Radiofrequency Renal Sympathetic Denervation Research Articles

SPONTANEOUS, INDEPENDENT, SINGLE-CENTER RDN REGISTRY OF A RESISTANT HYPERTENSION MULTIDISCIPLINARY TEAM

Objective: Uncontrolled resistant hypertension (URH) is defined as Systolic Blood Pressure above 140mmHg despite at least 3 maximally tolerated doses of antihypertensive drugs including a diuretic. Renal sympathetic denervation (RDN) has proved efficacy in the sponsored SPYRAL and RADIANCE studies. However, little evidence is available from independent studies. Furthermore, patients with glomerular filtrate rate <45ml/min have been systematically excluded. This study aims to evaluate the safety and the efficacy of catheter-based radiofrequency RDN in patients with URH, including those with renal impairment. Design and method: Consecutive unselected patients with URH undergoing RDN were enrolled, assessed in a multidisciplinary team involving cardiologist, nephrologist and hypertension specialists, that excluded secondary forms. Efficacy was defined as change of office (OBP) and ambulatory blood pressure monitoring (ABPM) after RDN, safety as the absence of device-related major complication (BARC classification), end-stage renal disease, stroke, acute myocardial infarction and any cause of death within 1 month. 107 patients underwent RDN from 2012 to December 2023. The population had multiple comorbidities: 45% were smokers, 43% diabetic, 35% had peripheral artery disease, 30% coronary artery disease, 57% CKD. The average number of antihypertensive medications was 4.83±1.2 Baseline ABPM and OBP were 151.18±20,97/87,88±14,39mmHg and 155,92±24/85,25±15,5 mmHg, respectively Results: . At 12-month a significant reduction of systolic OBP and ABPM, respectively by -17.51±3.70 mmHg (P=0.001) and -7.03±3.37 mmHg (P=0.04) was noticed. BP reduction at 12-month follow-up was observed also among eGFR <45 ml/min, with a reduction by -18.73±7.14mmHg (P=0.02) in systolic OBP and by -17.81±7.49 (P=0.03) in ABPM. The therapeutic burden was slightly reduced baseline to 4 (3-5) at follow-up (p<0.01). No major complications were observed and renal function was stable up to 12 months, compared to baseline (1.87±2.37 vs. 2.44±3.56; -0.57±0.32; p=0.08). Conclusions: RDN on top of medical therapy is safe and feasible in patients with URH, even in a high-risk CKD population with multiple comorbidities. A significant reduction of SBP also in this subgroup up to 12 months was reported without undesired effects. Furthermore, our experience underlines the central role of multidisciplinary team evaluation for the appropriate management of URH.

Safety and efficacy of renal sympathetic denervation: a 9-year long-term follow-up of 24-hour ambulatory blood pressure measurements.

Renal sympathetic denervation (RDN) has been shown to lower arterial blood pressure both in the presence and in the absence of antihypertensive medication in an observation period of up to 3 years. However, long-term results beyond 3 years are scarcely reported. We performed a long-term follow-up on patients who were previously enrolled in a local renal denervation registry and who underwent radiofrequency RDN with the Symplicity Flex® renal denervation system between 2011 and 2014. The patients were assessed to evaluate their renal function by performing 24-hour ambulatory blood pressure measurement (ABPM), recording their medical history, and conducting laboratory tests. Ambulatory blood pressure readings for 24 h were available for 72 patients at long-term follow-up (FU) [9.3 years (IQR: 8.5-10.1)]. We found a significant reduction of ABP from 150.1/86.1 ± 16.9/12.0 mmHg at baseline to 138.3/77.1 ± 16.5/11.1 mmHg at long-term FU (P < 0.001 for both systolic and diastolic ABP). The number of antihypertensive medications used by the patients significantly decreased from 5.4 ± 1.5 at baseline to 4.8 ± 1.6 at long-term FU (P < 0.01). Renal function showed a significant but expected age-associated decrease in the eGFR from 87.8 (IQR: 81.0-100.0) to 72.5 (IQR: 55.8-86.8) ml/min/1.73 m2 (P < 0.01) in patients with an initial eGFR > 60 ml/min/1.73 m2, while a non-significant decrease was observed in patients with an initial eGFR < 60 ml/min/1.73 m2 at long-term FU [56.0 (IQR: 40.9-58.4) vs. 39.0 (IQR: 13.5-56.3) ml/min/1.73 m2]. RDN was accompanied by a long-lasting reduction in blood pressure with a concomitant reduction in antihypertensive medication. No negative effects could be detected, especially with regard to renal function.

Long-term safety and efficacy of renal sympathetic denervation in atrial fibrillation: 3-year results of the AFFORD study

BackgroundAtrial fibrillation (AF) is the most common sustained arrhythmia which has been associated with increased sympathetic nervous system activity and hypertension. Recent evidence indicated that renal sympathetic denervation (RDN) could safely contribute to an improvement in AF burden.ObjectiveTo investigate the long-term safety and efficacy of radiofrequency RDN in hypertensive patients with symptomatic AF.MethodsThis pilot study included patients with symptomatic paroxysmal or persistent AF (European Hearth Rhythm Association class ≥ II) despite optimal medical therapy, office systolic blood pressure (BP) ≥ 140 mmHg and ≥ 2 antihypertensive drugs. AF burden was measured using an implantable cardiac monitor (ICM), implanted 3 months prior to RDN. ICM interrogation and 24-h ambulatory BP monitoring were performed at baseline and at 3/6/12/24/36 months post RDN. The primary efficacy outcome was daily AF burden. Statistical analyses were performed using Poisson and negative binomial models.ResultsA total of 20 patients with a median age [25th–75th percentiles] of 66.2 [61.2–70.8] years (55% female) were included. At baseline, office BP ± standard deviation (SD) was 153.8/87.5 ± 15.2/10.4 mmHg, while mean 24-h ambulatory BP was 129.5/77.3 ± 15.5/9.3 mmHg. Baseline daily AF burden was 1.4 [0.0–10.9] minutes/day and throughout a 3-year follow-up period, no significant change was observed (− 15.4%/year; 95% confidence interval (CI) − 50.2%, + 43.7%; p = 0.54). The number of defined daily doses of antiarrhythmic drugs and antihypertensive drugs remained stable over time, while mean 24-h ambulatory systolic BP decreased with − 2.2 (95% CI − 3.9, − 0.6; p = 0.01) mmHg/year.ConclusionsIn patients with hypertension and symptomatic AF, stand-alone RDN reduced BP but did not significantly reduce AF burden up until 3 years of follow-up.Graphical abstract

Association between renal sympathetic denervation and arterial stiffness: the ASORAS study.

Renal sympathetic denervation (RDN) reduces blood pressure (BP). However, one out of three patients does not exhibit a significant BP response to the therapy. This study investigates the association between noninvasive vascular stiffness indices and RDN-mediated BP reduction. In this prospective, single-arm pilot study, patients with systolic office BP at least 140 mmHg, mean 24-h systolic ambulatory blood pressure (ABP) at least 130 mmHg and at least three prescribed antihypertensive drugs underwent radiofrequency RDN. The primary efficacy endpoint was temporal evolution of mean 24-h systolic ABP throughout 1-year post RDN (measured at baseline and 3-6-12 months). Effect modification was studied for baseline ultrasound carotid-femoral and magnetic resonance (MR) pulse wave velocity (PWV), MR aortic distensibility, cardiac MR left ventricular parameters and clinical variables. Statistical analyses were performed using linear mixed-effects models, and effect modification was assessed using interaction terms. Thirty patients (mean age 62.5 ± 10.7 years, 50% women) with mean 24-h ABP 146.7/80.8 ± 13.7/12.0 mmHg were enrolled. Following RDN, mean 24-h systolic ABP changed with -8.4 (95% CI: -14.5 to -2.3) mmHg/year ( P = 0.007). Independent effect modifiers were CF-PWV [+2.7 (0.3 to 5.1) mmHg/year change in outcome for every m/s increase in CF-PWV; P = 0.03], daytime diastolic ABP [-0.4 (-0.8 to 0.0) mmHg/year per mmHg; P = 0.03], age [+0.6 (0.2 to 1.0) mmHg/year per year of age; P = 0.006], female sex [-14.0 (-23.1 to -5.0) mmHg/year as compared with men; P = 0.003] and BMI [+1.2 (0.1 to 2.2) mmHg/year per kg/m 2 ; P = 0.04]. Higher CF-PWV at baseline was associated with a smaller reduction in systolic ABP following RDN. These findings could contribute to improve identification of RDN responders.

RADIOFREQUENCY RENAL SYMPATHETIC DENERVATION WITH MULTIELECTRODE CATHETERS IN PATIENTS WITH RESISTANT HYPERTENSION: EARLY PROCEDURAL RESULTS

Objective: Renal sympathetic denervation (RD) is the most promising invasive options to treat resistant hypertension (HTN). In Russian practice radiofrequency (RF) is the only feasible option. Emergence of the new RF RD multielectrode catheter systems in Russian HTN Excellence Centers provide a way to test this method. The aim of the study was to investigate the baseline characteristics of patients with resistant HTN undergoing RF RD and to determine immediate postprocedural clinical effects. Design and method: During 2018–2019, two series of RF RD procedures were performed in patients with truly resistant HTN using balloon-type (bipolar ablation) or spiral-type (unipolar ablation) multielectorde catheters. A comparative analysis of two groups of patients was carried out according to the type of catheter used. Dynamics of office systolic blood pressure (SBP) were assessed as delta between the two timepoints: at screening and at hospital discharge. The safety assessment of RF RD was performed. We applied multiple linear regression method to determine the factors associated with the delta of office SBP after RF RD. Results: A total of 48 patients taking 4 (4;6) antihypertensive drugs were included. Radiofrequency RD was performed with a balloon-type catheter in 27 patients (mean age 56 ± 12 y.o.; 12 males) and with a spiral-type catheter in 21 patients (50 ± 14 y.o.; 8 males). The duration of RF RD was significantly longer in the spiral catheter group (110 vs 60 min, p &lt; 0.001), but twice as much RF ablations (24 vs 12, p = 0.002). None had acute kidney injury after RD (delta creatinine -0.6 micromol/L; 95% CI [-3.97; 2.78]). At discharge there was a pronounced decrease in office SBP (adjusted for baseline covariates) of -26 mm Hg (95% CI [-29; -23]). The main factors associated with the delta of office SBP were: smoking status (beta = -7.95; positive if “yes’’), baseline office SBP (beta = -0.48; positive), and blood glucose (beta = 5.28; negative). Conclusions: Radiofrequency renal denervation using multielectode catheters is characterized by pronounced and favorable short-term hemodynamic effects. We have found new potential predictors of these effects. Further research will focus on testing initial hypotheses in the long term run.

Experience of using multielectrode catheter systems to perform radiofrequency renal sympathetic denervation in patients with resistant hypertension: immediate procedural effects

Aim. To investigate the baseline characteristics of patients with resistant hypertension (HTN) undergoing radiofrequency renal sympathetic denervation (RD) and to determine immediate procedural effects.Material and methods. During 2018-2019, two series of radiofrequency RD procedures were performed in patients with true resistant HTN using balloon-type (bipolar ablation) or spiral-type (unipolar ablation) multielectorde catheters. The basic demographic, clinical and laboratory characteristics of included patients were assessed. A comparative analysis of two groups was carried out depending on the type of catheter used. Dynamics of office systolic blood pressure (SBP) were assessed as ∆ between the two following timepoints: at screening and at hospital discharge. The safety of radiofrequency RD was assessed. Multiple linear regression was used to determine the factors associated with the ∆ of office SBP after radiofrequency RD.Results. A total of 48 patients taking 4 (4;6) antihypertensive drugs were sequentially included. Radiofrequency RD was performed with a balloon-type catheter in 27 patients (mean age, 56±12 years old; 12 males) and with a spiral-type catheter in 21 patients (50±14 years old; 8 males). Radiofrequency RD was significantly longer in the spiral catheter group than in balloon one (110 versus 60 minutes, p&lt;0,001), as was the mean number of RF applications (24 versus 12, p=0,002). None of the patients had acute kidney injury after RD (creatinine ∆, -0,6 µmol/L; 95% CI [-3,97; 2,78]). A total of 4 patients had complications (3 femoral arterial pseudoaneurisms, one renal arterial dissection), all of which did not affect the average length of hospital stay (from 4 to 5 days). At discharge, there was a pronounced decrease in office SBP (adjusted for baseline characteristics) with the mean of -26 mm Hg (95% CI [-29; -23]). There were following main factors associated with the office SBP ∆: smoking status (positive), baseline office SBP (positive), and blood glucose (negative).Conclusion. Radiofrequency RD using multielectode catheters is characterized by favorable short-term hemodynamic effects. We have found novel potential predictors of these effects. Further research will focus on testing initial hypotheses in the long term.

120 Safety and efficacy of renal artery denervation for uncontrolled-resistant hypertension in a high risk population with CKD: the Verona real-world experience

Abstract Aims To evaluate the safety and the efficacy of catheter-based radiofrequency renal sympathetic denervation (RSD) in a daily practice population of patients with uncontrolled resistant hypertension on top of medical therapy. Methods and results Consecutive unselected patients with uncontrolled resistant hypertension undergoing RSD were enrolled. Office and ambulatory blood pressure (BP) monitoring were collected at baseline and 3, 6, and 12 months after RSD. Efficacy was assessed also in patients with an estimated glomerular filtration rate below 45 ml/min/1.73 m2. Patients were defined responders to RSD if systolic BP decreased by at least 5 mmHg at ambulatory BP or by 10 mmHg at office BP at the last follow-up available. Fifty-four patients with multiple comorbidities underwent RSD for uncontrolled-resistant hypertension from 2012 to 2021. Baseline office and ambulatory BP was 161.0/87.2 ± 24.1/15.6 mmHg and 155.4/87.5 ± 19.3/14.6 mmHg, respectively. At 12-month follow-up a significant reduction of office and ambulatory systolic BP, respectively by − 15.66 ± 29.73 mmHg (P &amp;lt; 0.01) and by − 11.3 ± 23.1 mmHg (P &amp;lt; 0.05), was noticed. BP reduction at 12-month follow-up among patients with eGFR &amp;lt;45 ml/min was similar to that obtained in patients with higher eGFR. Among patients treated before July 2020 with available follow-up (45/54) 36 patients (80%) were classified as responders. Combined hypertension, higher ambulatory systolic BP and lower E/E’ at baseline emerged as predictors of success of RSD at univariate analysis. Among responders and non-responders, the average medication number showed no significant difference at baseline and during follow-up. No major complications were observed and renal function was stable up to 12 months, even in patients with lowest eGFR at baseline. Conclusions RSD is safe and feasible in patients with uncontrolled resistant hypertension on top of medical therapy, even in a high-risk CKD population with multiple comorbidities, with a significant reduction of systolic BP and a trend of reduction of the diastolic BP up to 12 months. 775 Figure

Catheter-Based Radiofrequency Renal Sympathetic Denervation Decreases Left Ventricular Hypertrophy in Hypertensive Dogs.

This study explored the effects of renal sympathetic denervation (RDN) on hyperlipidity-induced cardiac hypertrophy in beagle dogs. Sixty beagles were randomly assigned to the control group, RDN group, or sham-operated group. The control group was fed with a basal diet, while the other two groups were given a high-fat diet to induce model hypertension. The RDN group underwent an RDN procedure, and the sham-operated group underwent only renal arteriography. At 1, 3, and 6 months after the RDN procedure, the diastolic blood pressure (DBP) and systolic blood pressure (SBP) levels were markedly decreased in the RDN group relative to the sham group (P < 0.05). After 6 months, serum norepinephrine (NE) and angiotensin II (AngII), as well as left ventricular levels, in the RDN group were statistically lower than those in the sham group (P < 0.05). Also, the left ventricular mass (LVM) and left ventricular mass index (LVMI) were significantly decreased, while the E/A peak ratio was drastically elevated (P < 0.05). Pathological examination showed that the degree of left ventricular hypertrophy and fibrosis in the RDN group was statistically decreased relative to those of the sham group and that the collagen volume fraction (CVF) and perivascular circumferential collagen area (PVCA) were also significantly reduced (P < 0.05). Renal sympathetic denervation not only effectively reduced blood pressure levels in hypertensive dogs but also reduced left ventricular hypertrophy and myocardial fibrosis and improved left ventricular diastolic function. The underlying mechanisms may involve a reduction of NE and AngII levels in the circulation and myocardial tissues, which would lead to the delayed occurrence of left ventricular remodeling.

Insights on safety and efficacy of renal artery denervation for uncontrolled-resistant hypertension in a high risk population with chronic kidney disease: first Italian real-world experience

AimsTo evaluate the safety and efficacy of catheter-based radiofrequency renal sympathetic denervation (RSD) in a daily practice population of patients with uncontrolled resistant hypertension, on top of medical therapy.MethodsConsecutive unselected patients with uncontrolled resistant hypertension undergoing RSD were enrolled. Office and ambulatory blood pressure (BP) measurements were collected at baseline and 3, 6 and 12 months after RSD. Efficacy was assessed even in patients with an estimated glomerular filtration rate (eGFR) below 45 mL/min/1.73 m2. Patients were defined as responders if systolic BP decreased by at least 5 mmHg at ambulatory BP or by 10 mmHg at office BP at their last follow-up visit.ResultsForty patients with multiple comorbidities underwent RSD from 2012 to 2019. Baseline office and ambulatory BP was 159.0/84.9 ± 26.2/14.9 mmHg and 155.2/86.5 ± 20.9/14.0 mmHg, respectively. At 12-month follow up a significant reduction in office and ambulatory systolic BP, respectively by − 19.7 ± 27.1 mmHg and by − 13.9 ± 23.6 mmHg, was observed. BP reduction at 12-month follow-up among patients with eGFR < 45 mL/min was similar to that obtained in patients with higher eGFR. Twenty-nine patients (74.4%) were responders. Combined hypertension, higher ambulatory systolic BP and lower E/E’ at baseline emerged as predictors of successful RSD at univariate analysis. No major complications were observed and renal function (was stable up to 12 months), even in patients with the lowest eGFR values at baseline.ConclusionRSD is safe and feasible in patients with uncontrolled resistant hypertension on top of medical therapy, even in a high-risk CKD population with multiple comorbidities, with a significant reduction in systolic BP and a trend towards a reduction in diastolic BP lasting up to 12 months.Graphic abstract

Abstract MP163: Renal Sympathetic Denervation (RDN) Improves Exercise Performance and Vascular Function in the Setting of Cardiometabolic HFpEF

Background: Heart failure with preserved ejection fraction (HFpEF) has emerged as a subclass of heart failure for which there are no effective treatments. HFpEF is induced in a large number of patients by central obesity, metabolic syndrome, and sustained activation of the sympathetic nervous system (SNS). Methods: We examined the effects of RDN in a clinically relevant model of HFpEF. The ZSF1-Obese rat exhibits the key components of cardiometabolic HFpEF including hypertension and diabetes. At 20 wks of age, ZSF1-Obese rats underwent bilateral radiofrequency RDN (RF-RDN) or sham RF-RDN and were followed for 6 weeks. LV function, blood pressure, LVEDP, vascular function, myocardial fibrosis, metabolic profiling, and exercise capacity were evaluated. We also assessed mitochondrial function of cardiac and skeletal muscle. Results: RF-RDN resulted in significant improvements in LV diastolic function, vascular relaxation, and exercise capacity. Significant reductions in blood pressure and LVEDP were observed following RF-RDN treatment. RF-RDN ameliorated cardiac fibrosis while improving cardiac and skeletal muscle mitochondrial function. We did not observe any effects of RF-RDN on the metabolic status of the ZSF-1 rat. Conclusion: Our data suggest that RF-RDN is a viable treatment option for cardiometabolic HFpEF through halting renal SNS hyperactivation and enhancing mitochondrial function to exert beneficial effects on the heart and circulation.

1198Women and non-diabetic patients react more strongly to radiofrequency renal sympathetic denervation

Abstract Background/Introduction Three recently published sham-controlled studies proved the efficacy of renal denervation (RDN) in hypertensive patients. However, there it is still unclear which patients should be selected for RDN. Purpose This study seeks to clarify which patient subgroups benefit most from radiofrequency RDN by analysing a nationwide multicentre registry database. 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 systolic blood pressure (BP) after RDN to gender and presence/absence of comorbidities. Bivariate correlation and multiple linear regression analyses were performed. Results 291 patients (43% female, median age 64 years) undergoing RDN between April 2011 and September 2014 were included in this analysis. Mean baseline ambulatory 24-hour 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-hour BP reduction was 9±19/6±16 mmHg. The following features were associated with a good response to RDN: high baseline systolic ambulatory BP (ρ=0.53, p&lt;0.001), high baseline diastolic office BP (ρ=0.40, p&lt;0.001), female gender (ρ=0.10, p=0.049), absence of diabetes mellitus (DM, ρ=0.11, p=0.033), and absence of peripheral arterial disease (ρ=0.17, p=0.002). Multivariate analysis identified high baseline systolic ambulatory BP, female gender and absence of DM as independent predictors for systolic ambulatory BP reduction (systolic ambulatory BP: HR 5.83 [95% CI 4.83–6.83], p&lt;0.001; absence of DM: HR 5.82 [2.04–9.60], p=0.003; female gender: HR 5.07 [1.46–8.68], p=0.006), although women and patients without DM had lowest baseline ambulatory BP. Furthermore, both women and patients without DM used significantly less antihypertensives after RDN (female vs male: 4.0±1.3 vs 4.4±1.3, p=0.002; no DM vs DM: 4.0±1.3 vs 4.6±1.3, p&lt;0.001). Figure 1 Discussion Ambulatory BP reductions after RDN were substantially more pronounced in female and in non-diabetic patients despite lower baseline BP. It is concluded that in terms of efficacy female patients and non-diabetics might be more suitable for RDN. Acknowledgement/Funding The Austrian Renal Denervation Registry was funded by the Austrian Society of Hypertension.

Renal sympathetic denervation lowers arterial pressure in canines with obesity-induced hypertension by regulating GAD65 and AT1R expression in rostral ventrolateral medulla

ABSTRACTTo explore the roles of glutamate acid decarboxylase 65 (GAD65) and angiotensin II type 1 receptor (AT1R) in the action of renal sympathetic denervation (RSD) on obesity-induced hypertension in canines. Thirty-two beagles were randomly divided into a hypertensive model (n = 22) and control (n = 10) groups. A hypertensive canine model was established by feeding a high-fat diet. Twenty hypertensive beagles were randomized equally to a sham-surgery and RSD-treated group receiving catheter-based radiofrequency RSD. Compared with the control group, the sham-surgery group exhibited significant increases in blood pressure, serum angiotensin II level, rostral ventrolateral medulla (RVLM) glutamate level, and AT1R mRNA and protein expression and decreases in γ-amino acid butyric acid (γ-GABA) level and GAD65 mRNA and protein expression in the RVLM (all P < 0.05). Treatment with RSD significantly attenuated the above abnormal alterations (all P < 0.05). Linear correlation analysis revealed that angiotensin II level was positively correlated with glutamate level (r = 0.804) and inversely correlated with γ-GABA level (r = −0.765). GAD65 protein expression was positively correlated with γ-GABA level (r = 0.782). Catheter-based radiofrequency RSD can decrease blood pressure in obesity-induced hypertensive canines. The antihypertensive mechanism might be linked to upregulation of GAD65 and downregulation of AT1R in the RVLM.

Renal Sympathetic Denervation System via Intraluminal Ultrasonic Ablation: Therapeutic Intravascular Ultrasound Design and Preclinical Evaluation

PurposeTo assess the safety and performance of a nonfocused and nonballooned ultrasonic (US) catheter–based renal sympathetic denervation (RDN) system in normotensive swine. Materials and MethodsRDN with the therapeutic intravascular US catheter was evaluated in 3 experiments: (i) therapeutic intravascular US RDN vs a control group of untreated animals with follow-up of 30, 45, and 90 days (n = 6; n = 12 renal arteries for each group); (ii) therapeutic intravascular US RDN vs radiofrequency (RF) RDN in the contralateral artery in the same animal (n = 2; n = 4 renal arteries); and (iii) therapeutic intravascular US RDN in a recently stent-implanted renal artery (n = 2; n = 4 renal arteries). ResultsIn the first experiment, therapeutic intravascular US RDN was safe, without angiographic evidence of dissection or renal artery stenosis. Neuronal tissue vacuolization, nuclei pyknosis, and perineuronal inflammation were evident after RDN, without renal artery wall damage. Norepinephrine levels were significantly lower after therapeutic intravascular US RDN after 30, 45, and 90 days compared with the control group (200.17 pg/mg ± 63.35, 184.75 pg/mg ± 44.51, and 203.43 pg/mg ± 58.54, respectively, vs 342.42 pg/mg ± 79.97). In the second experiment, deeper neuronal ablation penetrance was found with therapeutic intravascular US RDN vs RF RDN (maximal penetrance from endothelium of 7.0 mm vs 3.5 mm, respectively). There was less damage to the artery wall after therapeutic intravascular US RDN than with RF RDN, after which edema and injured endothelium were seen. In the third experiment, denervation inside the stent-implanted segments was feasible without damage to the renal artery wall or stent. ConclusionsThe therapeutic intravascular US system performed safely and reduced norepinephrine levels. Deeper penetrance and better preservation of vessel wall were observed with therapeutic intravascular US RDN vs RF RDN. Neuronal ablations were observed in stent-implanted renal arteries.

PP.10.11] RADIOFREQUENCY RENAL SYMPATHETIC DENERVATION IN PATIENTS WITH RESISTANT ARTERIAL HYPERTENSION – 12-MONTH FOLLOW-UP

Objective: To evaluate safety and efficacy of radiofrequency renal sympathetic denervation (RDN) in patients with resistant arterial hypertension (AH) in mid-term follow-up period. Design and method: In the group of 21 patients (54 ± 10 years, M:F 13:8) with inadequately controlled AH on 3 or more antihypertensives including diuretics (average office blood pressure /BP/ 187/112 > mmHg with average number of antihypertensive drugs 7 ± 1), we realized RDN intervention with the use of Symplicity (Medtronic) or EnligHTN (St. Jude) catheters. During the 12-month follow-up we analyzed changes in office BP, ambulatory BP monitoring (ABPM), and presence of complications after intervention. As responders to RDN were defined patients with decrease in office systolic (s)BP > 10 > mmHg. Results: Global or local complications linked to intervention were not detected. The change in renal filtration did not occur, and we did not register renal artery stenosis on control CT angiography after 3 months. One patient died 11 months after RDN due to acute myocardial infarction. In 20 observed patients a significant decrease in office BP 12 months after RDN was present (sBP 187 ± 20 vs 162 ± 32 > mmHg, p = 0.002; dBP 112 ± 20 vs 97 ± 20 > mmHg, p = 0.0006), however only a borderline decrease of ABPM values was reached (sTK 169 ± 16 vs 163 ± 30 > mmHg, p = 0.13). Target decrease in office BP 12 months after RDN was achieved in 15/20 patients (75%). The number or dosage of antihypertensive drugs were reduced in 10/20 patients (50%). In the subgroup of 11 “super-responders” (55%) the decrease in office sBP > 20 mmHg, and ABPM sBP > 15 mmHg was achieved, with average drop in office BP −51/−26 > mmHg and ABPM −23/−9 > mmHg. Responders were characterized by higher office sBP before RDN (191 ± 21 vs 175 ± 15 > mmHg, p = 0.04), lower night-time ABPM before RDN (149/80 vs 165/97 > mmHg, p < 0.05), and by a higher number of ablation points (12.5 ± 2.7 vs 10.2 ± 1.1, p = 0.009), compared to non-responders. Conclusions: Radiofrequency RDN is a safe method of achievement decrease in BP in patients with resistant AH. Higher office sBP, lower night-time ABPM values, and higher number of ablation points are important predictors of RDN clinical success. An increase in number of responders could be expected after the introduction of a newer generation of ablation catheters.

Endovascular ultrasound for renal sympathetic denervation in patients with therapy-resistant hypertension not responding to radiofrequency renal sympathetic denervation

Recent studies have reported a considerable number of non-responders after renal sympathetic de-nervation (RSD) with radiofrequency technology. Here we report our results of repeat RSD using ultrasound in these patients. A cohort study was performed in patients who underwent ultrasound RSD after non-response to RSD with radiofrequency. Non-response was defined as mean daytime systolic blood pressure ≥140 mmHg and/or a reduction of ≤10 mmHg in ambulatory blood pressure measurement (ABPM) ≥6 months after radiofrequency denervation. ABPM was recorded at baseline, post radiofrequency RSD as well as at three and six months post ultrasound RSD. A total of 24 non-responders underwent retreatment with the ultrasound device at a mean 15.3±8.2 months after radiofrequency RSD. Ultrasound RSD was performed successfully in all patients without severe adverse events. Mean daytime systolic blood pressure changed from 161.7±14.6 mmHg at baseline to 158.5±9.5 mmHg post radiofrequency RSD and to 150.5±10.4 mmHg and 151.6±11.0 mmHg at three and six months, respectively, post ultrasound RSD (p<0.01 with repeated measures analysis of variance). The main results of post hoc testing were as follows: baseline versus post radiofrequency RSD, p=0.83; baseline versus three months post ultrasound RSD, p=0.01; and baseline versus six months post ultrasound RSD, p=0.04. Ultrasound RSD appears to be safe and an effective therapeutic approach in patients not responding to previous RSD with radiofrequency technology.

Investigation of the mechanism underlying the antihypertensive effect of catheter-based radiofrequency renal sympathetic denervation in hypertensive dogs.

The present study aimed to assess the antihypertensive efficacy and safety of catheter-based radiofrequency renal sympathetic denervation (RSD) in hypertensive dogs. Furthermore, the study investigated the possible antihypertensive mechanism of radiofrequency RSD through measuring the postoperative serum concentrations of angiotensin II (AngII), nicotinamide adenine dinucleotide phosphate oxidase (NADPH-ox), malondialdehyde (MDA), nitric oxide (NO) and endothelial NO synthase (eNOS). A total of 12 beagles were randomly divided into the surgery (n=6) and the sham-surgery groups (n=6). The hypertension model was established using a high-fat diet. The surgery group received catheter-based radiofrequency RSD, while the sham-surgery group only received renal arteriography. Blood pressure was measured prior to the surgery and 3 days, 1 and 2 weeks, and 1, 2 and 3 months after the surgery. The serum concentrations of AngII, NADPH-ox, MDA, NO and eNOS were measured prior to the surgery and 1 week, and 1 and 3 months after the surgery. Following the establishment of the model, the systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and mean arterial pressure (MAP) of the surgery and the sham-surgery groups were all significantly increased above the baseline (P<0.05), but there was no significant difference between the two groups. SAP, DAP and MAP in the surgery group at 1 and 3 months after the surgery were significantly decreased compared to the levels measured prior to the surgery and those in the sham-surgery group (P<0.05). Three months after the surgery, the serum creatinine level was normal and renal arteriography did not show renal artery stenosis. Compared to those measured prior to the surgery, the concentrations of serum AngII, NADPH-ox and MDA in the surgery group at 1 week, and 1 and 3 months after the surgery were decreased, while the concentrations of serum NO and eNOS were increased (P<0.05). The above indicators measured at the same time points demonstrated statistically significant differences between the surgery and the sham-surgery groups (P<0.05). In conclusion, catheter-based radiofrequency RSD may inhibit the renin-angiotensin system and the oxidative stress response, as well as improve vascular endothelial function, thus significantly reducing blood pressure through the reduction of sympathetic activity in hypertensive dogs.

GW25-e0597 Investigation of the mechanism underlying the antihypertensive effect of catheter-based radiofrequency renal sympathetic denervation on hypertension in hypertensive dogs

GW25-e0597 Investigation of the mechanism underlying the antihypertensive effect of catheter-based radiofrequency renal sympathetic denervation on hypertension in hypertensive dogs

Renal sympathetic denervation for treatment of resistant hypertension: Egyptian experience.

Among the Egyptian population with essential hypertension, a minority are under control (systolic pressure <140 mmHg and diastolic pressure <90 mmHg), despite the use of multiple antihypertensive medications. In this article, we describe our experience with percutaneous treatment using renal artery radiofrequency (RF) ablation. To evaluate the feasibility, efficacy, and safety of catheter-based radiofrequency renal sympathetic denervation for treatment of resistant hypertension in Egyptian patients. Patients with essential hypertension unresponsive to at least 3 types of antihypertensive medical therapy (baseline office systolic blood pressure ≥160 mmHg) (n = 55) were enrolled between February 2012 and June 2013 and received percutaneous RF ablation. Patients were followed up for 6 months after treatment to detect any change in office-based measurement of blood pressure. Urine and blood samples were taken to evaluate the effects on renal function. A reduction of mean office blood pressure was seen from 174/103 ± 9/5 mmHg at baseline to 150/91 ± 8/5 mmHg at 6 months follow-up (P = 0.001). Also, we noted a significant decrease in plasma renin activity (3.66 ± 0.64 vs. 3.37 ± 0.47 ng/mL per hour; P = 0.003), and there were no periprocedural complications, no adverse events, and no change in renal function during the follow-up period. Also, no change was noted in the number of medications after 6 months (3.95 ± 1.64 vs. 3.67 ± 0.72; P = 0.27). In this observational study, catheter-based renal denervation causes sustained blood pressure reduction in patients with resistant hypertension, without serious adverse events.

Catheter-based radiofrequency renal sympathetic denervation for resistant hypertension: initial Egyptian experience

To evaluate the feasibility, efficacy, and safety of catheter-based radiofrequency renal sympathetic denervation for treatment of resistant hypertension. In a subpopulation of patients with essential hypertension, therapeutic targets are not met, despite the use of multiple types of medication. In this paper we describe our first experience with a novel percutaneous treatment modality using renal artery radiofrequency (RF) ablation. Thirty patients with essential hypertension unresponsive to at least three types of antihypertensive medical therapy (baseline office systolic blood pressure ⩾160 mmHg) were selected between March and September 2012 and received percutaneous RF ablation. Patients were followed up for 6 months after treatment. The primary effectiveness endpoint was change in seated office-based measurement of systolic blood pressure at 6 months. Another thirty patients were taken as control. A reduction of mean office blood pressure was seen from 170/102 ± 9/5 mmHg at baseline to 151/91 ± 8/6 mmHg at 6 months follow-up ( p = 0.001). Also, we noted a significant decrease in plasma renin activity (3.66 ± 0.64 versus 3.37 ± 0.47 ng/mL/h; p = 0.003). No periprocedural complications, adverse events or change in renal function were noted during follow-up. Catheter-based renal denervation seems an attractive minimally invasive treatment option in patients with resistant hypertension, with a low risk of serious adverse events.

Catheter-based radiofrequency renal sympathetic denervation for resistant hypertension; initial Egyptian experience

To evaluate the feasibility, efficacy, and safety of catheter-based radiofrequency renal sympathetic denervation for treatment of resistant hypertension. In a subpopulation of patients with essential hypertension, therapeutic targets are not met, despite the use of multiple types of medication. In this paper we describe our first experience with a novel percutaneous treatment modality using renal artery radiofrequency (RF) ablation. Thirty patients with essential hypertension unresponsive to at least three types of antihypertensive medical therapy (baseline office systolic blood pressure ⩾160 mmHg) were selected between March and September 2012 and received percutaneous RF ablation. Patients were followed up for 6 months after treatment. The primary effectiveness endpoint was change in seated office-based measurement of systolic blood pressure at 6 months. Another thirty patients were taken as control. A reduction of mean office blood pressure was seen from 170/102 ± 9/5 mmHg at baseline to 151/91 ± 8/6 mmHg at 6 months follow-up ( p = 0.001). Also, we noted a significant decrease in plasma renin activity (3.66 ± 0.64 versus 3.37 ± 0.47 ng/mL/h; p = 0.003). No periprocedural complications, adverse events or change in renal function were noted during follow-up. Catheter-based renal denervation seems an attractive minimally invasive treatment option in patients with resistant hypertension, with a low risk of serious adverse events.