Renal Denervation for the Treatment of Hypertension: Making a New Start, Getting It Right

Patient-Level Pooled Analysis of Ultrasound Renal Denervation in the Sham-Controlled RADIANCE II, RADIANCE-HTN SOLO, and RADIANCE-HTN TRIO Trials

Importance

Ultrasound renal denervation (uRDN) was shown to lower blood pressure (BP) in patients with uncontrolled hypertension (HTN). Establishing the magnitude and consistency of the uRDN effect across the HTN spectrum is clinically important.

Objective

To characterize the effectiveness and safety of uRDN vs a sham procedure from individual patient-level pooled data across uRDN trials including either patients with mild to moderate HTN on a background of no medications or with HTN resistant to standardized triple-combination therapy.

Data Sources

A Study of the ReCor Medical Paradise System in Clinical Hypertension (RADIANCE-HTN SOLO and TRIO) and A Study of the ReCor Medical Paradise System in Stage II Hypertension (RADIANCE II) trials.

Study Selection

Trials with similar designs, standardized operational implementation (medication standardization and blinding of both patients and physicians to treatment assignment), and follow-up.

Data Extraction and Synthesis

Pooled analysis using individual patient-level data using linear regression models to compare uRDN with sham across the trials.

Main Outcomes and Measures

The primary outcome was baseline-adjusted change in 2-month daytime ambulatory systolic BP (dASBP) between groups.

Results

A total of 506 patients were randomized in the 3 studies (uRDN, 293; sham, 213; mean [SD] age, 54.1 [9.3]; 354 male [70.0%]). After a 1-month medication stabilization period, dASBP was similar between the groups (mean [SD], uRDN, 150.3 [9.2] mm Hg; sham, 150.8 [10.5] mm Hg). At 2 months, dASBP decreased by 8.5 mm Hg to mean (SD) 141.8 (13.8) mm Hg among patients treated with uRDN and by 2.9 mm Hg to 147.9 (14.6) mm Hg among patients treated with a sham procedure (mean difference, -5.9; 95% CI, -8.1 to -3.8 mm Hg; P < .001 in favor of uRDN). BP decreases from baseline with uRDN vs sham were consistent across trials and across BP parameters (office SBP: -10.4 mm Hg vs -3.4 mm Hg; mean difference, -6.4 mm Hg; 95% CI, -9.1 to -3.6 mm Hg; home SBP: -8.4 mm Hg vs -1.4 mm Hg; mean difference, -6.8 mm Hg; 95% CI, -8.7 to -4.9 mm Hg, respectively). The BP reductions with uRDN vs sham were consistent across prespecified subgroups. Independent predictors of a larger BP response to uRDN were higher baseline BP and heart rate and the presence of orthostatic hypertension. No differences in early safety end points were observed between groups.

Conclusions and Relevance

Results of this patient-level pooled analysis suggest that BP reductions with uRDN were consistent across HTN severity in sham-controlled trials designed with a 2-month primary end point to standardize medications across randomized groups.

Trial Registration

ClinicalTrials.gov Identifier: NCT02649426 and NCT03614260.

Impact of drug adherence on blood pressure response to alcohol-mediated renal denervation

PURPOSE

While poor drug adherence is frequent in patients with resistant hypertension, detailed analyses of the impact of drug adherence on the success of renal denervation are scarce. We report drug adherence at baseline, changes in drug adherence, and the influence of these parameters on blood pressure changes at 6 and 12 months in patients treated with alcohol-mediated renal denervation as part of the Peregrine study.

MATERIALS AND METHODS

Urinary detection of antihypertensive drugs was performed using high-performance liquid chromatography-tandem mass spectrometry. Full adherence, partial adherence, and complete non-adherence were defined as 0, 1, or ≥2 drugs not detected, respectively.

RESULTS

Renal denervation was performed in 45 patients with uncontrolled hypertension on ≥3 antihypertensive medications (62% men, age 55 ± 10 years). At baseline, the proportion of fully, partially, and non-adherent patients was 62% (n = 28), 16% (n = 7), and 22% (n = 10), respectively. At 6 months, adherence improved by 21% (n = 9), remained unchanged at 49% (n = 21), and worsened by 30% (n = 13). Mean 24-h systolic blood pressure decreased by 10 ± 13, 10 ± 4, and 14 ± 19 mmHg in fully, partially, and non-adherent patients (p = 0.77), and by 14 ± 14, 8 ± 11, and 14 ± 18 mmHg in patients who improved, maintained, or decreased adherence, respectively (p = 0.35). The results at 12 months were similar.

CONCLUSION

About 40% of patients with apparently treatment-resistant hypertension were not fully adherent at baseline, and adherence decreased further in 30%. Nevertheless, mean blood pressure changes after renal denervation were similar irrespective of drug adherence. Our results suggest that such patients may benefit from alcohol-mediated renal denervation, irrespective of drug adherence. These findings are hypothesis-generating and need to be confirmed in ongoing sham-controlled trials.

Renal sympathetic denervation for resistant hypertension: where do we stand after more than a decade

Despite the current availability of safe and efficient drugs for treating hypertension, a substantial number of patients are drug-resistant hypertensives. Aiming this condition, a relatively new approach named catheter-based renal denervation was developed. We have now a clinically relevant time window to review the efficacy of renal denervation for treating this form of hypertension. This short review addresses the physiological contribution of renal sympathetic nerves for blood pressure control and discusses the pros and cons of renal denervation procedure for the treatment of resistant hypertension.

Six-Month Results of Treatment-Blinded Medication Titration for Hypertension Control After Randomization to Endovascular Ultrasound Renal Denervation or a Sham Procedure in the RADIANCE-HTN SOLO Trial

BACKGROUND

The multicenter, international, randomized, blinded, sham-controlled RADIANCE-HTN SOLO trial (A Study of the ReCor Medical Paradise System in Clinical Hypertension) demonstrated a 6.3 mm Hg greater reduction in daytime ambulatory systolic blood pressure (BP) at 2 months by endovascular ultrasound renal denervation (RDN) compared with a sham procedure among patients not treated with antihypertensive medications. We report 6-month results after the addition of a recommended standardized stepped-care antihypertensive treatment to the randomized endovascular procedure under continued blinding to initial treatment.

METHODS

Patients with a daytime ambulatory BP ≥135/85 mm Hg and <170/105 mm Hg after a 4-week discontinuation of up to 2 antihypertensive medications, and a suitable renal artery anatomy, were randomized to RDN (n=74) or sham (n=72). Patients were to remain off antihypertensive medications throughout the first 2 months of follow-up unless safety BP criteria were exceeded. Between 2 and 5 months, if monthly measured home BP was ≥135/85 mm Hg, a standardized stepped-care antihypertensive treatment was recommended consisting of the sequential addition of amlodipine (5 mg/d), a standard dose of an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and hydrochlorothiazide (12.5 mg/d), followed by the sequential uptitration of hydrochlorothiazide (25 mg/d) and amlodipine (10 mg/d). Outcomes included the 6-month (1) change in daytime ambulatory systolic BP adjusted for medications and baseline systolic BP, (2) medication burden, and (3) safety.

RESULTS

A total of 69/74 RDN patients and 71/72 sham patients completed the 6-month ambulatory BP measurement. At 6 months, 65.2% of patients in the RDN group were treated with the standardized stepped-care antihypertensive treatment versus 84.5% in the sham group (P=0.008), and the average number of antihypertensive medications and defined daily dose were less in the RDN group than in the sham group (0.9±0.9 versus 1.3±0.9, P=0.010 and 1.4±1.5 versus 2.0±1.8, P=0.018; respectively). Despite less intensive standardized stepped-care antihypertensive treatment, RDN reduced daytime ambulatory systolic BP to a greater extent than sham (-18.1±12.2 versus -15.6±13.2 mm Hg, respectively; difference adjusted for baseline BP and number of medications: -4.3 mm Hg, 95% confidence interval, -7.9 to -0.6, P=0.024). There were no major adverse events in either group through 6 months.

CONCLUSIONS

The BP-lowering effect of endovascular ultrasound RDN was maintained at 6 months with less prescribed antihypertensive medications compared with a sham control.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT02649426.

Mineralocorticoid Receptor Antagonists in Essential and Resistant Hypertension

Background:

Mineralocorticoid receptor antagonists are a second-line class of antihypertensive drugs, which have been accounted for as the optimal add-on therapy in the triple algorithm for the management of resistant hypertension.

Objectives:

To assess the effects of mineralocorticoid receptor antagonists in the treatment of patients with essential hypertension and resistant hypertension.

Method:

We conducted a meticulous review of the literature and comprehensive identification of the clinical trials assessing the efficacy of mineralocorticoid receptor antagonists in individuals with primary and resistant hypertension.

Results:

MRAs have been thoroughly tested in several clinical studies in relevance to blood pressure lowering effects, over the last six decades. Accumulating data observed that MRAs resulted in a significant reduction in blood pressure level in patients with resistant hypertension. In addition, spironolactone was found to beneficially affect the management of resistant hypertension.

Conclusion:

Mineralocorticoid receptor antagonists exert a significant antihypertensive effect. Future welldesigned randomized controlled studies are greatly needed to address crucial clinical aspects in the field.

Effect of renal denervation on blood pressure in the presence of antihypertensive drugs: 6-month efficacy and safety results from the SPYRAL HTN-ON MED proof-of-concept randomised trial

BACKGROUND

Previous catheter-based renal denervation studies have reported variable efficacy results. We aimed to evaluate safety and blood pressure response after renal denervation or sham control in patients with uncontrolled hypertension on antihypertensive medications with drug adherence testing.

METHODS

In this international, randomised, single-blind, sham-control, proof-of-concept trial, patients with uncontrolled hypertension (aged 20-80 years) were enrolled at 25 centres in the USA, Germany, Japan, UK, Australia, Austria, and Greece. Eligible patients had an office systolic blood pressure of between 150 mm Hg and 180 mm Hg and a diastolic blood pressure of 90 mm Hg or higher; a 24 h ambulatory systolic blood pressure of between 140 mm Hg and 170 mm Hg at second screening; and were on one to three antihypertensive drugs with stable doses for at least 6 weeks. Patients underwent renal angiography and were randomly assigned to undergo renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were masked to randomisation assignments. The primary efficacy endpoint was blood pressure change from baseline (measured at screening visit two), based on ambulatory blood pressure measurements assessed at 6 months, as compared between treatment groups. Drug surveillance was used to assess medication adherence. The primary analysis was done in the intention-to-treat population. Safety events were assessed through 6 months as per major adverse events. This trial is registered with ClinicalTrials.gov, number NCT02439775, and follow-up is ongoing.

FINDINGS

Between July 22, 2015, and June 14, 2017, 467 patients were screened and enrolled. This analysis presents results for the first 80 patients randomly assigned to renal denervation (n=38) and sham control (n=42). Office and 24 h ambulatory blood pressure decreased significantly from baseline to 6 months in the renal denervation group (mean baseline-adjusted treatment differences in 24 h systolic blood pressure -7·0 mm Hg, 95% CI -12·0 to -2·1; p=0·0059, 24 h diastolic blood pressure -4·3 mm Hg, -7·8 to -0·8; p=0.0174, office systolic blood pressure -6·6 mm Hg, -12·4 to -0·9; p=0·0250, and office diastolic blood pressure -4·2 mm Hg, -7·7 to -0·7; p=0·0190). The change in blood pressure was significantly greater at 6 months in the renal denervation group than the sham-control group for office systolic blood pressure (difference -6·8 mm Hg, 95% CI -12·5 to -1·1; p=0·0205), 24 h systolic blood pressure (difference -7·4 mm Hg, -12·5 to -2·3; p=0·0051), office diastolic blood pressure (difference -3·5 mm Hg, -7·0 to -0·0; p=0·0478), and 24 h diastolic blood pressure (difference -4·1 mm Hg, -7·8 to -0·4; p=0·0292). Evaluation of hourly changes in 24 h systolic blood pressure and diastolic blood pressure showed blood pressure reduction throughout 24 h for the renal denervation group. 3 month blood pressure reductions were not significantly different between groups. Medication adherence was about 60% and varied for individual patients throughout the study. No major adverse events were recorded in either group.

INTERPRETATION

Renal denervation in the main renal arteries and branches significantly reduced blood pressure compared with sham control with no major safety events. Incomplete medication adherence was common.

FUNDING

Medtronic.

Endovascular ultrasound renal denervation to treat hypertension (RADIANCE-HTN SOLO): a multicentre, international, single-blind, randomised, sham-controlled trial

BACKGROUND

Early studies suggest that radiofrequency-based renal denervation reduces blood pressure in patients with moderate hypertension. We investigated whether an alternative technology using endovascular ultrasound renal denervation reduces ambulatory blood pressure in patients with hypertension in the absence of antihypertensive medications.

METHODS

RADIANCE-HTN SOLO was a multicentre, international, single-blind, randomised, sham-controlled trial done at 21 centres in the USA and 18 in Europe. Patients with combined systolic-diastolic hypertension aged 18-75 years were eligible if they had ambulatory blood pressure greater than or equal to 135/85 mm Hg and less than 170/105 mm Hg after a 4-week discontinuation of up to two antihypertensive medications and had suitable renal artery anatomy. Patients were randomised (1:1) to undergo renal denervation with the Paradise system (ReCor Medical, Palo Alto, CA, USA) or a sham procedure consisting of renal angiography only. The randomisation sequence was computer generated and stratified by centres with randomised blocks of four or six and permutation of treatments within each block. Patients and outcome assessors were blinded to randomisation. The primary effectiveness endpoint was the change in daytime ambulatory systolic blood pressure at 2 months in the intention-to-treat population. Patients were to remain off antihypertensive medications throughout the 2 months of follow-up unless specified blood pressure criteria were exceeded. Major adverse events included all-cause mortality, renal failure, an embolic event with end-organ damage, renal artery or other major vascular complications requiring intervention, or admission to hospital for hypertensive crisis within 30 days and new renal artery stenosis within 6 months. This study is registered with ClinicalTrials.gov, number NCT02649426.

FINDINGS

Between March 28, 2016, and Dec 28, 2017, 803 patients were screened for eligibility and 146 were randomised to undergo renal denervation (n=74) or a sham procedure (n=72). The reduction in daytime ambulatory systolic blood pressure was greater with renal denervation (-8·5 mm Hg, SD 9·3) than with the sham procedure (-2·2 mm Hg, SD 10·0; baseline-adjusted difference between groups: -6·3 mm Hg, 95% CI -9·4 to -3·1, p=0·0001). No major adverse events were reported in either group.

INTERPRETATION

Compared with a sham procedure, endovascular ultrasound renal denervation reduced ambulatory blood pressure at 2 months in patients with combined systolic-diastolic hypertension in the absence of medications.

FUNDING

ReCor Medical.

A multinational clinical approach to assessing the effectiveness of catheter-based ultrasound renal denervation: The RADIANCE-HTN and REQUIRE clinical study designs

Catheter-based renal denervation is a new approach to treat hypertension via modulation of the renal sympathetic nerves. Although nonrandomized and small, open-label randomized studies resulted in significant reductions in office blood pressure 6months after renal denervation with monopolar radiofrequency catheters, the first prospective, randomized, sham-controlled study (Symplicity HTN-3) failed to meet its blood pressure efficacy end point. New clinical trials with new catheters have since been designed to address the limitations of earlier studies. Accordingly, the RADIANCE-HTN and REQUIRE studies are multicenter, blinded, randomized, sham-controlled trials designed to assess the blood pressure-lowering efficacy of the ultrasound-based renal denervation system (Paradise) in patients with established hypertension either on or off antihypertensive medications, is designed to evaluate patients in 2 cohorts-SOLO and TRIO, in the United States and Europe. The SOLO cohort includes patients with essential hypertension, at low cardiovascular risk, and either controlled on 1 to 2 antihypertensive medications or uncontrolled on 0 to 2 antihypertensive medications. Patients undergo a 4-week medication washout period before randomization to renal denervation (treatment) or renal angiogram (sham). The TRIO cohort includes patients with hypertension resistant to at least 3 antihypertensive drugs including a diuretic. Patients will be stabilized on a single-pill, triple-antihypertensive-drug combination for 4weeks before randomization to treatment or sham. Reduction in daytime ambulatory systolic blood pressure (primary end point) will be assessed at 2months in both cohorts. A predefined medication escalation protocol, as needed for blood pressure control, is implemented between 2 and 6months in both cohorts by a study staff member blinded to the randomization process. At 6months, daytime ambulatory blood pressure and antihypertensive treatment score will be assessed. REQUIRE is designed to evaluate patients with resistant hypertension on standard of care medication in Japan and Korea. Reduction in 24-hour ambulatory systolic blood pressure will be assessed at 3months (primary end point). Both studies are enrolling patients, and their results are expected in 2018.

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

BACKGROUND

Previous randomised renal denervation studies did not show consistent efficacy in reducing blood pressure. The objective of our study was to evaluate the effect of renal denervation on blood pressure in the absence of antihypertensive medications.

METHODS

SPYRAL HTN-OFF MED was a multicentre, international, single-blind, randomised, sham-controlled, proof-of-concept trial. Patients were enrolled at 21 centres in the USA, Europe, Japan, and Australia. Eligible patients were drug-naive or discontinued their antihypertensive medications. Patients with an office systolic blood pressure (SBP) of 150 mm Hg or greater and less than 180 mm Hg, office diastolic blood pressure (DBP) of 90 mm Hg or greater, and a mean 24-h ambulatory SBP of 140 mm Hg or greater and less than 170 mm Hg at second screening underwent renal angiography and were randomly assigned to renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were blinded to randomisation assignments. The primary endpoint, change in 24-h blood pressure at 3 months, was compared between groups. Drug surveillance was done to ensure patient compliance with absence of antihypertensive medication. The primary analysis was done in the intention-to-treat population. Safety events were assessed at 3 months. This study is registered with ClinicalTrials.gov, number NCT02439749.

FINDINGS

Between June 25, 2015, and Jan 30, 2017, 353 patients were screened. 80 patients were randomly assigned to renal denervation (n=38) or sham control (n=42) and followed up for 3 months. Office and 24-h ambulatory blood pressure decreased significantly from baseline to 3 months in the renal denervation group: 24-h SBP -5·5 mm Hg (95% CI -9·1 to -2·0; p=0·0031), 24-h DBP -4·8 mm Hg (-7·0 to -2·6; p<0·0001), office SBP -10·0 mm Hg (-15·1 to -4·9; p=0·0004), and office DBP -5·3 mm Hg (-7·8 to -2·7; p=0·0002). No significant changes were seen in the sham-control group: 24-h SBP -0·5 mm Hg (95% CI -3·9 to 2·9; p=0·7644), 24-h DBP -0·4 mm Hg (-2·2 to 1·4; p=0·6448), office SBP -2·3 mm Hg (-6·1 to 1·6; p=0·2381), and office DBP -0·3 mm Hg (-2·9 to 2·2; p=0·8052). The mean difference between the groups favoured renal denervation for 3-month change in both office and 24-h blood pressure from baseline: 24-h SBP -5·0 mm Hg (95% CI -9·9 to -0·2; p=0·0414), 24-h DBP -4·4 mm Hg (-7·2 to -1·6; p=0·0024), office SBP -7·7 mm Hg (-14·0 to -1·5; p=0·0155), and office DBP -4·9 mm Hg (-8·5 to -1·4; p=0·0077). Baseline-adjusted analyses showed similar findings. There were no major adverse events in either group.

INTERPRETATION

Results from SPYRAL HTN-OFF MED provide biological proof of principle for the blood-pressure-lowering efficacy of renal denervation.

FUNDING

Medtronic.

Interventional procedures and future drug therapy for hypertension

Hypertension management poses a major challenge to clinicians globally once non-drug (lifestyle) measures have failed to control blood pressure (BP). Although drug treatment strategies to lower BP are well described, poor control rates of hypertension, even in the first world, suggest that more needs to be done to surmount the problem. A major issue is non-adherence to antihypertensive drugs, which is caused in part by drug intolerance due to side effects. More effective antihypertensive drugs are therefore required which have excellent tolerability and safety profiles in addition to being efficacious. For those patients who either do not tolerate or wish to take medication for hypertension or in whom BP control is not attained despite multiple antihypertensives, a novel class of interventional procedures to manage hypertension has emerged. While most of these target various aspects of the sympathetic nervous system regulation of BP, an additional procedure is now available, which addresses mechanical aspects of the circulation. Most of these new devices are supported by early and encouraging evidence for both safety and efficacy, although it is clear that more rigorous randomized controlled trial data will be essential before any of the technologies can be adopted as a standard of care.

Renal denervation in hypertensive patients not on blood pressure lowering drugs

Introduction

Studies on the blood pressure lowering effect of renal denervation (RDN) in resistant hypertensive patients have produced conflicting results. Change in medication usage during the studies may be responsible for this inconsistency. To eliminate the effect of medication usage on blood pressure we focused on unmedicated hypertensive patients who underwent RDN.

Methods and results

Our study reports on a cohort of patients, who were not on blood pressure lowering drugs at baseline and during follow-up, from eight tertiary centers. Data of patients were used when they were treated with RDN and had a baseline office systolic blood pressure (SBP) ≥140 mmHg and/or 24-h ambulatory SBP ≥130 mmHg. Our primary outcome was defined as change in office and 24-h SBP at 12 months after RDN, compared to baseline. Fifty-three patients were included. There were three different reasons for not using blood pressure lowering drugs: (1) documented intolerance or allergic reaction (57 %); (2) temporary cessation of medication for study purposes (28 %); and (3) reluctance to take antihypertensive drugs (15 %). Mean change in 24-h SBP was −5.7 mmHg [95 % confidence interval (CI) −11.0 to −0.4; p = 0.04]. Mean change in office SBP was −13.1 mmHg (95 % CI −20.4 to −5.7; p = 0.001). No changes were observed in other variables, such as eGFR, body–mass-index and urinary sodium excretion.

Conclusion

This explorative study in hypertensive patients, who are not on blood pressure lowering drugs, suggests that at least in some patients RDN lowers blood pressure.

Electronic supplementary material

The online version of this article (doi:10.1007/s00392-016-0984-y) contains supplementary material, which is available to authorized users.