Durability of blood pressure reduction after ultrasound renal denervation: three-year follow-up of the treatment arm of the randomised RADIANCE-HTN SOLO trial

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.

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.

Selected highlights in the updated treatment of hypertension

Hypertension remains the leading international risk factor for cardiovascular disease and premature death but, despite effective treatments, hypertension remains significantly underdiagnosed and undertreated. In the present review paper, we provide a selected update on recent developments of interest in the management of hypertension. We focus on summarizing four topics that we believe are worth highlighting to a clinical audience: (1) the evidence and strong motivation for new lower systolic BP treatment targets; (2) new studies reporting on the efficacy of renal denervation in the management of hypertension; (3) interesting new data to inform the great salt debate; and (4), perhaps most importantly, pioneering new work highlighting the huge potential of multi-disciplinary care in the management of hypertension.

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.

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).

Diagnosis and management of resistant hypertension

Resistant hypertension is defined as blood pressure that remains above the therapeutic goal despite concurrent use of at least three antihypertensive agents of different classes, including a diuretic, with all agents administered at maximum or maximally tolerated doses. Resistant hypertension is also diagnosed if blood pressure control requires four or more antihypertensive drugs. Assessment requires the exclusion of apparent treatment resistant hypertension, which is most often the result of non-adherence to treatment. Resistant hypertension is associated with major cardiovascular events in the short and long term, including heart failure, ischemic heart disease, stroke, and renal failure. Guidelines from several professional organizations recommend lifestyle modification and antihypertensive drugs. Medications typically include an angiotensin converting enzyme inhibitor or angiotensin receptor blocker, a calcium channel blocker, and a long acting thiazide-type/like diuretic; if a fourth drug is needed, evidence supports addition of a mineralocorticoid receptor antagonist. After a long pause since 2007 when the last antihypertensive class was approved, several novel agents are now under active development. Some of these may provide potent blood pressure lowering in broad groups of patients, such as aldosterone synthase inhibitors and dual endothelin receptor antagonists, whereas others may provide benefit by allowing treatment of resistant hypertension in special populations, such as non-steroidal mineralocorticoid receptor antagonists in patients with chronic kidney disease. Several device based approaches have been tested, with renal denervation being the best supported and only approved interventional device treatment for resistant hypertension.

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.

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.

Sympathetic Pathophysiology in Hypertension Origins: The Path to Renal Denervation

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

Long-Term Safety and Efficacy of Transcatheter Microwave and Radiofrequency Denervation in a Chronic Ovine Model

BACKGROUND

Transcatheter renal denervation (RDN) has had inconsistent efficacy and concerns for durability of denervation. We aimed to investigate long-term safety and efficacy of transcatheter microwave RDN in vivo in normotensive sheep in comparison to conventional radiofrequency ablation.

METHODS AND RESULTS

Sheep underwent bilateral RDN, receiving 1 to 2 microwave ablations (maximum power of 80-120 W for 240 s-480 s) and 12 to 16 radiofrequency ablations (180 s-240 s) in the main renal artery in a paired fashion, alternating the side of treatment, euthanized at 2 weeks (acute N=15) or 5.5 months (chronic N=15), and compared with undenervated controls (N=4). Microwave RDN produced substantial circumferential perivascular injury compared with radiofrequency at both 2 weeks [area 239.8 (interquartile range [IQR] 152.0-343.4) mm2 versus 50.1 (IQR, 32.0-74.6) mm2, P <0.001; depth 16.4 (IQR, 13.9-18.9) mm versus 7.5 (IQR, 6.0-8.9) mm P <0.001] and 5.5 months [area 20.0 (IQR, 3.4-31.8) mm2 versus 5.0 (IQR, 1.4-7.3) mm2, P=0.025; depth 5.9 (IQR, 1.9-8.8) mm versus 3.1 (IQR, 1.2-4.1) mm, P=0.005] using mixed models. Renal denervation resulted in significant long-term reductions in viability of renal sympathetic nerves [58.9% reduction with microwave (P=0.01) and 45% reduction with radiofrequency (P=0.017)] and median cortical norepinephrine levels [71% reduction with microwave (P <0.001) and 72.9% reduction with radiofrequency (P <0.001)] at 5.5 months compared with undenervated controls.

CONCLUSIONS

Transcatheter microwave RDN produces deep circumferential perivascular ablations without significant arterial injury to provide effective and durable RDN at 5.5 months compared with radiofrequency RDN.

Renal denervation in the management of hypertension

Arterial hypertension is a global leading cause of cardiovascular, cerebrovascular, and renal disease, as well as mortality. Although pharmacotherapy is safe and effective in lowering blood pressure (BP) and cardiovascular disease risk, BP control remains poor, and the mortality rates associated with high BP have been steadily increasing. Device-based therapies have been investigated to overcome barriers to pharmacotherapy, including non-adherence and low rates of persistence to daily medications. Among these device-based therapies, catheter-based renal denervation (RDN) has been most extensively examined over the past 15 years. In this state-of-the-art article, we summarise the rationale for RDN, review the available evidence, provide recommendations for a safe procedure, and discuss the role of RDN in current guidelines and clinical practice.

Renal Denervation for Hypertension: The Current Landscape and Future Directions

Hypertension (HTN) is one of the largest contributors to cardiovascular (CV) morbidity and mortality in the USA and is estimated to affect 47% of the US population; however, recent estimates suggest that over 40% continue to have uncontrolled HTN. In the past decade, multiple placebo-controlled randomized studies have shown the safety and efficacy of renal denervation as an adjunctive therapy, culminating in the recent approval of two devices by the US Food and Drug Administration (FDA). These devices use either radiofrequency or ultrasound energies to ablate the perivascular sympathetic nerves in the renal arteries and have been shown to reduce blood pressure. In this immediate post-FDA approval era, there are still multiple issues regarding the future of the technology in its applications and reimbursement landscapes.

Ultra-long-term efficacy and safety of catheter-based renal denervation in resistant hypertension: 10-year follow-up outcomes

BACKGROUND

Randomized sham-controlled trials have confirmed the efficacy and safety of catheter-based renal denervation in hypertension. Data on the very long-term effects of renal denervation are scarce.

AIMS

This study evaluates the 10-year safety and efficacy of renal denervation in resistant hypertension.

METHODS

This prospective single-center study included patients with resistant hypertension undergoing radio-frequency renal denervation between 2010 and 2012. Office blood pressure, 24-h ambulatory blood pressure, antihypertensive medication, color duplex sonography, and renal function were assessed after 1-, 2- and 10-years.

RESULTS

Thirty-nine patients completed the 10-year follow-up (mean follow-up duration 9.4 ± 0.7 years). Baseline office and 24-h ambulatory systolic blood pressure were 164 ± 23 mmHg and 153 ± 16 mmHg, respectively. After 10 years, 24-h ambulatory and office systolic blood pressure were reduced by 16 ± 17 mmHg (P < 0.001) and 14 ± 23 mmHg (P = 0.001), respectively. The number of antihypertensive drugs remained unchanged from 4.9 ± 1.4 to 4.5 ± 1.2 drugs (P = 0.087). The estimated glomerular filtration rate declined within the expected range from 69 (95% CI 63 to 74) to 60 mL/min/1.73m2 (95% CI 53 to 68; P < 0.001) through 10-year follow-up. Three renal artery interventions were documented for progression of pre-existing renal artery stenosis in two patients and one patient with new-onset renal artery stenosis. No other adverse events were observed during the follow-up.

CONCLUSION

Renal denervation was safe and sustainedly reduced ambulatory and office blood pressure out to 10 years in patients with resistant hypertension.

Patient-Level Pooled Analysis of Endovascular Ultrasound Renal Denervation or a Sham Procedure 6 Months After Medication Escalation: The RADIANCE Clinical Trial Program

BACKGROUND

The randomized, sham-controlled RADIANCE-HTN (A Study of the Recor Medical Paradise System in Clinical Hypertension) SOLO, RADIANCE-HTN TRIO, and RADIANCE II (A Study of the Recor Medical Paradise System in Stage II Hypertension) trials independently met their primary end point of a greater reduction in daytime ambulatory systolic blood pressure (SBP) 2 months after ultrasound renal denervation (uRDN) in patients with hypertension. To characterize the longer-term effectiveness and safety of uRDN versus sham at 6 months, after the blinded addition of antihypertensive treatments (AHTs), we pooled individual patient data across these 3 similarly designed trials.

METHODS

Patients with mild to moderate hypertension who were not on AHT or with hypertension resistant to a standardized combination triple AHT were randomized to uRDN (n=293) versus sham (n=213); they were to remain off of added AHT throughout 2 months of follow-up unless specified blood pressure (BP) criteria were exceeded. In each trial, if monthly home BP was ≥135/85 mm Hg from 2 to 5 months, standardized AHT was sequentially added to target home BP <135/85 mm Hg under blinding to initial treatment assignment. Six-month outcomes included baseline- and AHT-adjusted change in daytime ambulatory, home, and office SBP; change in AHT; and safety. Linear mixed regression models using all BP measurements and change in AHT from baseline through 6 months were used.

RESULTS

Patients (70% men) were 54.1±9.3 years of age with a baseline daytime ambulatory/home/office SBP of 150.5±9.8/151.0±12.4/155.5±14.4 mm Hg, respectively. From 2 to 6 months, BP decreased in both groups with AHT titration, but fewer uRDN patients were prescribed AHT (P=0.004), and fewer additional AHT were prescribed to uRDN patients versus sham patients (P=0.001). Whereas the unadjusted between-group difference in daytime ambulatory SBP was similar at 6 months, the baseline and medication-adjusted between-group difference at 6 months was -3.0 mm Hg (95% CI, -5.7, -0.2; P=0.033), in favor of uRDN+AHT. For home and office SBP, the adjusted between-group differences in favor of uRDN+AHT over 6 months were -5.4 mm Hg (-6.8, -4.0; P<0.001) and -5.2 mm Hg (-7.1, -3.3; P<0.001), respectively. There was no heterogeneity between trials. Safety outcomes were few and did not differ between groups.

CONCLUSIONS

This individual patient-data analysis of 506 patients included in the RADIANCE trials demonstrates the maintenance of BP-lowering efficacy of uRDN versus sham at 6 months, with fewer added AHTs.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02649426 and NCT03614260.

Taming resistant hypertension: The promise of novel pharmacologic approaches and renal denervation

Resistant hypertension is associated with an exceedingly high cardiovascular risk and there remains an unmet therapeutic need driven by pathophysiologic pathways unaddressed by guideline-recommended therapy. While spironolactone is widely considered as the preferable fourth-line drug, its broad application is limited by its side effect profile, especially off-target steroid receptor-mediated effects and hyperkalaemia in at-risk subpopulations. Recent landmark trials have reported promising safety and efficacy results for a number of novel compounds targeting relevant pathophysiologic pathways that remain unopposed by contemporary drugs. These include the dual endothelin receptor antagonist, aprocitentan, the aldosterone synthase inhibitor, baxdrostat and the nonsteroidal mineralocorticoid receptor antagonist finerenone. Furthermore, the evidence base for consideration of catheter-based renal denervation as a safe and effective adjunct therapeutic approach across the clinical spectrum of hypertension has been further substantiated. This review will summarise the recently published evidence on novel antihypertensive drugs and renal denervation in the context of 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.

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. Global Paradise System registry study design. ABP, ambulatory blood pressure; BP, blood pressure; FU, follow-up; M, month; OBP, office blood pressure.

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.

Twenty-Four-Month Blood Pressure Results After Renal Denervation Using Endovascular Ultrasound

BACKGROUND Renal denervation has proven its efficacy to lower blood pressure in comparison to sham treatment in recent randomized clinical trials. Although there is a large body of evidence for the durability and safety of radiofrequency-based renal denervation, there are a paucity of data for endovascular ultrasound-based renal denervation (uRDN). We aimed to assess the long-term efficacy and safety of uRDN in a single-center cohort of patients. METHODS AND RESULTS Data from 2 previous studies on uRDN were pooled. Ambulatory 24-hour blood pressure measurements were taken before as well as 3, 6, 12, and 24 months after treatment with uRDN. A total of 130 patients (mean age 63±9 years, 24% women) underwent uRDN. After 3, 6, 12, and 24 months, systolic mean 24-hour ambulatory blood pressure values were reduced by 10±12, 10±14, 8±15, and 10±15 mm Hg, respectively, when compared with baseline (P<0.001). Corresponding diastolic values were reduced by 6±8, 6±8, 5±9, and 6±9 mm Hg, respectively (P<0.001). Periprocedural adverse events occurred in 16 patients, and all recovered without sequelae. CONCLUSIONS In this single-center study, uRDN effectively lowered blood pressure up to 24 months after treatment.

Sequential afferent and sympathetic renal denervation impact on cardiovascular and renal homeostasis in the male Sprague-Dawley rat

Renal denervation (RDNx) is emerging as a promising treatment for cardiovascular disease, yet the underlying mechanisms and contributions of afferent (sensory) and efferent (sympathetic) renal nerves in healthy conditions remains limited. We hypothesize that sympathetic renal nerves contribute to long-term MAP and renal function, whereas afferent renal nerves do not contribute to the maintenance of cardiovascular and renal function. To test this hypothesis, we performed two experiments. In experiment one, we performed total renal denervation (T-RDNx), ablating afferent and sympathetic renal nerves, in normotensive adult SD rats to determine effects on MAP and renal function. Experiment 2 employed a sequential surgical ablation using: (1) afferent targeted renal denervation (A-RDNx), then (2) sympathetic (T-RDNx) denervation to determine the individual contributions to cardiovascular and renal homeostasis. In experiment 1, MAP decreased following T-RDNx and GFR increased. In experiment 2, A-RDNx led to an increase in MAP but did not change renal function. In contrast, T-RDNx decreased MAP and improved renal filtration. Together, these data partially support our hypothesis that renal sympathetic nerves contribute to the chronic regulation of arterial pressure and renal function. Contrary to the hypothesis, A-RDNx produced an increase in MAP without a detected change in renal function. We concluded that renal sympathetic nerves influence MAP and renal function regulation through a well-defined tonic contribution to renal vascular resistance and sodium reabsorption, whereas afferent renal nerves likely contribute to the maintenance of MAP through a tonic sympatho-inhibitory, negative feedback regulation in the normotensive, healthy rat.

Efficacy of Antihypertensive Drugs of Different Classes After Renal Denervation in Spontaneously Hypertensive Rats

BACKGROUND

Renal denervation (RDN) lowers blood pressure (BP) in patients with uncontrolled hypertension. Limited data exist on the effectiveness of different antihypertensive medications following RDN on BP and maladaptive cardiac phenotypes.

METHODS

Eighty-nine male spontaneously hypertensive rats with continuous BP recording underwent RDN or sham operation. Ten days postsurgery, spontaneously hypertensive rats were randomized to receive no antihypertensive medication, amlodipine, olmesartan, hydrochlorothiazide, bisoprolol, doxazosin, or moxonidine for 28 days. Cardiac remodeling was determined histologically, and activation of the renin-angiotensin-aldosterone system was explored.

RESULTS

Before initiation of antihypertensive drugs, RDN reduced mean arterial pressure (-12.6 mm Hg [95% CI, -14.4 to -10.8]; P<0.001). At study end, mean arterial pressure was lower in RDN compared with sham operation in drug-naïve controls (P=0.006), olmesartan (P=0.002), amlodipine (P=0.0004), hydrochlorothiazide (P=0.006), doxazosin (P=0.001), and bisoprolol (P=0.039) but not in animals receiving moxonidine (P=0.122). Compared with pooled BP change of all other drug classes, mean arterial pressure change was largest for olmesartan (-15.9 mm Hg [95% CI, -18.6 to -13.2]; P<0.001) and amlodipine (-12.0 mm Hg [95% CI, -14.7 to -9.3]; P<0.001). In drug-naïve controls, RDN reduced plasma renin activity (-5.6%¸ P=0.03) and aldosterone concentration (-53.0%; P=0.005). In the presence of antihypertensive medication, plasma renin activity and aldosterone remained unchanged after RDN. Cardiac remodeling was not affected by RDN alone. In animals receiving olmesartan after RDN, cardiac perivascular fibrosis was attenuated. Amlodipine and bisoprolol following RDN reduced cardiomyocyte diameter.

CONCLUSIONS

Following RDN, treatment with amlodipine and olmesartan resulted in the largest BP reduction. Antihypertensive medications mediated heterogeneous effects on renin-angiotensin-aldosterone system activity and cardiac remodeling.

Patient-Level Pooled Analysis of Ultrasound Renal Denervation in the Sham-Controlled RADIANCE II, RADIANCE-HTN SOLO, and RADIANCE-HTN TRIO Trials

Importance

Ultrasound renal denervation (uRDN) was shown to lower blood pressure (BP) in patients with uncontrolled hypertension (HTN). Establishing the magnitude and consistency of the uRDN effect across the HTN spectrum is clinically important.

Objective

To characterize the effectiveness and safety of uRDN vs a sham procedure from individual patient-level pooled data across uRDN trials including either patients with mild to moderate HTN on a background of no medications or with HTN resistant to standardized triple-combination therapy.

Data Sources

A Study of the ReCor Medical Paradise System in Clinical Hypertension (RADIANCE-HTN SOLO and TRIO) and A Study of the ReCor Medical Paradise System in Stage II Hypertension (RADIANCE II) trials.

Study Selection

Trials with similar designs, standardized operational implementation (medication standardization and blinding of both patients and physicians to treatment assignment), and follow-up.

Data Extraction and Synthesis

Pooled analysis using individual patient-level data using linear regression models to compare uRDN with sham across the trials.

Main Outcomes and Measures

The primary outcome was baseline-adjusted change in 2-month daytime ambulatory systolic BP (dASBP) between groups.

Results

A total of 506 patients were randomized in the 3 studies (uRDN, 293; sham, 213; mean [SD] age, 54.1 [9.3]; 354 male [70.0%]). After a 1-month medication stabilization period, dASBP was similar between the groups (mean [SD], uRDN, 150.3 [9.2] mm Hg; sham, 150.8 [10.5] mm Hg). At 2 months, dASBP decreased by 8.5 mm Hg to mean (SD) 141.8 (13.8) mm Hg among patients treated with uRDN and by 2.9 mm Hg to 147.9 (14.6) mm Hg among patients treated with a sham procedure (mean difference, -5.9; 95% CI, -8.1 to -3.8 mm Hg; P < .001 in favor of uRDN). BP decreases from baseline with uRDN vs sham were consistent across trials and across BP parameters (office SBP: -10.4 mm Hg vs -3.4 mm Hg; mean difference, -6.4 mm Hg; 95% CI, -9.1 to -3.6 mm Hg; home SBP: -8.4 mm Hg vs -1.4 mm Hg; mean difference, -6.8 mm Hg; 95% CI, -8.7 to -4.9 mm Hg, respectively). The BP reductions with uRDN vs sham were consistent across prespecified subgroups. Independent predictors of a larger BP response to uRDN were higher baseline BP and heart rate and the presence of orthostatic hypertension. No differences in early safety end points were observed between groups.

Conclusions and Relevance

Results of this patient-level pooled analysis suggest that BP reductions with uRDN were consistent across HTN severity in sham-controlled trials designed with a 2-month primary end point to standardize medications across randomized groups.

Trial Registration

ClinicalTrials.gov Identifier: NCT02649426 and NCT03614260.

Novel Invasive Methods as the Third Pillar for the Treatment of Essential Uncontrolled Hypertension

Pharmacologic therapies remain the treatment of choice for patients with essential hypertension, as endorsed by international guidelines. However, several cases warrant additional modalities, such as invasive antihypertensive therapeutics. The major target of these interventions is the modulation of the sympathetic nervous system, which is a common pathophysiologic mechanism in essential hypertension. In this narrative review, we elaborate on the role of invasive antihypertensive treatments with a focus on renal denervation, stressing their potential as well as the drawbacks that prevent their widespread implementation in everyday clinical practice. In the field of renal denervation, several trials have shown significant and sustained reductions in the level of office and ambulatory blood pressure, regardless of the type of energy that was used (radiofrequency or ultrasound). Critically, renal denervation is considered a safe intervention, as evidenced by follow-up data from large clinical trials. Baroreflex activation therapy may result in enhanced parasympathetic nervous system activation, thus lowering blood pressure levels. Along the same lines, carotid body ablation could also produce a significant antihypertensive effect, which has not been tested in appropriately designed randomized trials. Moreover, cardiac neuromodulation therapy could prove efficacious by altering the duration of the atrioventricular interval in order to regulate the preload of the left ventricle and, therefore, lower blood pressure.

C, Renkin J, Maes F, Beauloye C, Lengelé JP, Huyberechts D, Bouvie A, Witkowski A, Januszewicz A, Kądziela J, Prejbisj A, Hering D, Ciecwierz D, Jaguszewski MJ, Owczuk R. Effects of Renal Denervation vs Sham in Resistant Hypertension After Medication Escalation: Prespecified Analysis at 6 Months of the RADIANCE-HTN TRIO Randomized Clinical Trial

Importance

Although early trials of endovascular renal denervation (RDN) for patients with resistant hypertension (RHTN) reported inconsistent results, ultrasound RDN (uRDN) was found to decrease blood pressure (BP) vs sham at 2 months in patients with RHTN taking stable background medications in the Study of the ReCor Medical Paradise System in Clinical Hypertension (RADIANCE-HTN TRIO) trial.

Objectives

To report the prespecified analysis of the persistence of the BP effects and safety of uRDN vs sham at 6 months in conjunction with escalating antihypertensive medications.

Design, Setting, and Participants

This randomized, sham-controlled, clinical trial with outcome assessors and patients blinded to treatment assignment, enrolled patients from March 11, 2016, to March 13, 2020. This was an international, multicenter study conducted in the US and Europe. Participants with daytime ambulatory BP of 135/85 mm Hg or higher after 4 weeks of single-pill triple-combination treatment (angiotensin-receptor blocker, calcium channel blocker, and thiazide diuretic) with estimated glomerular filtration rate (eGFR) of 40 mL/min/1.73 m2 or greater were randomly assigned to uRDN or sham with medications unchanged through 2 months. From 2 to 5 months, if monthly home BP was 135/85 mm Hg or higher, standardized stepped-care antihypertensive treatment starting with aldosterone antagonists was initiated under blinding to treatment assignment.

Interventions

uRDN vs sham procedure in conjunction with added medications to target BP control.

Main Outcomes and Measures

Six-month change in medications, change in daytime ambulatory systolic BP, change in home systolic BP adjusted for baseline BP and medications, and safety.

Results

A total of 65 of 69 participants in the uRDN group and 64 of 67 participants in the sham group (mean [SD] age, 52.4 [8.3] years; 104 male [80.6%]) with a mean (SD) eGFR of 81.5 (22.8) mL/min/1.73 m2 had 6-month daytime ambulatory BP measurements. Fewer medications were added in the uRDN group (mean [SD], 0.7 [1.0] medications) vs sham (mean [SD], 1.1 [1.1] medications; P = .045) and fewer patients in the uRDN group received aldosterone antagonists at 6 months (26 of 65 [40.0%] vs 39 of 64 [60.9%]; P = .02). Despite less intensive standardized stepped-care antihypertensive treatment, mean (SD) daytime ambulatory BP at 6 months was 138.3 (15.1) mm Hg with uRDN vs 139.0 (14.3) mm Hg with sham (additional decreases of -2.4 [16.6] vs -7.0 [16.7] mm Hg from month 2, respectively), whereas home SBP was lowered to a greater extent with uRDN by 4.3 mm Hg (95% CI, 0.5-8.1 mm Hg; P = .03) in a mixed model adjusting for baseline and number of medications. Adverse events were infrequent and similar between groups.

Conclusions and Relevance

In this study, in patients with RHTN initially randomly assigned to uRDN or a sham procedure and who had persistent elevation of BP at 2 months after the procedure, standardized stepped-care antihypertensive treatment escalation resulted in similar BP reduction in both groups at 6 months, with fewer additional medications required in the uRDN group.

Trial Registration

ClinicalTrials.gov Identifier: NCT02649426.