Effects of Renal Denervation Documented in the Austrian National Multicentre Renal Denervation Registry

Renal sympathetic denervation 2024 in Austria: recommendations from the Austrian Society of Hypertension : Endorsed by the Austrian Society of Nephrology and the Working Group of Interventional Cardiology of the Austrian Society of Cardiology

Renal sympathetic denervation (RDN) is an interventional supplement to medical treatment in patients with arterial hypertension. While the first sham-controlled trial, SYMPLICITY HTN‑3 was neutral, with improved procedural details, patient selection and follow-up, recent randomized sham-controlled trials of second-generation devices show a consistent blood pressure lowering effect of RDN, as compared to sham controls. These new data and the recent U.S. Food and Drug Administration (FDA) premarket approval of two RDN devices are the basis for the present recommendations update.This joint position paper from the Austrian Society of Hypertension, together with the Austrian Society of Nephrology and the Working Group of Interventional Cardiology from the Austrian Society of Cardiology includes an overview about the available evidence on RDN and gives specific recommendations for the work-up, patient selection, pretreatment, procedural management and follow-up in patients undergoing RDN in Austria. Specifically, RDN may be used in clinical routine care, together with lifestyle measures and antihypertensive drugs, in patients with resistant hypertension (i.e. uncontrolled blood pressure on 3 antihypertensive drugs) and in those with uncontrolled hypertension, after adequate work-up, if institutional, patient-related and procedural conditions are fulfilled.

Consensus and inconsistency between different consensus documents on renal denervation worldwide: the way forward

ABSTRACT

Given the unsatisfactory hypertension control rates and high rates of non-adherence to antihypertensive medications worldwide, device therapy which can safely provide durable blood pressure-lowering effects can fulfill the unmet need. A series of second-generation randomized sham-controlled renal denervation (RDN) trials have demonstrated the efficacy and safety of RDN in a wide range of hypertensive patients. The four representative consensus documents on RDN (from the Chinese Taiwan Hypertension Society and Taiwan Society of Cardiology [THS/TSOC 2019], Asia Renal Denervation Consortium 2019, European Society of Hypertension [ESH 2021], and Society for Cardiovascular Angiography & Intervention and National Kidney Foundation [SCAI/NKF 2021]) consistently recommend RDN as an alternative or complementary treatment strategy for patients with uncontrolled hypertension. In addition, both documents from Asia further recommend that RDN can be considered as an initial treatment strategy for drug-naïve hypertensive patients. There is still inconsistency regarding whether ambulatory blood pressure monitoring should be used routinely both before and after RDN, and whether patients with a secondary cause of hypertension could be treated with RDN if their blood pressure remains uncontrolled after definitive treatment (treatment-resistant secondary hypertension). The THS/TSOC consensus provides acronyms to summarize key aspects of patient selection (RDNi2) and pre-RDN assessments (RAS). The ESH and SCAI/NKF documents recommend establishing structured pathways for clinical practice and issues regarding reimbursement. All documents identify knowledge gaps in RDN, from identifying predictors of super-responders to demonstrating effects on cardiovascular events. These gaps should be urgently filled to facilitate the wider application of this device therapy for patients with hypertension.

Blood pressure changes after renal denervation are more pronounced in women and nondiabetic patients: findings from the Austrian Transcatheter Renal Denervation Registry

OBJECTIVES

Three recently published sham-controlled studies proved the efficacy of renal denervation (RDN) in hypertensive patients. The study presented here analyzed a nationwide multicentre registry database to clarify which patient subgroups benefit most from radiofrequency RDN.

METHODS

This is a post hoc analysis from the multicentre Austrian Transcatheter Renal Denervation Registry hosted by the Austrian Society of Hypertension. We correlated change of SBP after RDN to sex and presence/absence of comorbidities. Univariable correlation and multiple linear regression analyses were performed.

RESULTS

Two hundred and ninety-one patients (43% women, median age 64 years) undergoing RDN between April 2011 and September 2014 were included in this analysis. Mean baseline ambulatory 24 h BP (systolic/diastolic) was 150 ± 18/89 ± 14 mmHg and mean baseline office BP was 170 ± 16/94 ± 14 mmHg.After RDN, mean ambulatory 24 h BP reduction was 9 ± 19/6 ± 16 mmHg. The following features were associated with a good response to RDN: high baseline systolic ambulatory BP, high baseline diastolic office BP, female sex, absence of diabetes mellitus, and absence of peripheral artery disease. Multivariable analysis identified female sex and absence of diabetes mellitus as strongest predictors for ambulatory BP reduction, although those groups had the lowest baseline ambulatory BP.

DISCUSSION

Ambulatory BP reductions after RDN were substantially more pronounced in female and in nondiabetic patients despite lower baseline BP. It is concluded that in terms of efficacy female patients and nondiabetic patients might benefit more from RDN.

New data, new studies, new hopes for renal denervation in patients with uncontrolled hypertension

Background

following the publication of SYMPLICITY HTN-3 the field of renal of denervation was put on hold. Although SYMPLICITY HTN-3 was well-designed and sham-controlled trial it failed to show any meaningful reduction in office or 24 h ambulatory blood pressure. The procedure was however safe and allowed research to continue. Although several pitfalls of the study have been pointed out, incomplete renal denervation was also implicated. Since then, a great deal of basic and clinical research took place and will be briefly commented on in this article.

Methods and results

Before and after SYMPLICITY-HTN-3, numerous uncontrolled, single or unblinded studies have shown substantial office BP reduction ranging from -7.7 to -32 mmHg and ambulatory BP ranging from -2.2 to 10.2 mmHg. Average weighted office systolic BP reduction was -20.8 mmHg and weighted average 24 h ambulatory BPM reduction was -7.8 mmHg. National and international registries have shown similar BP reductions, but results remained unconvincing due to lack of reliable sham controls. In recent years, 5 well-designed sham - controlled studies (beyond, SYMPLICITY-HTN-3) have been published. Of those studies two were single center and three were multicenter international studies. Four studies used single tip or multi-electrode, radiofrequency catheters and one used focused ultrasound. The three multicenter studies reported positive-placebo subtracted results and established BP reductions measured both in the office and by ambulatory monitoring. No serious adverse events were reported.

Conclusions

It can therefore be concluded that the latest sham controlled studies established efficacy and safety of renal denervation.

Renal denervation for the treatment of resistant hypertension in Spain. The Flex-Spyral Registry

INTRODUCTION AND OBJECTIVES

Renal denervation is a percutaneous intervention for the treatment of resistant hypertension. Randomized studies have shown contradictory results on its efficacy. We present the results of a renal denervation registry for the treatment of resistant hypertension in real-life patients in Spain.

METHODS

Multicenter registry of consecutive patients with resistant hypertension treated with renal denervation in Spain between 2009 and 2018.

RESULTS

We included 125 patients (mean age, 56 years; 41% female; mean onset of hypertension 14±9 years previously). Office systolic and diastolic blood pressure and ambulatory blood pressure monitoring decreased 6 months after the intervention (166±20/95±16 to 149±22/87±16 mmHg and 151±14/89±12 to 143±15/84±11, both P <.0001). At 12 months, the blood pressure reduction was maintained and the number of antihypertensive drugs decreased from 4.9±1.2 to 4.4±1.5 (P=.0001). There were no significant procedure-related complications. The response rate to denervation at 1 year was 80%, but there were wide differences between centers.

CONCLUSIONS

In patients with resistant hypertension, treatment with renal denervation was related to a decrease in office blood pressure and, more importantly, in ambulatory blood pressure monitoring, with a significant reduction in pharmacological treatment.

Erythrocyte Salt Sedimentation Assay Does Not Predict Response to Renal Denervation

Renal denervation (RDN) has recently been shown to be effective in patients without antihypertensive medication. However, about 30% of patients do not respond to RDN, and therefore, there exists a need to find predictors of response. Individuals are either salt-sensitive (SS) or non-salt-sensitive (NSS) in terms of their blood pressure (BP) regulation. The sympathetic nervous system can influence water and salt handling. RDN reduces sympathetic drive and has an impact on salt excretion. The present study was conducted to test the influence of salt sensitivity in terms of the BP reducing effect after RDN procedure. Salt sensitivity was estimated using the in vitro Erythrocyte Salt Sedimentation Assay (ESS). In 88 patients with resistant hypertension, RDN was performed. Office BP and lab testing were performed at baseline and at month 1, 3, 6, 12, 18, and 24 after RDN. A responder rate of 64.7% has been observed. Salt sensitivity measurements (ESS-Test) were completed in a subgroup of 37 patients with resistant hypertension. In this group, 15 were SS and 17 were salt-resistant according to the in vitro assay, respectively. The responder rate was 60% in SS patients and 59.1% in NSS patients, respectively. Electrolytes as well as aldosterone and renin levels did not differ between the two groups at baseline and in the follow-up measurements. The present study showed that salt sensitivity, estimated using the ESS in vitro test, did not affect the outcome of RDN and, therefore, does not help to identify patients suitable for RDN.