Effectiveness of Renal Denervation in Resistant Hypertension: A Meta-Analysis of 11 Controlled Studies

Efficacy of catheter-based ultrasound renal denervation in the treatment of hypertension

BACKGROUND

Hypertension (HTN) is a prevalent chronic health condition that significantly increases the risk of cardiovascular diseases-associated mortalities. Despite the use of antihypertensive medications, numerous patients fail to achieve guideline-recommended blood pressure (BP) targets.

AIM

To evaluates the efficacy of catheter-based ultrasound renal denervation (uRDN) for the treatment of HTN.

METHODS

Relevant studies were identified through searches in PubMed, Embase, the Cochrane Library, Web of Science, and China National Knowledge Infrastructure, with a cut-off date at April 1, 2024. A random-effects model was employed in this study to mitigate potential biases. The risk of bias for included studies was assessed using the Cochrane Risk of Bias assessment tool. Statistical analyses were conducted using Review Manager version 5.3. This meta-analysis incorporated four studies encompassing a total of 627 patients. The reporting bias of this study was deemed acceptable.

RESULTS

Compared to the Sham group, the uRDN group demonstrated a significant reduction in daytime ambulatory systolic BP (SBP) [mean difference (MD) -3.87 mmHg, 95% confidence interval (CI): -7.02 to -0.73, P = 0.02], office SBP (MD -4.13 mmHg, 95%CI: -7.15 to -1.12, P = 0.007), and home SBP (MD -5.51 mmHg, 95%CI: -8.47 to -2.55, P < 0.001). However, there was no statistically significant reduction observed in either 24-hour or nighttime ambulatory SBP levels. Subgroup analysis shows that uRDN can significantly reduce the SBP in patients with non-resistant HTN (MD -6.19 mmHg, MD -6.00 mmHg, MD -7.72 mmHg, MD -5.02 mmHg, MD -3.61 mmHg).

CONCLUSION

The current evidence suggests that uRDN may effectively reduce home, office, and daytime SBP in patients with HTN, particularly in those with non-resistant HTN.

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.

The Implementation of Renal Denervation in the Management of Resistant Hypertension Despite Use of Multitherapy Antihypertensives at Maximally Tolerated Doses: A Contemporary Literature Review

Refractory hypertension is highly prevalent among the hypertensive population, and current clinical management has failed to provide optimal control for these individuals. This subtype of arterial hypertension is defined as a persistently elevated systolic blood pressure reading of 140 mmHg, or higher, despite multiple antihypertensive use at maximally tolerated dosing. These patients have an elevated risk of cardiovascular and renal complications, urging for the need of more effective therapeutic management. Renal sympathetic efferent nerves have been noted to play an important role in volume and blood pressure homeostasis. Before the implementation of oral antihypertensives, the use of surgical lumbar sympathectomy for the reduction of persistent hypertension was considered a life-saving approach. However, individuals were left with debilitating side effects, such as postural hypotension, syncope, and impotence. A new and minimally invasive technique has been proposed, where the kidneys undergo selective denervation in hopes of providing decreased cardiovascular morbidity and mortality for patients with resistant hypertension. Some studies demonstrated promising outcomes with a reduction in blood pressure, a decrease in medication reliance, and a potential long-lasting effect of the procedure with an overall improvement in cardiovascular health. Unfortunately, most of the available data was obtained from observational, uncontrolled studies with short-term follow-up, small sample sizes, and high variability in blood pressure measurement. Therefore, further evidence is needed to determine whether renal denervation provides long-term benefits for blood pressure control and improves outcomes for mortality and cardiovascular events in this patient population.

When blood pressure refuses to budge: exploring the complexity of resistant hypertension

Resistant hypertension, defined as blood pressure that remains above goal despite using three or more antihypertensive medications, including a diuretic, affects a significant proportion of the hypertensive population and is associated with increased cardiovascular morbidity and mortality. Despite the availability of a wide range of pharmacological therapies, achieving optimal blood pressure control in patients with resistant hypertension remains a significant challenge. However, recent advances in the field have identified several promising treatment options, including spironolactone, mineralocorticoid receptor antagonists, and renal denervation. In addition, personalized management approaches based on genetic and other biomarkers may offer new opportunities to tailor therapy and improve outcomes. This review aims to provide an overview of the current state of knowledge regarding managing resistant hypertension, including the epidemiology, pathophysiology, and clinical implications of the condition, as well as the latest developments in therapeutic strategies and future prospects.

[Renal denervation : Really an alternative to reducing blood pressure?]

Since the current guidelines were published in 2018, a total of 5 sham-controlled high-quality studies evaluating renal denervation have been conducted and the results were published. These five studies clearly confirmed the efficacy and safety of renal denervation, which correspond to the knowledge of the Clinical Consensus Conference. Thus, an update of the guidelines for the treatment of arterial hypertension regarding the clinical significance of renal denervation is urgently necessary. For this reason, the position paper of the working group of the European Society of Hypertension on the current state of renal denervation was reviewed. An approval of this procedure can soon be expected. In Germany there is a diagnosis-related group (DRG) for the reimbursement of renal denervation, which was suspended due to the erroneous Symplicity 3 study. This DRG should be revived in practice by a structured process of the implementation of renal denervation. It will then be a joint task of treating physicians and specialists in certified centers to identify eligible patients. In the future, antihypertensive treatment will consist of three pillars: lifestyle measures, pharmacotherapy and interventional treatment. These three treatment options should not be regarded as competitive (which is better) but alternative (patient preference) and additive (the aim is blood pressure control). It is the task of the treating physician to provide the patient with the ideal treatment concept. Clearly, renal denervation will not replace antihypertensive pharmacotherapy; however, it can lead to a reduction of the drug burden and increase of patient adherence to medication. It represents an option of modern antihypertensive treatment and will also become increasingly more important in special patient groups.

New Aspects in the Management of Hypertension in Patients with Chronic Kidney Disease not on Renal Replacement Therapy

With chronic kidney disease (CKD) being a global arising health problem, strategies for delaying kidney disease progression and reducing the high cardiovascular risk inherent to CKD, are the main objectives of the actual management of patients with kidney diseases. In these patients, the control of arterial hypertension is essential, as high blood pressure (BP) is a strong determinant of worst cardiovascular and renal outcomes. Achieving target blood pressures recommended by international guidelines is mandatory and often demands a multiple levels management, including several pharmacological and lifestyle measures. Even in the presence of adequate BP control, the residual cardiovascular risk remains high. In this respect, the recent demonstration that novel agents such as sodium glucose transporter 2 (SGLT2) inhibitors or the new non-steroidal mineralocorticoid antagonist finerenone can retard the progression of kidney diseases and reduce cardiovascular mortality on top of standard of care treatment with renin-angiotensin system inhibitors represent enormous progresses. These studies also demonstrate that cardiovascular and renal protection can be obtained beyond blood pressure control. Other promising novelties are still to come such as renal denervation and endothelin receptor antagonists in the setting of diabetic and non-diabetic kidney diseases. In the present review, we shall discuss the classic and the new aspects for the management of hypertension in CKD, integrating the new data from recent clinical studies.

Novel approaches to management of hypertension

PURPOSE OF REVIEW

Of the roughly 1.4 billion people with hypertension worldwide, only about one in seven has their blood pressure (BP) successfully treated and adequately controlled. This review will focus on new therapeutic approaches of hypertension.

RECENT FINDINGS

Several recent clinical studies and guidelines have favoured the assessment of target organ damage and cardiovascular risk scores for the diagnosis and treatment approach of hypertension. Paradigm shifts recommended in the guidelines are the initiation of antihypertensive treatment with combination (not mono) therapy and the recommendation of single-pill combinations (SPC), which improve adherence and result in rapid and effective BP control. In clinical trials with optimized design and renal denervation (RDN) technology, the biological proof of concept has been established. Consistent, durable ambulatory and office BP reductions without procedure associated serious adverse events have been documented. The challenges are now to identify patients who respond best to interventional treatment.

SUMMARY

Major key points in the treatment strategy for hypertension are: individualization of the therapy according to total cardiovascular risk, combination therapy as initial step, recommendation of SPC and RDN as promising interventional therapy.

Renal denervation: where do we stand and what is the relevance to the nephrologist?

Catheter-based renal denervation to reduce high blood pressure (BP) has received well-deserved attention after a recent series of sham-controlled trials reported significant antihypertensive efficacy and very favourable tolerability and safety of the intervention. This emerging treatment option is of high relevance to nephrologists. Patients with chronic kidney disease (CKD) are at elevated risk of cardiovascular adverse events and often present with hypertension, which is very difficult to control with medication. Renal denervation promises a new tool to reduce BP and to prevent loss of renal function in this population. The current review considers the role of the kidney and neurohormonal activation in the development of hypertension and the rationale for renal denervation. The current state of the evidence for the effectiveness and tolerability of the procedure is considered from the nephrologists’ perspective, with a focus on the potential future role of renal denervation in the management of CKD patients with hypertension.

Sham-Controlled Randomized Trials of Catheter-Based Renal Denervation in Patients With Hypertension

BACKGROUND

There are conflicting data regarding the relative effectiveness of renal sympathetic denervation (RSD) in patients with hypertension.

OBJECTIVES

The purpose of this study was to evaluate the blood pressure (BP) response after RSD in sham-controlled randomized trials.

METHODS

Databases were searched through June 30, 2018. Randomized trials (RCTs) with ≥50 patients comparing catheter-based RSD with a sham control were included. The authors calculated summary treatment estimates as weighted mean differences (WMD) with 95% confidence intervals (CIs) using random-effects meta-analysis.

RESULTS

The analysis included 977 patients from 6 trials. The reduction in 24-h ambulatory systolic blood pressure (ASBP) was significantly greater for patients treated with RSD than sham procedure (WMD -3.65 mm Hg, 95% CI: -5.33 to -1.98; p < 0.001). Compared with sham, RSD was also associated with a significant decrease in daytime ASBP (WMD -4.07 mm Hg, 95% CI: -6.46 to -1.68; p < 0.001), office systolic BP (WMD -5.53 mm Hg, 95% CI: -8.18 to -2.87; p < 0.001), 24-h ambulatory diastolic BP (WMD -1.71 mm Hg, 95% CI: -3.06 to -0.35; p = 0.01), daytime ambulatory diastolic BP (WMD -1.57 mm Hg, 95% CI: -2.73 to -0.42; p = 0.008), and office diastolic BP (WMD -3.37 mm Hg, 95% CI: -4.86 to -1.88; p < 0.001). Compared with first-generation trials, a significantly greater reduction in daytime ASBP was observed with RSD in second-generation trials (6.12 mm Hg vs. 2.14 mm Hg; p interaction = 0.04); however, this interaction was not significant for 24-h ASBP (4.85 mm Hg vs. 2.23 mm Hg; p interaction = 0.13).

CONCLUSIONS

RSD significantly reduced blood pressure compared with sham control. Results of this meta-analysis should inform the design of larger, pivotal trials to evaluate the long-term efficacy and safety of RSD in patients with hypertension.

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.

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.

Association of LIPC -250G/A and -514C/T polymorphisms and hypertension: a systematic review and meta-analysis

Background

Hypertension is the most common chronic disease, and most important risk factor for cardiovascular disease. This meta-analysis aimed to explore the association between hepatic lipase gene (LIPC) gene -250G/A (rs2070895) and -514C/T (rs1800588) polymorphisms and the susceptibility to hypertension.

Methods

Published studies were searched using the PubMed, Embase and Cochrane Library databases. Newcastle-Ottawa Scale (NOS) was used to assess the quality of the included studies. Sensitivity analysis was performed using “leave one out” method. Egger’s test was used to evaluate the publication bias. The random effect model was used to calculate the pooled effect size if P < 0.05 or I² ≥ 50%; otherwise, the fixed effect model was selected.

Results

Four eligible studies, including 2599 participants, were enrolled in the included studies from 2007 to 2014. Quality evaluation revealed that each study had high NOS scores ranged from 5 to 7. The LIPC rs1800588 polymorphism was not found to be associated with the susceptibility to hypertension under all genetic models (T vs C, P = 0.38; CT vs CC, P = 0.46; TT vs CC, P = 0.38; TT vs CC + CT, P = 0.54; TT + CT vs CC, P = 0.34). Notably, the frequencies of the AA+GA genotypes of LIPC rs2070895 polymorphism were related to an increased risk of hypertension (AA+GA vs. GG, OR = 1.1954, 95% CI: 1.0001–1.4288, P = 0.05).

Conclusion

The LIPC rs2070895 polymorphism was found to be related to an increased risk of hypertension. However, LIPC rs1800588 polymorphism was not associated with the susceptibility to hypertension.