Renal denervation in treatment-resistant essential hypertension. A randomized, SHAM-controlled, double-blinded 24-h blood pressure-based trial

Renal Denervation Effects on Blood Pressure in Resistant and Uncontrolled Hypertension: A Meta-Analysis of Sham-Controlled Randomized Clinical Trials

BACKGROUND

Although some guidelines recommend Renal denervation (RDN) as an alternative to anti-HTN medications, there are concerns about its efficacy and safety. We aimed to evaluate the benefits and harms of RDN in a systematic review and meta-analysis of sham-controlled randomized clinical trials (RCT).

METHODS

Databases were searched until September 10th, 2024, to identify RCTs evaluating RDN for treating URH versus sham control. The primary outcomes were the change in office and ambulatory 24-h systolic (SBP) and diastolic blood pressure (DBP). Secondary outcomes were changes in daytime and nighttime SBP and DBP, home BP, number of anti-HTN drugs, and related complications. Mean differences (MD) and relative risks (RR) described the effects of RDN on BP and complications, respectively, using random effects meta-analyses. GRADE methodology was used to assess the certainty of evidence (COE).

RESULTS

We found 16 included sham-controlled RCTs [RDN (n = 1594) vs. sham (n = 1225)]. RDN significantly reduced office SBP (MD -4.26 mmHg, 95% CI: -5.68 to -2.84), 24 h ambulatory SBP (MD -2.63 mmHg), office DBP (MD -2.15 mmHg), 24-h ambulatory DBP (MD -1.27 mmHg), and daytime SBP and DBP (MD -3.29 and 2.97 mmHg), compared to the sham. The rate of severe complications was low in both groups (0%-2%). The heterogeneity was high among most indices, and CoE was very low for most outcomes.

CONCLUSION

RDN significantly reduced several SBP and DBP outcomes versus sham without significantly increasing complications. This makes RDN a potentially effective alternative to medications in URH.

Renal denervation - radiofrequency vs. ultrasound: insights from a mixed treatment comparison meta-analysis of randomized sham controlled trials

BACKGROUND AND AIMS

Multiple randomized trials have shown that renal denervation (RDN) reduces blood pressure (BP) when compared with sham control but the antihypertensive efficacy of radiofrequency vs. ultrasound-based RDN is uncertain. We aimed to compare the outcomes of radiofrequency RDN (rRDN) and ultrasound RDN (uRDN), when compared with sham in patients with hypertension.

METHODS

PubMed, EMBASE, and clinicaltrials.gov databases were searched for randomized sham-controlled trials (RCTs) of rRDN or uRDN or for trials of rRDN vs. uRDN. Primary efficacy outcome was 24-h ambulatory SBP. A mixed treatment comparison meta-analysis was performed comparing the efficacy and safety against sham and against each other.

RESULTS

Among 13 RCTs that enrolled 2285 hypertensive patients, rRDN reduced 24-h ambulatory SBP [(MD = 2.34 mmHg; 95% confidence interval (95% CI): 0.72-3.95], office SBP (MD = 5.04 mmHg; 95% CI: 2.68-7.40)], and office DBP (MD = 2.95 mmHg; 95% CI: 1.68-4.22) when compared with sham. Similarly, uRDN reduced 24-h ambulatory SBP (MD = 4.74 mmHg; 95% CI: 2.80-6.67), day-time ambulatory SBP (MD = 5.40 mmHg; 95% CI: 3.68-7.13), night-time ambulatory SBP (MD = 3.84 mmHg; 95% CI: 0.02-7.67), and office SBP (3.98 mmHg; 95% CI: 0.78-7.19) when compared with sham. There was significantly greater reduction in 24-h ambulatory SBP (MD = 2.40 mmHg; 95% CI: 0.09-4.71), day-time ambulatory SBP (MD = 4.09 mmHg; 95% CI: 1.61-6.56), and night-time ambulatory SBP (MD = 5.76 mmHg; 95% CI: 0.48-11.0) with uRDN when compared with rRDN. For primary efficacy outcome, uRDN ranked #1, followed by rRDN (#2), and sham (#3).

CONCLUSION

In hypertensive patients, rRDN and uRDN significantly reduced 24-h ambulatory and office SBP when compared with sham control with significantly greater reduction in ambulatory BP with uRDN than with rRDN at 4 months (mean) of follow-up. A large-scale randomized head-to-head trial of rRDN or uRDN is warranted to evaluate if there are differences in efficacy.

Assessing the efficacy of renal denervation in patients with resistant arterial hypertension : Systematic review and meta-analysis

BACKGROUND

Renal denervation (RDN) is an innovative procedure designed to regulate the renal sympathetic nervous system for the control of arterial hypertension (HTN). RDN has emerged as an alternative for patients with resistant HTN. However, the clinical efficacy of RDN remains incompletely elucidated.

METHODS

PubMed, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs) comparing the use of RDN with sham procedure or pharmacological treatment in patients with resistant HTN. Statistical analyses were performed using R Studio 4.3.2 (R Foundation for Statistical Computing, Vienna, Austria). Heterogeneity was examined with the Cochran Q test I2 statistics. Mean difference (MD) with 95% confidence interval (CI) were pooled across trials. P values of <0.05 were considered statistically significant. The primary outcomes of interest were changes from baseline in systolic blood pressure (SBP), diastolic blood pressure (DBP), and serum creatinine.

RESULTS

Twenty-one RCTs comprising 3345 patients were included in this meta-analysis, whereby 2004 (59.91%) received renal denervation and 1341 (40.09%) received pharmacological treatment or sham procedure. Follow-up ranged from 2 to 48 months. Compared to control group, RDN significantly reduced SBP (MD -3.53 mm Hg; 95% CI -5.94 to -1.12; p = 0.004; I2 = 74%) and DBP (MD -1.48 mm Hg; 95% CI -2.56 to -0.40; p = 0.007; I2 = 51%). Regarding serum creatinine (MD -2.51; 95% CI -7.90 to 2.87; p = 0.36; I2 = 40%), there was no significant difference between RDN and control groups.

CONCLUSION

In this meta-analysis of RCTs of patients with resistant HTN, RDN was associated with a reduction in SBP and DBP compared to sham procedure or pharmacological treatment.

Effects of Catheter-Based Renal Denervation in Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Several sham-controlled trials have investigated the efficacy and safety of catheter-based renal denervation (RDN) with mixed outcomes. We aimed to perform a comprehensive meta-analysis of all randomized, sham-controlled trials investigating RDN with first- and second-generation devices in hypertension.

METHODS

We searched MEDLINE and the Cochrane Library for eligible trials. Outcomes included both efficacy (24-hour and office systolic [SBP] and diastolic blood pressure [DBP]) and safety (all-cause death, vascular complication, renal artery stenosis >70%, hypertensive crisis) of RDN. We performed a study-level, pairwise, random-effects meta-analysis of the summary data.

RESULTS

Ten trials comprising 2478 patients with hypertension while being either off or on treatment were included. Compared with sham, RDN reduced 24-hour and office systolic blood pressure by 4.4 mm Hg (95% CI, 2.7 to 6.1; P<0.00001) and 6.6 mm Hg (95% CI, 3.6 to 9.7; P<0.0001), respectively. The 24-hour and office diastolic blood pressure paralleled these findings (-2.6 mm Hg [95% CI, -3.6 to -1.5]; P<0.00001; -3.5 mm Hg [95% CI, -5.4 to -1.6]; P=0.0003). There was no difference in 24-hour and office systolic blood pressure reduction between trials with and without concomitant antihypertensive medication (P for interaction, 0.62 and 0.73, respectively). There was no relevant difference in vascular complications (odds ratio, 1.69 [95% CI, 0.57 to 5.0]; P=0.34), renal artery stenosis (odds ratio, 1.50 [95% CI, 0.06 to 36.97]; P=0.80), hypertensive crisis (odds ratio, 0.65 [95% CI, 0.30 to 1.38]; P=0.26), and all-cause death (odds ratio, 1.76 [95% CI, 0.34 to 9.20]; P=0.50) between RDN and sham groups. Change of renal function based on estimated glomerular filtration rate was comparable between groups (P for interaction, 0.84). There was significant heterogeneity between trials.

CONCLUSIONS

RDN safely reduces ambulatory and office systolic blood pressure/diastolic blood pressure versus a sham procedure in the presence and absence of antihypertensive medications.

Systematic Review and Meta-Analysis of Second-Generation Sham-Controlled Randomized Trials of Renal Denervation Therapy for Patients with Hypertension

INTRODUCTION

Renal denervation has been associated with substantial and sustained blood pressure reduction and is considered to serve as an alternative treatment for patients with resistant hypertension. However, the first published SHAM-controlled trial assessing RDN safety and efficacy showed no difference between groups.

AIM

We aimed to perform a meta-analysis quantifying the magnitude of blood pressure decrease secondary to renal denervation in patients with resistant hypertension.

METHODS

Databases were searched for RCTs that compared RDN therapy to SHAM procedure and reported the outcomes of (1) 24-hour ambulatory blood pressure; (2) Office systolic blood pressure; (3) Daytime systolic blood pressure; and (4) Night-time systolic blood pressure. Mean differences with 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was examined with I² statistics. P values of < 0.05 were considered statistically significant. Statistical analyses were performed using RStudio 4.2.3.

RESULTS

Nine studies and 1622 patients were included. The AMBP [MD -3.72 95%CI -5.44, -2.00 p < 0.001; I²=34%] and DSBP [MD -4.10 95%CI -5.84, -2.37 p < 0.001; I²=0%] were significantly reduced in the RDN arm. ODBP [MD -6.04 95%CI -11.31, -0.78 p = 0.024; I²=90%] and NSBP [MD -1.81 95%CI -3.90, 0.27 p = 0.08; I²=0%] did not reach a statistically significant difference between groups.

CONCLUSION

Renal denervation demonstrates greater efficacy in reducing 24-hour ambulatory and daytime systolic blood pressure in patients diagnosed with resistant hypertension.

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

The efficacy of renal denervation (RDN) has been controversial, but recent randomized sham-controlled trials demonstrated significant blood pressure reductions after RDN in patients with hypertension. We conducted a systematic review and updated meta-analysis to evaluate the effects of RDN on ambulatory and office blood pressures in patients with hypertension. Databases were searched up to 15 November 2023 to identify randomized, sham-controlled trials of RDN. The primary endpoint was change in 24 h ambulatory systolic blood pressure (SBP) with RDN versus sham control. The secondary endpoints were changes in 24 h ambulatory diastolic blood pressure, daytime and nighttime blood pressure (BP), office BP, and home BP. A sub-analysis determined outcomes by medication, procedure, and device. From twelve trials, 2222 patients with hypertension were randomized to undergo RDN (n = 1295) or a sham procedure (n = 927). At 2-6 months after treatment, RDN significantly reduced 24 h ambulatory SBP by 2.81 mmHg (95% confidence interval: -4.09, -1.53; p < 0.001) compared with the sham procedure. RDN also reduced daytime SBP by 3.17 mmHg (- 4.75, - 1.58; p < 0.001), nighttime SBP by 3.41 mmHg (- 4.69, - 2.13; p < 0.001), office SBP by 4.95 mmHg (- 6.37, - 3.54; p < 0.001), and home SBP by 4.64 mmHg (- 7.44, - 1.84; p = 0.001) versus the sham control group. There were no significant differences in the magnitude of BP reduction between first- and second-generation trials, between devices, or between with or without medication. These data from randomized sham-controlled trials showed that RDN significantly reduced all blood pressure metrics in medicated or unmedicated patients with hypertension, including resistant/uncontrolled hypertension.

Comparing the Efficacy of Renal Artery Denervation in Uncontrolled Hypertension: A Systematic Review and Network Meta-Analysis

The study aims to compare the outcomes of different renal denervation (RDN) procedures in the treatment of uncontrolled hypertension. We searched Scopus, PubMed, Web of Science, and Cochrane for RCTs evaluating different procedures of RDN for hypertension. The outcomes of this study were systolic blood pressure (SBP) daytime, diastolic blood pressure (DBP) daytime, SBP nighttime, DBP nighttime, SBP 24-hour, DBP 24-hour, SBP home, DBP home, SBP office, and DBP office. We did a frequentist network meta-analysis of 38 published RCTs evaluating the efficacy of different renal artery denervation procedures for uncontrolled hypertension compared to sham procedures or standardized stepped-care antihypertensive treatment (SSAHT). Radiofrequency (RF) alone showed a statistically significant reduction in DBP (24 hours), DBP (daytime), and DBP (nighttime): standardized mean difference (SMD): -2.01 (95% CI: (-3.34; -0.68)), SMD: -4.36 (95% CI: (-8.28; -0.44)), and SMD: -3.50 (95% CI: (-6.23; -0.76)), respectively, and showed a statistically significant reduction in SBP (24 hours), SBP (daytime), and SBP (nighttime): SMD: -3.93 (95% CI: (-6.01; -1.84)), SMD: -5.88 (95% CI: (-9.91; -1.85)), and SMD: -5.79 (95% CI: (-10.0; -1.58)), respectively. RF added to SSAHT has statistical significance in the reduction of DBP (nighttime), SBP (daytime), SBP (home), and SBP (nighttime) with a SMD of -7.63 (95% CI: (-14.21; -1.06)), SMD of -10.56 (95% CI: (-21.03; -0.08)), SMD of -23.20 (95% CI: (-36.72; -9.26)), and SMD of -14.03 (95% CI: (-25.43; -2.63)), respectively. We found that renal denervation, especially by RF, when added to SSAHT may be a promising therapeutic option for patients with treatment-resistant hypertension, particularly in cases where medication alone fails to achieve adequate blood pressure control.

Renal Denervation for the Treatment of Hypertension: A Scientific Statement From the American Heart Association

Hypertension is a leading risk factor for cardiovascular morbidity and mortality. Despite the widespread availability of both pharmacological and lifestyle therapeutic options, blood pressure control rates across the globe are worsening. In fact, only 23% of individuals with high blood pressure in the United States achieve treatment goals. In 2023, the US Food and Drug Administration approved renal denervation, a catheter-based procedure that ablates the renal sympathetic nerves, as an adjunctive treatment for patients in whom lifestyle modifications and antihypertensive medications do not adequately control blood pressure. This approval followed the publication of multiple randomized clinical studies using rigorous trial designs, all incorporating renal angiogram as the sham control. Most but not all of the new generation of trials reached their primary end point, demonstrating modest efficacy of renal denervation in lowering blood pressure across a spectrum of hypertension, from mild to truly resistant. Individual patient responses vary, and further research is needed to identify those who may benefit most. The initial safety profile appears favorable, and multiple ongoing studies are assessing longer-term efficacy and safety. Multidisciplinary teams that include hypertension specialists and adequately trained proceduralists are crucial to ensure that referrals are made appropriately with full consideration of the potential risks and benefits. Incorporating patient preferences and engaging in shared decision-making conversations will help patients make the best decisions given their individual circumstances. Although further research is clearly needed, renal denervation presents a novel treatment strategy for patients with uncontrolled blood pressure.

Renal sympathetic denervation 2024 in Austria: recommendations from the Austrian Society of Hypertension : Endorsed by the Austrian Society of Nephrology and the Working Group of Interventional Cardiology of the Austrian Society of Cardiology

Renal sympathetic denervation (RDN) is an interventional supplement to medical treatment in patients with arterial hypertension. While the first sham-controlled trial, SYMPLICITY HTN‑3 was neutral, with improved procedural details, patient selection and follow-up, recent randomized sham-controlled trials of second-generation devices show a consistent blood pressure lowering effect of RDN, as compared to sham controls. These new data and the recent U.S. Food and Drug Administration (FDA) premarket approval of two RDN devices are the basis for the present recommendations update.This joint position paper from the Austrian Society of Hypertension, together with the Austrian Society of Nephrology and the Working Group of Interventional Cardiology from the Austrian Society of Cardiology includes an overview about the available evidence on RDN and gives specific recommendations for the work-up, patient selection, pretreatment, procedural management and follow-up in patients undergoing RDN in Austria. Specifically, RDN may be used in clinical routine care, together with lifestyle measures and antihypertensive drugs, in patients with resistant hypertension (i.e. uncontrolled blood pressure on 3 antihypertensive drugs) and in those with uncontrolled hypertension, after adequate work-up, if institutional, patient-related and procedural conditions are fulfilled.

Renal denervation for uncontrolled hypertension: a systematic review and meta-analysis examining multiple subgroups

This systematic review and meta-analysis was conducted to assess the randomized controlled trial (RCT) evidence available for renal denervation (RDN) in uncontrolled arterial hypertension. Twenty-five RCTs met the eligibility criteria for the systematic review, and 16 RCTs were included in the meta-analysis. The results of the random effects meta-analysis estimated a mean difference of -8.5 mmHg [95% confidence interval (CI) -13.5 to -3.6] for office SBP, -3.6 mmHg (95% CI -5.2 to -2.0) for 24 h SBP and -3.9 mmHg (95% CI -5.6 to -2.2) for ambulatory daytime SBP in favour of RDN compared with control (medication and/or sham-only) at primary follow-up. Similarly favourable results were observed across a range of prespecified subgroup analyses, including treatment-resistant hypertension. This meta-analysis suggests that the use of RDN in uncontrolled hypertension leads to consistent reductions in blood pressure. Reductions appear to be statistically consistent in the presence or absence of medications and in populations resistant to the use of three medications.

Efficacy and Safety of Radiofrequency-Based Renal Denervation on Resistant Hypertensive Patients: A Systematic Review and Meta-analysis

INTRODUCTION

New therapies for resistant hypertension (RH), including renal denervation (RDN), have been studied.

AIM

Access the safety and effectiveness of radiofrequency-based RDN vs pharmacological treatment for RH.

METHODS

A thorough literature search was conducted across PubMed, EMBASE, and the Cochrane databases, focusing on studies that compared the effects of radiofrequency-based RDN versus pharmacological treatment for RH. Treatment effects for binary and continuous endpoints were pooled and used, respectively, odds-ratio (OR) and mean differences (MD) with 95% confidence intervals (CI) to analyze continuous outcomes.

RESULTS

In the 10 included studies, involving 1.182 patients, 682 received radiofrequency-based RDN. The follow-up period ranged from 6 to 84 months. Analysis revealed that the RDN group had a significant reduction in office systolic blood pressure (BP) (MD - 9.5 mmHg; 95% CI - 16.81 to - 2.29; P = 0.01), office diastolic BP (MD - 5.1 mmHg; 95% CI - 8.42 to - 2.80; P < 0.001), 24 h systolic BP (MD - 4.8 mmHg; 95% CI - 7.26 to - 2.42; P < 0.001). For 24 h diastolic BP RDN did not have a significant reduction (MD - 2.3 mmHg; 95% CI - 4.19 to - 0.52; P = 0.012). The heterogeneity between the studies was high, visible in the funnel and Baujat plots. The OR was non-significant for non-serious adverse events, but also clinically significant for hypertensive crises and strokes for the RDN group.

CONCLUSIONS

While the pharmacological regimen of 3 or more anti-hypertensive, including a diuretic, still be the first-line option for RH treatment, our results support that radiofrequency-based RDN is superior in reducing global BP and is safe.

Placebo Control and Blinding in Randomized Trials of Procedural Interventions: A Systematic Review and Meta-Regression

Importance

Unlike medications, procedural interventions are rarely trialed against placebo prior to becoming accepted in clinical practice. When placebo-controlled trials are eventually conducted, procedural interventions may be less effective than previously believed.

Objective

To investigate the importance of including a placebo arm in trials of surgical and interventional procedures by comparing effect sizes from trials of the same procedure that do and do not include a placebo arm.

Data Sources

Searches of MEDLINE and Embase identified all placebo-controlled trials for procedural interventions in any specialty of medicine and surgery from inception to March 31, 2019. A secondary search identified randomized clinical trials assessing the same intervention, condition, and end point but without a placebo arm for paired comparison.

Study Selection

Placebo-controlled trials of anatomically site-specific procedures requiring skin incision or endoscopic techniques were eligible for inclusion; these were then matched to trials without placebo control that fell within prespecified limits of heterogeneity.

Data Extraction and Synthesis

Random-effects meta-regression, with placebo and blinding as a fixed effect and intervention and end point grouping as random effects, was used to calculate the impact of placebo control for each end point. Data were analyzed from March 2019 to March 2020.

Main Outcomes and Measures

End points were examined in prespecified subgroups: patient-reported or health care professional-assessed outcomes, quality of life, pain, blood pressure, exercise-related outcomes, recurrent bleeding, and all-cause mortality.

Results

Ninety-seven end points were matched from 72 blinded, placebo-controlled trials (hereafter, blinded) and 55 unblinded trials without placebo control (hereafter, unblinded), including 111 500 individual patient end points. Unblinded trials had larger standardized effect sizes than blinded trials for exercise-related outcomes (standardized mean difference [SMD], 0.59; 95% CI, 0.29 to 0.89; P < .001) and quality-of-life (SMD, 0.32; 95% CI, 0.11 to 0.53; P = .003) and health care professional-assessed end points (SMD, 0.40; 95% CI, 0.18 to 0.61; P < .001). The placebo effect accounted for 88.1%, 55.2%, and 61.3% of the observed unblinded effect size for these end points, respectively. There was no significant difference between unblinded and blinded trials for patient-reported end points (SMD, 0.31; 95% CI, -0.02 to 0.64; P = .07), blood pressure (SMD, 0.26; 95% CI, -0.10 to 0.62; P = .15), all-cause mortality (odds ratio [OR], 0.23; 95% CI, -0.26 to 0.72; P = .36), pain (SMD, 0.03; 95% CI, -0.52 to 0.57; P = .91), or recurrent bleeding events (OR, -0.12; 95% CI, -1.11 to 0.88; P = .88).

Conclusions and Relevance

The magnitude of the placebo effect found in this systematic review and meta-regression was dependent on the end point. Placebo control in trials of procedural interventions had the greatest impact on exercise-related, quality-of-life, and health care professional-assessed end points. Randomized clinical trials of procedural interventions may consider placebo control accordingly.

Effects of catheter-based renal denervation in hypertension: a systematic review and meta-analysis

Background

Several sham-controlled trials have investigated the efficacy and safety of catheter-based renal denervation (RDN) with mixed outcomes.

Aim

To perform a comprehensive meta-analysis of all randomized, sham-controlled trials investigating RDN with first- and second-generation devices in hypertension.

Methods

We searched MEDLINE and Cochrane Library for eligible trials. Outcomes included both efficacy (24-hour and office systolic [SBP] and diastolic blood pressure [DBP]) and safety (all-cause death, vascular complication, renal artery stenosis >70%, hypertensive crisis) of RDN. We performed a study-level, pairwise, random-effects meta-analysis of the summary data.

Results

Ten trials comprising 2,478 patients with hypertension while being either off- or on-treatment were included. Compared with sham, RDN reduced 24-hour and office systolic BP by 4.4 mmHg (95%CI -6.1, -2.7, p<0.00001) and 6.6 mmHg (95%CI -9.7, -3.6, p<0.0001), respectively. The 24-hour and office diastolic BP paralleled these findings (-2.6 mmHg, 95%CI - 3.6, -1.5, p<0.00001; -3.5 mmHg, 95%CI -5.4, -1.6, p=0.0003). There was no difference in 24-hour and office SBP reduction between trials with and without concomitant antihypertensive medication (p for interaction 0.62 and 0.73, respectively). There was no relevant difference concerning vascular complications (OR 1.69, 95%CI 0.57-5.0, p=0.34), renal artery stenosis (OR 1.50, 95%CI 0.06-36.97, p=0.80), hypertensive crisis (OR 0.65, 95%CI 0.30-1.38, p=0.26) and all-cause death (OR 1.76, 95%CI 0.34-9.20, p=0.50) between RDN and sham groups. Change of renal function based on eGFR was comparable between groups (p for interaction 0.84). There was significant heterogeneity between trials.

Conclusions

RDN safely reduces ambulatory and office SBP/DBP vs. a sham procedure in the presence and absence of antihypertensive medication.

Clinical Perspective

What is new?Several sham-controlled trials have investigated the efficacy and safety of catheter-based renal denervation (RDN) with mixed outcomes.This comprehensive meta-analysis comprising 2,478 patients shows that irrespective of the utilized method (radiofrequency-, ultrasound-or alcohol-mediated), renal denervation effectively reduced ambulatory and office systolic blood pressure.Renal denervation exhibited no additional risk concerning vascular injury or renal function impairment.What are the clinical implications?This meta-analysis supports current guidelines/consensus statements that renal denervation represents an additive treatment option in carefully selected patients with uncontrolled hypertension.

Decreasing the blood flow of non-compressible intra-abdominal organs with non-invasive transcutaneous electrical stimulation

Non-invasive neuromodulation of non-compressible internal organs has significant potential for internal organ bleeding and blood-shift in aero/space medicine. The present study aims to investigate the potential influences of the non-invasive transcutaneous electrical nerve stimulation (TENS) on multiple non-compressible internal organs' blood flow. Porcine animal model (n = 8) was randomized for a total of 48 neuromodulation sessions with two different TENS stimulation frequencies (80 Hz, 10 Hz) and a placebo stimulation. A combination of two different electrode configurations (Abdominal-only or Abdominal and hind limb) were also performed. Intraarterial blood flow measurements were taken during pre and post-stimulation periods at the left renal artery, common hepatic artery, and left coronary artery. Intracranial, and extracranial arterial blood flows were also assessed with digital subtraction angiography. TENS with abdominal-only electrode configurations at 10 Hz demonstrated significant reductions in average peak blood flow velocity (APV) of the common hepatic artery (p = 0.0233) and renal arteries (p = 0.0493). Arterial pressures (p = 0.0221) were also significantly lower when renal APV was reduced. The outcome of the present study emphasises the potential use of TENS in decreasing the blood flow of non-compressible internal organs when the correct combination of electrodes configuration and frequency is used.

Efficacy of pharmacological and interventional treatment for resistant hypertension: a network meta-analysis

AIMS

Resistant hypertension is associated with a high risk of cardiovascular disease, chronic kidney disease, and mortality. Yet, its management is challenging. This study aims to establish the comparative effectiveness of pharmacologic and interventional treatments by conducting a network meta-analysis.

METHODS AND RESULTS

MEDLINE, Cochrane Register of Controlled Trials, and Web of Science Core Collection were systematically searched in March 2022. Randomized controlled trials comparing treatment options for management of resistant hypertension were included. Outcomes were blood pressure (BP) changes, measured in the office and in 24 h ambulatory BP measurement. We applied a frequentist random effects model to perform a network meta-analysis combining placebo medication and sham procedure as the reference comparator. From 4771 records, 24 studies met the inclusion criteria with 3458 included patients in total. Twelve active treatment alternatives [spironolactone, doxazosin, β-blocker, clonidine, darusentan, guanfacine, various types of renal sympathetic denervation, lifestyle intervention, continuous positive airway pressure, and baroreflex activation therapy (BAT)] were analysed. Among all comparators, spironolactone had the highest ranking probability and was considered the most effective treatment to reduce office systolic blood pressure (sBP) [-13.30 mmHg (-17.89; -8.72); P < 0.0001] and 24 h sBP [-8.46 mmHg (-12.54; -4.38); P < 0.0001] in patients with resistant hypertension. Lifestyle interventions were the most effective non-pharmacological treatment, lowering office sBP by -7.26 mmHg (-13.73; -0.8), whereas BAT lowered office sBP by -7.0 (-18.59; 4.59). Renal denervation lowered office sBP by -5.64 mmHg (-12.95; 1.66) and -3.79 mmHg (-11.39; 3.8) depending on the type of the procedure.

CONCLUSION

Among all pharmacologic and interventional treatments, spironolactone is the most effective treatment in reducing BP in patients with resistant hypertension. More comparative trials and especially trials with long-term follow-up are needed. In the meanwhile, we have to conclude that a combination of spironolactone and lifestyle modification are the most effective treatments in resistant hypertension.

Taming resistant hypertension: The promise of novel pharmacologic approaches and renal denervation

Resistant hypertension is associated with an exceedingly high cardiovascular risk and there remains an unmet therapeutic need driven by pathophysiologic pathways unaddressed by guideline-recommended therapy. While spironolactone is widely considered as the preferable fourth-line drug, its broad application is limited by its side effect profile, especially off-target steroid receptor-mediated effects and hyperkalaemia in at-risk subpopulations. Recent landmark trials have reported promising safety and efficacy results for a number of novel compounds targeting relevant pathophysiologic pathways that remain unopposed by contemporary drugs. These include the dual endothelin receptor antagonist, aprocitentan, the aldosterone synthase inhibitor, baxdrostat and the nonsteroidal mineralocorticoid receptor antagonist finerenone. Furthermore, the evidence base for consideration of catheter-based renal denervation as a safe and effective adjunct therapeutic approach across the clinical spectrum of hypertension has been further substantiated. This review will summarise the recently published evidence on novel antihypertensive drugs and renal denervation in the context of resistant hypertension.

Management of Resistant Hypertension

Resistant hypertension (RH) is a severe form of hypertension associated with increased cardiovascular risk. Although true RH affects less than 10% of the patients receiving antihypertensive therapy, the absolute number is high and continues to increase. The workup of these patients requires screening for secondary hypertension and pseudoresistance, including poor adherence to prescribed medicines and the white-coat phenomenon. The treatment of RH consists of lifestyle modifications and pharmacological therapies. Lifestyle modifications include dietary adjustments, weight loss, physical activity, and limiting alcohol consumption; pharmacological therapies include diuretics, mineralocorticoid receptor antagonists, beta blockers, angiotensin receptor-neprilysin inhibitors, and others. Over the last 15 years, interventional approaches have emerged as adjunct treatment options; we highlight catheter-based renal denervation. This review summarizes the rationales and latest clinical evidence and, based thereon, proposes an updated algorithm for the management of RH.

Update on advanced interventional neuromodulatory approaches to lower blood pressure

Herein, we review interventional peripheral neuromodulatory approaches to reduce blood pressure (BP), specifically focusing on catheter-based renal denervation (RDN), as well as the latest data from recent clinical trials underpinning its clinical use. Given the apparent failure of established lifestyle measures and pharmacologic BP-lowering approaches to improve hypertension (HTN) control rates, the past decade has seen remarkable scientific efforts to explore the utility of interventional strategies for BP management. Experimental studies and human clinical trials have demonstrated the crucial role of the sympathetic nervous system in the development and mainenance of HTN - consequently, most recent interventional technologies aimed primarily at modulating neural pathways. Advanced approaches that were rigorously tested in human studies include RDN, endovascular baroreflex amplification, baroreflex activation therapy and cardiac neuromodulation stimulation.Amongst these, RDN is by far the most established technology. With recent robust evidence from clinical trials and real-world data showing the safety and efficacy of both ultrasound and radiofrequency-based approaches, a recent clinical consensus statement of the European Society of Cardiology Council on Hypertension and the European Association of Percutaneous Cardiovascular Interventions concludes that RDN represents an ancillary therapeutic option in patients with uncontrolled resistant HTN confirmed by ambulatory blood pressure measurement and in spite of attention to lifestyle changes and optimised pharmacological treatment. Furthermore, RDN could alos be considered for patienst unlikley to adhere to or tolerate long-term antihypertensive drug treatment. Very recent data indicate long-term safety and efficacy up to 10 years. Appropriate implementation of RDN into clinical practice is now warranted.For all other interventions additional data from adequately designed human studies are required to establish their safety and clinical utility for potential future use in routine practice.

Catheter-based renal artery denervation: facts and expectations

Catheter-based renal artery denervation (RAD) is entering a new era. After the disappointing results of SYMPLICITY-HTN 3 trial in year 2014, several technical and methodological advancements led to execution of important SHAM-controlled randomized trials with promising results. Now, the 2023 ESH Guidelines give RAD a class of recommendation II with a Level of Evidence B. Currently, catheter-based RAD has two main areas of application: (a) Hypertensive patients who are still untreated, in whom RAD is a sort of a first-line treatment; (b) Difficult-to-control or true resistant hypertensive patients. Notably, randomized SHAM-controlled trials met their primary end-point in both these conditions. So far, we do not dispose of established predictors of the antihypertensive response to RAD. Some data suggest that younger patients with systo-diastolic hypertension, absence of diffuse atherosclerosis and evidence of sympathetic nervous system overactivity experience a better BP response to the procedure. We reviewed the available data on catheter-based RAD and included an updated meta-analysis of the results of the available SHAM-controlled trials. Overall, the reduction in 24-h systolic blood pressure (BP) after RAD exceeded that after SHAM by 4.58 mmHg (95% CI 3.07-6.10) in untreated patients, and by 3.82 mmHg (95% CI 2.46-5.18) in treated patients, without significant heterogeneity across trials, patient phenotype (untreated versus treated patients) and technique (radiofrequency versus ultrasound). There were no important safety signals related to the procedure. Notably, some data suggest that RAD could be an effective additional approach in patients with atrial fibrillation and other conditions characterized by sympathetic nervous system overactivity.

Renal denervation in hypertension: An updated meta-analysis of the randomized controlled trials

BACKGROUND

Radiofrequency or ultrasound renal denervation (RDN) has shown conflicting results when used as an adjunctive option for hypertension management in randomized controlled trials (RCTs).

METHODS

We searched Pubmed, MEDLINE, and other online databases for RCTs comparing RDN versus sham-control procedures in patients with uncontrolled or resistant hypertension. The endpoints of interest were 24-h ambulatory (AMB) blood pressure (BP), daytime AMB BP, and office BP. We performed a random-effects meta-analysis using the inverse variance method to estimate mean difference (MD) with a 95% confidence interval (CI).

RESULTS

Nine studies with 1643 patients were included in the final analysis. The mean follow-up was 5 months. As compared with the sham-controlled group, RDN was associated with a significant decrease in 24-h AMB BP (systolic [MD -4.20; 95% CI -5.36 to -3.03; p < 0.00001], diastolic [-2.38; -3.42 to -1.35]), and daytime AMB BP (systolic: -5.11; -6.75 to -3.47, diastolic: -2.88; -3.91 to -1.85). Similarly, office BP was reduced with RDN (systolic: -5.46; -7.12 to -3.81; diastolic: -3.17; -4.23 to -2.12) when compared with placebo.

CONCLUSION

Our meta-analysis shows that RDN is associated with a significant reduction in the 24-h AMB BP, daytime AMB BP, and office BP.

Controversies in Hypertension IV: Renal Denervation

Renal denervation is not a cure for hypertension. Although more recent sham-controlled trials were positive, a significant minority of patients in each trial were unresponsive. The optimal patient or patients need to be defined. Combined systolic/diastolic hypertension appears more responsive than isolated systolic hypertension. It remains uncertain whether patients with comorbidities associated with higher adrenergic tone should be targeted, including obesity, diabetes, sleep apnea, and chronic kidney disease. No biomarker can adequately predict response. A key to a successful response is the adequacy of denervation, which currently cannot be assessed in real time. It is uncertain what is the optimal denervation methodology: radiofrequency, ultrasound, or ethanol injection. Radiofrequency requires targeting the distal main renal artery plus major branches and accessory arteries. Although denervation appears to be safe, conclusive data on quality of life, improved target organ damage, and reduced cardiovascular events/mortality are required before denervation can be generally recommended.

Celiac ganglia neurolysis suppresses high blood pressure in rats

The efficacy of renal denervation in the treatment of resistant hypertension has been controversial, and new strategies for its therapy are urgently needed. We performed the celiac ganglia neurolysis (CGN) or sham surgery on both spontaneously hypertensive rat (SHR) and Dahl salt-sensitive rat models of hypertension. Following CGN surgery in both strains, systolic blood pressure, diastolic blood pressure and mean arterial pressure were all lower than the levels in the respective sham surgery rats, which were maintained until the end of the study, 18 weeks postoperatively in SHRs and 12 weeks postoperatively in Dahl rats. CGN therapy destroyed ganglion cell structure and significantly inhibited celiac ganglia nerve viability. Four and twelve weeks after CGN, the plasma renin, angiotensin II and aldosterone levels were markedly attenuated, and the nitric oxide content was significantly increased in the CGN group compared with the respective sham surgery rats. However, CGN did not result in statistical difference in malondialdehyde levels compared with sham surgery in both strains. The CGN has efficacy in reducing high blood pressure and may be an alternative for resistant hypertension. Minimally invasive endoscopic ultrasound-guided celiac ganglia neurolysis (EUS-CGN) and percutaneous CGN are safe and convenient treatment approaches. Moreover, for hypertensive patients who need surgery due to abdominal disease or pain relief from pancreatic cancer, intraoperative CGN or EUS-CGN will be a good choice for hypertension therapy. The graphical abstract of antihypertensive effect of CGN.

A systematic review and meta-analysis of all sham and placebo controlled trials for resistant hypertension

INTRODUCTION

There is a lack of consensus regarding the best add on therapy for treatment of resistant hypertension (RH). This is likely secondary to a paucity of data on the comparative effectiveness of proposed therapies for RH.

METHODS

Placebo-controlled and sham-controlled randomized clinical trials testing therapies for the treatment of RH were included in this meta-analysis. Therapies with two or more studies were included as subgroups in this meta-analysis. The primary outcomes being tested were 24-hr systolic blood pressure (SBP) and office SBP.

RESULTS

Eight studies were identified that tested mineralocorticoid receptor antagonist (MRA) including 1,414 participants. The raw mean difference (RMD) between MRA and placebo control was statistically significant for 24-hour SBP (-10.56 mmHg; 95% confidence interval (CI) -12.82 to -8.30), 24-hour diastolic (DBP) (-5.48 mmHg; 95% CI -8.48 to -2.58), office SBP (-11.97 mmHg; 95% CI -16.41 to -7.54), and office DBP (-4.14 mmHg; 95% CI -5.62 to -2.65). Six studies were identified that tested renal denervation (RD) including 989 participants. The RMD between RD and sham control was not statistically significant for 24-hour SBP (-1.84 mmHg; 95% CI -3.92 to 0.24), 24-hour DBP (-0.66 mmHg; 95% CI -1.85 to 0.54), office SBP (-1.57 mmHg; 95% CI -6.04 to 2.89), and office DBP (-1.49 mmHg; 95% CI -3.52 to 0.55). Four studies were identified that tested endothelin receptor antagonists (ERA) including 1,193 participants. The raw mean difference (RMD) between ERA and placebo control was statistically significant for 24-hr systolic (SBP) (-7.02 mmHg; 95% CI -9.15 to -4.90, 24-hr diastolic (DBP) (-6.22 mmHg; 95% CI -7.61 to -4.82), office SBP (-5.84 mmHg; 95% CI -10.08 to -1.60), and office DBP (-3.73 mmHg; 95% CI -5.87 to -1.59).

DISCUSSION

MRA lowers BP in patients with RH more than RD, which seems to have little to no effect in RH. ERAs lead to a statistically significant reduction in BP but the confidence in efficacy is limited due to the low number of studies and differences in trial population. Individual factors and their impact on treatment response in RH should be investigated in future research.

The effect of catheter-based sham renal denervation in hypertension: systematic review and meta-analysis

BACKGROUND

Renal denervation (RDN) has emerged in recent years as a possible treatment for hypertension. The first sham-controlled trial showed a small magnitude and non-significant in the blood pressure (BP) lowering effect, also due to a substantial decrease of BP in sham arm. Considering this, we aimed to quantify the magnitude of BP decrease within the sham arm of Randomized Controlled Trials (RCT) with RDN in patients with hypertension.

METHODS

Electronic databases were searched since inception until January 2022 for randomized sham-controlled trials which assessed the efficacy in lowering BP of the sham intervention for catheter-based RDN in adult patients with hypertension. The outcomes were change in ambulatory/office systolic and diastolic BP.

RESULTS

A total of 9 RCT were included in the analysis enrolling a total of 674 patients. Sham intervention showed a decrease in all evaluated outcomes. Office systolic BP had a reduction of -5.52 mmHg [95%CI -7.91, -3.13] and office diastolic BP of -2.13 mmHg [95%CI -3.08, -1.17]. Sham procedure for RDN also showed a reduction of -3.41 mmHg [95%CI -5.08, -1.75] in ambulatory systolic BP and - 2.44 mmHg [95%CI -3.31, -1.57] in ambulatory diastolic BP.

CONCLUSION

Despite recent data indicating that RDN might be an effective treatment for patients with resistant hypertension when compared to a sham intervention, our results indicate that the sham intervention for RDN also has a significant effect on lowering Office and Ambulatory (24-h) Blood Pressure in adult patients with hypertension. This highlights that BP itself might be sensitive to placebo-like effect and also brings further difficulties in establishing the BP lowering efficacy of invasive interventions due to the magnitude of the sham effect.

Renal denervation in the management of hypertension in adults. A clinical consensus statement of the ESC Council on Hypertension and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

Since the publication of the 2018 European Society of Cardiology/European Society of Hypertension (ESC/ESH) Guidelines for the Management of Arterial Hypertension, several high-quality studies, including randomised, sham-controlled trials on catheter-based renal denervation (RDN) were published, confirming both the blood pressure (BP)-lowering efficacy and safety of radiofrequency and ultrasound RDN in a broad range of patients with hypertension, including resistant hypertension. A clinical consensus document by the ESC Council on Hypertension and the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on RDN in the management of hypertension was considered necessary to inform clinical practice. This expert group proposes that RDN is an adjunct treatment option in uncontrolled resistant hypertension, confirmed by ambulatory BP measurements, despite best efforts at lifestyle and pharmacological interventions. RDN may also be used in patients who are unable to tolerate antihypertensive medications in the long term. A shared decision-making process is a key feature and preferably includes a patient who is well informed on the benefits and limitations of the procedure. The decision-making process should take (i) the patient's global cardiovascular (CV) risk and/or (ii) the presence of hypertension-mediated organ damage or CV complications into account. Multidisciplinary hypertension teams involving hypertension experts and interventionalists evaluate the indication and facilitate the RDN procedure. Interventionalists require expertise in renal interventions and specific training in RDN procedures. Centres performing these procedures require the skills and resources to deal with potential complications. Future research is needed to address open questions and investigate the impact of BP-lowering with RDN on clinical outcomes and potential clinical indications beyond hypertension.

A Subgroup Meta-Analysis Comparing the Renal Denervation Sham-Controlled Randomized Trials Among Those With Resistant and Nonresistant Hypertension

Renal denervation (RD) has been investigated as an invasive blood pressure (BP) lowering treatment for hypertension (HTN). Resistant HTN (RHTN) has been defined as uncontrolled BP despite use of 3 antihypertensive medications of different classes, including a diuretic, at maximum tolerated doses. The impact of RD on RHTN remains under investigation. Ten sham-controlled trials testing RD were included in this trial-level analysis. A prespecified subgroup analysis was conducted to test whether efficacy of RD differed in patients with and without RHTN. The primary end points were change in 24-hour ambulatory systolic (SBP) and diastolic (DBP) using raw mean difference (RMD) between sham control and RD. Ten studies (6 RHTN and 4 nonresistant HTN) were identified that included 1,544 participants (1,001 RHTN and 543 essential HTN) with cumulative mean age (±SD) of 57 years (±3). Cochran risk of bias assessment showed 69% of the domains to be at low risk of bias. The RMD for 24-hour SBP between RD and sham control was statistically significant for nonresistant HTN trials (-4.19 mm Hg; 95% confidence interval [CI] -6.07 to -2.30) but was not statistically significant for RHTN trials (-1.86 mm Hg; 95% CI - 3.89 to 0.16). Despite the numerical difference in the subgroups, the interaction between subgroups failed to reach statistical significance (p = 0.10). The RMD for 24-hour DBP between RD and sham control was statistically significant for nonresistant HTN trials (-2.60 mm Hg; 95% CI -3.79 to -1.42) but was not statistically significant for RHTN trials (-0.67 mm Hg; 95% CI -1.84 to 0.50). The interaction between subgroups was statistically significant (p = 0.02). Our analysis indicates RD is a less effective intervention for patients with RHTN. These data may be beneficial for clinicians to consider when assessing patients with RHTN for RD.

National Heart Center/Saudi Heart Association 2023 Guidelines on the Management of Hypertension

Background

Hypertension is a highly prevalent disease in Saudi Arabia with poor control rates. Updated guidelines are needed to guide the management of hypertension and improve treatment outcomes.

Methodology

A panel of experts representing the National Heart Center (NHC) and the Saudi Heart Association (SHA) reviewed existing evidence and formulated guidance relevant to the local population, clinical practice and the healthcare system. The recommendations were reviewed to ensure scientific and medical accuracy.

Recommendations

Hypertension was defined and a new classification was proposed as relevant to the Saudi population. Recommendations on diagnosis, clinical evaluation, cardiovascular assessment were detailed, along with guidance on measurement modalities and screening/follow-up. Non-pharmacological management is the first line of hypertension treatment. Pharmacological therapy should be used appropriately as needed. Treatment priority is to control blood pressure regardless of the drug class used. The choice of treatment should be tailored to the patient profile in order to achieve treatment targets and ensure patient compliance. Recommendations were provided on pharmacological options available in Saudi Arabia, as well as guidance on the treatment of special conditions.

Conclusion

Hypertension management should be based on appropriate screening, timely diagnosis and lifestyle changes supplemented with pharmacological therapy, as needed. Clinical management should be individualized, and careful consideration should be given to special conditions and patient groups.

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.

Device-based neuromodulation for cardiovascular diseases and patient' s age

The autonomic nervous system plays an important role in the pathogenesis of cardiovascular diseases. With aging, autonomic activity changes, and this impacts the physiological reactions to internal and external signals. Both sympathetic and parasympathetic responses seem to decline, reflecting functional and structural changes in nervous regulation. Although some investigators suggested that both the sympathetic and parasympathetic activities were suppressed, others found that only the parasympathetic activity was suppressed while the sympathetic activity increased. In addition, cardiac innervation progressively diminishes with aging. Therefore, one may suggest that neuromodulation interventions may have different effects, and older age groups can express an attenuated response. This article aims to discuss the effect of device-based neuromodulation in different cardiovascular diseases, depending on the patient's age. Thus, we cover renal denervation, pulmonary artery denervation, baroreceptor activation therapy, vagus nerve stimulation, spinal cord stimulation, ganglionated plexi ablation for the management of arterial and pulmonary hypertension, heart failure, angina and arrhythmias. The results of many clinical studies appeared to be unconvincing. In view of the low rate of positive findings in clinical studies incorporating neuromodulation approaches, we suggest the underestimation of advanced age as a potential contributing factor to poorer response. Analysis of outcomes between different age groups in clinical trials may shed more light on the true effects of neuromodulation when neutral/ambiguous results are obtained.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Renal denervation in 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.

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 ).

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.

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.

Renal denervation for resistant hypertension

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Approach to Resistant Hypertension from Cardiology and Nephrology Standpoints: Tailoring Therapy

Resistant hypertension is commonly encountered in primary care, cardiology, and nephrology clinics. In patients presenting for the evaluation of resistant hypertension, taking a thoughtful approach to excluding pseudoresistant hypertension or a secondary cause of hypertension is important. When a patient is deemed to have true resistant hypertension, following an evidence-based treatment approach while considering patient-specific comorbidities results not only in better blood pressure control but also better patient long-term adherence to lifestyle and pharmacologic interventions. This article details an approach to the diagnosis and treatment of resistant hypertension with special consideration for patients with preexisting renal and/or cardiovascular disease.

Current Status and Future Perspectives of Renal Denervation

Despite the availability of numerous antihypertensive medications, hypertension treatment and control rates remain low, and uncontrolled hypertension is well-known to be one of the most important cardiovascular risk factors. Endovascular catheter-based renal denervation (RDN) has been developed to be a complementary or alternative treatment option for patients who cannot take medication, poor adherence, or have resistant hypertension despite the use of maximal doses of medications. Recently, several randomized trials for evaluating the efficacy and safety of second-generation RDN devices consistently show solid evidence for their blood pressure-lowering efficacy. This review summarizes the current evidence and future perspectives of RDN.

Catheter-based renal denervation (RDN) therapy, a new procedure that uses radiofrequency ablation to interrupt efferent and afferent renal sympathetic nerve fibers, is a complementary or alternative treatment to antihypertensive medications for optimal control of blood pressure (BP). Although several single-arm early proof-of-concept studies showed significant BP reduction, the largest sham-controlled study using the first-generation RDN device (SYMPLICITY HTN-3) failed to significantly reduce BP in patients with resistant hypertension who were taking the guideline-based combination of antihypertensive medications. Since then, new devices and techniques have been developed to improve the efficacy and safety of RDN procedures. Sham-controlled trials using second-generation RDN devices (radiofrequency- and ultrasound-based) have provided solid evidence for their BP-lowering efficacy with and without the use of concomitant antihypertensive medication. Moreover, the safety profile of RDN in several registries and clinical trials appears to be excellent. This review summarizes the current evidence for RDN and discusses its current issues, future trials, Asian perspectives, and potential roles in both hypertension and other morbidities.

Impact of renal sympathetic denervation on cardiac magnetic resonance-derived cardiac indices in hypertensive patients - A meta-analysis

BACKGROUND

Renal sympathetic denervation (RDN) is a safe device-based option for the treatment of hypertension although current guidelines do not recommend its use in routine clinical practice. In this meta-analysis, we investigated the effects of RDN in cardiac magnetic resonance (CMR)-derived cardiac indices.

METHODS

This meta-analysis was performed in accordance with the PRISMA statement. A comprehensive systematic search of MEDLINE database and Cochrane library through to January 2021 was performed. The inclusion criteria were studies that enrolled patients undergoing RDN in whom CMR data were provided for left ventricular end-diastolic volume indexed to body surface area (BSA) (LVEDVI), left ventricular end-systolic volume indexed (LVESVI), left ventricular mass indexed (LVMI), and left ventricular ejection fraction (LVEF) pre and post RDN. A random effects model was used for the analyses.

RESULTS

Our search strategy revealed 9 studies that were finally included in the meta-analysis (n=300 patients, mean age: 60 years old, males: 59%). Compared to control group, RDN patients showed significantly lower values in the attained volumes (LVEDVI: -6.70 ml/m², p=0.01; LVESVI: -3.63 ml/m², p=0.006). Moreover, RDN group achieved a statistically significant higher attained LVEF (3.49%, p=0.01). A non-significant difference was found in the attained LVMI between RDN and control groups (-2.59 g/m², p=0.39). Compared to pre-RDN values, RDN reduces significantly the LVMI, the LVEDVI, and the LVESVI while a non-significant change of LVEF was found.

CONCLUSIONS

In conclusion, the current study demonstrates the potential beneficial role of RDN in CMR-derived cardiac indices that reflect adverse remodeling. However, large, randomized studies are needed to elucidate the role of RDN in cardiac remodeling in hypertension, heart failure, and other clinical settings.

Randomized trials of invasive cardiovascular interventions that include a placebo control: a systematic review and meta-analysis

AIMS

The difference in the benefit of invasive cardiovascular interventions compared with placebo controls has not been analysed systematically.

METHODS AND RESULTS

MEDLINE and Web of Science were searched through 29 March 2020. Randomized, placebo-controlled trials of invasive cardiovascular interventions (including catheter-based interventions and pacemaker-like devices) investigating predefined primary outcomes were included. Standardized mean differences (SMD) and odds ratios were calculated for continuous and dichotomous outcomes, respectively. Meta-regression analyses were performed to assess whether estimates of treatment effects were associated with methodological characteristics of trials. Thirty trials, including 4102 patients, were analysed. The overall risk of bias was judged to be low in only 43% of the trials. Ten trials (33%) demonstrated statistically significant superiority of invasive interventions over placebo controls for the respective predefined primary outcomes. In almost half of the 16 trials investigating continuous predefined primary outcomes, the SMD between the active and placebo procedure indicated a small (n = 4) to moderate (n = 3) treatment effect of active treatment over placebo. In contrast, one trial indicated a small treatment effect in favour of the placebo procedure. In the remaining trials, there was no relevant treatment effect of active treatment over placebo. In trials with a protocol-mandated stable and symmetrical use of co-interventions, the superiority of active procedures vs. invasive placebo procedures was significantly larger as compared with trials with frequent or unbalanced changes in co-interventions (P for interaction 0.027).

CONCLUSIONS

The additional treatment effect of invasive cardiovascular interventions compared with placebo controls was small in most trials.

Joint ESH excellence centers' national meeting on renal sympathetic denervation: A Greek experts' survey

OBJECTIVE

The efficacy of renal sympathetic denervation (RDN) has been affirmed by a number of recent clinical studies, despite controversies in this field over the last five years. Therefore, it is of paramount importance that hypertension experts debate the merits of RDN by revealing and expressing their personal beliefs and perspectives regarding this procedure.

METHODS

A cross-sectional survey was conducted among Greek leaders of the Hypertension Excellence Centers with the use of a closed-type questionnaire specifically designed to elicit information and evaluate the respondent's views and perspectives about RDN efficacy, safety and ideal target patient population.

RESULTS

A total of 36 participants completed the survey. Based on the results, RDN was considered efficient (91.7%) and safe (94.5%), while the overwhelming majority of the participants felt confident in the long-term efficacy (88.9%) of the intervention and that it lacks reliable predictors of blood pressure response (94.5%). Patients with resistant (91.7%), ultra-resistant (94.4%), and uncontrolled hypertension (80.6%) were suggested as ideal candidates for RDN. Establishing a close co-operation between interventionalists and hypertension experts was considered essential to ensure the efficacy (97.2%) as well as the safety (97.3%) of the procedure.

CONCLUSION

The vast majority of Greek hypertension experts surveyed were convinced of the efficacy and safety of RDN based on the preponderance of available scientific and clinical data. Identification of the ideal patient group remains controversial. Respondents generally agreed on the necessity of building close collaborative relationships between interventionalists and hypertension experts in order to improve RDN clinical outcome.

Renal Denervation for Uncontrolled and Resistant Hypertension: Systematic Review and Network Meta-Analysis of Randomized Trials

Comparative efficacy and safety of renal denervation (RDN) interventions for uncontrolled (UH) and resistant hypertension (RH) is unknown. We assessed the comparative efficacy and safety of existing RDN interventions for UH and RH. Six search engines were searched up to 1 May 2020. Primary outcomes were mean 24-h ambulatory and office systolic blood pressure (SBP). Secondary outcomes were mean 24-h ambulatory and office diastolic blood pressure (DBP), clinical outcomes, and serious adverse events. Frequentist random-effects network meta-analyses were used to evaluate effects of RDN interventions. Twenty randomized controlled trials (RCTs) (n = 2152) were included, 15 in RH (n = 1544) and five in UH (n = 608). Intervention arms included radiofrequency (RF) in main renal artery (MRA) (n = 10), RF in MRA and branches (n = 4), RF in MRA+ antihypertensive therapy (AHT) (n = 5), ultrasound (US) in MRA (n = 3), sham (n = 8), and AHT (n = 9). RF in MRA and branches ranked as the best treatment to reduce 24-h ambulatory, daytime, and nighttime SBP and DBP versus other interventions (p-scores: 0.83 to 0.97); significant blood pressure effects were found versus sham or AHT. RF in MRA+AHT was the best treatment to reduce office SBP and DBP (p-scores: 0.84 and 0.90, respectively). RF in MRA and branches was the most efficacious versus other interventions to reduce 24-h ambulatory SBP and DBP in UH or RH.

A Systematic Review of Randomized Controlled Trials Comparing Renal Sympathetic Denervation Versus Sham Procedure for the Management of Uncontrolled Hypertension

ABSTRACT

The efficacy of renal sympathetic denervation (RSD) in the treatment of uncontrolled hypertension (HTN) remains uncertain. A systematic review of randomized controlled trials was performed to evaluate the efficacy and safety of RSD for resistant HTN. PubMed, EMBASE, MEDLINE, Cochrane, Directory of Open Access Journals, CINAHL, and Google Scholar were searched from January 01, 2001, through July 30, 2020. Randomized controlled trials comparing RSD with the sham procedure for uncontrolled HTN were selected. The primary efficacy outcome was the reduction in ambulatory systolic blood pressure. We used random-effects models. Nine prospective clinical trials met the inclusion criteria. The ReSet and Symplicity HTN-3 Trial showed no significant changes because of discrepancies in complete circumferential ablation during RSD. The Relief study, The Radiance HTN solo, and the SPYRAL HTN OFF medical trials showed a significant reduction in systolic blood pressure in the group that had undergone the intervention compared with the sham group attributed to rigorous trial design. In conclusion, our systematic review suggests that efficacy of RSD seems to be superior to sham-controlled interventions provided circumferential denervation is performed. However, difference in efficacy is marginal.

[Interventional treatment of high blood pressure-Current state]

Arterial hypertension is a real global burden with a very high prevalence. In the last decades, many pharmaceutical approaches have been successfully developed for treating hypertension. Currently, novel medications for influencing blood pressure are not in sight. In recent years alternatives, such as interventional procedures for reducing blood pressure, have been developed and tested. Ablation of the renal sympathetic nerves (renal denervation, RDN), which are wrapped around the renal arteries in particular, has been intensively investigated as a procedure. After the first RDN studies a clear influence on the blood pressure could be shown; however, in the first sham-controlled studies the reduction in blood pressure by RDN could no longer consistently be shown. In very systematic sham-controlled, blinded studies in patients with hypertension but without medication a robust blood pressure reducing effect of RDN could be shown, which corresponded to the effect of a blood pressure-reducing drug. It is obvious that larger studies and also long-term studies have to sustainably confirm this effect. In recent years, active and passive stimulation of the baroreceptors could also be established as a blood pressure reducing principle, at least in studies but the evidence is still very low.