associated with a deterioration in renal function, even in patients with chronic kidney disease. RSD with or without adjunctive pulmonary vein isolation (PVI) is associated with improvements in freedom from atrial fibrillation (AF), premature atrial complexes (PACs), ventricular arrhythmias and other echocardiographic parameters. Significant reductions in ambulatory and office blood pressure were also observed in the majority of studies.

Conclusion

This review provides evidence based on original research that ‘second generation’ RSD is safe and is associated with reductions in short-term blood pressure and AF burden. However, the authors cannot draw firm conclusions with regards to less prominent arrhythmia subtypes due to the paucity of evidence available. Large multi-centre RCTs investigating the role of RSD are necessary to comprehensively assess the efficacy of the procedure treating various arrhythmias.

Graphic abstract

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.

Optimal Strategy for HIFU-Based Renal Sympathetic Denervation in Canines

Background: The association between the treatment efficacy and safety of high-intensity focused ultrasound (HIFU)-based renal sympathetic denervation (RDN) and the acoustic energy dose applied has not been fully studied and may provide important understanding of the mechanism that led to failure of the WAVE IV trial. The objective of this study was to externally deliver different HIFU doses to canines for RDN treatment and to investigate the optimal energy dose for HIFU-based RDN.

Methods: Thirty canines were divided into five RDN groups according to dose of acoustic energy applied, and a sham control group that consisted of four canines was used for comparisons. All animals in the RDN groups underwent the RDN procedure with different acoustic energy doses, while in the sham control group, renal arteries were harvested without being subjected to acoustic energy delivery and were imaged using color Doppler flow imaging (CDFI). Blood pressure (BP) was recorded, and blood samples were collected before the RDN procedure and at 28 days after the RDN procedure. Histological examinations and measurement of renal tissue norepinephrine concentration were performed in all retrieved samples.

Results: Suppression of BP was significant in the 300 W (15.17/8.33 ± 1.47/1.21 mmHg), 250 W (14.67/9.33 ± 1.21/1.37 mmHg), and 200 W (13.17/9.17 ± 2.32/1.84 mmHg) groups. Semiquantitative histological assessment of periarterial nerves around the kidney revealed that target nerves in the 300 W (9.77 ± 0.63), 250 W (9.42 ± 0.67), and 200 W (9.58 ± 0.54) groups had the highest nerve injury scores, followed by the 150 W group (5.29 ± 0.62). Furthermore, decreased renal tissue norepinephrine concentration, together with decreased expression of tyrosine hydroxylase in the 300, 250, and 200 W groups demonstrated effective sympathetic depression following sufficient acoustic energy deposition. However, the renal artery injury score in the 300 W group (0.93 ± 0.13) was significantly higher than in the other groups (p < 0.001).

Conclusion: This study provides evidence that RDN effectiveness is based on the energy dose delivered and that 200–250 W is effective and safe in normal-sized canines.

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.

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.