Efficacy and safety of renal denervation for the management of arterial hypertension: A systematic review and meta-analysis of randomized, sham-controlled, catheter-based trials

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.

Efficacy and safety of 3D reconstruction and basket multi-electrode renal denervation (RDN) for refractory hypertensive patients with chronic kidney disease

Renal Artery Sympathetic Denervation (RDN) can lower blood pressure. Different ablation catheters (single electrode, multi-electrode) have different scopes of ablation (renal artery main stem and branches). Few studies have compared the advantages and disadvantages of different ablation catheters and different procedures in terms of antihypertensive efficacy. To compare the efficacy and safety of 3D reconstruction radiofrequency ablation (3DRA) and basket multi-electrode radiofrequency ablation (BMRA) in Renal Artery Sympathetic Denervation. Fifty-three patients with Refractory hypertension (RHT) were divided into BMRA, (n = 28) and 3DRA(n = 25). BMRA group used a stereobasket multi-electrode ablation catheter with a controlled ablation temperature of 60°C and an ablation time of 120 s per site. 3DRA group used a NavStar pressure-monitored perfusion monopolar ablation catheter with a controlled ablation temperature of 40°C, an ablation time of 40 s per site, and an ablation energy of 12 W. Baseline and RDN parameters and complications were compared in both groups. Home and 24 h ambulatory blood pressure, type of anti-hypertensive medication taken, and serum creatinine were followed up at 1, 3, 6, 12, and 24 months after the RDN. There were no differences in baseline characteristics between the two groups. (23.14 ± 2.00)months of follow-up in the BMRA group resulted in a total of (25.86 ± 8.61) loci ablation. (19.28 ± 7.40)months of follow-up in the 3DRA group resulted in a total of (21.04 ± 6.47)loci ablation. Home SBP was significantly lower in both groups at 1 month after RDN treatment compared to baseline(H-SBP/mmHg: BMRA 149.9 ± 10.59 vs. baseline 168.36 ± 12.76; 3DRA 152.6 ± 14.91 vs. 164.89 ± 12.96, both p < .05). The proportion of people with 24 h ambulatory SBP attainment was significantly higher in both groups and was maintained for 24 months. At each follow-up time point, there were no differences in home and 24-h flow SBP, DBP, or Scr between the two groups. There were two cases of severe renal artery complications from implanted vascular stents and one case of femoral artery pseudoaneurysm in the 3DRA group. At follow-up, 1 (1.9%) patient in the 3DRA group died of unexplained death and 1 (1.9%) patient developed heart failure, and 1 (1.9%) patient in the BMRA group died of unexplained death. Basket multi-electrode radiofrequency ablation and 3D reconstruction radiofrequency ablation of the renal artery applied to RDN have comparable efficacy in reducing systolic blood pressure.

Dapagliflozin and Blood Pressure in Patients with Chronic Kidney Disease and Albuminuria

BACKGROUND AND AIMS

Sodium-glucose cotransporter 2 inhibitors decrease blood pressure in patients with type 2 diabetes, but the consistency and magnitude of blood pressure lowering with dapagliflozin in patients with chronic kidney disease (CKD) is unknown. We conducted a prespecified analysis of the DAPA-CKD trial to investigate the effect of dapagliflozin on systolic blood pressure (SBP) in patients with CKD, with and without type 2 diabetes.

METHODS

A total of 4304 adults with baseline estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73m2 and urinary albumin-to-creatinine ratio (UACR) 200-5000 mg/g were randomized to either dapagliflozin 10 mg or placebo once daily; median follow-up was 2.4 years. The primary endpoint was a composite of sustained ≥50% eGFR decline, end-stage kidney disease, or death from a kidney or cardiovascular cause. Change in SBP was a prespecified outcome.

RESULTS

Baseline mean (SD) SBP was 137.1 mmHg (17.4). By Week 2, dapagliflozin compared to placebo reduced SBP by 3.6 mmHg (95% CI 2.8-4.4 mmHg), an effect maintained over the duration of the trial (2.9 mmHg, 2.3-3.6 mmHg). Time-averaged reductions in SBP were 3.2 mmHg (2.5-4.0 mmHg) in patients with diabetes and 2.3 mmHg (1.2-3.4 mmHg) in patients without diabetes. The time-averaged effect of dapagliflozin on diastolic blood pressure (DBP) was 1.0 mmHg (0.6-1.4 mmHg); 0.8 mmHg (0.4-1.3 mmHg) in patients with diabetes and 1.4 mmHg (0.7-2.1 mmHg) in patients without diabetes. Benefits of dapagliflozin on the primary composite and secondary endpoints were evident across the spectrum of baseline SBP and DBP.

CONCLUSION

In patients with CKD and albuminuria, randomization to dapagliflozin was associated with modest reductions in systolic and diastolic BP.

Unravelling the effect of renal denervation on glucose homeostasis: more questions than answers?

Renal Denervation (RDN) is an interventional, endovascular procedure used for the management of hypertension. The procedure itself aims to ablate the renal sympathetic nerves and to interrupt the renal sympathetic nervous system overactivation, thus decreasing blood pressure (BP) levels and total sympathetic drive in the body. Recent favorable evidence for RDN resulted in the procedure being included in the recent European Guidelines for the management of Hypertension, while RDN is considered the third pillar, along with pharmacotherapy, for managing hypertension. Sympathetic overactivation, however, is associated with numerous other pathologies, including diabetes, metabolic syndrome and glycemic control, which are linked to adverse cardiovascular health and outcomes. Therefore, RDN, via ameliorating sympathetic response, could be also proven beneficial for maintaining an euglycemic status in patients with cardiovascular disease, alongside its BP-lowering effects. Several studies have aimed, over the years, to provide evidence regarding the pathophysiological effects of RDN in glucose homeostasis as well as investigate the potential clinical benefits of the procedure in glucose and insulin homeostasis. The purpose of this review is, thus, to analyze the pathophysiological links between the autonomous nervous system and glycemic control, as well as provide an overview of the available preclinical and clinical data regarding the effect of RDN in glycemic control.

A systematic review, meta-analysis, and meta regression of the sham controlled renal denervation randomized controlled trials

Renal denervation (RD) has been investigated as a novel blood pressure (BP) lowering treatment for hypertension. The primary objective of this meta-analysis was to assess the efficacy of RD and factors that may associate with treatment effect heterogeneity. The primary outcomes were raw mean differences (RMD) in 24-hour ambulatory, daytime ambulatory, nighttime, and office systolic BP (SBP) and diastolic BP (DBP) between sham control and RD. A prespecified subgroup analysis was performed comparing studies with follow-up less than versus greater than 4 months. If inter-study heterogeneity was found for any of the above outcomes, additional analyses were performed to assess potential moderator variables. Ten sham-controlled randomized trials were identified and included 1,544 participants, followed for a mean of 4.20 months. RD was associated with a statistically significant reduction in all SBP and DBP measures except for nighttime SBP (-2.64 mmHg; 95% confidence interval (CI) -5.84 to 0.56, p = 0.11) and nighttime DBP (- 1.21 mmHg; 95% CI -3.17 to 0.75, p = 0.23). Mild to moderate inter-study heterogeneity was identified for three outcomes (office SBP and nighttime SBP and DBP). Studies that followed patients for longer than 4 months had numerically lower reductions in most BP outcomes; however, there were no statistically significant interactions between subgroups. Compared to a sham procedure, RD was associated with statistically significant reductions in most measures of SBP and DBP that were within bounds of what would be expected from standard blood pressure lowering medications.

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.

Effects of Renal Denervation on Sympathetic Nerve Traffic and Correlates in Drug-Resistant and Uncontrolled Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Whether and to what extent the reported blood pressure (BP) lowering effects of renal denervation (RDN) are associated with a central sympathoinhibition is controversial. We examined this issue by performing a meta-analysis of the microneurographic studies evaluating the BP and muscle sympathetic nerve activity (MSNA) responses to RDN in drug-resistant or uncontrolled hypertension (RHT).

METHODS

This analysis comprised 11 studies including a total of >400 RHT patients undergoing RDN and were followed up for 6 months. Evaluation was extended to the relationships of MSNA with clinic heart rate and BP changes associated with RDN.

RESULTS

MSNA showed a significant reduction after RDN (-4.78 bursts/100 heart beats; P<0.04), which was also accompanied by a significant systolic (-11.45 mm Hg; P<0.002) and diastolic (-5.24 mm Hg; P=0.0001) BP decrease. No significant quantitative relationship was found between MSNA and systolic (r=-0.96, P=0.19) or diastolic BP (r=-0.97, P=0.23) responses to RDN. This was also the case for clinic heart rate (r=0.53, P=0.78, respectively), whose post RDN values were not significant different from the pre-RDN ones. More than 10 renal nerves ablations were found to be needed for obtaining a significant sympathoinhibition.

CONCLUSIONS

This meta-analysis, the first ever done on the MSNA responses to RDN, shows that in a consistent number of RHT patients RDN is associated with a significant, although modest, central sympathoinhibition, which appears to be unrelated to the BP lowering effects of the procedure. Thus factors other than the central sympathetic outflow inhibition may concur at the BP lowering effects of RDN.

Effectiveness of renal denervation in the treatment of hypertension: a literature review

BACKGROUND

Catheter-based renal denervation has been studied as a potential therapeutic option to reduce high blood pressure (BP). Preclinical studies in some experimental models have demonstrated an antihypertensive effect of renal denervation but reports from clinical trials have been mixed METHODS: We performed a literature search using combinations of the key terms 'Cardiovascular diseases, Clinical trial, Pre-clinical trials, Resistant hypertension, Renal denervation, Ablation technique, Radiofrequency ablation, Ultrasound ablation, RADIANCE SOLO, SYMPLICITY HTN, SYPRAL HTN'. The databases searched were PubMed and OVID Medline.

RESULTS

The initial SYMPLICITY HTN-1 AND HTN-2 clinical trials reported significant decreases in office BP but results from the more robustly designed SYMPLICITY HTN-3 trial, which included sham controls and ambulatory BP monitoring, showed no significant antihypertensive effect. Interest in the use of renal denervation in hypertension was once again sparked by favourable results from the SPYRAL HTN-OFF Med trial CONCLUSION: We provide a thorough, critical analysis of key preclinical and clinical studies investigating the efficacy of catheter-based renal denervation as a treatment for hypertension and highlight future areas for research to allow better translation into clinical practice.

Successful treatment of refractory hypertension with bilateral nephrectomy in a patient with chronic kidney disease stage 3

We present a case of life-threatening refractory hypertension (rHTN) in a patient with stage 3b chronic kidney disease that was unresponsive to open surgical renal denervation (RDN) but responded to bilateral nephrectomy (BLN). Both RDN and BLN reduce the increased sympathetic activation in rHTN. However, RDN has yet to show reductions in blood pressure adequate for the average patient with rHTN, and BLN has thus far been reserved for patients with preexisting end-stage kidney disease (ESKD). Our case suggests that there are patients with rHTN that warrant consideration of BLN prior to developing ESKD.

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.

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.

Pacemaker-Based Cardiac Neuromodulation Therapy in Patients With Hypertension: A Pilot Study

Background In prior unblinded studies, cardiac neuromodulation therapy (CNT) employing a sequence of variably timed short and longer atrioventricular intervals yielded sustained reductions of systolic blood pressure (SBP) in patients with hypertension. The effects of CNT on SBP were investigated in this double-blind randomized pilot study. Methods and Results Eligible patients had daytime ambulatory SBP (aSBP) ≥130 mm Hg and office SBP ≥140 mm Hg despite taking ≥1 antihypertensive medication, and an indication for a dual-chamber pacemaker. Patients underwent Moderato device implantation, which was programmed as a standard pacemaker during a 1-month run-in phase. Patients whose daytime aSBP was ≥125 mm Hg at the end of this period were randomized (1:1, double blind) to treatment (CNT) or control (CNT inactive). The primary efficacy end point was the between-group difference of the change in 24-hour aSBP at 6 months. Of 68 patients initially enrolled and who underwent implantation with the Moderato system, 47 met criteria for study continuation and were randomized (26 treatment, 21 control). The mean age was 74.0±8.7 years, 64% were men, left ventricular ejection fraction was 59.2%±5.7%, and aSBP averaged 141.0±10.8 mm Hg despite the use of 3.3±1.5 antihypertensive medications; 81% had isolated systolic hypertension. Six months after randomization, aSBP was 11.1±10.5 mm Hg (95% CI, -15.2 to -8.1 mm Hg) lower than prerandomization in the treatment group compared with 3.1±9.5 mm Hg (-7.4 to 1.2 mm Hg) lower in controls, yielding a net treatment effect of 8.1±10.1 mm Hg (-14.2 to -1.9 mm Hg) (P=0.012). There were no Moderato device- or CNT-related adverse events. Conclusions CNT significantly reduced 24-hour aSBP in patients with hypertension with a clinical indication for a pacemaker. The majority of patients had isolated systolic hypertension, a particularly difficult group of patients to treat. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02837445.

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.

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.

Kidney function and markers of renal damage after renal denervation. Does method of measurement matter? The Reshape CV-Risk Study

Data suggest that renal denervation (RDN) in treatment‐resistant hypertension (TRHT) is safe in terms of renal function. However, most studies report kidney function as creatinine‐based estimated glomerular filtration rate (eGFR), which may be biased by non‐renal factors. Damage markers other than albuminuria have never been evaluated after RDN. In this non‐randomized RDN trial, we studied changes in kidney function, assessed as measured GFR (mGFR) and various GFR estimates, six months and two years after RDN. We also examined changes in albuminuria and a biomarker of tubular dysfunction. Adult non‐diabetic patients with TRHT and eGFR ≥45 ml/min/1.73 m² were recruited from hypertension clinics. Before bilateral RDN, mGFR was measured by iohexol clearance. We estimated eGFR from serum creatinine and cystatin C (eGFR_crea, eGFR_cys, and eGFR_creacys), and albumin‐creatinine ratio (ACR) and N‐acetyl‐β‐D‐glucosaminidase (NAG)‐creatinine ratio (NAG‐CR) were measured in spot urines. All measurements were repeated after six and twenty‐four months.

Twenty patients, mean age 54 (±9) years and baseline mGFR 83 (±20) ml/min/1.73 m² underwent RDN. After six months, mGFR fell, eGFR_crea remained unchanged, whereas eGFR_cys and eGFR_creacys increased. At 2 years’ follow‐up, eGFR_creacys was significantly lower than at baseline. mGFR was 78 (±28) ml/min/1.73 m². Change in ambulatory systolic BP predicted change in eGFR_crea. Urinary NAG‐CR, but not ACR, increased during follow‐up.

Different GFR assessments gave diverging results after RDN. Therefore, care should be taken to method when evaluating kidney function after RDN. Increases in a tubular dysfunction biomarker suggest that kidney damage may occur. Long‐term renal follow‐up is needed after RDN.

How Do I Manage Hypertension in Patients with Advanced Chronic Kidney Disease Not on Dialysis? Perspectives from Clinical Practice

In the general population, the prevalence of moderate and severe chronic kidney disease (CKD) is usually below 5% but this figure is often higher in specific groups of patients such as those with type 2 diabetes. Patients with advanced CKD (CKD stage 3b and 4) are at high or very high cardiovascular risk, and their risk of progressing towards end-stage kidney disease (CKD stage 5) and the need of renal replacement therapy are elevated. Hypertension is a major cause of poor cardiovascular and renal outcomes in severe CKD. Therefore, an adequate control of blood pressure (BP) is mandatory. However, normalizing BP is often challenging in these patients because the clinical management of hypertension in advanced CKD is not well defined and rarely supported by large randomized controlled trials. In the present review, we discuss the characteristics of hypertension in advanced CKD, excluding dialysis, and its management integrating data from recent clinical studies and a pragmatic approach enriched by a long-standing clinical experience.

Recent advances in managing primary hypertension

Hypertension remains a leading risk factor for cardiovascular mortality and morbidity globally despite the availability of effective and well-tolerated antihypertensive medications. Accumulating evidence suggests a more aggressive blood pressure regulation aimed at lower targets, particularly for selected patient groups. Our concepts of the optimal method for blood pressure measurement have radically changed, maintaining appropriate standard office measurements for initial assessment but relying on out-of-office measurement to better guide our decisions. Thorough risk stratification provides guidance in decision making; however, an individualized approach is highly recommended to prevent overtreatment. Undertreatment, on the other hand, remains a major concern and is mainly attributed to poor adherence and resistant or difficult-to-control forms of the disease. This review aims to present modern perspectives, novel treatment options, including innovative technological applications and developing interventional and pharmaceutical therapies, and the major concerns emerging from several years of research and epidemiological observations related to hypertension management.

A Pilot Study of Perioperative External Circumferential Cryoablation of Human Renal Arteries for Sympathetic Denervation

Purpose

Cryoablation, which induces cellular death without extensive tissue damage, has been extensively used to denervate the myocardium. However, periadventitial external circumferential application of cryotherapy to denervate the renal artery sympathetic nerves has, to our knowledge, never been tested in humans. The main aim of this study was to examine the safety and potential effects of cryotherapy on ambulatory blood pressure levels and other outcomes that are indirectly related to sympathetic tone, including pulse-wave velocity, central pulse pressure, and glucose levels.

Materials and Methods

Five patients who underwent the denervation of the renal arteries during open surgery of the abdominal aortic aneurysm and four controls who did not undergo denervation during the surgery were enrolled. An argon-powered cryotherapy catheter (Cardioblate; Medtronic Inc., USA) was applied periadventitially to each renal artery in the five patients and then activated by infusion with liquid nitrogen for 1 minute.

Results

No cryoablation-related complications occurred in the five consecutive patients. Their ambulatory blood pressures 3 to 5 months after surgery did not demonstrate any general blood pressure-reducing effects, but two patients responded favorably with the reduction of antihypertensive medication and decreased 24-hour blood pressure. The patients’ mean HbA1C levels decreased from 5.9±0.78% to 5.6±0.71% (P=0.042).

Conclusion

This pilot study suggests that periadventitial cryoablation during open surgery can be used in the study of renal denervation in humans, as it had no complications in five patients in this study. The effectiveness of cryoablation for treating hypertension should be proven in a phase II clinical trial.

Resistant Hypertension in Chronic Kidney Disease (CKD): Prevalence, Treatment Particularities, and Research Agenda

PURPOSE OF REVIEW

To explore the prevalence, treatment particularities, and research agenda in the management of resistant hypertension among patients with chronic kidney disease (CKD).

RECENT FINDINGS

The prevalence of resistant hypertension is reported to be 2-3 times higher in patients with CKD than in the general hypertensive population. Based in part on the results of the PATHWAY-2 trial showing add-on spironolactone to be superior to placebo or active treatment with an α- or β-blocker in reducing BP, international guidelines recommend the use of spironolactone as fourth-line agent in pharmacotherapy of resistant hypertension. Despite the several-fold higher burden of resistant hypertension among patients with stage 3b-4 CKD, the use of spironolactone in this population has been restricted, mainly due to the risk of hyperkalemia. The recently reported AMBER trial showed that among patients with uncontrolled resistant hypertension and an estimated glomerular filtration rate of 25-45 ml/min/1.73m², the newer potassium-binder patiromer prevented the development of hyperkalemia and increased the proportion of participants who remained on add-on spironolactone over 12 weeks of follow-up. Administration of spironolactone was associated with a clinically meaningful reduction of 11-12 mmHg in unattended automated office systolic blood pressure (BP) over the course of the AMBER trial. Newer potassium-binding therapies overcome the barrier of hyperkalemia and facilitate the persistent use of spironolactone, which is an effective add-on therapy to control BP in patients with resistant hypertension and advanced CKD. Future trials are now warranted to explore whether this strategy confers benefits on "hard" clinical outcomes in this high-risk population.

Renal denervation: can we press the "ON" button again in 2020?

In December 2018, an article summarizing available results of randomized studies on renal denervation (RDN), entitled "Renal denervation: can we press the ON button again?" was published in the Advances in Interventional Cardiology. Since then, several positive reports, including SPYRAL HTN OFF-MED Pivotal trial have been presented. In the current review the authors discuss the latest data on RDN in arterial hypertension treatment and try to answer the burning question: can we press the ON button again in 2020? The results of recently published studies potentially justify new recommendations for the use of RDN in clinical practice in appropriately selected patients in the new hypertension guidelines. The current review also summarizes the results of trials on RDN applied in another potential indication - atrial fibrillation. Six most important, prospective, randomized trials assessing RDN as adjunct therapy to pulmonary vein isolation for treatment of atrial fibrillation were discussed. In 5 studies, patients had uncontrolled BP despite treatment with three antihypertensive agents. The ratio for recurrence of atrial fibrillation for pulmonary vein isolation with RDN procedure was reduced by 57% as compared to pulmonary vein isolation (PVI) alone. BP was also reduced significantly after RDN in this subset of patients. Further multicenter studies involving standardized PVI and RDN procedures are needed.