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International audience; Purpose: To assess the variability of renal artery (RA) anatomy and presence of RA-pathology in patients with mild-to-moderate hypertension enrolled in the RADIANCE-HTN SOLO trial.Background: RADIANCE-HTN SOLO was a multicenter, international, blinded, randomized, sham-controlled trial evaluating ultrasound-based endovascular renal denervation (RDN) in patients with mild-to-moderate hypertension while off antihypertensive medications.Methods: Eligible subjects had pre-randomization renal CT- or MR- angiography (CTA, MRA) to confirm anatomic suitability and to define RA ablation sites. All images were sent for independent review for evaluation of RA anatomy and other vascular pathology.Results: A total of 324 patients underwent RA imaging (282 CTA and 42 MRA). Of those, 178 had simple anatomy with a single left and single right RA with mean diameters of 5.4 ± 0.9 and 5.1 ± 0.8 mm and mean lengths of 40.0 ± 12.9 and 52.0 ± 13.1 mm, respectively. Twenty-seven patients (8.3%) had unilateral or bilateral dual RAs with mean diameters of 4.0 ± 0.9 mm on the left and 3.9 ± 0.9 mm on the right. Forty percent (129/324) of patients had at least 1 accessory RA, with mean accessory diameters of 2.4 ± 0.8 mm on the left and 2.3 ± 0.8 mm on the right. Twenty-eight patients (8.6%) had at least 1 short (

Summary Background Endovascular renal denervation reduces blood pressure in patients with mild-to-moderate hypertension, but its efficacy in patients with true resistant hypertension has not been shown. We aimed to assess the efficacy and safety of endovascular ultrasound renal denervation in patients with hypertension resistant to three or more antihypertensive medications. Methods In a randomised, international, multicentre, single-blind, sham-controlled trial done at 28 tertiary centres in the USA and 25 in Europe, we included patients aged 18–75 years with office blood pressure of at least 140/90 mm Hg despite three or more antihypertensive medications including a diuretic. Eligible patients were switched to a once daily, fixed-dose, single-pill combination of a calcium channel blocker, an angiotensin receptor blocker, and a thiazide diuretic. After 4 weeks of standardised therapy, patients with daytime ambulatory blood pressure of at least 135/85 mm Hg were randomly assigned (1:1) by computer (stratified by centres) to ultrasound renal denervation or a sham procedure. Patients and outcome assessors were masked to randomisation. Addition of antihypertensive medications was allowed if specified blood pressure thresholds were exceeded. The primary endpoint was the change in daytime ambulatory systolic blood pressure at 2 months in the intention-to-treat population. Safety was also assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov , NCT02649426 . Findings Between March 11, 2016, and March 13, 2020, 989 participants were enrolled and 136 were randomly assigned to renal denervation (n=69) or a sham procedure (n=67). Full adherence to the combination medications at 2 months among patients with urine samples was similar in both groups (42 [82%] of 51 in the renal denervation group vs 47 [82%] of 57 in the sham procedure group; p=0·99). Renal denervation reduced daytime ambulatory systolic blood pressure more than the sham procedure (−8·0 mm Hg [IQR –16·4 to 0·0] vs –3·0 mm Hg [–10·3 to 1·8]; median between-group difference –4·5 mm Hg [95% CI –8·5 to –0·3]; adjusted p=0·022); the median between-group difference was –5·8 mm Hg (95% CI –9·7 to –1·6; adjusted p=0·0051) among patients with complete ambulatory blood pressure data. There were no differences in safety outcomes between the two groups. Interpretation Compared with a sham procedure, ultrasound renal denervation reduced blood pressure at 2 months in patients with hypertension resistant to a standardised triple combination pill. If the blood pressure lowering effect and safety of renal denervation are maintained in the long term, renal denervation might be an alternative to the addition of further antihypertensive medications in patients with resistant hypertension. Funding ReCor Medical.

The aim of this study was to understand the anatomy of periarterial nerve distribution in human accessory renal arteries (ARAs).Renal denervation is a promising technique for blood pressure control. Despite the high prevalence of ARAs, the anatomic distribution of periarterial nerves around ARAs remains unknown.Kidneys with surrounding tissues were collected from human autopsy subjects, and histological evaluation was performed using morphometric software. An ARA was defined as an artery arising from the aorta above or below the dominant renal artery (DRA) or an artery that bifurcated within 20 mm of the takeoff of the DRA from the aorta. The DRA was defined as an artery that perfused50% of the kidney.A total of 7,287 nerves from 14 ARAs and 9 DRAs were evaluated. The number of nerves was smaller in the ARA than DRA (median: 30 [interquartile range: 17.5 to 48.5] vs. 49 [interquartile range: 36 to 76]; p 0.0001). In both ARAs and DRAs, the distance from the arterial lumen to nerve was shortest in the distal, followed by the middle and proximal segments. On the basis of the post-mortem angiography, ARAs were divided into large (≥3 mm diameter) and small (3 mm) groups. The number of nerves was greatest in the DRA, followed by the large and small ARA groups (53 [41 to 97], 38 [25 to 53], and 24.5 [10.5 to 36.3], respectively; p = 0.001).ARAs showed a smaller number of nerves than DRAs, but these results were dependent on the size of the ARA. Ablation, especially in large ARAs, may allow more complete denervation with the potential to further reduce blood pressure.

Summary Background Early studies suggest that radiofrequency-based renal denervation reduces blood pressure in patients with moderate hypertension. We investigated whether an alternative technology using endovascular ultrasound renal denervation reduces ambulatory blood pressure in patients with hypertension in the absence of antihypertensive medications. Methods RADIANCE-HTN SOLO was a multicentre, international, single-blind, randomised, sham-controlled trial done at 21 centres in the USA and 18 in Europe. Patients with combined systolic–diastolic hypertension aged 18–75 years were eligible if they had ambulatory blood pressure greater than or equal to 135/85 mm Hg and less than 170/105 mm Hg after a 4-week discontinuation of up to two antihypertensive medications and had suitable renal artery anatomy. Patients were randomised (1:1) to undergo renal denervation with the Paradise system (ReCor Medical, Palo Alto, CA, USA) or a sham procedure consisting of renal angiography only. The randomisation sequence was computer generated and stratified by centres with randomised blocks of four or six and permutation of treatments within each block. Patients and outcome assessors were blinded to randomisation. The primary effectiveness endpoint was the change in daytime ambulatory systolic blood pressure at 2 months in the intention-to-treat population. Patients were to remain off antihypertensive medications throughout the 2 months of follow-up unless specified blood pressure criteria were exceeded. Major adverse events included all-cause mortality, renal failure, an embolic event with end-organ damage, renal artery or other major vascular complications requiring intervention, or admission to hospital for hypertensive crisis within 30 days and new renal artery stenosis within 6 months. This study is registered with ClinicalTrials.gov, number NCT02649426. Findings Between March 28, 2016, and Dec 28, 2017, 803 patients were screened for eligibility and 146 were randomised to undergo renal denervation (n=74) or a sham procedure (n=72). The reduction in daytime ambulatory systolic blood pressure was greater with renal denervation (−8·5 mm Hg, SD 9·3) than with the sham procedure (−2·2 mm Hg, SD 10·0; baseline-adjusted difference between groups: −6·3 mm Hg, 95% CI −9·4 to −3·1, p=0·0001). No major adverse events were reported in either group. Interpretation Compared with a sham procedure, endovascular ultrasound renal denervation reduced ambulatory blood pressure at 2 months in patients with combined systolic–diastolic hypertension in the absence of medications. Funding ReCor Medical.

Purpose To develop an ex-vivo arterial perfusion model to evaluate vascular responses to bare metal stents (BMS) and drug-eluting stents (DES) in porcine carotid arteries. Materials and Methods Porcine carotid arteries with BMS or DES were cultured under hemodynamic stimuli for 24 hours and 72 hours. Vascular responses of arteries with stents were assessed by cellular functionality and gene expression and compared with a noninjured (NI) control group at each time point. Cellular functionality was confirmed with sequential dosing of norepinephrine (NE), acetylcholine (ACH), and sodium nitroprusside (SNP). QuantiGene (Panomics, Fremont, California) branched DNA (bDNA) assay was used to evaluate gene expression of endothelial cell (EC) and smooth muscle cell (SMC) biomarkers and compare it with responses of in-vivo arteries with stents. Bromodeoxyuridine (BrDU) stain was also used to detect cellular proliferation in the ex-vivo arteries with stents. Results EC relaxation and SMC contraction in response to vasoactivators indicated the arteries remained viable and functional for at least 72 hours in culture. SMC-dependent contractility and EC-dependent relaxation were lower in arteries with stents compared with NI arteries. Greater SMC proliferation was observed in BMS arteries compared with DES arteries. Cellular proliferation, EC function, and SMC marker expression at acute time points were similar between both models suggesting that the ex-vivo arterial model can provide comparative predictions of stent injury in vivo. Conclusions The ex-vivo arterial perfusion model can be used as a quick and less costly (than current in-vivo and some in-vitro perfusion testing models) approach for evaluating the vascular responses to various stent design parameters (eg, strut thickness, strut width).

Objectives This study aimed to evaluate the accuracy of optical coherence tomography (OCT) in analyzing the neointimal response to several drug-eluting stent (DES) types by comparing OCT images acquired in vivo with corresponding histological specimens using a nondiseased porcine injury model. Background Optical coherence tomography is emerging as a promising endovascular imaging tool for the evaluation of neointimal response after DES implantation. Methods A total of 84 stents were implanted—22 ML Vision (Abbott Vascular, Santa Clara, California), 22 Xience V (Abbott Vascular), 20 Endeavor (Medtronic, Minneapolis, Minnesota), and 20 Taxus Liberte (Boston Scientific, Natick, Massachusetts) stents—in normal porcine coronary arteries and were harvested at 28 (n = 42) and 90 (n = 42) days, with the different stent types equally distributed between the 2 follow-up periods. At termination, morphometric evaluation using OCT imaging was performed in all stented arteries. Histological morphometric analysis was performed and correlated with OCT. Results A total of 622 OCT–histology matched frames acquired from all stent designs were analyzed. The luminal (13.7%) and stent (6.1%) areas were consistently larger by OCT compared with histology. The mean neointimal thickness was very similar between techniques (∼3.27% variation). There was a high correlation between OCT and histology for the evaluation of neointimal area (R2 = 0.804), luminal area (R2 = 0.825), and neointimal thickness (R2 = 0.789). Correlation for total stent area was poor (R2 = 0.352). Although the proportion of individual struts determined to be uncovered by OCT and histology was similar, there was significant variation in the estimation of strut coverage between OCT and histology when the neointimal thickness was between 20 and 80 μm. This variation converged for neointimal thicknesses between 80 and 100 μm. Conclusions Subtle differences in neointimal formation induced by current DES can be reproducibly analyzed in vivo by OCT. However, OCT measurement of stent area seems to have less correlation with histology.

Background: The XIENCE V™ everolimus-eluting coronary stent system is a second-generation drug-eluting stent designed for safety and efficacy in the interventional treatment of coronary artery disease and in preventing in-stent restenosis. A comprehensive preclinical program was completed to aid in the scientific design and to demonstrate the safety of XIENCE V. Methods: Studies evaluating clinical dose selection, pharmacokinetics, single and overlapping stent safety, polymer safety, and maximum dose (8× everolimus) safety were conducted in the porcine coronary arterial model at 28, 90, 180 days, and 1 and 2 years. Additionally, a subset of studies was conducted in the rabbit iliac arterial model. Results: Morbidity and mortality rates for all preclinical studies were exceptionally low, being less than 1%. The arterial response observed in the clinical dose selection study and in all safety studies was typified by benign neointimal hyperplasia with endothelialization by 28 days. Everolimus was released in a controlled manner for 120 days and remained primarily localized within the stented arterial region, which was evidenced histologically as peristrut fibrin. The temporal presence of peristrut fibrin matched the everolimus-elution profile. Thrombosis, malapposition, medial loss, or other adverse effects were not observed in any preclinical studies. Conclusion: XIENCE V has demonstrated safety via an extremely comprehensive preclinical program published to date for a DES system, with data generated in two species to 2 years. The preclinical data, along with the SPIRIT clinical trial data, demonstrate the excellent safety and potential efficacy profile of XIENCE V.

After pivotal clinical trials, drug-eluting stents (DES) are now considered the standard of care for the management of acute coronary syndrome. However, late stent thrombosis has emerged as a major concern. Preclinical testing is an important regulatory process that determines the safety and efficacy of devices prior to human clinical trials. Histopathologic analysis following placement of DES has typically been performed in porcine coronary artery models to ensure safety in these devices. The recently issued consensus report from the US FDA, for the approval of DES recommends the use of the porcine model for the safety assessment of these devices in the vascular bed for which they are intended. Other models are also recommended, as vascular responses to stents are much slower in man than in animals, and no animal truly elicits the response seen in humans. The rabbit iliac artery can provide further data, especially regarding endothelialization, which is slower in the rabbit model than in the porcine model. Furthermore, inflammation is not as extensive in the rabbit and may thus be a closer model of humans than the porcine models. The FDA recognizes that it may be more appropriate to test these devices in atherosclerosis. The choice of animal model may mask the serious drawbacks of the devices; therefore, we suggest the use of both models to understand the healing following DES implantation, with emphasis on endothelialization, inflammation and neointimal formation and, whenever possible, to complement the observations in the environment of atherosclerosis.

Aims Circumferential ablation of renal sympathetic nerves using catheter-based ultrasound energy was studied in a preclinical in vivo model. The aim was to investigate the benefit of cooling the arterial wall and the extent of renal nerve injury based on histopathology, and to correlate the injury with kidney norepinephrine levels. Methods and results Computer simulations of the ultrasound transducer within the cooling balloon demonstrated a circumferentially uniform heating profile. In vivo characterisation was performed in 10 normotensive pigs. Nine were treated bilaterally with ultrasound and survived for seven days (n=8) or were sacrificed acutely (n=1). Acutely, TTC staining of the renal arteries treated with ultrasound energy in the presence of cooling demonstrated viable tissue consistent with preservation of the arterial medial layer. Histological studies demonstrated no endothelial injury and minimal to no injury to the media of the renal arterial wall at seven days. Overall, circumferential nerve damage with up to 76% of nerve bundles affected within 7.5 mm of the arterial lumen was observed. Kidney norepinephrine (NEPI) levels were significantly reduced in all animals compared to a non-treated control animal (n=1) and correlated with the degree of nerve damage. A greater reduction in NEPI and a greater percentage of affected nerves was observed in arteries treated with two or three bilateral ultrasound emissions. Conclusions Catheter-based ultrasound delivered within a cooling balloon is effective at targeting the majority of the renal nerves circumferentially, resulting in significantly decreased kidney NEPI levels without damaging the arterial wall in a porcine model.

Introduction: Rapamycin and its analogs are now being coated on different stent platforms, using different polymer matrices to prevent restenosis by impairing vascular smooth muscle cell proliferation and neointimal formation. Methods: We evaluated the feasibility and compared the efficacy of biostable polymeric everolimus and sirolimus (CYPHER®, Cordis) eluting stents in a porcine coronary model. Cobalt chromium balloon expandable stents (ML VISION®, Guidant) were coated with a polymer containing everolimus (190 μg/cm2). Twelve pigs underwent placement of 36 oversized sirolimus (n = 12), everolimus (n = 12), and bare metal (cobalt chromium, n = 12) stents in the coronary arteries. Results: At day 28, vessel injury scores were low (

OBJECTIVES: We sought to demonstrate the safety and performance of the actinomycin D-coated Multilink-Tetra stent(Guidant Corp., Santa Clara, California) in the treatment of patients with single de novo native coronary lesions. BACKGROUND: Drug-eluting stents (DES) releasing sirolimus or paclitaxel dramatically reduce restenosis. The anti-proliferative drug, actinomycin D, which is highly effective in reducing neointimal proliferation in preclinical studies, was selected for clinical evaluation. METHODS: The multi-center, single-blind, three-arm ACTinomycin-eluting stent Improves Outcomes by reducing Neointimal hyperplasia (ACTION) trial randomized 360 patients to receive a DES (2.5 or 10 microg/cm(2) of actinomycin D) or metallic stent (MS). The primary end points were major adverse cardiac events (MACE) at 30 days, diameter stenosis by angiography, tissue effects, and neointimal volume by intravascular ultrasound (IVUS) at six months. When early monitoring revealed an increased rate of repeat revascularization, the protocol was amended to allow for additional follow-up for DES patients. Angiographic control of MS patients was no longer mandatory. RESULTS: The biased selection of DES patients undergoing IVUS follow-up invalidated the interpretation of the IVUS findings. The in-stent late lumen loss and that at the proximal and distal edges were higher in both DES groups than in the MS group and resulted in higher six-month and one-year MACE (34.8% and 43.1% vs. 13.5%), driven exclusively by target vessel revascularization without excess death or myocardial infarction. CONCLUSIONS: The results of the ACTION trial indicate that all anti-proliferative drugs will not uniformly show a drug class effect in the prevention of restenosis.

Aims The Paradise Ultrasound Renal Denervation System is a next-generation catheter-based device which was used to investigate whether the target ablation area can be controlled by changing ultrasound energy and duration to optimise nerve injury while preventing damage to the arterial wall. Methods and results Five ultrasound doses were tested in a thermal gel model. Catheter-based ultrasound denervation was performed in 15 swine (29 renal arteries) to evaluate five different doses in vivo, and animals were euthanised at seven days for histopathologic assessment. In the gel model, the peak temperature was highest in the low power-long duration (LP-LD) dose, followed by the mid-low power-mid duration (MLP-MD) dose and the mid-high power-short duration (MHP-SD) dose, and lowest in the mid power-short duration (MP-SD) dose and the high power-ultra short duration (HP-USD) dose. In the animal study, total ablation area was significantly greater in the LP-LD group, followed by the MLP-MD group, and it was least in the HP-USD, MP-SD and MHP-SD groups (p=0.02). Maximum distance was significantly greater in the LP-LD group, followed by the MLP-MD group, the MHP-SD group, and the HP-USD group, and shortest in the MP-SD group (p=0.007). The short spare distance was not different among the five groups (p=0.38). Renal artery damage was minimal, while preserving significant nerve damage in all groups. Conclusions The Paradise Ultrasound Renal Denervation System is a controllable system where total ablation area and depth of ablation can be optimised by changing ultrasound power and duration while sparing renal arterial tissue damage but allowing sufficient peri-arterial nerve damage.

The ReCor Medical Paradise® Renal Denervation System delivers ultrasound energy to perform targeted circumferential denervation to the renal afferent and efferent sympathetic nerves with the goal of achieving a reduction in systemic arterial blood pressure, and mitigating end organ effects due to sympathetic over-activity. Ultrasound energy is a controllable energy source which does not require direct tissue contact to heat the tissue providing a unique therapeutic advantage in the application of renal denervation. The Paradise System has been designed to deliver energy to create an optimized tissue thermal profile to achieve targeted ablation of nerves surrounding the renal artery, while preserving the integrity of the renal arterial wall through a unique cooling mechanism. The tissue thermal profile has been optimized through pre-clinical in vitro and in vivo testing. Feasibility clinical studies have demonstrated the safety and effectiveness in controlling resistant hypertension of the system out to 12 months. On-going and future clinical studies will allow for a continued assessment of the overall safety, effectiveness, and durability of the Paradise System.

Vorphal and Kelm raise an intriguing nuance regarding vascular repair after drug-eluting stent implantation. Their insightful letter and pioneering work suggest limited thrombosis may be important for optimal healing, and complete elimination of clot may adversely affect repair. Interestingly, early studies of drug-free stent coatings reported reduced thrombogenicity compared with bare metal devices without effecting intimal hyperplasia.1 …

Author Manuscript: 2012 April 5, Background—Stent thrombosis is a lethal complication of endovascular intervention. Concern has been raised about the inherent risk associated with specific stent designs and drug-eluting coatings, yet clinical and animal support is equivocal. Methods and Results—We examined whether drug-eluting coatings are inherently thrombogenic and if the response to these materials was determined to a greater degree by stent design and deployment with custom-built stents. Drug/polymer coatings uniformly reduce rather than increase thrombogenicity relative to matched bare metal counterparts (0.65-fold; P=0.011). Thick-strutted (162 μm) stents were 1.5-fold more thrombogenic than otherwise identical thin-strutted (81 μm) devices in ex vivo flow loops (P

This study compares the effects of two polymers currently being marketed on commercially available drug-eluting stents, PVDF-HFP fluorinated copolymer (FP) and phosphorylcholine polymer (PC), on re-endothelialization, acute thrombogenicity, and monocyte adhesion and activity. Rabbit iliac arteries were implanted with cobalt-chromium stents coated with FP or PC polymer (without drug) and assessed for endothelialization at 14 days by confocal and scanning electron microscopy (SEM). Endothelialization was equivalent and near complete for FP and PC polymer-coated stents (>80% by SEM). Acute thrombogenicity was assessed in a Chandler loop model using porcine blood. Thrombus adherence was similar for both polymers as assessed by clot weight, thrombin-antithrombin III complex, and lactate dehydrogenase expression. In vitro cell adhesion assays were performed on FP and PC polymer-coated glass coupon surfaces using HUVECs, HCAECs, and THP-1 monocytes. The number of ECs adhered to FP and control surfaces were equivalent and significantly greater than on PC surfaces (p

Objectives The purpose of this study was to assess trends in endothelial coverage and recovery among leading polymer-based drug-eluting stents (DES). Background Autopsy studies of human U.S. Food and Drug Administration (FDA)–approved DES implanted coronary arteries suggest that complications of late stent thrombosis are associated with incomplete endothelial coverage of struts. Methods Rabbits received sirolimus-eluting stents (SES), paclitaxel-eluting stents (PES), zotarolimus-eluting stents (ZES), and everolimus-eluting stents (EES) for 14 or 28 days along with MULTI-LINK (ML) Vision control stents. Endothelial coverage above and between struts was measured by morphometric analysis of images acquired through en face scanning electron microscopy. Dual fluorescent immunolabeling was performed for platelet-endothelial cell adhesion molecule (PECAM)-1 and thrombomodulin (TM), factors involved in cell-to-cell contact and thrombogenicity, respectively. In a separate analysis, the endothelial mitogen, vascular endothelial growth factor (VEGF), was also assessed. Results Varying rates of endothelialization among comparator DES were most notable at 14 days, where coverage above struts remained poor in SES, PES, and ZES (≤30%) relative to EES and ML Vision controls (≥70%), whereas no significant differences were observed at 28 days. Select DES with poor endothelialization showed a further reduced expression of PECAM-1. All DES showed an absence or weak expression of the antithrombotic cofactor TM. Incomplete endothelialization in select DES was further associated with increased VEGF secretion and messenger ribonucleic acid levels at 14 days, providing evidence of a transitional healing surface. Conclusions The present study marks the first comparator analysis of endothelial coverage in leading polymeric DES, supporting disparities in arterial healing based on endothelial regrowth and recovery, favoring newer designs over the current generation of FDA-approved stents.

The PARADISE system (ReCor Medical, Menlo Park, CA) is a unique therapeutic non-focused ultrasound system designed to perform renal denervation while preventing circumferential damage to the renal artery for resistant hypertension. The system allows for targeted delivery of ultrasound energy with

The Paradise® Renal Denervation System (ReCor Medical, Palo Alto, CA) is designed to deliver ultrasound (US) energy to perform circumferential denervation of the renal sympathetic nerves. As current renal denervation systems do not allow for immediate biofeedback to the user regarding effective