Management of Resistant Hypertension.

Resistant hypertension (RH) is a severe form of hypertension associated with increased cardiovascular risk. Although true RH affects less than 10% of the patients receiving antihypertensive therapy, the absolute number is high and continues to increase. The workup of these patients requires screening for secondary hypertension and pseudoresistance, including poor adherence to prescribed medicines and the white-coat phenomenon. The treatment of RH consists of lifestyle modifications and pharmacological therapies. Lifestyle modifications include dietary adjustments, weight loss, physical activity, and limiting alcohol consumption; pharmacological therapies include diuretics, mineralocorticoid receptor antagonists, beta blockers, angiotensin receptor-neprilysin inhibitors, and others. Over the last 15 years, interventional approaches have emerged as adjunct treatment options; we highlight catheter-based renal denervation. This review summarizes the rationales and latest clinical evidence and, based thereon, proposes an updated algorithm for the management of RH.

Function of Renal Nerves in Kidney Physiology and Pathophysiology.

Renal sympathetic (efferent) nerves play an important role in the regulation of renal function, including glomerular filtration, sodium reabsorption, and renin release. The kidney is also innervated by sensory (afferent) nerves that relay information to the brain to modulate sympathetic outflow. Hypertension and other cardiometabolic diseases are linked to overactivity of renal sympathetic and sensory nerves, but our mechanistic understanding of these relationships is limited. Clinical trials of catheter-based renal nerve ablation to treat hypertension have yielded promising results. Therefore, a greater understanding of how renal nerves control the kidney under physiological and pathophysiological conditions is needed. In this review, we provide an overview of the current knowledge of the anatomy of efferent and afferent renal nerves and their functions in normal and pathophysiological conditions. We also suggest further avenues of research for development of novel therapies targeting the renal nerves.

Renal Denervation to Treat Heart Failure.

Heart failure (HF) is a global pandemic with a poor prognosis after hospitalization. Despite HF syndrome complexities, evidence of significant sympathetic overactivity in the manifestation and progression of HF is universally accepted. Confirmation of this dogma is observed in guideline-directed use of neurohormonal pharmacotherapies as a standard of care in HF. Despite reductions in morbidity and mortality, a growing patient population is resistant to these medications, while off-target side effects lead to dismal patient adherence to lifelong drug regimens. Novel therapeutic strategies, devoid of these limitations, are necessary to attenuate the progression of HF pathophysiology while continuing to reduce morbidity and mortality. Renal denervation is an endovascular procedure, whereby the ablation of renal nerves results in reduced renal afferent and efferent sympathetic nerve activity in the kidney and globally. In this review, we discuss the current state of preclinical and clinical research related to renal sympathetic denervation to treat HF.

Evaluation and Management of Resistant Hypertension: Core Curriculum 2024.

Resistant hypertension is defined as blood pressure above goal despite confirmed adherence to 3 first-line antihypertensive agents or when blood pressure is controlled with 4 or more medications at maximal or maximally tolerated doses. In addition to meeting these criteria, identifying patients with true resistant hypertension requires both accurate in-office blood pressure measurement as well as excluding white coat effects through out-of-office blood pressure measurements. Patients with resistant hypertension are at higher risk for adverse cardiovascular events and are more likely to have a potentially treatable secondary cause contributing to their hypertension. Effective treatment of resistant hypertension includes ongoing lifestyle modifications and collaboration with patients to detect and address barriers to optimal medication adherence. Pharmacologic treatment should prioritize optimizing first-line, once daily, longer acting medications followed by the stepwise addition of second-, third-, and fourth-line agents as tolerated. Physicians should systematically evaluate for and address any underlying secondary causes. A coordinated, multidisciplinary team approach including clinicians with experience in treating resistant hypertension is essential. New treatment options, including both pharmacologic and device-based therapies, have recently been approved, and more are in the pipeline; their optimal role in the management of resistant hypertension is an area of ongoing research.

Emerging Role of Renal Sympathetic Denervation as an Adjunct Therapy to Atrial Fibrillation Ablation.

The central anatomical locus in the context of atrial fibrillation (AF) ablation has been the pulmonary veins. Despite the attainment of a modest long-term success rate through pulmonary vein isolation (PVI), the pursuit of achieving a therapeutic efficacy nearing a definitive cure has spurred an investigation into alternative strategies and anatomical loci beyond the pulmonary veins. Despite extensive exploration, none of these alternative targets have succeeded in establishing themselves as routine ablation sites comparable to the pulmonary veins. Consequently, there exists an imperative for further inquiry and refinement of ablation strategies to propel advancements within the domain of AF ablation, thereby augmenting patient outcomes. Simultaneously, the examination of the autonomic system's role in AF pathophysiology introduces an additional ablation target aimed at rectifying sympathovagal imbalance. This discourse presents a contemporary review of renal denervation (RDN) as an emergent and auspicious technique poised to complement PVI, thereby contributing substantively to the augmentation of long-term success within the ambit of AF rhythm-control strategies.

Advances on the Experimental Research in Resistant Hypertension.

PURPOSE OF REVIEW: Resistant Hypertension (RH) poses a significant public health challenge, contributing to increased mortality, cardiovascular events and organ damage. Both clinical and experimental research are striving for higher standards in a translational manner to integrate new findings and confirm hypotheses. Considering that many are the aspects of RH that are still under investigation, this review aims to shed light on the advances made in experimental research concerning RH. It seeks to underscore the pivotal role of experimental studies in shaping clinical practices and also explore future perspectives. RECENT FINDINGS: It is important to emphasize the significance of experimental models, primarily for advancing our understanding: experimental models have greatly contributed to our comprehension of the underlying mechanisms in RH, including factors like sympathetic activation, endothelial dysfunction and structural vessel abnormalities. Secondly, for assessing treatment approaches: animal models have also played a crucial role in evaluating the potential effectiveness of diverse treatment approaches for RH. These encompass both pharmacological options, involving combinations of established drugs or novel pharmaceuticals, and non-pharmacological alternatives, which include surgical procedures like renal denervation, medical devices like baroreceptor stimulators, and lifestyle modifications. The most lacking component in translational research is the fact that there is no well-established animal model that perfectly replicates RH. Consequently, alternative strategies, including the combination of models, must be considered. What remains clear is that the development of animal models closely mimicking RH holds the promise of providing valuable insights into the essential mechanisms and responses necessary to combat or slow the global progression of RH.

Consensus Statement on Renal Denervation by the Joint Committee of Japanese Society of Hypertension (JSH), Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT), and the Japanese Circulation Society (JCS).

This is the first consensus statement of the Joint Committee on Renal Denervation of the Japanese Society of Hypertension (JSH)/Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT)/Japanese Circulation Society (JCS). The consensus is that the indication for renal denervation (RDN) is resistant hypertension or "conditioned" uncontrolled hypertension, with high office and out-of-office blood pressure (BP) readings despite appropriate lifestyle modification and antihypertensive drug therapy. "Conditioned" uncontrolled hypertension is defined as having one of the following: 1) inability to up-titrate antihypertensive medication due to side effects, the presence of complications, or reduced quality of life. This includes patients who are intolerant of antihypertensive drugs; or 2) comorbidity at high cardiovascular risk due to increased sympathetic nerve activity, such as orthostatic hypertension, morning hypertension, nocturnal hypertension, or sleep apnea (unable to use continuous positive airway pressure), atrial fibrillation, ventricular arrythmia, or heart failure. RDN should be performed by the multidisciplinary Hypertension Renal Denervation Treatment (HRT) team, led by specialists in hypertension, cardiovascular intervention and cardiology, in specialized centers validated by JSH, CVIT, and JCS. The HRT team reviews lifestyle modifications and medication, and the patient profile, then determines the presence of an indication of RDN based on shared decision making with each patient. Once approval for real-world clinical use in Japan, however, the joint RDN committee will update the indication and treatment implementation guidance as appropriate (annually if necessary) based on future real-world evidence.

Impacts of renal denervation on blood pressure in patients with obstructive sleep apnea.

BACKGROUND: Sympathetic nerve activation followed by obstructive sleep apnea (OSA) accounts for blood pressure elevation. The effectiveness of renal denervation (RDN) in controlling blood pressure in patients with OSA remains controversial. In this systematic review, we tried to pool currently available data to assess the effects of RDN therapy on blood pressure in OSA patients. METHODS: We retrieved Pubmed, EMbase and Cochrane Library through 17 May 2023, using the following key words: "renal denervation" and"obstructive sleep apnea". Full articles reporting the change of blood pressure after RDN procedure were included. RESULTS: A total of five studies were included in the meta-analysis. Pooled analysis showed that RDN markedly reduced both 24-h ambulatory systolic blood pressure (24 h-SBP) (Mean difference (MD): -7.54mmHg; 95%Cl: -10.16 to -4.91mmHg; I2 = 0%) and 24-h ambulatory diastolic blood pressure (24 h-DBP) (MD: -5.28mmHg; 95%Cl: -7.35 to -3.22mmHg; I2=0%). Daytime systolic blood pressure (dSBP) was reduced after RDN (MD: -7.54mmHg; 95%Cl: -10.82 to -4.57mmHg; I2 = 54%). With regards to nocturnal blood pressure, we found that RDN resulted in a significant reduction in nighttime systolic blood pressure (nSBP) (MD: -6.91mmHg; 95%Cl: -10.69 to -2.85mmHg; I2=0%). Subgroup analysis showed that dSBP was reduced by 12.00 mmHg, 12.00 mmHg, and 7.25 mmHg at 1 month, 3 months and 6 months, respectively. Our pooled analysis showed that AHI was not significantly changed by RDN. No major compilations were associated with RDN. CONCLUSIONS: RDN exerts a considerable blood pressure-lowering effect in hypertensive patients with OSA, which was sustained at least 6 months.

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.

Echocardiographic findings following renal sympathetic denervation for treatment resistant hypertension, the ReShape CV-risk study.

OBJECTIVE: The aim of this study was to describe and compare echocardiographic findings before renal sympathetic denervation (RDN) and 6 and 24 months after the procedure. MATERIALS AND METHODS: Patients with treatment resistant hypertension (TRH) were included in this non-randomised intervention study. RDN was performed by a single experienced operator using the Symplicity Catheter System. Echocardiographic measurements were performed at baseline, and after 6 and 24 months. RESULTS: The cohort consisted of 21 patients with TRH, with a mean systolic office blood pressure (BP) of 163 mmHg and mean diastolic BP 109 mmHg. Mixed model analysis showed no significant change in left ventricular (LV) mass index (LVMI) or left atrium volume index (LAVI) after the RDN procedure. Higher LVMI at baseline was significantly associated with greater reduction in LVMI (p < 0.001). Relative wall thickness (RWT) increased over time (0.48 mm after two years) regardless of change in BP. There was a small but significant reduction in LV end-diastolic (LVIDd) and end-systolic (LVIDs) diameters after RDN, with a mean reduction of 2.6 and 2.4 mm, respectively, after two years. Progression to concentric hypertrophy was observed only in in patients who did not achieve normal BP values, despite BP reduction after RDN. CONCLUSION: There was no reduction of LV mass after RDN. We found a small statistically significant reduction in LVIDd and LVIDs, which together with increase in RWT can indicate progression towards concentric hypertrophy. BP reduction after RDN on its own does not reverse concentric remodelling if target BP is not achieved.

A meta-analysis and review on the effectiveness and safety of renal denervation in managing heart failure with reduced ejection fraction.

OBJECTIVE: This study aimed to systematically evaluate the effectiveness and safety of renal denervation (RDN) in managing heart failure with reduced ejection fraction (HFrEF). METHODS: A comprehensive search was done in multiple databases: Cochrane Library, PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP Database for Chinese Technical Periodicals. All clinical trials investigating RDN treatment for HFrEF through 15 March 2024 were gathered. The quality of the included studies was evaluated utilizing the Cochrane risk assessment tool. The pertinent data were gathered, and a meta-analysis was done using Review Manager 5.3, accompanied by sensitivity and publication bias analyses. RESULTS: After applying the inclusion and exclusion criteria, eight randomized controlled trials (RCTs) were selected for analysis, encompassing 314 patients; 154 patients underwent RDN treatment during hospitalization, while 150 were randomized to the control group to receive medication therapy. The meta-analysis demonstrated that compared to medication therapy, RDN contributed to a 9.59% increase in left ventricular ejection fraction (LVEF) (95% CI: 7.92-11.27, Z = 11.20, p < 0.01); a decrease in brain natriuretic peptide (BNP) (95% CI: -364.19--191.75, Z = 6.32, p < 0.01); a decrease in N-terminal pro B-type natriuretic peptide (NT-proBNP) (95% CI: -1300.15--280.95, Z = 3.04, p < 0.01); a decrease in the New York Heart Association (NYHA) classification (95% CI: -1.58--0.34, Z = 3.05, p < 0.01); a 90.00-m increase in 6-min walk test (6MWT) (95% CI: 68.24-111.76, Z = 8.11, p < 0.01); a reduction of 4.05 mm in left ventricular end-diastolic diameter (LVEDD) (95% CI: -5.65--2.48, Z = 5.05, p < 0.01); a decrease of 4.60 heart beats·min-1 (95% CI: -8.83--0.38, Z = 2.14, p < 0.05); and a 4.67-mm reduction in left atrial diameter (LAD) (95% CI: -6.40--2.93, Z = 5.27, p < 0.01). Left ventricular end-systolic diameter (LVESD) and systolic/diastolic blood pressure (OSBP/ODBP) were similar between groups (p > 0.01). As the safety indicator, estimated glomerular filtration rate (eGFR) improved by 7.11 in the RDN group [ml/(min·1.73 m2)] (95% CI: 1.10-13.12, Z = 2.32, p < 0.05). LVEF, BNP, 6MWT, LVEDD, LAD and eGFR were meta-analyzed using a fixed-effects model, the other indicators a random-effects model. CONCLUSION: RDN significantly ameliorated cardiac function in HFrEF patients while exhibiting commendable safety.

Patient Preference for Catheter-Based Hypertension Therapy and Subgroup Analysis: A Pilot Study Based on Taiwan Consensus on Renal Denervation.

Ojective: To understand hypertensive patients' preference for catheter-based therapy to manage hypertension. Methods: Survey data regarding catheter-based therapies performed at MacKay Memorial Hospital in Taipei, Taiwan, between 2019-2020 were analyzed. The questionnaire was circulated either in the clinics or during admission. A total of 46 patients completed the questionnaire. Results: A total of 46 patients (mean age 53.4 ± 13.5 years, 78.3% male) completed the questionnaire. In subgroup analysis according to Taiwan renal denervation (RDN) consensus, patients with drug intolerance (61.8% vs. 31.3%, p = 0.02) were more likely to choose RDN. Moreover, although lacking statistical significance, it is noteworthy that numerically more of the resistant hypertension group (55.6% vs. 28.0%, p = 0.09) and non-adherence group (38.5% vs. 30.0%, p = 0.20) were willing to undergo RDN. Conversely, numerically fewer patients with hypertension-mediated organ damage accepted RDN compared to those who did not have hypertension-mediated organ damage (26.1% vs. 43.5%, p = 0.21), although this disparity did not reach statistical significance. Conclusions: Approximately one-third of the patients expressed interest in considering RDN in this study. The most influential factor in patients' preference for RDN was drug intolerance due to medication-related side effects.

Clinical Trial Design Principles and Outcomes Definitions for Device-Based Therapies for Hypertension: A Consensus Document From the Hypertension Academic Research Consortium.

The clinical implications of hypertension in addition to a high prevalence of both uncontrolled blood pressure and medication nonadherence promote interest in developing device-based approaches to hypertension treatment. The expansion of device-based therapies and ongoing clinical trials underscores the need for consistency in trial design, conduct, and definitions of clinical study elements to permit trial comparability and data poolability. Standardizing methods of blood pressure assessment, effectiveness measures beyond blood pressure alone, and safety outcomes are paramount. The Hypertension Academic Research Consortium (HARC) document represents an integration of evolving evidence and consensus opinion among leading experts in cardiovascular medicine and hypertension research with regulatory perspectives on clinical trial design and methodology. The HARC document integrates the collective information among device-based therapies for hypertension to better address existing challenges and identify unmet needs for technologies proposed to treat the world's leading cause of death and disability. Consistent with the Academic Research Consortium charter, this document proposes pragmatic consensus clinical design principles and outcomes definitions for studies aimed at evaluating device-based hypertension therapies.

Renal nerve stimulation identifies renal innervation and optimizes the strategy for renal denervation in canine.

BACKGROUND: Renal denervation (RDN) was still performed without any intra-procedural method for nerve mapping. Whether renal nerve stimulation (RNS) is an efficient way to identify renal autonomic innervation and optimize the strategy for RDN remain to be worthy for further exploration. METHODS: The characteristics of renal autonomic innervation at the sites with different blood pressure (BP) responses to RNS were explored. Then, dogs anatomically eligible for RDN were randomly assigned into elevated BP response ablation group, reduced BP response ablation group, and RNS-control group. The postoperative outcomes were measured at baseline and after 4 weeks follow-up. RESULTS: The proportion of afferent sensory nerve was higher at elevated BP response sites (ERS) than reduced BP response sites (RRS) and non-response sites (NRS) (P = 0.012 and P = 0.004). Conversely, the proportion of parasympathetic nerve at RRS was the highest (RRS vs. ERS, P = 0.017; RRS vs. NRS, P = 0.023). More importantly, there was a significant correlation between systolic blood pressure changes and the area ratios of afferent sensory and parasympathetic nerve (R = 0.859; P < 0.001). In addition, ablation at BP-elevation sites can result in a significant decrease in BP and plasma norepinephrine (NE) after 4 weeks (P = 0.002; P = 0.008), while ablation at BP-reduction sites can lead to significant increases in BP and plasma NE (P = 0.016; P = 0.033). CONCLUSIONS: RNS is an effective method to identify renal autonomic innervation. It could not only help to identify optimal target sites, but also avoid ablation of sympathetic-inhibitory areas during RDN.

Effect of concomitant Renal DeNervation and cardiac ablation on Atrial Fibrillation recurrence - RDN+AF study.

BACKGROUND: Renal denervation (RDN) can reduce cardiac sympathetic activity maintained by arterial hypertension (aHT). Its potential antiarrhythmic effect on rhythm outcome in patients with multi-drug resistant aHT undergoing catheter ablation for atrial fibrillation (AF) is unclear. METHODS: The RDN+AF study was a prospective, randomized, two-center trial. Patients with paroxysmal or persistent AF and uncontrolled aHT (mean systolic 24-h ambulatory BP > 135 mmHg) despite taking at least three antihypertensive drugs were enrolled. Patients were 1:2 randomized to either RDN+AF ablation or AF-only ablation. Primary endpoint was freedom from any AF episode > 2 min at 12 months assessed by implantable loop recorder (ILR) or 7d-holter electrocardiogram. Secondary endpoints included rhythm outcome at 24 months, blood pressure control, periprocedural complications, and renovascular safety. RESULTS: The study randomized 61 patients (mean age 65 ± 9 years, 53% men). At 12 months, RDN+AF patients tended to have a greater decrease in ambulatory BPs but did not reach statistical significance. No differences in rhythm outcome were observed. Freedom from AF recurrence in the RDN+AF and AF-only group measured 61% versus 53% p = .622 at 12 months and 39% versus 47% p = .927 at 24 months, respectively. Periprocedural complications occurred in 9/61 patients (15%). No patient died. CONCLUSION: Among patients with multidrug-resistant aHT and paroxysmal or persistent AF, concomitant RDN+AF ablation was not associated with better blood pressure control or rhythm outcome in comparison to AF-only ablation and medical therapy.

Denervation aggravates renal ischemia reperfusion injury via BMAL1-mediated Nrf2/ARE pathway.

AIM: To explore the change of clock gene rhythm under renal denervation (RDN) and its effect on renal function and oxidative stress during renal ischemia-reperfusion (IR) injury. METHOD: C57/BL6 mice were randomly divided into 4 groups at daytime 7 A M (zeitgeber time [ZT] 0) or at nighttime 7 P M (ZT12) in respectively: Sham (S) group, RDN group, IR group and RDN + IR (DIR) group. Renal pathological and functional changes were assessed by H&E staining, and serum creatinine, urea nitrogen and neutrophil gelatinase-associated lipocalin levels. Renal oxidative stress was detected by SOD and MDA levels, and renal inflammation was measured by IL-6, IL-17 A F and TNF-ɑ levels. BMAL1, CLOCK, Nrf2 and HO-1 mRNA and protein expressions were tested by qPCR and Western Blot. RESULT: Compared with S groups, the rhythm of BMAL1, CLOCK and Nrf2 genes in the kidney were disordered in RDN groups, while renal pathological and functional indexes did not change significantly. Compared with IR groups, renal pathological and functional indexes were significantly higher in the DIR groups, as well as oxidative stress and inflammation in renal tissues. The nocturnal IR injury in the RDN kidney was the worst while the BMAL1, Nrf2 and HO-1 expressions were the highest. In DIR groups, renal injury was aggravated after the Brusatol treatment, but there was no significant improvement after the t-BHQ treatment at night, which might be consistent with the changes of Nrf2 and HO-1 protein expressions. CONCLUSION: RDN lead to the disruption of BMAL1-mediated Nrf2 rhythm accumulation in the kidney, which reduced the renal ability to resist oxidative stress and inflammation, due to the impaired effect of activating Nrf2/ARE pathway in renal IR injury at nighttime.

Renal denervation in hypertension: An updated meta-analysis of the randomized controlled trials.

BACKGROUND: Radiofrequency or ultrasound renal denervation (RDN) has shown conflicting results when used as an adjunctive option for hypertension management in randomized controlled trials (RCTs). METHODS: We searched Pubmed, MEDLINE, and other online databases for RCTs comparing RDN versus sham-control procedures in patients with uncontrolled or resistant hypertension. The endpoints of interest were 24-h ambulatory (AMB) blood pressure (BP), daytime AMB BP, and office BP. We performed a random-effects meta-analysis using the inverse variance method to estimate mean difference (MD) with a 95% confidence interval (CI). RESULTS: Nine studies with 1643 patients were included in the final analysis. The mean follow-up was 5 months. As compared with the sham-controlled group, RDN was associated with a significant decrease in 24-h AMB BP (systolic [MD -4.20; 95% CI -5.36 to -3.03; p < 0.00001], diastolic [-2.38; -3.42 to -1.35]), and daytime AMB BP (systolic: -5.11; -6.75 to -3.47, diastolic: -2.88; -3.91 to -1.85). Similarly, office BP was reduced with RDN (systolic: -5.46; -7.12 to -3.81; diastolic: -3.17; -4.23 to -2.12) when compared with placebo. CONCLUSION: Our meta-analysis shows that RDN is associated with a significant reduction in the 24-h AMB BP, daytime AMB BP, and office BP.

Renal denervation in patients with chronic kidney disease: current evidence and future perspectives.

Supported by several high-quality randomized controlled trials and registry analyses, catheter-based renal denervation is becoming an important adjunctive treatment modality for the safe and efficacious treatment of hypertension besides lifestyle modifications and antihypertensive medication. Renal denervation is of particular interest to nephrologists as the intervention may provide additional benefits to hypertensive people with chronic kidney disease (CKD), a condition typically characterized by sympathetic hyperactivity. A growing body of clinical evidence supports the safety and efficacy of renal denervation in this difficult-to-control population. In addition, preclinical and clinical research works indicate potential nephroprotective effects in CKD patients. The current review examines recent research on renal denervation with a focus on renal disease and assesses the latest findings and their implications from a nephrologist's perspective.

The effect of catheter-based sham renal denervation in hypertension: systematic review and meta-analysis.

BACKGROUND: Renal denervation (RDN) has emerged in recent years as a possible treatment for hypertension. The first sham-controlled trial showed a small magnitude and non-significant in the blood pressure (BP) lowering effect, also due to a substantial decrease of BP in sham arm. Considering this, we aimed to quantify the magnitude of BP decrease within the sham arm of Randomized Controlled Trials (RCT) with RDN in patients with hypertension. METHODS: Electronic databases were searched since inception until January 2022 for randomized sham-controlled trials which assessed the efficacy in lowering BP of the sham intervention for catheter-based RDN in adult patients with hypertension. The outcomes were change in ambulatory/office systolic and diastolic BP. RESULTS: A total of 9 RCT were included in the analysis enrolling a total of 674 patients. Sham intervention showed a decrease in all evaluated outcomes. Office systolic BP had a reduction of -5.52 mmHg [95%CI -7.91, -3.13] and office diastolic BP of -2.13 mmHg [95%CI -3.08, -1.17]. Sham procedure for RDN also showed a reduction of -3.41 mmHg [95%CI -5.08, -1.75] in ambulatory systolic BP and - 2.44 mmHg [95%CI -3.31, -1.57] in ambulatory diastolic BP. CONCLUSION: Despite recent data indicating that RDN might be an effective treatment for patients with resistant hypertension when compared to a sham intervention, our results indicate that the sham intervention for RDN also has a significant effect on lowering Office and Ambulatory (24-h) Blood Pressure in adult patients with hypertension. This highlights that BP itself might be sensitive to placebo-like effect and also brings further difficulties in establishing the BP lowering efficacy of invasive interventions due to the magnitude of the sham effect.

Differential effects of renal denervation on skin and muscle sympathetic nerve traffic in resistant and uncontrolled hypertension.

PURPOSE: Renal denervation (RDN) exerts sympathoinhibitory effects. No information is available, however, on whether these effects have a regional or a more generalized behavior. METHODS: In 14 patients with resistant hypertension (RHT, age 58.3 ± 2.2 years, mean ± SEM), we recorded muscle and skin sympathetic nerve traffic (MSNA and SSNA, respectively) using the microneurographic technique, before, 1 month, and 3 months after RDN. Measurements included clinic blood pressure (BP), heart rate (HR), 24-h BP and HR, as well as routine laboratory and echocardiographic variables. Ten age-matched RHT patients who did not undergo RDN served as controls. RESULTS: MSNA, but not SSNA, was markedly higher in RHT. RDN caused a significant reduction in MSNA 1 month after RDN, with this reduction increasing after 3 months (from 68.1 ± 2.5 to 64.8 ± 2.4 and 63.1 ± 2.6 bursts/100 heartbeats, P < 0.05). This effect was not accompanied by any significant change in SSNA (from 13.1 ± 0.5 to 13.4 ± 0.6 and 13.3 ± 0.4 bursts/min, P = NS). No quantitative or, in some cases, qualitative relationship was found between BP and the MSNA reduction induced by RDN. No significant changes in various sympathetic markers were detected in the control group who did not undergo RDN and were followed for 3-months observation. CONCLUSIONS: These data provide the first evidence that RDN exerts heterogeneous effects on sympathetic cardiovascular drive, inducing a marked reduction in MSNA but not in SSNA, which appears to be within the normal range in this condition.These effects may depend on the different reflex modulation regulating neuroadrenergic drive in these cardiovascular districts.