Research status and frontiers of renal denervation for hypertension: a bibliometric analysis from 2004 to 2023.

BACKGROUND: Renal Denervation (RDN) is a novel non-pharmacological technique to treat hypertension. This technique lowers blood pressure by blocking the sympathetic nerve fibers around the renal artery, then causing a decrease in system sympathetic nerve excitability. This study aimed to visualize and analyze research hotspots and development trends in the field of RDN for hypertension through bibliometric analysis. METHODS: In total, 1479 studies were retrieved on the Web of Science Core Collection (WoSCC) database from 2004 to 2023. Using CiteSpace (6.2.R4) and VOSviewer (1.6.18), visualization maps were generated by relevant literature in the field of RDN for hypertension to demonstrate the research status and frontiers. RESULTS: The number of publications was found to be generally increasing. Europe and the United States were the first countries to carry out research on different techniques and related RDN clinical trials. The efficacy and safety of RDN have been repeatedly verified and gained increasing attention. The study involves multiple disciplines, including the cardiovascular system, peripheral vascular disease, and physiological pathology, among others. Research hotspots focus on elucidating the mechanism of RDN in the treatment of hypertension and the advantages of RDN in appliance therapy. Additionally, the research frontiers include improvement of RDN instruments and techniques, as well as exploration of the therapeutic effects of RDN in diseases with increased sympathetic nerve activity. CONCLUSION: The research hotspots and frontiers reflect the status and development trend of RDN in hypertension. In the future, it is necessary to strengthen international collaboration and cooperation, conduct long-term clinical studies with a large sample size, and continuously improve RDN technology and devices. These measures will provide new options for more patients with hypertension, thereby improving their quality of life.

Randomized Trials of Renal Denervation for Uncontrolled Hypertension: An Updated Meta-Analysis.

BACKGROUND: Despite optimal medical therapy, a significant proportion of patients' blood pressure remains uncontrolled. Catheter-based renal denervation (RDN) has been proposed as a potential intervention for uncontrolled hypertension. We conducted an updated meta-analysis to assess the efficacy and safety of RDN in patients with uncontrolled hypertension, with emphasis on the differential effect of RDN in patients on and off antihypertensive medications. METHODS AND RESULTS: Online databases were searched to identify randomized clinical trials comparing efficacy and safety of RDN versus control in patients with uncontrolled hypertension. Subgroup analyses were conducted for sham-controlled trials and studies that used RDN devices that have gained or are currently seeking US Food and Drug Administration approval. Fifteen trials with 2581 patients (RDN, 1723; sham, 858) were included. In patients off antihypertensive medications undergoing RDN, a significant reduction in 24-hour ambulatory (-3.70 [95% CI, -5.41 to -2.00] mm Hg), office (-4.76 [95% CI, -7.57 to -1.94] mm Hg), and home (-3.28 [95% CI, -5.96 to -0.61] mm Hg) systolic blood pressures was noted. In patients on antihypertensive medications, a significant reduction was observed in 24-hour ambulatory (-2.23 [95% CI, -3.56 to -0.90] mm Hg), office (-6.39 [95% CI, -11.49 to -1.30]), home (-6.08 [95% CI, -11.54 to -0.61] mm Hg), daytime (-2.62 [95% CI, -4.14 to -1.11]), and nighttime (-2.70 [95% CI, -5.13 to -0.27]) systolic blood pressures, as well as 24-hour ambulatory (-1.16 [95% CI, -1.96 to -0.35]), office (-3.17 [95% CI, -5.54 to -0.80]), and daytime (-1.47 [95% CI, -2.50 to -0.27]) diastolic blood pressures. CONCLUSIONS: RDN significantly lowers blood pressure in patients with uncontrolled hypertension, in patients off and on antihypertensive medications, with a favorable safety profile. The efficacy of RDN was consistent in sham-controlled trials and contemporary trials using US Food and Drug Administration-approved devices.

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

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

Patient-Specific Factors Predicting Renal Denervation Response in Patients With Hypertension: A Systematic Review and Meta-Analysis.

BACKGROUND: The accurate selection of patients likely to respond to renal denervation (RDN) is crucial for optimizing treatment outcomes in patients with hypertension. This systematic review was designed to evaluate patient-specific factors predicting the RDN response. METHODS AND RESULTS: We focused on individuals with hypertension who underwent RDN. Patients were categorized based on their baseline characteristics. The primary outcome was blood pressure (BP) reduction after RDN. Both randomized controlled trials and nonrandomized studies were included. We assessed the risk of bias using corresponding tools and further employed the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the overall quality of evidence. A total of 50 studies were ultimately included in this systematic review, among which 17 studies were for meta-analysis. Higher baseline heart rate and lower pulse wave velocity were shown to be associated with significant antihypertensive efficacy of RDN on 24-hour systolic BP reduction (weighted mean difference, -4.05 [95% CI, -7.33 to -0.77]; weighted mean difference, -7.20 [95% CI, -9.79 to -4.62], respectively). In addition, based on qualitative analysis, higher baseline BP, orthostatic hypertension, impaired baroreflex sensitivity, and several biomarkers are also reported to be associated with significant BP reduction after RDN. CONCLUSIONS: In patients with hypertension treated with the RDN, higher heart rate, and lower pulse wave velocity were associated with significant BP reduction after RDN. Other factors, including higher baseline BP, hypertensive patients with orthostatic hypertension, BP variability, impaired cardiac baroreflex sensitivity, and some biomarkers are also reported to be associated with a better BP response to RDN.

Investigations of Laser-Assisted Renal Denervation for Treatment of Resistant Hypertension.

BACKGROUND AND OBJECTIVES: Renal denervation (RDN) is an emerging surgical treatment for resistant hypertension. However, the current RDN using radiofrequency can cause undesirable thermal damage to the medial and luminal layers due to direct contact between the arterial lumen and energy source. The aim of this study is to evaluate the feasibility of the new laser-assisted RDN by exploring the potential treatment conditions. METHODS: For ex vivo testing, six different treatment conditions (10 and 20 W applied for delivery of 300, 450, and 600 J) were tested on the porcine liver and renal artery (RA) by using a continuous wave 1064 nm laser wavelength. The ablated area in the liver tissue was measured to estimate the extent of the coagulated area. Histological evaluation was performed on the treated RA tissues to confirm the extent of thermal nerve damage. RESULTS: The ablated depth, length, and area in the liver tissue increased with laser power and total energy. According to the histological results, 20 W groups yielded more significant damage to the RA nerves than 10 W groups at the total energy of 300 J (0.0 ± 0.0 mm for 10 W vs. 2.9 ± 1.0 mm for 20 W), 450 J (1.9 ± 0.6 mm for 10 W vs. 6.8 ± 1.5 mm for 20 W), and 600 J (2.9 ± 0.4 mm for 10 W vs. 7.3 ± 0.8 mm for 20 W). The treated RA exhibited insignificant medial injury in depth (medial thinning ≤ 25%), and no difference in the medial thinning was found among the six groups (p = 0.4). CONCLUSION: The current study demonstrated that the 1064 nm laser at 20 W with delivery of 450 J could effectively damage the RA nerves with no or minimal injury to the surrounding tissue. The proposed laser-assisted RDN may enhance physiological effects with insignificant complications in in vivo situations. Further in vivo studies will be conducted to validate the current findings by evaluating the extent of blood pressure reduction and norepinephrine changes after the laser-assisted RDN on a large animal model.

Intra-operative hypertension as a predictor of surgical outcomes in microvascular decompression surgery for trigeminal neuralgia.

PURPOSE: The trigeminocardiac reflex (TCR) has traditionally been characterized by a sudden decrease in heart rate, asystole, or hypotension during the manipulation of the trigeminal nerve (MTN) or its branches. While this classical TCR is well-documented, there is limited literature on alternative forms of TCR, such as the development of intraoperative hypertension (HTN) or tachycardia, and the underlying pathogenesis. Furthermore, a gap exists in understanding the correlation between intraoperative blood pressure readings and postoperative outcomes, particularly regarding pain relief in patients with trigeminal neuralgia (TN). Our study aims to examine intraoperative blood pressure trends during microvascular decompression (MVD) for TN and assess their impact on postoperative outcomes. METHODS: We selected 90 patients who underwent MVD for TN treatment. Blood pressure and heart rate were recorded both preoperatively and during the procedure, specifically during the MTN period, using an arterial line. The Barrow Neurological Institute (BNI) Pain Scale was calculated for all patients both pre- and post-operatively to evaluate pain relief after surgery. RESULTS: The mean age of the patients was 61.0 ± 12.35 years, with 64.4% being females. Classical TCR (hypotension) was observed in only 2.2% of patients, whereas 80% of patients developed hypertension (≥ 140/90) during MTN. The mean preoperative systolic blood pressure was 128 ± 22.25, and the mean intraoperative systolic blood pressure during MTN was 153.1 ± 20.2. An analysis of covariance, utilizing either preoperative BNI or duration of symptoms as covariate variables, revealed a statistically significant association between intraoperative HTN and postoperative BNI. A linear regression model demonstrated that intraoperative HTN following MTN significantly predicted a lower postoperative BNI score (p = 0.006). CONCLUSIONS: Intraoperative HTN during MTN, an observed yet underexplored phenomenon, demonstrated a correlation with improved postoperative outcomes. Furthermore, it is recommended to conduct additional investigations into potential neurovascular conflicts in patients not manifesting intraoperative HTN following MTN. A comprehensive understanding of TCR, encompassing its various forms, is vital for optimizing surgical management. This study underscores the imperative for further research to unravel the mechanisms linking intraoperative HTN to surgical outcomes in TN patients.

Adrenalectomy for primary aldosteronism and its related surgical characteristics.

Primary aldosteronism (PA) is a common cause of secondary hypertension. Adrenalectomy is an effective treatment for unilateral PA, particularly aldosterone-producing adenoma (APA), resulting in improvements in biochemical parameters and blood pressure in the vast majority of patients. The article provides a comprehensive overview of PA, focusing on the outcomes of adrenalectomy for PA and the factors that may suggest prognostic implications. Analysis of the outcome of different PA patients undergoing adrenalectomy in terms of preoperative factors, vascular and adipose conditions, type of pathology, and somatic variants. In addition, it is recommended to use the histopathology of primary aldosteronism (HISTALDO) consensus to classify the patient's pathological type, with classical and nonclassical pathological types showing a different prognosis and possibly being associated with an unresected contralateral adrenal gland. The primary aldosteronism surgical outcome (PASO) consensus sets uniform standards for postoperative outcomes in unilateral PA, but its setting of thresholds remains controversial. Partial adrenalectomy shows similar surgical results and fewer postoperative complications than total adrenalectomy, but there is a risk of missing the true source of abnormal aldosterone secretion. Steroid profiling and functional imaging techniques offer alternative options to adrenal vein sampling (AVS) for unilateral and bilateral judgments in patients with PA. A combination of factors is needed to predict the prognosis of PA patients undergoing adrenalectomy in order to manage patient expectations of the outcome of the procedure and to closely monitor blood pressure and biochemical parameters in patients who suggest a poorer prognosis.

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

INTRODUCTION: New therapies for resistant hypertension (RH), including renal denervation (RDN), have been studied. AIM: Access the safety and effectiveness of radiofrequency-based RDN vs pharmacological treatment for RH. METHODS: A thorough literature search was conducted across PubMed, EMBASE, and the Cochrane databases, focusing on studies that compared the effects of radiofrequency-based RDN versus pharmacological treatment for RH. Treatment effects for binary and continuous endpoints were pooled and used, respectively, odds-ratio (OR) and mean differences (MD) with 95% confidence intervals (CI) to analyze continuous outcomes. RESULTS: In the 10 included studies, involving 1.182 patients, 682 received radiofrequency-based RDN. The follow-up period ranged from 6 to 84 months. Analysis revealed that the RDN group had a significant reduction in office systolic blood pressure (BP) (MD - 9.5 mmHg; 95% CI - 16.81 to - 2.29; P = 0.01), office diastolic BP (MD - 5.1 mmHg; 95% CI - 8.42 to - 2.80; P < 0.001), 24 h systolic BP (MD - 4.8 mmHg; 95% CI - 7.26 to - 2.42; P < 0.001). For 24 h diastolic BP RDN did not have a significant reduction (MD - 2.3 mmHg; 95% CI - 4.19 to - 0.52; P = 0.012). The heterogeneity between the studies was high, visible in the funnel and Baujat plots. The OR was non-significant for non-serious adverse events, but also clinically significant for hypertensive crises and strokes for the RDN group. CONCLUSIONS: While the pharmacological regimen of 3 or more anti-hypertensive, including a diuretic, still be the first-line option for RH treatment, our results support that radiofrequency-based RDN is superior in reducing global BP and is safe.

Overview of the 2023 FDA Circulatory System Devices Advisory Panel meeting on the Recor Paradise Ultrasound-Based Renal Denervation System.

Hypertension continues to be a prominent, avoidable factor contributing to major vascular issues on a global scale. Even with lifestyle adjustments and more aggressive medical treatments, maintaining optimal blood pressure levels remains challenging. This challenge has driven the emergence of device-oriented approaches to address hypertension. To assess the safety and efficacy of the Recor Paradise Ultrasound Renal Denervation System, the Circulatory System Devices Panel was convened by the US Food and Drug Administration (FDA). This manuscript provides a condensed overview of the information put forth by the sponsor and the FDA, along with an account of the considerations and conversations that took place during the meeting.

Renal denervation by radiofrequency in patients with hypertension: systematic review and meta-analysis.

The Guidelines Project, which is an initiative of the Brazilian Medical Association, aims to combine information from the medical field to standardize how to conduct and assist in the reasoning and decision-making of doctors. The information provided by this project must be critically evaluated by the physician responsible for the conduct that will be adopted, depending on the conditions and the clinical condition of each patient.

Features of The Dynamics of Profibrotic Markers and Regression of Left Ventricular Hypertrophy After Renal Denervation in Patients With Resistant Hypertension and Stenosing Atherosclerosis of the Coronary Arteries.

AIM: To compare the changes in serum concentrations of matrix metalloproteinases (MMPs) and their tissue inhibitor (TIMP) to the dynamics of blood pressure (BP) and parameters of left ventricular hypertrophy (LVH) 6 months after renal denervation (RD) in patients with resistant arterial hypertension (RAH) and complicated coronary atherosclerosis. MATERIAL AND METHODS: In 22 RAH patients with complicated coronary atherosclerosis (revascularization and/or history of myocardial infarction (MI)), 24-hour BP monitoring, echocardiography, and measurement of blood MMPs and TIMP were performed at baseline and six months after RD. The comparison group consisted of 48 RAH patients without a history of coronary revascularization or MI. RESULTS: In 6 months after RD, BP was decreased comparably in both groups. In the group of complicated atherosclerosis, there were no significant changes in profibrotic markers or LVH parameters. Thus, at baseline and after 6 months, the values of the studied indicators were the following: left ventricular myocardial mass (LVMM) 233.1±48.1 and 243.0±52.0 g, LVMM index 60.6±14.5 and 62.8±10 .9 g/m2.7, proMMP-1 4.9 [2.1; 7.7] and 3.6 [2.0; 9.4]  ng/ml, MMP-2 290.4 [233.1; 352.5] and 352.2 [277.4; 402.9] ng/ml, MMP-9 220.6 [126.9; 476.7] and 263.5 [82.9; 726.2] ng/ml, TIMP-1 395.7 [124.7; 591.4] and 424.2 [118.2; 572.0] ng/ml, respectively. In the comparison group, on the contrary, there was a significant decrease in LVMM from 273.6±83.3 g to 254.1±70.4 g, LVMM index from 67.1±12.3 to 64.0±14.4 g/m2.7, proMMP-1 from 7.2 [3.6; 11.7] to 5.9 [3.5; 10.9] ng/ml, MMP-2 from 328.9 [257.1; 378.1] to 272.8 [230.2; 343.2] ng/ml, MMP-9 from 277.9 [137.0; 524.0] to 85.5 [34.2; 225.9] ng/ml, and the MMP-9/TIMP-1 ratio from 0.80 [0.31; 1.30] to 0.24 [0.07; 0.76]. The BP dynamics in this group was inversely correlated with MMP-2 at 6 months (r=-0.38), and the MMP-9/TIMP-1 ratio was correlated with LVMM and the LVMM index at baseline (r=0.39 and r=0.39) and at 6 months (r=0.37 and r=0.32). The change in TIMP-1 from 543.9 [277.5; 674.1] to 469.8 [289.7; 643.6] ng/ml was not significant (p=0.060). CONCLUSION: In RAH patients with complicated coronary atherosclerosis, the dynamics of profibrotic biomarkers and LVH parameters after RD was absent despite the pronounced antihypertensive effect, probably due to the low reversibility of cardiovascular remodeling processes or more complex regulatory mechanisms of the MMP system.

How effective is nephrectomy in curing hypertension in children with unilateral poorly functioning kidney? A systematic review.

PURPOSE: Some children with hypertension (HTN) have unilateral poorly functional kidney (PFK). This provides an opportunity for the clinician to cure the HTN by removal of the PFK, thereby avoiding the problems of long-term medication. However, there is sparse data in children regarding the effect of PFK nephrectomy on curing HTN. In this review, we analysed the etiology of PFK causing HTN and the effectiveness of nephrectomy in curing HTN in children. METHODS: We searched the databases to identify papers between January 2000 to December 2020 pertaining to children with PFK and HTN who underwent nephrectomy. Outcome analyzed was the resolution of HTN following nephrectomy. Duplicate publications, review articles and incomplete articles were excluded. Meta-analysis of heterogeneity was reported with I2statistics. Forest plot was constructed to compare the pooled prevalence of HTN resolution. RESULTS: Five articles with 88 patients were included. Majority (43%) of PFK were due to the unilateral atrophic kidney with or without vesicoureteral reflux (VUR); ureteropelvic junction obstruction and multicystic dysplastic kidney together accounted for 35% of cases and renovascular pathology for 22% of cases. With a follow-up of 1.5 to 3.3 years, nephrectomy was effective to cure HTN in 65.9% (95% CI 55-75%) children. CONCLUSIONS: In children with HTN and a unilateral PFK, nephrectomy cured the HTN in two-thirds of children. Unilateral atrophic kidney due to VUR was the most common cause of PFK. An increase in the utilisation of laparoscopy was observed in recent publications, hence laparoscopic nephrectomy may be considered a first choice of treatment in these children.

Opportunities and Limitations of Renal Denervation: Where Do We Stand?

Hypertension is a primary contributor to cardiovascular disease, and the leading risk factor for loss of quality adjusted life years. Up to 50% of the cases of hypertension in the United States remain uncontrolled. Additionally, 8%-18% of the hypertensive population have resistant hypertension; uncontrolled pressure despite 3 different antihypertensive agents. Recently, catheter-based percutaneous renal denervation emerged as a method for ablating renal sympathetic nerves for difficult-to-control hypertension. Initial randomized (non-sham) trials and registry analyses showed impressive benefit, but the first sham-controlled randomized controlled trial using monopolar radiofrequency ablation showed limited benefit. With refinement of techniques to include multipolar radiofrequency, ultrasound denervation, and direct ethanol injection, randomized controlled trials demonstrated significant blood pressure improvement, leading to US Food and Drug Administration approval of radiofrequency- and ultrasound-based denervation technologies. In this review article, we summarize the major randomized sham-controlled trials and societal guidelines regarding the efficacy and safety of renal artery denervation for the treatment of uncontrolled hypertension.

Effect of Alcohol-Mediated Renal Denervation on Blood Pressure in the Presence of Antihypertensive Medications: Primary Results From the TARGET BP I Randomized Clinical Trial.

BACKGROUND: Renal denervation (RDN) has demonstrated clinically relevant reductions in blood pressure (BP) among individuals with uncontrolled hypertension despite lifestyle intervention and medications. The safety and effectiveness of alcohol-mediated RDN have not been formally studied in this indication. METHODS: TARGET BP I is a prospective, international, sham-controlled, randomized, patient- and assessor-blinded trial investigating the safety and efficacy of alcohol-mediated RDN. Patients with office systolic BP (SBP) ≥150 and ≤180 mm Hg, office diastolic BP ≥90 mm Hg, and mean 24-hour ambulatory SBP ≥135 and ≤170 mm Hg despite prescription of 2 to 5 antihypertensive medications were enrolled. The primary end point was the baseline-adjusted change in mean 24-hour ambulatory SBP 3 months after the procedure. Secondary end points included mean between-group differences in office and ambulatory BP at additional time points. RESULTS: Among 301 patients randomized 1:1 to RDN or sham control, RDN was associated with a significant reduction in 24-hour ambulatory SBP at 3 months (mean±SD, -10.0±14.2 mm Hg versus -6.8±12.1 mm Hg; treatment difference, -3.2 mm Hg [95% CI, -6.3 to 0.0]; P=0.0487). Subgroup analysis of the primary end point revealed no significant interaction across predefined subgroups. At 3 months, the mean change in office SBP was -12.7±18.3 and -9.7±17.3 mm Hg (difference, -3.0 [95% CI, -7.0 to 1.0]; P=0.173) for RDN and sham, respectively. No significant differences in ambulatory or office diastolic BP were observed. Adverse safety events through 6 months were uncommon, with one instance of accessory renal artery dissection in the RDN group (0.7%). No significant between-group differences in medication changes or patient adherence were identified. CONCLUSIONS: Alcohol-mediated RDN was associated with a modest but statistically significant reduction in 24-hour ambulatory SBP compared with sham control. No significant differences between groups in office BP or 6-month major adverse events were observed. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02910414.

Can catheter-based renal denervation reduce frequency of hospitalization in patients who have resistant hypertension and heart failure with reduced ejection fraction?

Hypertension is one of the most powerful and modifiable risk factors for the development, progression and even decompensation of heart failure. Uncontrolled hypertension increases to frequency of heart failure hospitalizations by increase sympathetic tone. Catheter-based renal denervation has been shown to reduce blood pressure in the treatment of multidrug-resistant hypertension. We report the improvement in clinical status after renal denervation in a 47-year-old male patient with a history of hypertension, chronic ischemic heart failure, and recurrent hospitalizations for acute hypertensive pulmonary edema despite optimal medical therapy.

Sympathetic Pathophysiology in Hypertension Origins: The Path to Renal Denervation.

The importance of the sympathetic nervous system in essential hypertension has been recognized in 2 eras. The first was in early decades of the 20th century, through to the 1960s. Here, the sympathetic nervous system was identified as a target for the treatment of hypertension, and an extensive range of antiadrenergic therapies were developed. Then, after a period of lapsed interest, in a second era from 1985 on, the development of precise measures of human sympathetic nerve firing and transmitter release allowed demonstration of the importance of neural mechanisms in the initiation and maintenance of the arterial blood pressure elevation in hypertension. This led to the development of a device treatment of hypertension, catheter-based renal denervation, which we will discuss.