Results of a randomized controlled pilot trial of intravascular renal denervation for management of treatment-resistant hypertension

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.

Quality of life following renal sympathetic denervation in treatment-resistant hypertensive patients: a two-year follow-up study

Objective. Hypertension is a significant health burden. In the last 10 years, renal sympathetic denervation has been tested as a potential treatment option for a select group of patients with treatment-resistant hypertension. The aim of this study was to broadly assess the quality of life in patients undergoing renal sympathetic denervation with two years' follow-up. Materials and methods. Patients with treatment-resistant hypertension being treated by hypertension specialists were eligible for inclusion in this study. Bilateral renal sympathetic denervation was performed with the Symplicity Catheter System. Quality of life was measured using standardised questionnaires (Short Form 36, 15 D and a single-item question) and an open question before denervation, after six months and after two years. Results. A total of 23 patients were included. The typical participant was male, 53 years, had a mean office blood pressure of 162/108 mmHg, body mass index of 32 kg/m², and was prescribed 4.8 blood pressure lowering drug classes. At baseline, both physical and mental aspects of quality of life were affected negatively by the treatment-resistant hypertension. Over time, there were modest improvements in quality of life. The largest improvements were seen at six months. Simultaneously, the mean number of blood pressure lowering drug classes was reduced to 4.2. Conclusion. Following renal sympathetic denervation treatment, some aspects of health related quality of life showed an improved trend during follow-up. The observed improvement may reflect the impact of a reduced number of blood pressure lowering drug classes. Clinical Trial Number registered: NCT01630928.

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 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 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.

New data, new studies, new hopes for renal denervation in patients with uncontrolled hypertension

Background

following the publication of SYMPLICITY HTN-3 the field of renal of denervation was put on hold. Although SYMPLICITY HTN-3 was well-designed and sham-controlled trial it failed to show any meaningful reduction in office or 24 h ambulatory blood pressure. The procedure was however safe and allowed research to continue. Although several pitfalls of the study have been pointed out, incomplete renal denervation was also implicated. Since then, a great deal of basic and clinical research took place and will be briefly commented on in this article.

Methods and results

Before and after SYMPLICITY-HTN-3, numerous uncontrolled, single or unblinded studies have shown substantial office BP reduction ranging from -7.7 to -32 mmHg and ambulatory BP ranging from -2.2 to 10.2 mmHg. Average weighted office systolic BP reduction was -20.8 mmHg and weighted average 24 h ambulatory BPM reduction was -7.8 mmHg. National and international registries have shown similar BP reductions, but results remained unconvincing due to lack of reliable sham controls. In recent years, 5 well-designed sham - controlled studies (beyond, SYMPLICITY-HTN-3) have been published. Of those studies two were single center and three were multicenter international studies. Four studies used single tip or multi-electrode, radiofrequency catheters and one used focused ultrasound. The three multicenter studies reported positive-placebo subtracted results and established BP reductions measured both in the office and by ambulatory monitoring. No serious adverse events were reported.

Conclusions

It can therefore be concluded that the latest sham controlled studies established efficacy and safety of renal denervation.

Effect of Catheter-Based Renal Denervation on Uncontrolled Hypertension: A Systematic Review and Meta-analysis

OBJECTIVE

To assess the efficacy and safety of catheter-based renal denervation (RDN) for the treatment of uncontrolled hypertension by conducting a systematic review and a meta-analysis.

METHODS

The Medline, Cochrane Library, and Embase databases were searched for clinical studies between January 1, 2009, and July 16, 2018. Studies that evaluated the effect of RDN on uncontrolled hypertension were identified. The primary endpoints were changes in 24-hour ambulatory systolic blood pressure (BP) and office systolic BP. The secondary endpoints included changes in 24-hour ambulatory diastolic BP, office diastolic BP, and major adverse events.

RESULTS

After a literature search and detailed evaluation, 12 randomized controlled trials with a total of 1539 individuals were included in the quantitative analysis. Pooled analyses indicated that RDN was associated with a significantly greater reduction of 24-hour systolic BP (mean difference [MD], -4.02 mm Hg; 95% CI, -5.49 to -2.56; P<.001) and office systolic BP (MD, -8.93 mm Hg; 95% CI, -14.03 to -3.83; P<.001) than controls. Similarly, RDN significantly reduced 24-hour diastolic BP (MD, -2.05 mm Hg; 95% CI, -3.05 to -1.05; P<.001) and office diastolic BP (MD, -4.49 mm Hg; 95% CI, -6.46 to -2.52; P<.001). RDN was not associated with an increased risk of major adverse events (relative risk, 1.06; 95% CI, 0.72 to 1.57; P=.76).

CONCLUSIONS

Catheter-based RDN was associated with a significant BP-lowering benefit without increasing major adverse events.

Joint UK societies' 2019 consensus statement on renal denervation

Improved and durable control of hypertension is a global priority for healthcare providers and policymakers. There are several lifestyle measures that are proven to result in improved blood pressure (BP) control. Moreover, there is incontrovertible evidence from large scale randomised controlled trials (RCTs) that antihypertensive drugs lower BP safely and effectively in the long-term resulting in substantial reduction in cardiovascular morbidity and mortality. Importantly, however, evidence is accumulating to suggest that patients neither sustain long-term healthy behaviours nor adhere to lifelong drug treatment regimens and thus alternative measures to control hypertension warrant further investigation. Endovascular renal denervation (RDN) appears to hold some promise as a non-pharmacological approach to lowering BP and achieves renal sympathectomy using either radiofrequency energy or ultrasound-based approaches. This treatment modality has been evaluated in clinical trials in humans since 2009 but initial studies were compromised by being non-randomised, without sham control and small in size. Subsequently, clinical trial design and rigour of execution has been greatly improved resulting in recent sham-controlled RCTs that demonstrate short-term reduction in ambulatory BP without any significant safety concerns in both medication-naïve and medication-treated hypertensive patients. Despite this, the joint UK societies still feel that further evaluation of this therapy is warranted and that RDN should not be offered to patients outside of the context of clinical trials. This document reviews the updated evidence since our last consensus statement from 2014 and provides a research agenda for future clinical studies.

Renal Denervation for Resistant Hypertension in the contemporary era: A Systematic Review and Meta-analysis

Renal denervation (RDN) is a catheter-based ablation procedure designed to treat resistant hypertension (RH). The objective of our study is to determine the effect of RDN on blood pressure and renal function in patients with RH in comparison to medical therapy alone. We performed an extensive literature search for randomized control trials (RCT) reporting office and 24 hr. blood pressure changes and estimated glomerular filtration rate (eGFR) at baseline and 6 months. We calculated a weighted standardized mean difference of blood pressure and renal outcomes between RDN and control groups using random effects models. Our search yielded 608 studies of which we included 15 studies for the final analysis. A total of 857 patients were treated with RDN and 616 patients treated with medical therapy ± sham procedure. Only 5 studies were double-blinded RCT with sham control. The adjusted standardized mean difference in the change in office based systolic and diastolic pressures (p = 0.18; p = 0.14); 24 hr. systolic and diastolic pressures (p = 0.20; p = 0.18); and eGFR (p = 0.20) from baseline to 6 months is statistically insignificant with significant heterogeneity. Subgroup analysis showed that among sham controlled trials, 24 hr. systolic blood pressure showed a modest but statistically significant benefit favoring renal denervation in patients with RH. Our meta-analysis of 15 RCTs showed no significant benefit of RDN on blood pressure control in patients with resistant hypertension. Subgroup analysis of sham control studies showed a modest benefit in 24 hr. systolic blood pressure at 6 months with RDN.

Adherence to antihypertensive drug treatment in patients with apparently treatment-resistant hypertension in the INSPiRED pilot study

PURPOSE

Drug adherence may be a major problem in the therapy of hypertension and in the diagnosis of therapy resistance. Adherence can be assessed by indirect methods or by direct methods like drug detection in urine with liquid chromatography-mass spectrometric methods.

MATERIALS AND METHODS

The current analysis included patients with apparently treatment- resistant hypertension (TRH) referred for renal denervation (RDN) and included in the the INSPiRED pilot trial (NCT01505010). Adherence was repeatedly assessed by toxicological urine analysis over a time range of up to 17 months in a total of 18 patients.

RESULTS

In the first urine samples of 18 patients the adherence rate (percentage of number of detected vs. prescribed medical drugs) ranged from 0 to 100% with a median of 73.2%. In further urine samples collected during the following up to 17 months every individual patient exhibited considerable changes in the adherence rate, neither a constancy nor a tendency could be deduced.

CONCLUSIONS

Urine analysis results exhibit variation over time and an assessment at a certain time point cannot be regarded as representative or predictor for future behavior. Therefore, it appears necessary to perform drug adherence testing repeatedly over time.

Renal Denervation in High-risk Patients with Hypertension

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ECG Voltage in Relation to Peripheral and Central Ambulatory Blood Pressure

BACKGROUND

The heart ejects in the central elastic arteries. No previous study in workers described the diurnal profile of central blood pressure (BP) or addressed the question whether electrocardiogram (ECG) indexes are more closely associated with central than peripheral BP.

METHODS

In 177 men (mean age, 29.1 years), we compared the associations of ECG indexes with brachial and central ambulatory BP, measured over 24 hours by the validated oscillometric Mobil-O-Graph 24h PWA monitor.

RESULTS

From wakefulness to sleep, as documented by diaries, systolic/diastolic BP decreased by 11.7/13.1 mm Hg peripherally and 9.3/13.6 mm Hg centrally, whereas central pulse pressure (PP) increased by 4.3 mm Hg (P < 0.0001). Over 24 hours and the awake and asleep periods, the peripheral-minus-central differences in systolic/diastolic BPs averaged 11.8/–1.6, 12.7/–1.8, and 10.3/–1.2 mm Hg, respectively (P < 0.0001). Cornell voltage and index averaged 1.18 mV and 114.8 mV·ms. Per 1-SD increment in systolic/diastolic BP, the Cornell voltages were 0.104/0.086 mV and 0.082/0.105 mV higher in relation to brachial 24-hour and asleep BP and 0.088/0.90 mV and 0.087/0.107 mV higher in relation to central BP. The corresponding estimates for the Cornell indexes were 9.6/8.6 and 8.2/10.5 mV·ms peripherally and 8.6/8.9 and 8.8/10.7 mV·ms centrally. The regression slopes (P ≥ 0.067) and correlation coefficients (P ≥ 0.088) were similar for brachial and central BP. Associations of ECG measurements with awake BP and PP were not significant.

CONCLUSIONS

Peripheral and central BPs run in parallel throughout the day and are similarly associated with the Cornell voltage and index.