Renal Denervation for Hypertension: A Systematic Review and Meta-Analysis of Randomized, Blinded, Placebo-Controlled Trials

Renal denervation plus cardiac ablation vs. cardiac ablation alone for patients with atrial fibrillation and uncontrolled arterial hypertension : A systematic review and updated meta-analysis of randomized controlled trials

BACKGROUND

Atrial fibrillation (AF) is a complex arrhythmia often worsened by hypertension (HTN). Pharmacological treatments frequently underperform, and the best approach, particularly combining renal denervation (RDN) with cardiac ablation (CA), remains unclear.

OBJECTIVE

We conducted an updated meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of RDN combined with CA versus CA alone in patients with AF and uncontrolled HTN.

METHODS

We performed a systematic review and meta-analysis of RCTs retrieved from PubMed, Embase, and the Cochrane Library up to July 2024. Primary outcomes included AF recurrence, periprocedural complications, blood pressure changes, and estimated glomerular filtration rate (eGFR). Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were computed using a random-effects model.

RESULTS

Eight RCTs were included, involving 689 patients (37% female). Of these, 355 underwent RDN + CA, and 334 underwent CA alone, with a mean follow-up of at least 12 months. The RDN + CA group exhibited a significant reduction in AF recurrence (RR: 0.77; 95% CI: 0.61-0.97). There were no significant differences in periprocedural complications (RR: 1.06; 95% CI: 0.60-1.89), systolic blood pressure (MD: -6.79; 95% CI: -14.71-1.14), diastolic blood pressure (MD: -2.47; 95% CI: -8.13-3.20), or eGFR (MD: 1.14; 95% CI: -11.95-14.23).

CONCLUSION

Our findings show that RDN combined with CA significantly reduces AF recurrence compared to CA alone, presenting a promising approach for patients with resistant HTN and AF.

Interactive effect between Selenium and Vitamin C levels on risk of hypertension among adult women in the United States: evidence from NHANES 2011 to 2020

Background

Hypertension poses an imperative global health risk, affecting over 1 billion people and contributing to cardiovascular disease, especially for women. While previous studies suggest micronutrients such as Vitamin C or Selenium can help reduce blood pressure, research on their interactive effects remains limited.

Methods

This cross-sectional study analyzed data from 9,343 women aged 20 years and older in NHANES (2011-2020). Logistic regression analysis was conducted to evaluate the effect of each micronutrient on hypertension. To account for potential interactions between micronutrients, we calculated the relative excess risk due to interaction, which assessed their combined effect on hypertension.

Results

We confirmed the individual associations of Vitamin C and Selenium with hypertension, showing significant negative correlations (p < 0.05). Participants were then divided into four groups, and those with high intakes of both Vitamin C and Selenium had a significantly lower risk of hypertension (p < 0.05), supporting the association between the combined intake of these nutrients and lower hypertension risk, though no synergistic effect was observed.

Conclusion

The findings support the combined intake of Vitamin C and Selenium in hypertension prevention, broadening thoughts on the level of nutrition for the treatment of hypertension. These results suggest a potential association between adequate supplementation of Vitamin C and Selenium and lower blood pressure. However, further rigorous clinical studies are essential to validate and strengthen these findings.

Renal denervation - radiofrequency vs. ultrasound: insights from a mixed treatment comparison meta-analysis of randomized sham controlled trials

BACKGROUND AND AIMS

Multiple randomized trials have shown that renal denervation (RDN) reduces blood pressure (BP) when compared with sham control but the antihypertensive efficacy of radiofrequency vs. ultrasound-based RDN is uncertain. We aimed to compare the outcomes of radiofrequency RDN (rRDN) and ultrasound RDN (uRDN), when compared with sham in patients with hypertension.

METHODS

PubMed, EMBASE, and clinicaltrials.gov databases were searched for randomized sham-controlled trials (RCTs) of rRDN or uRDN or for trials of rRDN vs. uRDN. Primary efficacy outcome was 24-h ambulatory SBP. A mixed treatment comparison meta-analysis was performed comparing the efficacy and safety against sham and against each other.

RESULTS

Among 13 RCTs that enrolled 2285 hypertensive patients, rRDN reduced 24-h ambulatory SBP [(MD = 2.34 mmHg; 95% confidence interval (95% CI): 0.72-3.95], office SBP (MD = 5.04 mmHg; 95% CI: 2.68-7.40)], and office DBP (MD = 2.95 mmHg; 95% CI: 1.68-4.22) when compared with sham. Similarly, uRDN reduced 24-h ambulatory SBP (MD = 4.74 mmHg; 95% CI: 2.80-6.67), day-time ambulatory SBP (MD = 5.40 mmHg; 95% CI: 3.68-7.13), night-time ambulatory SBP (MD = 3.84 mmHg; 95% CI: 0.02-7.67), and office SBP (3.98 mmHg; 95% CI: 0.78-7.19) when compared with sham. There was significantly greater reduction in 24-h ambulatory SBP (MD = 2.40 mmHg; 95% CI: 0.09-4.71), day-time ambulatory SBP (MD = 4.09 mmHg; 95% CI: 1.61-6.56), and night-time ambulatory SBP (MD = 5.76 mmHg; 95% CI: 0.48-11.0) with uRDN when compared with rRDN. For primary efficacy outcome, uRDN ranked #1, followed by rRDN (#2), and sham (#3).

CONCLUSION

In hypertensive patients, rRDN and uRDN significantly reduced 24-h ambulatory and office SBP when compared with sham control with significantly greater reduction in ambulatory BP with uRDN than with rRDN at 4 months (mean) of follow-up. A large-scale randomized head-to-head trial of rRDN or uRDN is warranted to evaluate if there are differences in efficacy.

Sex-specific differences in the efficacy of renal denervation in patients with resistant hypertension depending on visceral obesity and kidney function

Objective

To investigate the sex differences in the efficacy of renal denervation (RDN) in patients with resistant hypertension (RHT) concerning the size of abdominal fat depots, changes in biomarkers of sympathetic activity, and renal function.

Materials and methods

24 men (56.5 ± 7.8 years) and 33 women (59.5 ± 8.4 years) with RHT were enrolled in the study and underwent RDN. 24-h ambulatory blood pressure (BP) [systolic/diastolic (SBP/DBP)], serum creatinine (with eGFR calculation), serum adipocytokines (leptin, adiponectin, resistin), serum metanephrines and normetanephrines were measured baseline and 12 months after RDN. The size of subcutaneous, visceral, and perirenal adipose tissue (SAT, VAT, and PRAT) was assessed using MRI.

Results

After RDN, BP decreased, leptin increased, and adiponectin, resistin, and metanephrine levels did not change in both sexes. There was a decrease in normetanephrine levels in women and a similar trend in men. In men, the eGFR did not change. In women, the eGFR remained unchanged only in those with chronic kidney disease (CKD) (n = 10) and decreased in the absence of CKD (n = 23) from 79.7 ± 14.1 to 72.1 ± 12.0 ml/min/1.73 m2 (p = 0.011). Men had larger visceral fat depots, and women had larger subcutaneous fat depots. After RDN, the size of adipose tissue in men remained unchanged, and in women, the PRAT thickness decreased from 2.36 ± 1.23 to 2.10 ± 1.17 cm (p = 0.002). Lowering BP in women was associated with increased leptin levels after RDN (r = -0.47 for SBP, r = -0.48 for DBP). Dependence of BP reduction on baseline eGFR was observed in men only [r = 0.44 for SBP, r = 0.48 for pulse pressure (PP)]. Additionally, in men, the decrease in SBP and PP depended on VAT areas (r = -0.44 and r = -0.58, respectively). In women, the SBP reduction showed an inverse correlation between baseline weight (r = -0.35) and waist circumference (r = -0.38).

Conclusions

The magnitude of the antihypertensive effect of RDN depends on signs of visceral obesity and, in men, also on the presence of CKD. Renoprotective effects of RDN in men are obtained regardless of the initial kidney function, while in women, it was observed only in individuals with CKD. Additional beneficial effects of RDN in women include a decrease in normetanephrine levels and a reduction in PRAT size.

Ultrasound renal denervation in hypertensive patients: A systematic review and meta-analysis

INTRODUCTION

Hypertension is the leading noncommunicable disease case affecting 1.28 billion individuals worldwide, with most cases located in low- and middle-income countries. While there are numerous techniques for treating mild to moderate hypertension, properly controlling severe or resistant hypertension poses substantial challenges. Ultrasound-based renal denervation (uRDN) has emerged as a promising non-pharmacological approach. This study aims to investigate the safety and efficacy of uRDN in hypertensive patients.

METHODS

The literature search across PubMed, ScienceDirect, BMJ Journals, ProQuest, and Springer databases yielded 419 articles. A total of 395 articles were filtered, leading to 24 articles assessed for eligibility and overall analysis, which resulted in eight included studies for quantitative synthesis. Quality appraisal used RoB 2.0, while meta-analysis used RevMan 5.4.

RESULTS

Our analysis results indicated significant improvements in 24-hour, daytime, and home ambulatory blood pressure measurements, favoring the uRDN over control. The mean difference (MD) for 24-hour measurements was -0.84 mmHg [95% CI -1.14, -0.55; p < 0.00001], for daytime measurements -1.27 mmHg [95% CI -1.59, -0.95; p < 0.00001], and for home measurements -1.98 mmHg [95% CI -2.32, -1.64; p < 0.00001], with moderate heterogeneity observed. Office ambulatory measurements also favored the uRDN with a significant MD of -1.51 mmHg [95% CI -1.91; -1.10; p < 0.00001]. Funnel plots revealed some outliers, indicating true heterogeneity among the studies.

CONCLUSION

uRDN was associated with a significant reduction (-2.32 to -0.10 mmHg) in blood pressure of hypertensive patients.

Renal nerves in physiology, pathophysiology and interoception

Sympathetic efferent renal nerves have key roles in the regulation of kidney function and blood pressure. Increased renal sympathetic nerve activity is thought to contribute to hypertension by promoting renal sodium retention, renin release and renal vasoconstriction. This hypothesis led to the development of catheter-based renal denervation (RDN) for the treatment of hypertension. Two RDN devices that ablate both efferent and afferent renal nerves received FDA approval for this indication in 2023. However, in animal models, selective ablation of afferent renal nerves resulted in comparable anti-hypertensive effects to ablation of efferent and afferent renal nerves and was associated with a reduction in sympathetic nerve activity. Selective afferent RDN also improved kidney function in a chronic kidney disease model. Notably, the beneficial effects of RDN extend beyond hypertension and chronic kidney disease to other clinical conditions that are associated with elevated sympathetic nerve activity, including heart failure and arrhythmia. These findings suggest that the kidney is an interoceptive organ, as increased renal sensory nerve activity modulates sympathetic activity to other organs. Future studies are needed to translate this knowledge into novel therapies for the treatment of hypertension and other cardiorenal diseases.

Response of Blood Pressure to Renal Denervation Is Not Associated With Genetic Variants

BACKGROUND

Renal denervation lowers blood pressure (BP) in patients with uncontrolled hypertension. We conducted an unbiased genomic screen to identify genetic variants that may associate with BP response to renal denervation (RDN).

METHODS

Patients (n=268) with uncontrolled resistant hypertension (baseline BP, 166±21/90±15 mm Hg) who underwent endovascular RDN using the Symplicity catheter (Medtronic, Inc, Santa Rosa, CA) were included. Reduction in 24-hour ambulatory systolic BP was assessed at 6 months and divided into 2 groups: above and below the median response of 6.0 mm Hg, taking preintervention 24-hour ambulatory BP and regression to the mean into account. Whole exome sequencing assessing 249 669 variants, was conducted using Illumina NovaSeq technology read on a NovaSeq S4 Flow Cell device.

RESULTS

We did not identify individual gene variants associated with BP response following RDN. These findings were confirmed after adjustment for sex and in a sensitivity analysis looking at tertiles of BP response. We also explored specific variants in AGT, ADD1, ADRB1, ADRB2, and SCNN1A that have been proposed as potential candidate genes for response and found no association (all P>0.13). Gene ontology analysis of variants across the 2 responder groups highlighted differences in biologic processes such as cell adhesion and molecular function such as protein tyrosine kinase activity.

CONCLUSIONS

The response to RDN, in terms of 24-hour BP reduction, was not associated with the genetic profile of patients with resistant hypertension. These data do not support the use of a genetic score to identify potential responders to RDN.

Outpatient management of essential hypertension: a review based on the latest clinical guidelines

Background: Essential hypertension, a prevalent cardiovascular condition, poses a significant health burden worldwide. Based on the latest American clinical guidelines, half of adults in the United States have hypertension. Of these, only about a half are treated and about a quarter are adequately controlled for hypertension. Given its impact on morbidity and mortality, ensuring effective management of high blood pressure is crucial to reduce associated risks and improve patient outcomes.Objective: This review aims to provide a comprehensive and up-to-date summary of the latest cardiology guidelines and evidence-based research on essential hypertension, with a focus on guiding outpatient clinical practice.Methods: The review evaluates both non-pharmacological approaches and pharmacological interventions to offer clinicians practical insights. Notably, it emphasizes the importance of individualized treatment plans tailored to patients' specific risk profiles and comorbidities.Results: By consolidating the latest advancements in hypertension management, this review provides clinicians with an up-to-date reference, offering a nuanced understanding of treatment goals and strategies.Conclusion: Through the incorporation of evidence-based recommendations, healthcare practitioners can optimize patient care, mitigate potential complications, and improve overall outcomes in essential hypertension.

Class I Recalls of Cardiovascular Devices Between 2013 and 2022 : A Cross-Sectional Analysis

BACKGROUND

Cardiovascular devices account for one third of all Class I recalls, the U.S. Food and Drug Administration's (FDA) most severe designation, indicating a reasonable probability of "serious adverse health consequences or death." Understanding recalls and their causes is important for patient safety.

OBJECTIVE

To characterize Class I recalls of cardiovascular devices and the clinical evidence supporting authorization.

DESIGN

In this cross-sectional study, cardiovascular device recalls from 1 January 2013 through 31 December 2022 were identified using the FDA's annual log. Information about devices was extracted from publicly available FDA decision summaries.

SETTING

The FDA Medical Device Recalls database.

PARTICIPANTS

Cardiovascular devices with Class I recalls.

MEASUREMENTS

Recalls were characterized by their causes and scope. Devices were characterized by their regulatory history (product code, special designations) and clinical evidence (premarket testing, postmarket surveillance). Clinical studies were analyzed for quality, including end point selection (clinical vs. surrogate, use of composites).

RESULTS

From 2013 to 2022, there were 137 Class I recall events affecting 157 unique cardiovascular devices, of which 112 (71.3%) were moderate-risk 510(k) devices and 45 (28.7%) were high-risk premarket approval (PMA) devices. Recalls affected a median of 7649 units (IQR, 953 to 28 446) and were most commonly attributed to device design (43 [31.4%]). Forty-two (26.8%) devices had multiple Class I recalls. Thirty (19.1%) devices underwent premarket clinical testing (7 [6.2%] 510(k) devices, 17 [85.0%] PMA devices, and 6 [24.0%] PMA supplement devices). Most studies used surrogate (27 [79.4%]) and composite (24 [70.6%]) measures as primary end points. Twenty-two (48.9%) PMA devices had required postapproval studies, with 14 reporting delays. No 510(k) devices were subject to postmarket surveillance.

LIMITATION

Details about clinical testing may be missing from FDA summaries.

CONCLUSION

Cardiovascular devices with Class I recalls were infrequently subjected to premarket or postmarket testing, with recalls affecting thousands of patients annually.

PRIMARY FUNDING SOURCE

None.

The Increasing Problem of Resistant Hypertension: We'll Manage till Help Comes!

Arterial hypertension remains the major cardiovascular risk worldwide. It is estimated that under 50 years of age one in every three adults is hypertensive while beyond the age of 50 the prevalence is almost 50% globally. The latest World Health Organization (WHO) Global Report on Hypertension indicated that the global number of hypertensive patients almost doubled in the last three decades, with related increasing deaths, disability, and costs annually. Because of this global increase, early diagnosis and timely treatment is of great importance. However, based on the WHO Global Report, it is estimated that up to 46% of individuals were never diagnosed. Of those diagnosed, less than 50% were on treatment, with nearly half among these at target according to the current guidelines. It is also important to note that an increasing number of hypertensive patients, despite the use of three or more drugs, still do not achieve a blood pressure normalization, thus defining the clinical scenario of resistant hypertension (RH). This condition is associated to a higher risk of hypertension-mediated organ damage and hospitalization due to acute cardiovascular events. Current guidelines recommend a triple combination therapy (renin angiotensin system blocking agent + a thiazide or thiazide-like diuretic + a dihydropyridinic calcium-channel blocker) to all patients with RH. Beta-blockers and mineralocorticoid receptor antagonists, alone or in combination, should be also considered based on concomitant conditions and potential contraindications. Finally, the renal denervation is also proposed in patients with preserved kidney function that remain hypertensive despite the use of maximum tolerated medical treatment. However, the failure of this procedure in the long term and the contraindication in patients with kidney failure is a strong call for a new therapeutic approach. In the present review, we will discuss the pharmacological novelties to come for the management of hypertension and RH in the next future.

Real-world experience with ultrasound renal denervation utilizing home blood pressure monitoring: the Global Paradise System registry study design

BACKGROUND

Hypertension is a major public health issue due to its association with cardiovascular disease risk. Despite the availability of effective antihypertensive drugs, rates of blood pressure (BP) control remain suboptimal. Renal denervation (RDN) has emerged as an effective non-pharmacological, device-based treatment option for patients with hypertension. The multicenter, single-arm, observational Global Paradise™ System (GPS) registry has been designed to examine the long-term safety and effectiveness of ultrasound RDN (uRDN) with the Paradise System in a large population of patients with hypertension.

METHODS

The study aims to enroll up to 3000 patients undergoing uRDN in routine clinical practice. Patients will be recruited over a 4-year period and followed for 5 years (at 3, 6, and 12 months after the uRDN procedure and annually thereafter). Standardized home BP measurements will be taken every 3 months with automatic upload to the cloud. Office and ambulatory BP and adverse events will be collected as per routine clinical practice. Quality-of-Life questionnaires will be used to capture patient-reported outcomes.

CONCLUSIONS

This observational registry will provide real-world information on the safety and effectiveness of uRDN in a large population of patients treated during routine clinical practice, and also allow for a better understanding of responses in prespecified subgroups. The focus on home BP in this registry is expected to improve completeness of long-term follow-up and provide unique insights into BP over time.

Catheter-based renal denervation in the treatment of arterial hypertension: An expert consensus statement on behalf of the French Society of Hypertension (SFHTA), French Society of Radiology (SFR), French Society of Interventional Cardiology (GACI), French Society of Cardiology (SFC), French Association of Private Cardiologists (CNCF), French Association of Hospital Cardiologists (CNCH), French Society of Thoracic and Cardiovascular Surgery (SFCTCV) and French Society of Vascular and Endovascular Surgery (SCVE)

Several high-quality, randomized, sham-controlled trials have provided evidence supporting the efficacy and safety of radiofrequency, ultrasound and alcohol catheter-based renal denervation (RDN) for reducing blood pressure (BP). A French clinical consensus document has therefore been developed to propose guidance for the appropriate use of RDN in the management of hypertension along with a dedicated care pathway and management strategy. The French experts group concluded that RDN can serve as an adjunct therapy for patients with confirmed uncontrolled, resistant essential hypertension despite treatment with≥3 antihypertensive drugs, including a long-acting calcium channel blocker, a renin-angiotensin system blocker and a thiazide/thiazide-like diuretic at maximally tolerated doses. Patients should have (1) an estimated glomerular filtration rate of≥40mL/min/1.73m2; (2) an eligible renal artery anatomy on pre-RDN scans and (3) exclusion of secondary forms of hypertension. Additional indications might be considered for patients with difficult-to-control hypertension. Any indication of RDN should be validated by multidisciplinary hypertension teams consisting of both hypertension specialists and endovascular interventionalists in European Society of Hypertension (ESH) Excellence Centres or ESH-BP clinics. Patients should be informed about the benefit/risk ratio of RDN. Expertise in renal artery interventions and training in RDN techniques are needed for endovascular interventionalists conducting RDN procedures while centres offering RDN should have the necessary resources to manage potential complications effectively. Lastly, all patients undergoing RDN should have their data collected in a nationwide French registry to facilitate monitoring and evaluation of RDN outcomes, contributing to ongoing research and quality improvement efforts.

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

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

Permanent Pacing Reduces Blood Pressure in Older Patients with Drug-resistant Hypertension: A New Pacing Paradigm?

Hypertension (HTN) is a major contributor to cardiovascular mortality. Many patients with drug-resistant hypertension (DRH) also require permanent pacing (PP). This large retrospective study evaluated the effect of PP for conventional PP indications in older patients with DRH. We reviewed the charts of 176 patients with dual-chamber PP and DRH. The effects of PP on systolic and diastolic blood pressure (sBP and dBP), the number of HTN-related medications, and left ventricular ejection fraction (LVEF) were assessed at 6 months post-implantation and compared with pre-implantation values. Patients were followed up with for ≥72 months. Patients with a decline of >5 mmHg in sBP and decrease in at least one anti-HTN medication were defined as responders (126/176; P < .01). The mean decline in sBP was 9 mmHg, while that in dBP was 3 mmHg (P < .001 for both). Among responders, optimal reductions in sBP, dBP, and medications were seen at a stratification of >50% atrial pacing and <40% ventricular pacing (-12, -6.3, and -1.6, respectively). When right ventricular pacing of <50% was used for dichotomizing, the optimal atrial/ventricular pacing stratification was atrial pacing > 50% and ventricular pacing < 40% (-11.3, -6.3, and -1.6, respectively). A relationship between increasing atrial pacing and a decline in sBP was noted but did not reach statistical significance. However, of those responders who had a >10-mmHg decline in sBP, the majority were paced between 60%-100% in the atria. The LVEF did not change post-PP in either group. In conclusion, PP results in significant improvement in BP control. The observed association warrants further investigation.

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.

Therapeutic options for neurocardiogenic syncope: a meta-analysis of randomised trials with and without blinding

BACKGROUND

Neurocardiogenic syncope is a common condition with significant associated psychological and physical morbidity. The effectiveness of therapeutic options for neurocardiogenic syncope beyond placebo remains uncertain.

METHODS

The primary endpoint was the risk ratio (RR) of spontaneously recurring syncope following any therapeutic intervention. We also examined the effect of blinding on treatment efficacy. We identified all randomised trials which evaluated the effect of any pharmacological, device-based or supportive intervention on patients with a history of syncope. A systematic search was conducted on Medline, Embase, PubMed databases and Cochrane Central Register for Controlled Trials from 1950 to 25 April 2023. Event rates, their RRs and 95% CIs were calculated, and a random-effects meta-analysis was conducted for each intervention. Data analysis was performed in R using RStudio.

RESULTS

We identified 47 eligible trials randomising 3518 patients. Blinded trials assessing syncope recurrence were neutral for beta blockers, fludrocortisone and conventional dual-chamber pacing but were favourable for selective serotonin reuptake inhibitors (SSRIs) (RR 0.40, 95% CI 0.26 to 0.63, p<0.001), midodrine (RR 0.70, 95% CI 0.53 to 0.94, p=0.016) and closed-loop stimulation (CLS) pacing (RR 0.15, 95% CI 0.07 to 0.35, p<0.001). Unblinded trials reported significant benefits for all therapy categories other than beta blockers and consistently showed larger benefits than blinded trials.

CONCLUSIONS

Under blinded conditions, SSRIs, midodrine and CLS pacing significantly reduced syncope recurrence. Future trials for syncope should be blinded to avoid overestimating treatment effects.

PROSPERO REGISTRATION NUMBER

CRD42022330148.

Is Renal Denervation Effective in Treating Resistant Hypertension?

Resistant hypertension is diagnosed in patients whose blood pressure target is unmet despite the use of three or more antihypertensive medications. Systemic sympathetic hyperactivation is associated with the development of resistant hypertension. As the kidney is largely pervasive of the sympathetic nervous system renal denervation procedure was developed to control blood pressure by attenuating the renal and systemic sympathetic hyperactivity. Renal denervation is a minimally invasive procedure that uses radiofrequency or ultrasound energy waves to reduce the activity of the renal artery nerves. Previous clinical trials have shown conflicting results regarding the efficacy of the procedure. Symplicity HTN-1 and -2 trials showed effective blood pressure lowering results in the renal denervation group with a good safety profile. However, the Symplicity HTN-3 trial showed no difference in blood pressure lowering effect between the renal denervation and control Sham procedure groups. Notwithstanding, some recent clinical trials with Sham control and meta-analysis showed clinical benefits of renal denervation. Other clinical benefits of renal denervation include glucose control, cardiovascular protective effect, reduction of obstructive sleep apnea, and neuralgia control. A subset of patients with satisfactory blood pressure control response to the procedure may experience improved glucose control due to the overall reduced sympathetic activity and insulin resistance. Sympathetic activity control after renal denervation has cardioprotective effects, especially for those with arrhythmia and left ventricular hypertrophy. Also, renal denervation could be helpful in renalorigin pain control. Renal denervation is an effective, safe, non-invasive procedure with many clinical benefits beyond blood pressure control. Further development in the procedure technique and selection of target patients are needed for wider clinical use of renal denervation in resistant 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.

Renal Denervation in the Management of Resistant Hypertension: A Comprehensive Review of Literature

Resistant hypertension is a condition in which blood pressure remains elevated despite using 3 or more antihypertensive medications. Though contemporary antihypertensive drug therapies have been essential in treating hypertension, in recent years different studies have explored renal denervation (RDN) as an adjunctive or a replacement modality. Here we summarize an open-label, Symplicity HTN 2 trial and 7 randomized, sham-controlled clinical trials: Spyral-HTN OFF MEDS (Spyral Pivotal), Spyral-HTN ON MEDS, RADIANCE-HTN SOLO, RADIANCE-HTN TRIO, RADIANCE II, SYMPLICITY-HTN 1, and SYMPLICITY-HTN 3, which evaluated safety and efficacy of multiple renal denervation systems (RDN) at lowering blood pressure from baseline, and in comparison, to control group. Prior systematic reviews and meta-analyses evinced a modest reduction of ambulatory and office blood; however, these trials and analyses were limited by short-term follow-up. In our updated comprehensive literature review we summarize the short-term, and long-term effects of RDN, based on the latest randomized clinical trials. Our conclusions based on each summary are unanimous with previous literature findings.

Renal Denervation in the Treatment of Resistant Hypertension and Difficult-to-Control Hypertension - Consensus Document of the Croatian Hypertension League - Croatian Society of Hypertension, Croatian Cardiac Society, Croatian Endovascular Initiative, Croatian Society for Diabetes and Metabolic Diseases, Croatian Renal Association, and Croatian Society of Family Physicians of the Croatian Medical Association

Renal denervation (RDN) as a method of treating arterial hypertension (AH) was introduced in Croatia in 2012. A multidisciplinary team and a network of hospitals that diagnose and treat patients with severe forms of AH were established, and a very strict diagnostic-treatment algorithm was prepared. At monthly meetings patients with truly resistant hypertension who were candidates for RDN were discussed. According to the 2021 ESH position statement and 2023 ESH guidelines, RDN is considered an alternative and additional, not a competitive method of treating patients with various forms of AH which must be performed by following a structured procedure and the patient's preference should be considered. In view of the changes in the global scientific community, the Croatian Hypertension League brings this consensus document on RDN conducted with radiofrequency-based catheter, the only currently available method in Croatia. In this document, exclusion and inclusion criteria are shown, as well as three groups of patients in whom RDN could be considered. The new diagnostic-treatment algorithm is prepared and follow-up procedure is explained. In Croatia, RDN is reimbursed by the national insurance company, thus pharmacoeconomic analyses is also shown. Criteria required by an individual centre to be approved of RDN are listed, and plans for prospective research on RDN in Croatia, including the Croatian registry for RDN, are discussed.

Current problems in renal denervation and a hope to break the stage

Renal denervation (RDN) is currently confronted with the considerable heterogeneity of different post-procedural blood pressure responses. The challenges predominantly arise from not only the lack of selection of appropriate responders but also the absence of detection for the successful endpoints of intervention. In this paper, we summarize the significant characteristics of potentially appropriate hypertensive patients and propose a hopeful way to improve the accuracy of RDN, that is, the application of three-dimensional reconstruction technology combined with electrical renal nerve stimulation to guide the radiofrequency catheter ablation, which may promote the development of selective and accurate RDN in real-world clinical practice. This paper focuses on two current critical concerns of renal denervation (RDN): appropriate patient selection and the improvement in the accuracy of selective RDN. A hopeful way of accurate RDN may be the combination of 3D electroanatomic mapping systems for the renal artery with modified renal nerve stimulation (RNS) techniques and technology for appropriate hypertensive candidates.

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.

Sympathetic Nerve Activation in Acute Kidney Injury and Cardiorenal Syndrome

The interactions between the kidney and heart are well studied and frequently lumped together as cardiorenal syndrome. It is believed that the sympathetic nervous system is involved in the mechanism of kidney injury caused by heart failure, but direct evidence is still lacking. In chronic renal fibrosis, sympathetic nerve activation was demonstrated to be harmful by unilateral ureteral obstruction and post-ischemia reperfusion injury models. On the other hand, sympathetic nerve activation seemed protective in acute kidney injury models such as ischemia reperfusion injury and lipopolysaccharide injection. Our recent investigation showed that post-ischemic renal fibrosis was attenuated when preexisting heart failure was induced by transverse aortic constriction surgery and renal denervation canceled this protection. These findings suggest sympathetic nerve activation in cardiorenal syndrome may be protective on chronic renal fibrosis development caused by ischemic an insult.

Circadian Urinary Excretion of Water, and Not Salt, Is Affected by the White Coat Effect

Hypertension is an important morbidity factor. The prognostic consequences of the white-coat effect have been studied extensively. The repercussion on the circadian rhythm of urinary water and salt excretion in the same subgroup remain, conversely, among the open topics. Postulating an impaired diurnal sodium and volume excretion we decided to investigate both, in subjects with or without a white-coat effect, in the general population. A sample of 1023 subjects, has been considered. We collected 24-h urine samples, divided in day and night, and we measured the blood pressure with an Ambulatory Blood Pressure Monitoring (ABPM). ABPM values were then compared with physician collected in-office values to assign subjects to the group with or without the white-coat effect. Concerning the circadian pattern of urinary sodium excretion, we found no significant differences between the groups. There was instead in the white-coat effect group a higher night/day ratio of urinary water excretion. The white-coat effect, has been considered a potential hypertension precursor, and its consequent handling could be prospectively relevant in hypertension prevention. The absence of repercussions on the urinary circadian sodium excretion pattern and on the potentially related risk factors in subjects with a white coat effect is reassuring. The clinical significance of the impact on the night/day ratio of water excretion needs to be further investigated.

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.

Anatomic Variations of Renal Arteries as an Important Factor in the Effectiveness of Renal Denervation in Resistant Hypertension

Hypertension remains the leading cause of death worldwide. Despite advances in drug-based treatment, many patients do not achieve target blood pressure. In recent years, there has been an increased interest in invasive hypertension treatment methods. Long-term effects and factors affecting renal denervation effectiveness are still under investigation. Some investigators found that the renal arteries' morphology is crucial in renal denervation effectiveness. Accessory renal arteries occur in 20-30% of the population and even more frequently in patients with resistant hypertension. Diversity in renal vascularization and innervation may complicate the renal denervation procedure and increase the number of people who will not benefit from treatment. Based on previous studies, it has been shown that the presence of accessory renal arteries, and in particular, the lack of their complete denervation, reduces the procedure's effectiveness. The following review presents the anatomical assessment of the renal arteries, emphasizing the importance of imaging tests. Examples of imaging and denervation methods to optimize the procedure are presented. The development of new-generation catheters and the advancement in knowledge of renal arteries anatomy may improve the effectiveness of treatment and reduce the number of patients who do not respond to treatment.

Anti-hypertensive medication adherence in the REQUIRE trial: post-hoc exploratory evaluation

Maintaining medication adherence is important in treating hypertension, especially resistant hypertension (RH), and variable medication adherence can confound results in blood pressure trials. This post-hoc analysis evaluated adherence at baseline and 3 months using available urine samples from the REQUIRE trial, comparing 24-h ambulatory systolic blood pressure (ASBP) lowering effects of ultrasound renal denervation (uRDN) versus sham in RH. At baseline, 45% (26/58) patients showed poor adherence. Among patients with good baseline adherence, adherence was unchanged at 3 months, and uRDN patients had a decreased ASBP whereas sham patients did not. In poorly adherent patients, sham patients showed a trend towards increased adherence and a significant ASBP reduction, whereas uRDN patients did not change. Accordingly, adherence changes and the resultant ASBP reduction in poorly adherent sham patients may explain the lack of between-group difference seen in REQUIRE. Monitoring and maintaining medication adherence is important for future interventional studies in RH.

Effects of Renal Denervation on Sympathetic Nerve Traffic and Correlates in Drug-Resistant and Uncontrolled Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Whether and to what extent the reported blood pressure (BP) lowering effects of renal denervation (RDN) are associated with a central sympathoinhibition is controversial. We examined this issue by performing a meta-analysis of the microneurographic studies evaluating the BP and muscle sympathetic nerve activity (MSNA) responses to RDN in drug-resistant or uncontrolled hypertension (RHT).

METHODS

This analysis comprised 11 studies including a total of >400 RHT patients undergoing RDN and were followed up for 6 months. Evaluation was extended to the relationships of MSNA with clinic heart rate and BP changes associated with RDN.

RESULTS

MSNA showed a significant reduction after RDN (-4.78 bursts/100 heart beats; P<0.04), which was also accompanied by a significant systolic (-11.45 mm Hg; P<0.002) and diastolic (-5.24 mm Hg; P=0.0001) BP decrease. No significant quantitative relationship was found between MSNA and systolic (r=-0.96, P=0.19) or diastolic BP (r=-0.97, P=0.23) responses to RDN. This was also the case for clinic heart rate (r=0.53, P=0.78, respectively), whose post RDN values were not significant different from the pre-RDN ones. More than 10 renal nerves ablations were found to be needed for obtaining a significant sympathoinhibition.

CONCLUSIONS

This meta-analysis, the first ever done on the MSNA responses to RDN, shows that in a consistent number of RHT patients RDN is associated with a significant, although modest, central sympathoinhibition, which appears to be unrelated to the BP lowering effects of the procedure. Thus factors other than the central sympathetic outflow inhibition may concur at the BP lowering effects of RDN.

Novel Therapies on the Horizon of Hypertension Management

BACKGROUND

The rates of uncontrolled hypertension, along with downstream cardiovascular outcomes, has been worsening in this country. Despite the plethora of antihypertensive medications on the market, the prevalence of resistant hypertension (RH) is estimated to be 13.7%. Therefore in addition to increased clinical education and focus on lifestyle management of hypertension and medication compliance, new therapies are needed to address this rise in hypertension.

METHODS

A systematic review of the available medical literature was performed to identify emerging treatment options for RH.

RESULTS

Six different pharmacologic classes and 2 procedural interventions were identified as being appropriate for review in this paper. The pharmacologic classes to be explored are non-steroidal mineralocorticoid receptor antagonists, aminopeptidase A inhibitors, dual endothelin antagonists, aldosterone synthetase inhibitors, atrial natriuretic peptide inhibitors, and attenuators of hepatic angiotensinogen. Discussion of procedural interventions to lower blood pressure will focus on renal denervation and devices that increase carotid baroreceptor activity.

CONCLUSIONS

Promising medication and procedural interventions are being developed and studied to expand our treatment arsenal for patients with uncontrolled essential hypertension and RH.

Etiological Diagnosis and Personalized Therapy for Hypertension: A Hypothesis of the REASOH Classification

With the epidemic of risk factors such as unhealthy lifestyle, obesity and mental stress, the prevalence of hypertension continues to rise across the world. Although standardized treatment protocols simplify the selection of antihypertensive drugs and ensure therapeutic efficacy, the pathophysiological state of some patients remains, which may also lead to the development of other cardiovascular diseases. Thus, there is an urgent need to consider the pathogenesis and selection of antihypertensive drug for different type of hypertensive patients in the era of precision medicine. We proposed the REASOH classification, based on the etiology of hypertension, including renin-dependent hypertension, elderly-arteriosclerosis-based hypertension, sympathetic-active hypertension, secondary hypertension, salt-sensitive hypertension and hyperhomocysteinemia hypertension. The aim of this paper is to propose a hypothesis and provide a brief reference for the personalized treatment of hypertensive patients.

Contribution of afferent renal nerve signals to acute and chronic blood pressure regulation in stroke-prone spontaneously hypertensive rats

The activation of sympathetic nervous system plays a critical role in the development of hypertension. The input from afferent renal nerves may affect central sympathetic outflow; however, its contribution to the development of hypertension remains unclear. We investigated the role of afferent renal nerves in acute and chronic blood pressure regulation using normotensive Wistar-Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). Acute chemical stimulation of afferent renal nerves elicited larger increases in blood pressure and renal sympathetic nerve activity in young 9-week-old SHRSP compared to WKY. Selective afferent renal denervation (ARDN) and conventional total renal denervation (TRDN) ablating both afferent and efferent nerves in young SHRSP revealed that only TRDN, but not ARDN, chronically attenuated blood pressure elevation. ARDN did not affect plasma renin activity or plasma angiotensin II levels, whereas TRDN decreased both. Neither TRDN nor ARDN affected central sympathetic outflow and systemic sympathetic activity determined by neuronal activity in the parvocellular region of hypothalamic paraventricular nucleus and rostral ventrolateral medulla and by plasma and urinary norepinephrine levels, respectively. Renal injury was not apparent in young SHRSP compared with WKY, suggesting that renal afferent input might not be activated in young SHRSP. In conclusion, the chronic input from afferent renal nerves does not contribute to the development of hypertension in SHRSP despite the increased blood pressure response to the acute stimulation of afferent renal nerves. Efferent renal nerves may be involved in the development of hypertension via activation of the renin-angiotensin system in SHRSP.

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

BACKGROUND

The SYMPLICITY HTN-3 (Renal Denervation in Patients With Uncontrolled Hypertension) trial showed the safety but not efficacy of the Symplicity system (Medtronic, Santa Rosa, CA, USA) at 6 months follow-up in patients with treatment-resistant hypertension. This final report presents the 36-month follow-up results.

METHODS

SYMPLICITY HTN-3 was a single-blind, multicentre, sham-controlled, randomised clinical trial, done in 88 centres in the USA. Adults aged 18-80 years, with treatment-resistant hypertension on stable, maximally tolerated doses of three or more drugs including a diuretic, who had a seated office systolic blood pressure of 160 mm Hg or more and 24 h ambulatory systolic blood pressure of 135 mm Hg or more were randomly assigned (2:1) to receive renal artery denervation using the single electrode (Flex) catheter or a sham control. The original primary endpoint was the change in office systolic blood pressure from baseline to 6 months for the renal artery denervation group compared with the sham control group. Patients were unmasked after the primary endpoint assessment at 6 months, at which point eligible patients in the sham control group who met the inclusion criteria (office blood pressure ≥160 mm Hg, 24 h ambulatory systolic blood pressure ≥135 mm Hg, and still prescribed three or more antihypertensive medications) could cross over to receive renal artery denervation. Changes in blood pressure up to 36 months were analysed in patients in the original renal artery denervation group and sham control group, including those who underwent renal artery denervation after 6 months (crossover group) and those who did not (non-crossover group). For comparisons between the renal artery denervation and sham control groups, follow-up blood pressure values were imputed for patients in the crossover group using their most recent pre-crossover masked blood pressure value. We report long-term blood pressure changes in renal artery denervation and sham control groups, and investigate blood pressure control in both groups using time in therapeutic blood pressure range analysis. The primary safety endpoint was the incidence of all-cause mortality, end stage renal disease, significant embolic event, renal artery perforation or dissection requiring intervention, vascular complications, hospitalisation for hypertensive crisis unrelated to non-adherence to medications, or new renal artery stenosis of more than 70% within 6 months. The trial is registered with ClinicalTrials.gov, NCT01418261.

FINDINGS

From Sep 29, 2011, to May 6, 2013, 1442 patients were screened, of whom 535 (37%; 210 [39%] women and 325 [61%] men; mean age 57·9 years [SD 10·7]) were randomly assigned: 364 (68%) patients received renal artery denervation (mean age 57·9 years [10·4]) and 171 (32%) received the sham control (mean age 56·2 years [11·2]). 36-month follow-up data were available for 219 patients (original renal artery denervation group), 63 patients (crossover group), and 33 patients (non-crossover group). At 36 months, the change in office systolic blood pressure was -26·4 mm Hg (SD 25·9) in the renal artery denervation group and -5·7 mm Hg (24·4) in the sham control group (adjusted treatment difference -22·1 mm Hg [95% CI -27·2 to -17·0]; p≤0·0001). The change in 24 h ambulatory systolic blood pressure at 36 months was -15·6 mm Hg (SD 20·8) in the renal artery denervation group and -0·3 mm Hg (15·1) in the sham control group (adjusted treatment difference -16·5 mm Hg [95% CI -20·5 to -12·5]; p≤0·0001). Without imputation, the renal artery denervation group spent a significantly longer time in therapeutic blood pressure range (ie, better blood pressure control) than patients in the sham control group (18% [SD 25·0] for the renal artery denervation group vs 9% [SD 18·8] for the sham control group; p≤0·0001) despite a similar medication burden, with consistent and significant results with imputation. Rates of adverse events were similar across treatment groups, with no evidence of late-emerging complications from renal artery denervation. The rate of the composite safety endpoint to 48 months, including all-cause death, new-onset end-stage renal disease, significant embolic event resulting in end-organ damage, vascular complication, renal artery re-intervention, and hypertensive emergency was 15% (54 of 352 patients) for the renal artery denervation group, 14% (13 of 96 patients) for the crossover group, and 14% (10 of 69 patients) for the non-crossover group.

INTERPRETATION

This final report of the SYMPLICITY HTN-3 trial adds to the totality of evidence supporting the safety of renal artery denervation to 36 months after the procedure. From 12 months to 36 months after the procedure, patients who were originally randomly assigned to receive renal artery denervation had larger reductions in blood pressure and better blood pressure control compared with patients who received sham control.

FUNDING

Medtronic.

Current and future use of neuromodulation in heart failure. Eur Heart J Suppl 2022;24:E28-E34. [PMID: 35991620 PMCID: PMC9385118 DOI: 10.1093/eurheartjsupp/suac031]

Autonomic imbalance is a common finding in heart failure (HF) with reduced ejection fraction (HFrEF). Addressing different targets within the autonomic nervous systems has been evaluated in patients with HF, including renal sympathetic denervation, vagal nerve stimulation, and baroreceptor activation therapy (BAT). Although all are pathophysiologically plausible and promising, only BAT shows sufficient evidence for implementation into clinical practice in randomized controlled trials. Baroreceptor activation therapy can be used in patients with symptomatic HFrEF despite optimal guideline-directed medication and device therapy. This article reviews the current and future use of neuromodulation in HF and provides an overview on current guideline recommendations and clinical practice.

Update on Renal Sympathetic Denervation for the Treatment of Hypertension

PURPOSE OF REVIEW

Hypertension is a leading risk factor for all-cause mortality in adults; however, medication non-adherence and intolerance present an enormous treatment challenge. Given the critical role of renal sympathetic nerves in neurogenic control of blood pressure and pathophysiology of hypertension, renal sympathetic denervation (RDN) has been explored as a therapeutic strategy in hypertension treatment over the last 15 years. In this review, we will discuss the role of renal sympathetic nerves in the pathophysiology of hypertension, provide an update on the available evidence regarding the short- and long-term safety and effectiveness of RDN in the treatment of hypertension, and consider its future perspectives.

RECENT FINDINGS

RDN is a percutaneous endovascular catheter-based neuromodulation approach that enables ablation of renal sympathetic nerve fibers within the adventitial layer of the renal arteries using radiofrequency (most extensively studied), ultrasound energy, or neurolytics (e.g., alcohol). In the last decade, advancements in procedural techniques and well-designed sham-controlled trials utilizing 24-h ambulatory blood pressure measurements have demonstrated that RDN has an excellent safety profile and results in a modest reduction of blood pressure, in a wide range of hypertensive phenotypes (mild to resistant), irrespective of antihypertensive drug use and this effect is sustained over a 3-year period. Superiority of a particular RDN modality has not been yet established. Despite strong evidence demonstrating efficacy and safety of RDN, current data does not support its use as a primary approach in the treatment of hypertension due to its modest treatment effect and concerns around long-term sustainability. Perhaps the best utility of RDN is in hypertensives intolerant to antihypertensive medications or as an adjunct to aldosterone antagonists in the management of resistant hypertension. Patient selection will be critical to demonstrate a meaningful benefit of RDN. Future well-designed studies are necessary to determine predictors and measures of response to RDN, long-term efficacy given question of renal nerve regeneration, comparison of available technologies, safety in patients with advanced kidney disease, and improvement in patient quality of life measures.

Safety and efficacy of renal denervation in patients with heart failure with reduced ejection fraction (HFrEF): A systematic review and meta-analysis

INTRODUCTION

A systematic analysis of clinical trials was performed in order to assess the effectiveness and risks of bilateral renal denervation (RDN) in patients with chronic heart failure with reduced ejection fraction (HFrEF).

METHODS

A systematic review was conducted of all clinical trials exploring the effectiveness of RDN in patients with HF who had reduced (<50%) EF. Primary outcomes were NYHA class, 6-min walk test, N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, left ventricular ejection fraction (LVEF) and other cardiac parameters including left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD), and left atrium diameter (LAD). Secondary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), glomerular filtration rate (GFR), and creatinine.

RESULTS

Seven studies were included in this analysis. From baseline to 6 months after RDN, the pooled mean NYHA class was decreased (mean difference [MD], -0.9; 95% confidence interval [CI], -1.6 to -0.2; P = 0.018), the mean 6-min walk test was increased (MD, 79.5 m; 95% CI, 26.9 to 132.1; P = 0.003), and the average NT-proBNP level was decreased (MD, -520.6 pg/mL; 95% CI, -1128.4 to 87.2; P = 0.093). Bilateral RDN increased the LVEF (MD, 5.7%; 95% CI, 1.6 to 9.6; P = 0.004), decreased the LVESD (MD, -0.4 cm; 95% CI, -0.5 to -0.2; P < 0.001), decreased the LVEDD (MD, -0.5 cm; 95% CI, -0.6 to -0.3; P < 0.001), and decreased the LAD (MD, -0.4 cm; 95% CI, -0.8 to 0; P = 0.045). In addition, RDN significantly decreased systolic BP (MD, -9.4 mmHg; 95% CI, -16.3 to -2.4; P = 0.008) and diastolic BP (MD, -4.9 mmHg; 95% CI, -9.5 to -0.4; P = 0.033), and decreased HR (MD, -4.5 bpm; 95% CI, -8.2to -0.9; P = 0.015). RDN did not significantly change GFR (MD, 7.9; 95% CI, -5.0 to 20.8; P = 0.230), or serum creatinine levels (MD, -7.2; 95% CI, -23.7 to 9.4; P = 0.397).

CONCLUSION

Bilateral RDN appears safe and well-tolerated in patients with HF. RDN improved the signs and symptoms of HF and slightly decreased systolic and diastolic BP without affecting renal function in the clinical trials performed to date.