Long-term outcomes after catheter-based renal artery denervation for resistant hypertension: final follow-up of the randomised SYMPLICITY HTN-3 Trial

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.

Options for patients with out-of-control blood pressure: after all avenues have been exhausted

INTRODUCTION

Uncontrolled hypertension is the leading risk factor for global mortality. Most hypertensive patients can be controlled with standard medication combinations, but some may not respond adequately to ≥3 or even to ≥5 antihypertensive agents.

AREAS COVERED

In this review, we summarize the recent literature on difficult-to-treat hypertension identified by a Medline search, and we discuss the options for fourth line and subsequent therapy.

EXPERT OPINION

It is essential to confirm resistant hypertension with out-of-office blood pressure measurements and to consider lifestyle factors, adherence to medication and secondary causes of hypertension. When true resistant hypertension is confirmed and blood pressure is not controlled with an optimal triple combination, preferably as a fixed dose combination tablet, spironolactone is usually recommended as the fourth medication. Comorbid conditions should be treated as appropriate with sodium-glucose-cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, sacubitril-valsartan or finerenone. Renal denervation appears to be a useful addition to overcome some of the problems of medication adherence. The endothelin antagonist aprocitentan may be a final option in some countries. Of the drugs in development, the RNA based therapeutics that inhibit angiotensinogen synthesis appear to be some of the most promising.

Assessing the efficacy of renal denervation in patients with resistant arterial hypertension : Systematic review and meta-analysis

BACKGROUND

Renal denervation (RDN) is an innovative procedure designed to regulate the renal sympathetic nervous system for the control of arterial hypertension (HTN). RDN has emerged as an alternative for patients with resistant HTN. However, the clinical efficacy of RDN remains incompletely elucidated.

METHODS

PubMed, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs) comparing the use of RDN with sham procedure or pharmacological treatment in patients with resistant HTN. Statistical analyses were performed using R Studio 4.3.2 (R Foundation for Statistical Computing, Vienna, Austria). Heterogeneity was examined with the Cochran Q test I2 statistics. Mean difference (MD) with 95% confidence interval (CI) were pooled across trials. P values of <0.05 were considered statistically significant. The primary outcomes of interest were changes from baseline in systolic blood pressure (SBP), diastolic blood pressure (DBP), and serum creatinine.

RESULTS

Twenty-one RCTs comprising 3345 patients were included in this meta-analysis, whereby 2004 (59.91%) received renal denervation and 1341 (40.09%) received pharmacological treatment or sham procedure. Follow-up ranged from 2 to 48 months. Compared to control group, RDN significantly reduced SBP (MD -3.53 mm Hg; 95% CI -5.94 to -1.12; p = 0.004; I2 = 74%) and DBP (MD -1.48 mm Hg; 95% CI -2.56 to -0.40; p = 0.007; I2 = 51%). Regarding serum creatinine (MD -2.51; 95% CI -7.90 to 2.87; p = 0.36; I2 = 40%), there was no significant difference between RDN and control groups.

CONCLUSION

In this meta-analysis of RCTs of patients with resistant HTN, RDN was associated with a reduction in SBP and DBP compared to sham procedure or pharmacological treatment.

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.

Revisiting sex as a biological variable in hypertension research

Half of adults in the United States have hypertension as defined by clinical practice guidelines. Interestingly, women are generally more likely to be aware of their hypertension and have their blood pressure controlled with treatment compared with men, yet hypertension-related mortality is greater in women. This may reflect the fact that the female sex remains underrepresented in clinical and basic science studies investigating the effectiveness of therapies and the mechanisms controlling blood pressure. This Review provides an overview of the impact of the way hypertension research has explored sex as a biological variable (SABV). Emphasis is placed on epidemiological studies, hypertension clinical trials, the genetics of hypertension, sex differences in immunology and gut microbiota in hypertension, and the effect of sex on the central control of blood pressure. The goal is to offer historical perspective on SABV in hypertension, highlight recent studies that include SABV, and identify key gaps in SABV inclusion and questions that remain in the field. Through continued awareness campaigns and engagement/education at the level of funding agencies, individual investigators, and in the editorial peer review system, investigation of SABV in the field of hypertension research will ultimately lead to improved clinical outcomes.

Resistant hypertension: diagnosis, evaluation, and treatment a clinical consensus statement from the Thai hypertension society

Resistant hypertension (RH) includes hypertensive patients with uncontrolled blood pressure (BP) while receiving ≥3 BP-lowering medications or with controlled BP while receiving ≥4 BP-lowering medications. The exact prevalence of RH is challenging to quantify. However, a reasonable estimate of true RH is around 5% of the hypertensive population. Patients with RH have higher cardiovascular risk as compared with hypertensive patients in general. Standardized office BP measurement, confirmation of medical adherence, search for drug- or substance-induced BP elevation, and ambulatory or home BP monitoring are mandatory to exclude pseudoresistance. Appropriate further investigations, guided by clinical data, should be pursued to exclude possible secondary causes of hypertension. The management of RH includes the intensification of lifestyle interventions and the modification of antihypertensive drug regimens. The essential aspects of lifestyle modification include sodium restriction, body weight control, regular exercise, and healthy sleep. Step-by-step adjustment of the BP-lowering drugs based on the available evidence is proposed. The suitable choice of diuretics according to patients' renal function is presented. Sacubitril/valsartan can be carefully substituted for the prior renin-angiotensin system blockers, especially in those with heart failure with preserved ejection fraction. If BP remains uncontrolled, device therapy such as renal nerve denervation should be considered. Since device-based treatment is an invasive and costly procedure, it should be used only after careful and appropriate case selection. In real-world practice, the management of RH should be individualized depending on each patient's characteristics.

Effects of renal denervation on the incidence and severity of cardiovascular diseases

Renal denervation (RDN) is a neuromodulation therapy performed in patients with hypertension using an intraarterial catheter. Recent randomized sham-controlled trials have shown that RDN has significant antihypertensive effects that last for more than 3 years. Based on this evidence, the US Food and Drug Administration has approved two devices, the ultrasound-based ReCor ParadiseTM RDN system and the radiofrequency-based Medtronic Symplicity SpyralTM RDN system, as adjunctive therapy for patients with refractory and uncontrolled hypertension. On the other hand, there have been no randomized sham-controlled prospective outcome trials on RDN, and the effects of RDN on cardiovascular events such as myocardial infarction, heart failure, and stroke have not been elucidated. This mini-review summarizes the latest findings focusing on the effects of RDN on organ protection and physiological function and symptoms in both preclinical and clinical studies. Furthermore, the feasibility of using blood pressure as surrogate marker for cardiovascular outcomes is discussed in the context of relevant clinical studies on RDN. A comprehensive understanding of the beneficial effects of RDN on the incidence and severity of cardiovascular diseases with their underlying mechanisms will enhance physicians' ability to incorporate RDN into clinical strategies to prevent cardiovascular events including myocardial infarction, heart failure, and stroke. This mini-review focuses on the effects of RDN on organ protection and physiological function and symptoms in preclinical and clinical studies. RDN is expected to reduce the onset and progression of cardiovascular diseases including myocardial infarction, heart failure, and stroke in clinical practice. LV left ventricular, LVEF left ventricular ejection fraction, VO2max maximal oxygen uptake, VT ventricular tachycardia, VF ventricular fibrillation, 6MWD 6-min walk distance, NT-proBNP N-terminal pro-B-type natriuretic peptide, NYHA New York Heart Association, BBB blood-brain barrier, BP blood pressure.

What are the ideal metrics for assessing the quality of long-term stabilized "perfect" 24-h BP control after renal denervation?

A significant number of individuals being treated for hypertension still have uncontrolled blood pressure (BP). In Japan, renal denervation (RDN) is being introduced into clinical practice as an adjunctive treatment for hypertension that is uncontrolled despite adequate lifestyle changes and maximal antihypertensive drug therapy. The pivotal SPYRAL ON-MED trial showed that there was a significant reduction in trough office and nighttime ambulatory BP values in the RDN group compared with sham control group, although 24-h and daytime BP values were not significantly different between the two groups. The trough office BP measurement (taken before morning antihypertensive dosing) is similar to guideline recommendations for taking morning home BP before taking the morning antihypertensive drug dose. Recent guidelines recommend the measurement of nighttime BP because nighttime BP is a stronger predictor of cardiovascular event risk than daytime BP. It is particularly important to assess nighttime BP in medicated individuals with hypertension because the up- or down-titration of antihypertensive drug dosing is primarily based on office and daytime BPs in clinical practice. This means that there may be significant risk relating to nocturnal hypertension during longer follow-up. Because RDN results in persistent, "always-on" 24-h BP-lowering effects, the best BP metrics to assess the potential benefit of RDN are nighttime BP (determined using home or ambulatory BP monitoring) and morning BP (determined using home BP monitoring or morning trough office BP measurement). The variability of office, home, and ambulatory BP values is another important metric to assess the quality of RDN-related BP lowering.

The Current State and Future of Renal Denervation: A Review

Renal denervation as an option for difficult to treat hypertension has been a concept for several decades, with recent U.S. FDA approval of new, minimally invasive devices. However, while renal denervation has the potential to improve hypertension management, several challenges require consideration prior to widespread adoption. The effect relative to sham control is modest, and generally similar to addition of a single blood pressure lowering medication. It is possible that with additional technique refinement greater effects may be possible. Key factors to consider beyond the direction, strengths, and limitations of the renal denervation technologies themselves, are an understanding of patient groups that derive greatest benefit and phenotypes or biomarkers that predict greater response. This review provides an update on these challenges in addition to the current state and future of renal denervation within the context of hypertension management and treatment.

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.

Italian Society of Interventional Cardiology (GISE) and Italian Society of Arterial Hypertension (SIIA) Position Paper on the role of renal denervation in the management of the difficult-to-treat hypertension

Renal denervation (RDN) is a safe and effective strategy for the treatment of difficult to treat hypertension. The blood pressure (BP)-lowering efficacy of RDN is comparable to those of many single antihypertensive medications and it allows to consider the RDN as a valuable option for the treatment of difficult to treat hypertension together with lifestyle modifications and medical therapy. A multidisciplinary team is of pivotal importance from the selection of the patient candidate for the procedure to the post-procedural management. Further studies are needed to investigate the effect of RDN on clinical outcomes and to better identify the predictors of BP response to RDN in order to recognize the patients who are more likely to benefit from the procedure.

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.

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.

Differences in the effectiveness and safety of different renal denervation devices

Renal denervation (RDN) is a minimally invasive, endovascular catheter-based procedure using radiofrequency, ultrasound, or alcohol-mediated ablation to treat resistant hypertension. RDN gained popularity in 2009 when it was shown to have an antihypertensive effect. However, concerns about the efficacy of RDN were raised in the HTN-3 trial published in 2014, and the development of several RDN devices was then discontinued. In the process, new randomized controlled trials were conducted after the development of some of the RDN devices, the quality assurance of the procedure, changes in ablation points, and improvements in study design. In November 2023, the U.S. Food and Drug Administration approved a radiofrequency RDN device and an ultrasound RDN device. The results of a randomized controlled trial of an alcohol-mediated RDN device have been published, and future trends are being watched closely. In this mini-review, we summarize the differences in the antihypertensive effect and safety of the different RDN devices and the endpoints of the procedure in order to contribute to the further development of RDN devices Currently available renal denervation device. A multielectrode radiofrequency ablation (Spyral), (B) ultrasound denervation (Paraise), and (C) alcohol-mediated perivascular denervation (Peregrine). ASBP ambulatory systolic blood pressure, ADBP ambulatory diastolic blood pressure, OSBP office systolic blood pressure, ODBP office diastolic blood pressure. Analysis according to types of renal denervation device (radiofrequency, ultrasound, or alcohol-mediated device). P values for interaction were 0.578 (ambulatory SBP), 0.499 (ambulatory diastolic BP), 0.853 (office SBP), and 0.870 (office diastolic BP).

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.

Controversies related to renal artery denervation and devices

PURPOSE OF REVIEW

This review article discusses the controversies, strengths, and limitations of the current literature on renal artery denervation in the management of resistant hypertension, as well as the future directions of this intervention.

RECENT FINDINGS

There have been conflicting data from the different randomized control trials assessing the efficacy of renal artery denervation in the management of resistant hypertension.

SUMMARY

Renal artery denervation is achieved by ablating the sympathetic nerves surrounding the renal arteries using endovascular ultrasound, radiofrequency, or alcohol. Our review article highlights that renal artery denervation is generally effective in improving blood pressure in patients with resistant hypertension. The Food and Drug Administration (FDA) has recently approved the ReCor Medical Paradise system, and the Symplicity Spyral RDN systems for renal artery denervation.

Effects of Renal Denervation on Ouabain-Induced Hypertension in Rats

Background

Ouabain, a Na+, K+-ATPase inhibitor, is elevated in hypertensive patients. Evidence suggests ouabain contributes to hypertension mainly through activation of the sympathetic nervous system (SNS). Renal nerves play a vital role in the regulation of SNS activity, so we hypothesize that renal denervation may attenuate the development of ouabain-induced hypertension.

Methods and Results

Forty Sprague-Dawley rats were divided into following groups (n = 10 each): control group (sham surgery plus intraperitoneal saline injection), RDN group (renal denervation (RDN) plus intraperitoneal saline injection), ouabain group (sham surgery plus intraperitoneal ouabain injection), and ouabain + RDN group (RDN plus intraperitoneal ouabain injection). After eight weeks, compared with the control group, rats in the ouabain group exhibited elevated blood pressure (P < 0.05), increased plasma epinephrine, norepinephrine, angiotensin II, and aldosterone levels (P < 0.05). These indexes could be significantly ameliorated by RDN. RDN also reduced the thickening of aortic tunica media and downregulated the expression of proliferating cell nuclear antigen (PCNA) in the thoracic aorta induced by ouabain. Masson staining and echocardiography showed that myocardial fibrosis and increased left ventricular mass in the ouabain group could be attenuated by RDN.

Conclusions

The present study reveals that renal nerves play an important role in the development of ouabain-induced hypertension. RDN could inhibit the pressor effect and the myocardial remodeling induced by ouabain potentially via inhibiting catecholamine release and vascular smooth muscle cell proliferation. Clinical studies are needed to explore whether RDN may exhibit better antihypertensive effects on hypertensive patients with high plasma ouabain levels as compared to those with normal plasma ouabain levels.

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.

Effects of catheter-based renal denervation in hypertension: a systematic review and meta-analysis

Background

Several sham-controlled trials have investigated the efficacy and safety of catheter-based renal denervation (RDN) with mixed outcomes.

Aim

To perform a comprehensive meta-analysis of all randomized, sham-controlled trials investigating RDN with first- and second-generation devices in hypertension.

Methods

We searched MEDLINE and Cochrane Library for eligible trials. Outcomes included both efficacy (24-hour and office systolic [SBP] and diastolic blood pressure [DBP]) and safety (all-cause death, vascular complication, renal artery stenosis >70%, hypertensive crisis) of RDN. We performed a study-level, pairwise, random-effects meta-analysis of the summary data.

Results

Ten trials comprising 2,478 patients with hypertension while being either off- or on-treatment were included. Compared with sham, RDN reduced 24-hour and office systolic BP by 4.4 mmHg (95%CI -6.1, -2.7, p<0.00001) and 6.6 mmHg (95%CI -9.7, -3.6, p<0.0001), respectively. The 24-hour and office diastolic BP paralleled these findings (-2.6 mmHg, 95%CI - 3.6, -1.5, p<0.00001; -3.5 mmHg, 95%CI -5.4, -1.6, p=0.0003). There was no difference in 24-hour and office SBP reduction between trials with and without concomitant antihypertensive medication (p for interaction 0.62 and 0.73, respectively). There was no relevant difference concerning vascular complications (OR 1.69, 95%CI 0.57-5.0, p=0.34), renal artery stenosis (OR 1.50, 95%CI 0.06-36.97, p=0.80), hypertensive crisis (OR 0.65, 95%CI 0.30-1.38, p=0.26) and all-cause death (OR 1.76, 95%CI 0.34-9.20, p=0.50) between RDN and sham groups. Change of renal function based on eGFR was comparable between groups (p for interaction 0.84). There was significant heterogeneity between trials.

Conclusions

RDN safely reduces ambulatory and office SBP/DBP vs. a sham procedure in the presence and absence of antihypertensive medication.

Clinical Perspective

What is new?Several sham-controlled trials have investigated the efficacy and safety of catheter-based renal denervation (RDN) with mixed outcomes.This comprehensive meta-analysis comprising 2,478 patients shows that irrespective of the utilized method (radiofrequency-, ultrasound-or alcohol-mediated), renal denervation effectively reduced ambulatory and office systolic blood pressure.Renal denervation exhibited no additional risk concerning vascular injury or renal function impairment.What are the clinical implications?This meta-analysis supports current guidelines/consensus statements that renal denervation represents an additive treatment option in carefully selected patients with uncontrolled hypertension.

Left ventricular structure and function following renal sympathetic denervation in patients with HFpEF: an echocardiographic 9-year long-term follow-up

Background

High blood pressure is a major risk factor for cardiac remodeling and left ventricular hypertrophy, increasing cardiovascular risk and leading to heart failure with preserved ejection fraction (HFpEF). Since renal sympathetic denervation (RDN) reduces blood pressure in the long term, we aimed to investigate the long-term effect of RDN in patients with HFpEF in the present analysis.

Methods

Patients previously enrolled in a local RDN registry who underwent high-frequency RDN with the use of the Symplicity Flex® renal denervation system between 2011 and 2014 were followed up. The patients were assessed by 24-h ambulatory blood pressure measurement, transthoracic echocardiography, and laboratory tests. We used the echocardiographic and biomarker criteria of the Heart Failure Association (HFA)-PEFF (Pre-test assessment, Echocardiography and Natriuretic Peptide Score, Funkctional testing, and Final aetiology) score to identify patients with HFpEF.

Results

Echocardiographic assessment was available for 70 patients at a 9-year long-term follow-up. Of these patients, 21 had HFpEF according to the HFA-PEFF score. We found a significant reduction of the HFA-PEFF score from 5.48 ± 0.51 points at baseline to 4.33 ± 1.53 points at the 9-year follow-up (P < 0.01). This decrease was due to a greater reduction in morphological and biomarker subcategories [from 1.95 ± 0.22 to 1.43 ± 0.51 points (P < 0.01) and from 1.52 ± 0.52 to 0.90 ± 0.63 points (P < 0.01), respectively] than in the functional one. Morphologically, there was a reduction in left ventricular hypertrophy and left atrial dilation.

Conclusions

The present analysis suggests that RDN may lead to a regression of the extent of HFpEF beyond a reduction in blood pressure and thus possibly contribute to an improvement in prognosis. More detailed information will be provided by ongoing randomized sham-controlled trials.

Effects of renal denervation on blood pressure in patients with hypertension: a latest systematic review and meta-analysis of randomized sham-controlled trials

The efficacy of renal denervation (RDN) has been controversial, but recent randomized sham-controlled trials demonstrated significant blood pressure reductions after RDN in patients with hypertension. We conducted a systematic review and updated meta-analysis to evaluate the effects of RDN on ambulatory and office blood pressures in patients with hypertension. Databases were searched up to 15 November 2023 to identify randomized, sham-controlled trials of RDN. The primary endpoint was change in 24 h ambulatory systolic blood pressure (SBP) with RDN versus sham control. The secondary endpoints were changes in 24 h ambulatory diastolic blood pressure, daytime and nighttime blood pressure (BP), office BP, and home BP. A sub-analysis determined outcomes by medication, procedure, and device. From twelve trials, 2222 patients with hypertension were randomized to undergo RDN (n = 1295) or a sham procedure (n = 927). At 2-6 months after treatment, RDN significantly reduced 24 h ambulatory SBP by 2.81 mmHg (95% confidence interval: -4.09, -1.53; p < 0.001) compared with the sham procedure. RDN also reduced daytime SBP by 3.17 mmHg (- 4.75, - 1.58; p < 0.001), nighttime SBP by 3.41 mmHg (- 4.69, - 2.13; p < 0.001), office SBP by 4.95 mmHg (- 6.37, - 3.54; p < 0.001), and home SBP by 4.64 mmHg (- 7.44, - 1.84; p = 0.001) versus the sham control group. There were no significant differences in the magnitude of BP reduction between first- and second-generation trials, between devices, or between with or without medication. These data from randomized sham-controlled trials showed that RDN significantly reduced all blood pressure metrics in medicated or unmedicated patients with hypertension, including resistant/uncontrolled hypertension.

Long-Term Blood Pressure Reductions Following Catheter-Based Renal Denervation: A Systematic Review and Meta-Analysis

BACKGROUND

Renal denervation is a recognized adjunct therapy for hypertension with clinically significant blood pressure (BP)-lowering effects. Long-term follow-up data are critical to ascertain durability of the effect and safety. Aside from the 36-month follow-up data available from randomized control trials, recent cohort analyses extended follow-up out to 10 years. We sought to analyze study-level data and quantify the ambulatory BP reduction of renal denervation across contemporary randomized sham-controlled trials and available long-term follow-up data up to 10 years from observational studies.

METHODS

A systematic review was performed with data from 4 observational studies with follow-up out to 10 years and 2 randomized controlled trials meeting search and inclusion criteria with follow-up data out to 36 months. Study-level data were extracted and compared statistically.

RESULTS

In 2 contemporary randomized controlled trials with 36-month follow-up, an average sham-adjusted ambulatory systolic BP reduction of -12.7±4.5 mm Hg from baseline was observed (P=0.05). Likewise, a -14.8±3.4 mm Hg ambulatory systolic BP reduction was found across observational studies with a mean long-term follow-up of 7.7±2.8 years (range, 3.5-9.4 years; P=0.0051). The observed reduction in estimated glomerular filtration rate across the long-term follow-up was in line with the predicted age-related decline. Antihypertensive drug burden was similar at baseline and follow-up.

CONCLUSIONS

Renal denervation is associated with a significant and clinically meaningful reduction in ambulatory systolic BP in both contemporary randomized sham-controlled trials up to 36 months and observational cohort studies up to 10 years without adverse consequences on renal function.

Efficacy and safety of sympathetic mapping and ablation of renal nerves for the treatment of hypertension (SMART): 6-month follow-up of a randomised, controlled trial

Background

Previous trials of renal denervation (RDN) have been designed to investigate reduction of blood pressure (BP) as the primary efficacy endpoint using non-selective RDN without intraoperatively verified RDN success. It is an unmet clinical need to map renal nerves, selectively denervate renal sympathetic nerves, provide readouts for the interventionalists and avoid futile RDN. We aimed to examine the safety and efficacy of renal nerve mapping/selective renal denervation (msRDN) in patients with uncontrolled hypertension (HTN) and determine whether antihypertensive drug burden is reduced while office systolic BP (OSBP) is controlled to target level (＜140 mmHg).

Methods

We conducted a randomized, prospective, multicenter, single-blinded, sham-controlled trial. The study combined two efficacy endpoints at 6 months as primary outcomes: The control rate of patients with OSBP ＜140 mmHg (non-inferior outcome) and change in the composite index of antihypertensive drugs (Drug Index) in the treatment versus Sham group (superior outcome). This design avoids confounding from excess drug-taking in the Sham group. Antihypertensive drug burden was assessed by a composite index constructed as: Class N (number of classes of antihypertensive drugs) × (sum of doses). 15 hospitals in China participated in the study and 220 patients were enrolled in a 1:1 ratio (msRDN vs Sham). The key inclusion criteria included: age (18-65 years old), history of essential HTN (at least 6 months), heart rate (≥70 bpm), OSBP (≥150 mmHg and ≤180 mmHg), ambulatory BP monitoring (ABPM, 24-h SBP ≥130 mmHg or daytime SBP ≥135 mmHg or nighttime SBP ≥120 mmHg), renal artery stenosis (＜50%) and renal function (eGFR ＞45 mL/min/1.73 m2). The catheter with both stimulation and ablation functions was inserted in the distal renal main artery. The RDN site (hot spot) was selected if SBP increased (≥5 mmHg) by intra-renal artery (RA) electrical stimulation; an adequate RDN was confirmed by repeated electronic stimulation if no increase in BP otherwise, a 2nd ablation was performed at the same site. At sites where there was decreased SBP (≥5 mmHg, cold spot) or no BP response (neutral spot) to stimulation, no ablation was performed. The mapping, ablation and confirmation procedure was repeated until the entire renal main artery had been tested then either treated or avoided. After msRDN, patients had to follow a predefined, vigorous drug titration regimen in order to achieve target OSBP (＜140 mmHg). Drug adherence was monitored by liquid chromatography-tandem mass spectrometry analysis using urine. This study is registered with ClinicalTrials.gov (NCT02761811) and 5-year follow-up is ongoing.

Findings

Between July 8, 2016 and February 23, 2022, 611 patients were consented, 220 patients were enrolled in the study who received standardized antihypertensive drug treatments (at least two drugs) for at least 28 days, presented OSBP ≥150 mmHg and ≤180 mmHg and met all inclusion and exclusion criteria. In left RA and right RA, mapped sites were 8.2 (3.0) and 8.0 (2.7), hot/ablated sites were 3.7 (1.4) and 4.0 (1.6), cold spots were 2.4 (2.6) and 2.0 (2.2), neutral spots were 2.0 (2.1) and 2.0 (2.1), respectively. Hot, cold and neutral spots was 48.0%, 27.5% and 24.4% of total mapped sites, respectively. At 6 M, the Control Rate of OSBP was comparable between msRDN and Sham group (95.4% vs 92.8%, p = 0.429), achieved non-inferiority margin -10% (2.69%; 95% CI -4.11%, 9.83%, p ＜ 0.001 for non-inferiority); the change in Drug Index was significantly lower in msRDN group compared to Sham group (4.37 (6.65) vs 7.61 (10.31), p = 0.010) and superior to Sham group (-3.25; 95% CI -5.56, -0.94, p = 0.003), indicating msRDN patients need significantly fewer drugs to control OSBP ＜140 mmHg. 24-hour ambulatory SBP decreased from 146.8 (13.9) mmHg by 10.8 (14.1) mmHg, and from 149.8 (12.8) mmHg by 10.0 (14.0) mmHg in msRDN and Sham groups, respectively (p < 0.001 from Baseline; p > 0.05 between groups). Safety profiles were comparable between msRDN and Sham groups, demonstrating the safety and efficacy of renal mapping/selective RDN to treat uncontrolled HTN.

Interpretation

The msRDN therapy achieved the goals of reducing the drug burden of HTN patients and controlling OSBP <140 mmHg, with only approximately four targeted ablations per renal main artery, much lower than in previous trials.

Funding

SyMap Medical (Suzhou), LTD, Suzhou, China.

siRNA takes a jab at hypertension

Hypertension is a modifiable risk factor for cardiovascular disease, the leading cause of death worldwide, yet most US adults with hypertension do not meet goal blood pressure. KARDIA-1 demonstrates the efficacy of zilebesiran, a subcutaneously administered small interfering RNA, for lowering blood pressure, presenting a novel treatment option for this deadly disease.1.

Ten-year follow-up of very-high risk hypertensive patients undergoing renal sympathetic denervation

OBJECTIVES

Renal denervation (RDN) has been proven to be effective in lowering blood pressure (BP) in patients, but previous studies have had short follow-ups and have not examined the effects of RDN on major cardiovascular outcomes. This study aimed to demonstrate the effectiveness and safety of RDN in the long-term treatment of hypertension and to determine if it has an effect on cardiovascular outcomes.

METHODS

All patients with resistant hypertension who underwent RDN between 2011 and 2015 at Tianjin First Central Hospital were included in the study. Patients were followed up at 1,5 and 10 years and the longest follow-up was 12 years. Data were collected on office BP, home BP, ambulatory BP monitoring (ABPM), renal function, antihypertensive drug regimen, major adverse events (including acute myocardial infarction, stroke, cardiovascular death and all cause death) and safety events.

RESULTS

A total of 60 participants with mean age 50.37 ± 15.19 years (43.33% female individuals) completed long-term follow-up investigations with a mean of 10.02 ± 1.72 years post-RDN. Baseline office SBP and DBP were 179.08 ± 22.05 and 101.17 ± 16.57 mmHg under a mean number of 4.22 ± 1.09 defined daily doses (DDD), with a reduction of -35.93/-14.76 mmHg as compared with baseline estimates ( P  < 0.0001). Compared with baseline, ambulatory SBP and DBP after 10-years follow-up were reduced by 14.31 ± 10.18 ( P  < 0.001) and 9 ± 4.35 ( P  < 0.001) mmHg, respectively. In comparison to baseline, participants were taking fewer antihypertensive medications ( P  < 0.001), and their mean heart rate had decreased ( P  < 0.001). Changes in renal function, as assessed by estimated glomerular filtration rate (eGFR) and creatinine, were within the expected rate of age-related decline. No major adverse events related to the RDN procedure were observed in long-term consequences. All-cause mortality and cardiovascular mortality rates were 10 and 8.34%, respectively, for the 10-year period.

CONCLUSION

The BP-lowering effect of RDN was safely sustained for at least 10 years post-procedure. More importantly, to the best of my knowledge, this is the first study to explore cardiovascular and all-cause mortality at 10 years after RDN.

Salt sensitivity risk derived from nocturnal dipping and 24-h heart rate predicts long-term blood pressure reduction following renal denervation

BACKGROUND

Renal denervation (RDN) has been consistently shown in recent sham-controlled clinical trials to reduce blood pressure (BP). Salt sensitivity is a critical factor in hypertension pathogenesis, but cumbersome to assess by gold-standard methodology. Twenty-four-hour average heart rate (HR) and mean arterial pressure (MAP) dipping, taken by ambulatory blood pressure monitoring (ABPM), stratifies patients into high, moderate, and low salt sensitivity index (SSI) risk categories.

OBJECTIVES

We aimed to assess whether ABPM-derived SSI risk could predict the systolic blood pressure reduction at long-term follow-up in a real-world RDN patient cohort.

METHODS

Sixty participants had repeat ABPM as part of a renal denervation long-term follow-up. Average time since RDN was 8.9 ± 1.2 years. Based on baseline ABPM, participants were stratified into low (HR < 70 bpm and MAP dipping > 10%), moderate (HR ≥70 bpm or MAP dipping ≤ 10%), and high (HR ≥ 70 bpm and MAP dipping ≤ 10%) SSI risk groups, respectively.

RESULTS

One-way ANOVA indicated a significant treatment effect ( P  = 0.03) between low ( n  = 15), moderate ( n  = 35), and high ( n  = 10) SSI risk with systolic BP reduction of 9.6 ± 3.7 mmHg, 8.4 ± 3.5 mmHg, and 28.2 ± 9.6 mmHg, respectively. Baseline BP was not significantly different between SSI Risk groups ( P  = 0.18). High SSI risk independently correlated with systolic BP reduction ( P  = 0.02).

CONCLUSIONS

Our investigation indicates that SSI risk may be a simple and accessible measure for predicting the BP response to RDN. However, the influence of pharmacological therapy on these participants is an important extraneous variable requiring testing in prospective or drug naive RDN cohorts.

Characterization of a phenol-based model for denervation of the abdominal aorta and its implications for aortic remodeling

Objective

Sympathetic innervation plays a pivotal role in regulating cardiovascular health, and its dysregulation is implicated in a wide spectrum of cardiovascular diseases. This study seeks to evaluate the impact of denervation of the abdominal aorta on its morphology and wall homeostasis.

Methods

Male and female Sprague-Dawley rats (N = 12), aged 3 months, underwent midline laparotomy for infrarenal aorta exposure. Chemical denervation was induced via a one-time topical application of 10% phenol (n = 6), whereas sham controls received phosphate-buffered saline (n = 6). Animals were allowed to recover and subsequently were sacrificed after 6 months for analysis encompassing morphology, histology, and immunohistochemistry.

Results

At 6 months post-treatment, abdominal aortas subjected to phenol denervation still exhibited a significant reduction in nerve fiber density compared with sham controls. Denervated aortas demonstrated reduced intima-media thickness, increased elastin fragmentation, decreased expression of vascular smooth muscle proteins (α-SMA and MYH11), and elevated adventitial vascular density. Sex-stratified analyses revealed additional dimorphic responses, particularly in aortic collagen and medial cellular density in female animals.

Conclusions

Single-timepoint phenol-based chemical denervation induces alterations in abdominal aortic morphology and vascular remodeling over a 6-month period. These findings underscore the potential of the sympathetic nervous system as a therapeutic target for aortic pathologies.

Clinical Relevance

Aortic remodeling remains an important consideration in the pathogenesis of aortic disease, including occlusive, aneurysmal, and dissection disease states. The paucity of medical therapies for the treatment of aortic disease has driven considerable interest in elucidating the pathogenesis of these conditions; new therapeutic targets are critically needed. Here, we show significant remodeling after phenol-induced denervation with morphologic, histologic, and immunohistochemical features. Future investigations should integrate sympathetic dysfunction as a potential driver of pathologic aortic wall changes with additional consideration of the sympathetic nervous system as a therapeutic target.

Comprehensive mapping of sensory and sympathetic innervation of the developing kidney

The kidney functions as a finely tuned sensor to balance body fluid composition and filter out waste through complex coordinated mechanisms. This versatility requires tight neural control, with innervating efferent nerves playing a crucial role in regulating blood flow, glomerular filtration rate, water and sodium reabsorption, and renin release. In turn sensory afferents provide feedback to the central nervous system for the modulation of cardiovascular function. However, the cells targeted by sensory afferents and the physiological sensing mechanisms remain poorly characterized. Moreover, how the kidney is innervated during development to establish these functions remains elusive. Here, we utilized a combination of light-sheet and confocal microscopy to generate anatomical maps of kidney sensory and sympathetic nerves throughout development and resolve the establishment of functional crosstalk. Our analyses revealed that kidney innervation initiates at embryonic day (E)13.5 as the nerves associate with vascular smooth muscle cells and follow arterial differentiation. By E17.5 axonal projections associate with kidney structures such as glomeruli and tubules and the network continues to expand postnatally. These nerves are synapsin I-positive, highlighting ongoing axonogenesis and the potential for functional crosstalk. We show that sensory and sympathetic nerves innervate the kidney concomitantly and classify the sensory fibers as calcitonin gene related peptide (CGRP)+, substance P+, TRPV1+, and PIEZO2+, establishing the presence of PIEZO2 mechanosensory fibers in the kidney. Using retrograde tracing, we identified the primary dorsal root ganglia, T10-L2, from which PIEZO2+ sensory afferents project to the kidney. Taken together our findings elucidate the temporality of kidney innervation and resolve the identity of kidney sympathetic and sensory nerves.

The feasibility, efficacy, and safety of RDN procedure using CO2 angiography through radial artery in severe chronic kidney disease patients

The recent evidence regarding the effectiveness of renal denervation (RDN) in blood pressure control is becoming increasingly substantial. However, many studies have excluded populations with severely impaired kidney function, even though these individuals have a higher prevalence of hypertension compared to the general population, and controlling their blood pressure is more challenging. The effectiveness and safety of RDN in patients with severe chronic kidney disease (CKD) lack strong evidence support. Concerns about worsening kidney function still exist, particularly in patients with CKD stage 5. We conducted an observational study involving 10 patients who were using at least 3 different antihypertensive medications and had an estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m2 but had not undergone dialysis. For these patients, we performed RDN via the radial artery approach, with the assistance of carbon dioxide (CO2) angiography. Utilizing this approach, the systolic 24-hour ambulatory blood pressure monitoring did not exhibit a significant decrease at 3 months; however, a significant reduction was observed at 6 months after RDN. We also minimized contrast agent usage, observed no kidney function decline 3 months post-RDN, and experienced no vascular-related complications. Using the radial artery approach and CO2 angiography assistance for RDN may be an effective and safe blood pressure control method for patients with severe kidney impairment.

Current perspective on circadian function of the kidney

Behavior and function of living systems are synchronized by the 24-h rotation of the Earth that guides physiology according to time of day. However, when behavior becomes misaligned from the light-dark cycle, such as in rotating shift work, jet lag, and even unusual eating patterns, adverse health consequences such as cardiovascular or cardiometabolic disease can arise. The discovery of cell-autonomous molecular clocks expanded interest in regulatory systems that control circadian physiology including within the kidney, where function varies along a 24-h cycle. Our understanding of the mechanisms for circadian control of physiology is in the early stages, and so the present review provides an overview of what is known and the many gaps in our current understanding. We include a particular focus on the impact of eating behaviors, especially meal timing. A better understanding of the mechanisms guiding circadian function of the kidney is expected to reveal new insights into causes and consequences of a wide range of disorders involving the kidney, including hypertension, obesity, and chronic kidney disease.

Efficacy of pharmacological and interventional treatment for resistant hypertension: a network meta-analysis

AIMS

Resistant hypertension is associated with a high risk of cardiovascular disease, chronic kidney disease, and mortality. Yet, its management is challenging. This study aims to establish the comparative effectiveness of pharmacologic and interventional treatments by conducting a network meta-analysis.

METHODS AND RESULTS

MEDLINE, Cochrane Register of Controlled Trials, and Web of Science Core Collection were systematically searched in March 2022. Randomized controlled trials comparing treatment options for management of resistant hypertension were included. Outcomes were blood pressure (BP) changes, measured in the office and in 24 h ambulatory BP measurement. We applied a frequentist random effects model to perform a network meta-analysis combining placebo medication and sham procedure as the reference comparator. From 4771 records, 24 studies met the inclusion criteria with 3458 included patients in total. Twelve active treatment alternatives [spironolactone, doxazosin, β-blocker, clonidine, darusentan, guanfacine, various types of renal sympathetic denervation, lifestyle intervention, continuous positive airway pressure, and baroreflex activation therapy (BAT)] were analysed. Among all comparators, spironolactone had the highest ranking probability and was considered the most effective treatment to reduce office systolic blood pressure (sBP) [-13.30 mmHg (-17.89; -8.72); P < 0.0001] and 24 h sBP [-8.46 mmHg (-12.54; -4.38); P < 0.0001] in patients with resistant hypertension. Lifestyle interventions were the most effective non-pharmacological treatment, lowering office sBP by -7.26 mmHg (-13.73; -0.8), whereas BAT lowered office sBP by -7.0 (-18.59; 4.59). Renal denervation lowered office sBP by -5.64 mmHg (-12.95; 1.66) and -3.79 mmHg (-11.39; 3.8) depending on the type of the procedure.

CONCLUSION

Among all pharmacologic and interventional treatments, spironolactone is the most effective treatment in reducing BP in patients with resistant hypertension. More comparative trials and especially trials with long-term follow-up are needed. In the meanwhile, we have to conclude that a combination of spironolactone and lifestyle modification are the most effective treatments in resistant hypertension.

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.

Renal Denervation in End-Stage Renal Disease: Current Evidence and Perspectives

In patients with end-stage renal disease (ESRD) undergoing haemodialysis, hypertension is of common detection and frequently inadequately controlled. Multiple pathophysiological mechanisms are involved in the development and progression of the ESRD-related high blood pressure state, which has been implicated in the increased cardiovascular risk reported in this hypertensive clinical phenotype. Renal sympathetic efferent and afferent nerves play a relevant role in the development and progression of elevated blood pressure values in patients with ESRD, often leading to resistant hypertension. Catheter-based bilateral renal nerves ablation has been shown to exert blood pressure lowering effects in resistant hypertensive patients with normal kidney function. Promising data on the procedure in ESRD patients with resistant hypertension have been reported in small scale pilot studies. Denervation of the native non-functioning kidney's neural excitatory influences on central sympathetic drive could reduce the elevated cardiovascular morbidity and mortality seen in ESRD patients. The present review article will focus on the promising results obtained with renal denervation in patients with ESRD, its mechanisms of action and future perspectives in these high risk patients.

Blood pressure reduction after renal denervation in patients with or without chronic kidney disease

Background

Renal denervation (RDN) has emerged as an adjacent option for the treatment of hypertension. This analysis of the Erlanger registry aimed to compare the blood pressure (BP)-lowering effects and safety of RDN in patients with and without chronic kidney disease (CKD).

Methods

In this single-center retrospective analysis, 47 patients with and 127 without CKD underwent radiofrequency-, ultrasound- or alcohol-infusion-based RDN. Office and 24-h ambulatory BP and estimated glomerular filtration rate (eGFR) were measured at baseline, and after 6 and 12 months.

Results

A total of 174 patients with a mean age of 59.0 ± 10 years were followed up for 12 months. At baseline, mean eGFR was 55.8 ± 21 mL/min/1.73 m2 in patients with CKD and 87.3 ± 13 mL/min/1.73 m2 in patients without CKD. There was no significant eGFR decline in either of the groups during 12 months of follow-up. In patients without CKD, office systolic and diastolic BP were reduced by -15.3 ± 17.5/-7.9 ± 10.8 mmHg 6 months after RDN and by -16.1 ± 18.2/-7.7 ± 9.6 mmHg 12 months after RDN. In patients with CKD, office systolic and diastolic BP were reduced by -10.7 ± 24.0/-5.8 ± 13.2 mmHg 6 months after RDN and by -15.1 ± 24.9/-5.9 ± 12.9 mmHg 12 months after RDN. Accordingly, in patients without CKD, 24-h ambulatory systolic and diastolic BP were reduced by -7.2 ± 15.8/-4.9 ± 8.8 mmHg 6 months after RDN and by -9.0 ± 17.0/-6.2 ± 9.8 mmHg 12 months after RDN. In patients with CKD, 24-h systolic and diastolic BP were reduced by -7.4 ± 12.9/-4.2 ± 9.9 mmHg 6 months after RDN and by -8.0 ± 14.0/-3.6 ± 9.6 mmHg 12 months after RDN. There was no difference in the reduction of office and 24-h ambulatory BP between the two groups at any time point (all P > .2). Similar results have been found for the 6 months data. With exception of rare local adverse events, we did not observe any safety signals.

Conclusion

According to our single-center experience, we observed a similar reduction in 24-h, day and night-time ambulatory BP as well as in-office BP in patients with and without CKD at any time point up to 12 months. We conclude that RDN is an effective and safe treatment option for patients with hypertension and CKD.

2023 update and perspectives

Total 276 manuscripts were published in Hypertension Research in 2022. Here our editorial members picked up the excellent papers, summarized the current topics from the published papers and discussed future perspectives in the sixteen fields. We hope you enjoy our special feature, 2023 update and perspectives in Hypertension Research.

Late outcomes of renal denervation are more favourable than early ones: facts or fancies?

Following second-generation randomized trials, there is evidence that renal denervation (RDN) decreases blood pressure (BP), although to a lesser extent than suggested in the initial controlled and observational studies. The recent publication of the 36-month follow-up of the Symplicity HTN-3 trial has raised expectations, suggesting increasing, late benefits of the procedure, despite initially negative results. These findings come after those obtained at 36 months in the sham-controlled trial SPYRAL HTN-ON MED and in the Global Symplicity Registry. However, they are susceptible to biases inherent in observational studies (after unblinding for sham-control) and non-random, substantial attrition of treatment groups at 36 months, and used interpolation of missing BPs. More importantly, in SPYRAL HTN-ON MED and Symplicity HTN-3, long-term BP changes in patients from the initial RDN group were compared with those in a heterogeneous control group, including both control patients who did not benefit from RDN and patients who eventually crossed over to RDN. In crossover patients, the last BP before RDN was imputed to subsequent follow-up. In Symplicity HTN-3, this particular approach led to the claim of increasing long-term benefits of RDN. However, comparison of BP changes in patients from the RDN group and control patients who did not undergo RDN, without imputation of BPs from crossover patients, does not support this view. The good news is that despite the suggestion of sympathetic nerve regrowth after RDN in some animal models, there is no strong signal in favour of a decreasing effect of RDN over time, up to 24 or even 36 months. Still, current data do not support a long-term increase in the effect of RDN and the durability of RDN-related BP reduction remains to be formally demonstrated.

Progression of obstructive sleep apnoea after renal denervation is not associated with hypertension exaggeration

PURPOSE

In a cohort, observational prospective trial, we assessed the long-term dynamics of sleep-disordered breathing in patients with resistant hypertension after renal denervation and their association with blood pressure change at remote follow-up.

MATERIALS AND METHODS

Twenty-eight patients with stable hypertension who were recruited for endovascular radiofrequency renal denervation in 2012-2019 and had valid both baseline and follow-up sleep study, were included in the analysis. All patients underwent physical examination, anthropometry, office and ambulatory blood pressure measurements, blood and urine tests, kidney visualization, and full polysomnography before and within 12-36 months after renal denervation.

RESULTS

The average follow-up comprised 30.1 ± 8.4 months. At long-term follow-up, no significant changes in creatinine level, estimated glomerular filtration rate, body mass index were registered. There was a significant increase in sleep apnea severity indices: the mean change in apnea-hypopnea index comprised 9.0(-21.1;25.2) episodes/h, in oxygen desaturation index 6.5(-16.8;35.9) episodes/h, in the average SpO2 -1.7(-5.6;1.9)%. Over 12-month follow-up, there were no significant differences in blood pressure response in patients with and without sleep apnea. The baseline apnea-hypopnea and oxygen desaturation indices and the mean SpO2 were associated with the circadian blood pressure profile at follow-up, but did not correlate with the blood pressure response.

CONCLUSIONS

Although the severity of sleep apnea worsens at > 12 months follow-up after renal denervation, this is not associated with hypertension exaggeration.

Safety and Efficacy of Renal Denervation in Patients Taking Antihypertensive Medications

BACKGROUND

Renal denervation (RDN) reduces blood pressure (BP) in patients with uncontrolled hypertension in the absence of antihypertensive medications.

OBJECTIVES

This trial assessed the safety and efficacy of RDN in the presence of antihypertensive medications.

METHODS

SPYRAL HTN-ON MED is a prospective, randomized, sham-controlled, patient- and assessor-blinded trial enrolling patients from 56 clinical centers worldwide. Patients were prescribed 1 to 3 antihypertensive medications. Patients were randomized to radiofrequency RDN or sham control procedure. The primary efficacy endpoint was the baseline-adjusted change in mean 24-hour ambulatory systolic BP at 6 months between groups using a Bayesian trial design and analysis.

RESULTS

The treatment difference in the mean 24-hour ambulatory systolic BP from baseline to 6 months between the RDN group (n = 206; -6.5 ± 10.7 mm Hg) and sham control group (n = 131; -4.5 ± 10.3 mm Hg) was -1.9 mm Hg (95% CI: -4.4 to 0.5 mm Hg; P = 0.12). There was no significant difference between groups in the primary efficacy analysis with a posterior probability of superiority of 0.51 (Bayesian treatment difference: -0.03 mm Hg [95% CI: -2.82 to 2.77 mm Hg]). However, there were changes and increases in medication intensity among sham control patients. RDN was associated with a reduction in office systolic BP compared with sham control at 6 months (adjusted treatment difference: -4.9 mm Hg; P = 0.0015). Night-time BP reductions and win ratio analysis also favored RDN. There was 1 adverse safety event among 253 assessed patients.

CONCLUSIONS

There was no significant difference between groups in the primary analysis. However, multiple secondary endpoint analyses favored RDN over sham control. (SPYRAL HTN-ON MED Study [Global Clinical Study of Renal Denervation With the Symplicity Spyral Multi-electrode Renal Denervation System in Patients With Uncontrolled Hypertension in the Absence of Antihypertensive Medications]; NCT02439775).

New Potential Treatments for Resistant Hypertension

PURPOSE OF REVIEW

To provide an update and review approaches to the treatment of resistant hypertension (RH) with a focus on emerging potential therapies.

RECENT FINDINGS

Resistant hypertension is defined as a blood pressure that remains elevated above a patient's individualized target despite the concurrent use of 3 antihypertensive agents of different classes including a diuretic or use of 4 or more antihypertensive agents. Patients with RH have an increased risk of adverse cardiovascular and renal outcomes. Most RH is attributed to apparent RH and is not true RH. True RH is a diagnosis of exclusion after apparent RH has been excluded. Treatment of RH is challenging, and blood pressure goal is often difficult to achieve. Currently several new therapies have emerged with forthcoming data that provide promise for improved blood pressure control in those with resistant hypertension. Once RH has been diagnosed, patients should be on standardized therapy that includes agents from three different classes including a diuretic with addition in most cases of a mineralocorticoid as a fourth line agent. There are newer agents in development currently being studied in clinical trials including dual endothelin receptor antagonists and aldosterone synthase inhibitors that appear to be efficacious. Other approved medications including SGLT2 inhibitors and non-steroidal mineralocorticoids such as finerenone also need to be incorporated into treatment paradigms. Renal denervation with catheter based devices is another potential promising treatment option in this population.

Catheter-based renal artery denervation: facts and expectations

Catheter-based renal artery denervation (RAD) is entering a new era. After the disappointing results of SYMPLICITY-HTN 3 trial in year 2014, several technical and methodological advancements led to execution of important SHAM-controlled randomized trials with promising results. Now, the 2023 ESH Guidelines give RAD a class of recommendation II with a Level of Evidence B. Currently, catheter-based RAD has two main areas of application: (a) Hypertensive patients who are still untreated, in whom RAD is a sort of a first-line treatment; (b) Difficult-to-control or true resistant hypertensive patients. Notably, randomized SHAM-controlled trials met their primary end-point in both these conditions. So far, we do not dispose of established predictors of the antihypertensive response to RAD. Some data suggest that younger patients with systo-diastolic hypertension, absence of diffuse atherosclerosis and evidence of sympathetic nervous system overactivity experience a better BP response to the procedure. We reviewed the available data on catheter-based RAD and included an updated meta-analysis of the results of the available SHAM-controlled trials. Overall, the reduction in 24-h systolic blood pressure (BP) after RAD exceeded that after SHAM by 4.58 mmHg (95% CI 3.07-6.10) in untreated patients, and by 3.82 mmHg (95% CI 2.46-5.18) in treated patients, without significant heterogeneity across trials, patient phenotype (untreated versus treated patients) and technique (radiofrequency versus ultrasound). There were no important safety signals related to the procedure. Notably, some data suggest that RAD could be an effective additional approach in patients with atrial fibrillation and other conditions characterized by sympathetic nervous system overactivity.

Long-Term Safety and Antihypertensive Effects of Renal Denervation: Current Insights

Hypertension is the most potent modifiable risk factor for the development of cardiovascular morbidity and mortality worldwide. Nevertheless, blood pressure (BP) control on a broad scale appears to be insurmountable and has even worsened in the US. Barriers to sustained hypertension control are multifactorial and although lack of patient awareness and socioeconomic barriers to healthcare access may play a role, medication non-compliance and therapeutic inertia are major causes. Renal denervation (RDN) is a minimally invasive procedure that has been the subject of interest in clinical trials for more than a decade and although the first sham-controlled trial could not detect group difference between treated and untreated hypertensives, subsequent, better designed sham-controlled trials clearly demonstrated the BP lowering effect of RDN, as well as its safety. While to-date, RDN is not available for routine clinical practice, one major requirement for broad implementation is that the BP lowering effect is durable. Therefore, this review will summarize the available long-term data of the different RDN modalities with respect to both effectiveness and safety.

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.

Arterial Hypertension-clinical trials update 2023

Arterial hypertension is associated with increased morbidity and mortality and research in the field is highly dynamic. This summary reviews the most important clinical trials published in 2022 and early 2023. Findings on new pharmacological approaches to treat resistant hypertension are presented and new knowledge about the optimal timing of the antihypertensive medication intake is discussed. It is focused on optimal blood pressure treatment targets and the problem of treatment and guideline inertia is acknowledged. Information about pregnancy-related hypertension is presented and blood pressure control following percutaneous thrombectomy after ischemic stroke is discussed. Finally, novel clinical data on device-based approaches to treat hypertension are summarized. The hypertension trials update summarizes the most important clincal trials on hypertension research in 2022 and early 2023. CTD - chlorthalidone, CV - cardiovascular, HCT - hydrochlorothiazide, SBP - systolic blood pressure, RDN - renal denervation *depicts systolic blood pressure only.

Renal Denervation as a Complementary Treatment Option for Uncontrolled Arterial Hypertension: A Situation Assessment

Uncontrolled arterial hypertension is a major global health issue. Catheter-based renal denervation has shown to lower blood pressure in sham-controlled trials and represents a device-based, complementary treatment option for hypertension. In this situation assessment, the authors, who are practicing experts in hypertension, nephrology, general practice and cardiology in the Republic of Ireland, discuss the current evidence base for the BP-lowering efficacy and safety of catheter-based renal denervation with different modalities. Although important questions remain regarding the identification of responders, and long-term efficacy and safety of the intervention, renal denervation has the potential to provide much-needed help to address hypertension and its adverse consequences. The therapeutic approach needs to be multidisciplinary and personalised to take into account the perspective of patients and healthcare professionals in a shared decision-making process.