Effect of Alcohol-Mediated Renal Denervation on Blood Pressure in the Presence of Antihypertensive Medications: Primary Results From the TARGET BP I Randomized Clinical Trial.

BACKGROUND: Renal denervation (RDN) has demonstrated clinically relevant reductions in blood pressure (BP) among individuals with uncontrolled hypertension despite lifestyle intervention and medications. The safety and effectiveness of alcohol-mediated RDN have not been formally studied in this indication. METHODS: TARGET BP I is a prospective, international, sham-controlled, randomized, patient- and assessor-blinded trial investigating the safety and efficacy of alcohol-mediated RDN. Patients with office systolic BP (SBP) ≥150 and ≤180 mm Hg, office diastolic BP ≥90 mm Hg, and mean 24-hour ambulatory SBP ≥135 and ≤170 mm Hg despite prescription of 2 to 5 antihypertensive medications were enrolled. The primary end point was the baseline-adjusted change in mean 24-hour ambulatory SBP 3 months after the procedure. Secondary end points included mean between-group differences in office and ambulatory BP at additional time points. RESULTS: Among 301 patients randomized 1:1 to RDN or sham control, RDN was associated with a significant reduction in 24-hour ambulatory SBP at 3 months (mean±SD, -10.0±14.2 mm Hg versus -6.8±12.1 mm Hg; treatment difference, -3.2 mm Hg [95% CI, -6.3 to 0.0]; P=0.0487). Subgroup analysis of the primary end point revealed no significant interaction across predefined subgroups. At 3 months, the mean change in office SBP was -12.7±18.3 and -9.7±17.3 mm Hg (difference, -3.0 [95% CI, -7.0 to 1.0]; P=0.173) for RDN and sham, respectively. No significant differences in ambulatory or office diastolic BP were observed. Adverse safety events through 6 months were uncommon, with one instance of accessory renal artery dissection in the RDN group (0.7%). No significant between-group differences in medication changes or patient adherence were identified. CONCLUSIONS: Alcohol-mediated RDN was associated with a modest but statistically significant reduction in 24-hour ambulatory SBP compared with sham control. No significant differences between groups in office BP or 6-month major adverse events were observed. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02910414.

Expanding the stroke team to include interventional cardiology.

Team-based care has been emphasized as a strategy to improve and optimize outcomes for broad groups of patients who have presented with often complex medical conditions including large vessel cerebral occlusion. Although neurointerventionalists from different specialties perform mechanical embolectomy, which has become the standard of care for large vessel cerebral occlusion, these specialties are limited by relatively low numbers typically concentrated in a small number of sites. In this single center experience, approximately 50 patients with large vessel stroke were transferred out of an emergency room to other centers despite the availability of an experienced cardiologist with extensive carotid experience. Such transfer strategies typically result in delays in receiving reperfusion and, therefore, may decrease the success rates and substantial improvement that can be obtained by patients in this setting. Trained interventional cardiologists in centers with limited 24/7/365 coverage could achieve rapid revascularization and reperfusion saving lives. In order to accommodate the need for treating these patients, carotid stent trained cardiologists should enter the arena, learn mechanical embolectomy, and be supported by their colleagues from other disciplines on acute stroke care teams.

Changes in ventricular remodelling and clinical status during the year following a single administration of stromal cell-derived factor-1 non-viral gene therapy in chronic ischaemic heart failure patients: the STOP-HF randomized Phase II trial.

BACKGROUND: Stromal cell-derived factor-1 (SDF-1) promotes tissue repair through mechanisms of cell survival, endogenous stem cell recruitment, and vasculogenesis. Stromal Cell-Derived Factor-1 Plasmid Treatment for Patients with Heart Failure (STOP-HF) is a Phase II, double-blind, randomized, placebo-controlled trial to evaluate safety and efficacy of a single treatment of plasmid stromal cell-derived factor-1 (pSDF-1) delivered via endomyocardial injection to patients with ischaemic heart failure (IHF). METHODS: Ninety-three subjects with IHF on stable guideline-based medical therapy and left ventricular ejection fraction (LVEF) ≤40%, completed Minnesota Living with Heart Failure Questionnaire (MLWHFQ) and 6-min walk distance (6 MWD), were randomized 1 : 1 : 1 to receive a single treatment of either a 15 or 30 mg dose of pSDF-1 or placebo via endomyocardial injections. Safety and efficacy parameters were assessed at 4 and 12 months after injection. Left ventricular functional and structural measures were assessed by contrast echocardiography and quantified by a blinded independent core laboratory. Stromal Cell-Derived Factor-1 Plasmid Treatment for Patients with Heart Failure was powered based on change in 6 MWD and MLWHFQ at 4 months. RESULTS: Subject profiles at baseline were (mean ± SD): age 65 ± 9 years, LVEF 28 ± 7%, left ventricular end-systolic volume (LVESV) 167 ± 66 mL, N-terminal pro brain natriuretic peptide (BNP) (NTproBNP) 1120 ± 1084 pg/mL, MLWHFQ 50 ± 20 points, and 6 MWD 289 ± 99 m. Patients were 11 ± 9 years post most recent myocardial infarction. Study injections were delivered without serious adverse events in all subjects. Sixty-two patients received drug with no unanticipated serious product-related adverse events. The primary endpoint was a composite of change in 6 MWD and MLWHFQ from baseline to 4 months follow-up. The primary endpoint was not met (P = 0.89). For the patients treated with pSDF-1, there was a trend toward an improvement in LVEF at 12 months (placebo vs. 15 mg vs. 30 mg ΔLVEF: -2 vs. -0.5 vs. 1.5%, P = 0.20). A pre-specified analysis of the effects of pSDF-1 based on tertiles of LVEF at entry revealed improvements in EF and LVESV from lowest-to-highest LVEF. Patients in the first tertile of EF (<26%) that received 30 mg of pSDF-1 demonstrated a 7% increase in EF compared with a 4% decrease in placebo (ΔLVEF = 11%, P = 0.01) at 12 months. There was also a trend towards improvement in LVESV, with treated patients demonstrating an 18.5 mL decrease compared with a 15 mL increase for placebo at 12 months (ΔLVESV = 33.5 mL, P = 0.12). The change in end-diastolic and end-systolic volume equated to a 14 mL increase in stroke volume in the patients treated with 30 mg of pSDF-1 compared with a decrease of -11 mL in the placebo group (ΔSV = 25 mL, P = 0.09). In addition, the 30 mg-treated cohort exhibited a trend towards improvement in NTproBNP compared with placebo at 12 months (-784 pg/mL, P = 0.23). CONCLUSIONS: The blinded placebo-controlled STOP-HF trial demonstrated the safety of a single endocardial administration of pSDF-1 but failed to demonstrate its primary endpoint of improved composite score at 4 months after treatment. Through a pre-specified analysis the STOP-HF trial demonstrates the potential for attenuating LV remodelling and improving EF in high-risk ischaemic cardiomyopathy. The safety profile supports repeat dosing with pSDF-1 and the degree of left ventricular remodelling suggests the potential for improved outcomes in larger future trials.

An open-label dose escalation study to evaluate the safety of administration of nonviral stromal cell-derived factor-1 plasmid to treat symptomatic ischemic heart failure.

RATIONALE: Preclinical studies indicate that adult stem cells induce tissue repair by activating endogenous stem cells through the stromal cell-derived factor-1:chemokine receptor type 4 axis. JVS-100 is a DNA plasmid encoding human stromal cell-derived factor-1. OBJECTIVE: We tested in a phase 1, open-label, dose-escalation study with 12 months of follow-up in subjects with ischemic cardiomyopathy to see if JVS-100 improves clinical parameters. METHODS AND RESULTS: Seventeen subjects with ischemic cardiomyopathy, New York Heart Association class III heart failure, with an ejection fraction ≤40% on stable medical therapy, were enrolled to receive 5, 15, or 30 mg of JVS-100 via endomyocardial injection. The primary end points for safety and efficacy were at 1 and 4 months, respectively. The primary safety end point was a major adverse cardiac event. Efficacy end points were change in quality of life, New York Heart Association class, 6-minute walk distance, single photon emission computed tomography, N-terminal pro-brain natruretic peptide, and echocardiography at 4 and 12 months. The primary safety end point was met. At 4 months, all of the cohorts demonstrated improvements in 6-minute walk distance, quality of life, and New York Heart Association class. Subjects in the 15- and 30-mg dose groups exhibited improvements in 6-minute walk distance (15 mg: median [range]: 41 minutes [3-61 minutes]; 30 mg: 31 minutes [22-74 minutes]) and quality of life (15 mg: -16 points [+1 to -32 points]; 30 mg: -24 points [+17 to -38 points]) over baseline. At 12 months, improvements in symptoms were maintained. CONCLUSIONS: These data highlight the importance of defining the molecular mechanisms of stem cell-based tissue repair and suggest that overexpression of stromal cell-derived factor-1 via gene therapy is a strategy for improving heart failure symptoms in patients with ischemic cardiomyopathy.

Adventitial delivery of an allogeneic bone marrow-derived adherent stem cell in acute myocardial infarction: phase I clinical study.

RATIONALE: MultiStem is an allogeneic bone marrow-derived adherent adult stem cell product that has shown efficacy in preclinical models of acute myocardial infarction (AMI). In this phase I clinical trial in patients with first ST-elevation-myocardial infarction (STEMI), we combine first-in-man delivery of MultiStem with a first-in-coronary adventitial delivery system to determine the effects of this system on left ventricular function at 4 months after AMI. OBJECTIVE: Test the effects of adventitial delivery of Multistem in the peri-infarct period in patients with first STEMI. METHODS AND RESULTS: This study was a phase I, open-label, dose-escalating registry control group study. Nineteen patients received MultiStem (20 million, n=6; 50 million, n=7; or 100 million, n=6) and 6 subjects were assigned to the registry control group. Two to 5 days after AMI, we delivered MultiStem to the adventitia of the infarct-related vessel in patients with first-time STEMI. All patients underwent primary percutaneous coronary intervention with resulting Thrombolysis In Myocardial Infarction grade 3 flow and with ejection fraction (EF) ≤45% as determined by echocardiogram or left ventriculogram within 12 hours of primary percutaneous coronary intervention. The cell product (20 million, 50 million, or 100 million) was well tolerated, and no serious adverse events were deemed related to MultiStem. There was no increase in creatine kinase-MB or troponin associated with the adventitial delivery of MultiStem. In patients with EF determined to be ≤45% by a core laboratory within 24 hours before the MultiStem injection, we observed a 0.9 (n=4), 3.9 (n=4), 13.5 (n=5), and 10.9 (n=2) percent absolute increases in EF in the registry, 20 million, 50 million, and 100 million dose groups, respectively. The increases in EF in the 50 million and 100 million groups were accompanied by 25.4 and 8.4 mL increases in left ventricular stroke volume. CONCLUSIONS: In this study, the delivery of MultiStem to the myocardium in patients with recent STEMI was well tolerated and safe. In patients who exhibited significant myocardial damage, the delivery of ≥50 million MultiStem resulted in improved EF and stroke volume 4 months later. These findings support further development of MultiStem in patients with AMI and they validate the potential of a system for delivery of adult stem cells at any time after primary percutaneous coronary intervention.

A phase 3, randomized, double-blinded, active-controlled, unblinded standard of care study assessing the efficacy and safety of intramyocardial autologous CD34+ cell administration in patients with refractory angina: design of the RENEW study.

Preclinical trials indicate that CD34+ cells represent an effective angiogenic stem cell component. Early-phase clinical trials suggest that intramyocardial administration of autologous CD34+ cells may improve functional capacity and symptoms of angina. RENEW is a pivotal phase 3 trial designed to determine the efficacy of granulocyte colony-stimulating factor (G-CSF)-mobilized CD34+ stem cells for the treatment for patients with refractory angina and chronic myocardial ischemia. Patients (n = 444) receiving maximally tolerated antianginal therapies and lacking conventional revascularization options with Canadian Cardiovascular Society class III or IV angina and ischemia on stress testing will be randomized 2:1:1 to cell therapy (G-CSF-mediated stem cell mobilization, apheresis, and intramyocardial injection of 1 × 10(5) autologous CD34(+) cells/kg), active control (G-CSF-mediated stem cell mobilization, apheresis, and intramyocardial placebo injection), or open-label standard of care. The primary efficacy end point is change in exercise treadmill time in the treated vs active control patients, with 90% power to detect a 60-second difference in exercise time between cell-treated (n = 200) and active control (n = 100) patients. Key secondary end points include total number of anginal episodes per week and the incidence of independently adjudicated major adverse cardiac events and serious adverse events. RENEW will be the first adequately powered study aimed at definitively determining the efficacy of a cell therapy (intramyocardially delivered autologous CD34+ cells) for improvement of functional capacity in patients with refractory angina.

Randomized Trial of Targeted Transendocardial Mesenchymal Precursor Cell Therapy in Patients With Heart Failure.

BACKGROUND: Mesenchymal precursor cells (MPCs) are allogeneic, immunoselected cells with anti-inflammatory properties that could improve outcomes in heart failure with reduced ejection fraction (HFrEF). OBJECTIVES: This study assessed the efficacy and safety of MPCs in patients with high-risk HFrEF. METHODS: This randomized, double-blind, multicenter study evaluated a single transendocardial administration procedure of MPCs or sham-control in 565 intention-to-treat patients with HFrEF on guideline-directed therapies. The primary endpoint was time-to-recurrent events caused by decompensated HFrEF or successfully resuscitated symptomatic ventricular arrhythmias. Hierarchical secondary endpoints included components of the primary endpoint, time-to-first terminal cardiac events, and all-cause death. Separate and composite major adverse cardiovascular events analyses were performed for myocardial infarction or stroke or cardiovascular death. Baseline and 12-month echocardiography was performed. Baseline plasma high-sensitivity C-reactive protein levels were evaluated for disease severity. RESULTS: The primary endpoint was similar between treatment groups (HR: 1.17; 95% CI: 0.81-1.69; P = 0.41) as were terminal cardiac events and secondary endpoints. Compared with control subjects, MPCs increased left ventricular ejection fraction from baseline to 12 months, especially in patients with inflammation. MPCs decreased the risk of myocardial infarction or stroke by 58% (HR: 0.42; 95% CI: 0.23-0.76) and the risk of 3-point major adverse cardiovascular events by 28% (HR: 0.72; 95% CI: 0.51-1.03) in the analysis population (n = 537), and by 75% (HR: 0.25; 95% CI: 0.09-0.66) and 38% (HR: 0.62; 95% CI: 0.39-1.00), respectively, in patients with inflammation (baseline high-sensitivity C-reactive protein ≥2 mg/L). CONCLUSIONS: The primary and secondary endpoints of the trial were negative. Positive signals in prespecified, and post hoc exploratory analyses suggest MPCs may improve outcomes, especially in patients with inflammation.

Micro-anatomy of the renal sympathetic nervous system: a human postmortem histologic study.

Hypertension remains an epidemic uncontrolled with pharmacologic therapies. A novel catheter inserted into the renal artery has been shown to lower blood pressure by ablating the renal sympathetic nerves with radiofrequency energy delivered through the arterial wall. We report a histologic study describing the anatomic substrate for this technique, specifically the renal sympathetic nervous system. Histological sections from proximal, middle, and distal renal artery segments from nine renal arteries (five human autopsies) were analyzed. Nerves were manually counted and their distance from the lumen-intima interface was measured using a micrometer. The nerves were then categorized by location into 0.5-mm-wide "rings" that were arranged circumferentially around the renal artery lumen. Of all nerves detected, 1.0% was in the 0-0.5 mm ring, 48.3% were in the 0.5-1.0 mm ring, 25.6% were in the 1.0-1.5 mm ring, 15.5% were in the 1.5-2.0 mm ring, and 9.5% were in the 2.0-2.5 mm ring. Beyond 0.5 mm, the proportion of nerves tended to decrease as the distance from the lumen increased. Totally, 90.5% of all nerves in this study existed within 2.0 mm of the renal artery lumen. Additionally, the number of nerves tended to increase along the length of the artery from proximal to distal segments (proximal = 216; middle = 323; distal = 417). In conclusion, our analysis indicates that a great proportion of renal sympathetic nerves have close proximity to the lumen-intima interface and should thus be accessible via renal artery interventional approaches such as catheter ablation. This data provides important anatomic information for the development of ablation and other type devices for renal sympathetic denervation.

Safety and efficacy of patient specific intramuscular injection of HGF plasmid gene therapy on limb perfusion and wound healing in patients with ischemic lower extremity ulceration: results of the HGF-0205 trial.

OBJECTIVES: We have previously reported the results of a dose-finding phase II trial showing that HGF angiogenic gene therapy can increase TcPO2 compared with placebo in patients with critical limb ischemia (CLI). The purpose of this randomized placebo controlled multi-center trial was to further assess the safety and clinical efficacy of a modified HGF gene delivery technique in patients with CLI and no revascularization options. METHODS: Patients with lower extremity ischemic tissue loss (Rutherford 5 and 6) received three sets of eight intramuscular injections every 2 weeks of HGF plasmid under duplex ultrasound guidance. Injection locations were individualized for each patient based on arteriographically defined vascular anatomy. Primary safety end point was incidence of adverse events (AE) or serious adverse events (SAE). Clinical end points included change from baseline in toe brachial index (TBI), rest pain assessment by a 10 cm visual analogue scale (VAS) as well as wound healing, amputation, and survival at 3 and 6 months. RESULTS: Randomization ratio was 3:1 HGF (n = 21) vs placebo (n = 6). Mean age was 76 ± 2 years, with 56% male and 59% diabetic. There was no difference in demographics between groups. There was no difference in AEs or SAEs, which consisted mostly of transient injection site discomfort, worsening of CLI, and intercurrent illnesses. Change in TBI significantly improved from baseline at 6 months in the HGF-treated group compared with placebo (0.05 ± 0.05 vs -0.17 ± 0.04; P = .047). Change in VAS from baseline at 6 months was also significantly improved in the HGF-treated group compared with placebo (-1.9 ± 1.3 vs +0.06 ± 0.2; P = .04). Complete ulcer healing at 12 months occurred in 31% of the HGF group and 0% of the placebo (P = .28) There was no difference in major amputation of the treated limb (HGF 29% vs placebo 33%) or mortality at 12 months (HGF 19% vs placebo 17%) between groups. CONCLUSION: HGF gene therapy using a patient vascular anatomy specific delivery technique appears safe, maintained limb perfusion, and decreased rest pain in patients with CLI compared with placebo. A larger study to assess the efficacy of this therapy on more clinically relevant end points is warranted.

Regional angiogenesis with vascular endothelial growth factor in peripheral arterial disease: a phase II randomized, double-blind, controlled study of adenoviral delivery of vascular endothelial growth factor 121 in patients with disabling intermittent claudication.

BACKGROUND: "Therapeutic angiogenesis" seeks to improve perfusion by the growth of new blood vessels. The Regional Angiogenesis with Vascular Endothelial growth factor (RAVE) trial is the first major randomized study of adenoviral vascular endothelial growth factor (VEGF) gene transfer for the treatment of peripheral artery disease (PAD). METHODS AND RESULTS: This phase 2, double-blind, placebo-controlled study was designed to test the efficacy and safety of intramuscular delivery of AdVEGF121, a replication-deficient adenovirus encoding the 121-amino-acid isoform of vascular endothelial growth factor, to the lower extremities of subjects with unilateral PAD. In all, 105 subjects with unilateral exercise-limiting intermittent claudication during 2 qualifying treadmill tests, with peak walking time (PWT) between 1 to 10 minutes, were stratified on the basis of diabetic status and randomized to low-dose (4x10(9) PU) AdVEGF121, high-dose (4x10(10) PU) AdVEGF121, or placebo, administered as 20 intramuscular injections to the index leg in a single session. The primary efficacy end point, change in PWT (DeltaPWT) at 12 weeks, did not differ between the placebo (1.8+/-3.2 minutes), low-dose (1.6+/-1.9 minutes), and high-dose (1.5+/-3.1 minutes) groups. Secondary measures, including DeltaPWT, ankle-brachial index, claudication onset time, and quality-of-life measures (SF-36 and Walking Impairment Questionnaire), were also similar among groups at 12 and 26 weeks. AdVEGF121 administration was associated with increased peripheral edema. CONCLUSIONS: A single unilateral intramuscular administration of AdVEGF121 was not associated with improved exercise performance or quality of life in this study. This study does not support local delivery of single-dose VEGF121 as a treatment strategy in patients with unilateral PAD.

Design of the Del-1 for therapeutic angiogenesis trial (DELTA-1), a phase II multicenter, double-blind, placebo-controlled trial of VLTS-589 in subjects with intermittent claudication secondary to peripheral arterial disease.

The objective of this phase II investigation is to assess the safety and efficacy of a plasmid mediated approach to induce angiogenesis/arteriogenesis with the angiomatrix protein Del-1 (developmentally regulated endothelial locus 1), in subjects with intermittent claudication (IC) secondary to peripheral arterial disease (PAD). VLTS-589 is an investigational nonviral therapeutic comprising a plasmid-expressing Del-1 formulated with poloxamer 188 (facilitating agent). One hundred subjects with bilateral PAD and IC will be randomized after careful screening to bilateral intramuscular delivery of VLTS-589 or placebo. A total of 84 mg of plasmid or placebo will be delivered as 42 intramuscular injections (2 ml per injection, 21 injections or 42 ml in each extremity of either plasmid or placebo) in both lower extremities. The subjects in the study will be followed at regular intervals for a year after study drug administration (days 30, 90, 180, and 365) with the primary endpoint being the safety and tolerability of VLTS-589 and change in peak walking time (PWT) at day 90. The secondary endpoints include percent and absolute change in resting ankle brachial Index, claudication onset time, and quality of life measured at various time points. DELTA-1 represents the largest plasmid-based gene transfer trial designed to test the efficacy of a Del-1 as a therapeutic approach in patients with IC caused by PAD. The novel aspects of the protocol include the usage of a Del-1 plasmid-polaxamer formulation to enhance gene transfer at doses that are an order of magnitude different than other comparable trials in a unique bilateral intramuscular dosing pattern to maximize transfection/clinical efficacy and general applicability to patients with PAD.

Regional Angiogenesis with Vascular Endothelial Growth Factor (VEGF) in peripheral arterial disease: Design of the RAVE trial.

BACKGROUND: Patients with intermittent claudication caused by infrainguinal atherosclerosis have limited pharmacologic options "Therapeutic angiogenesis" is a novel treatment approach that seeks to improve perfusion of ischemic limbs by the induction of collateral vessel formation. This trial is a phase 2 randomized double-blind placebo-controlled proof of concept trial that will use an intramuscular adenoviral gene transfer approach of vascular endothelial growth factor, 121 isoform (Ad(GV)VEGF(121.10)) to patients with severe IC caused by infrainguinal disease. METHODS: This is a phase 2, double-blind, randomized, placebo-controlled, dose-finding, multicenter study. Patients with severe intermittent claudication caused by infrainguinal atherosclerosis predominantly involving the superficial femoral artery confirmed with imaging studies that meet inclusion criteria will be stratified on the basis of the presence or absence of diabetes mellitus and randomized in a 1:1:1 fashion to low dose (4 x 10(9) particle units), high dose (4 x 10(10) particle units), or placebo arms (35-36 patients per group). Subjects are required to have exercise-limiting IC in the index extremity during 2 qualifying exercise treadmill tests, with peak walking times between 1 and 10 minutes. A single dose of Ad(GV)VEGF(121.10) will be administered as 20 intramuscular injections throughout the area of the lower limb requiring collateralization. RESULTS: The primary efficacy parameter for the Regional Angiogenesis With Vascular Endothelial Growth Factor (RAVE) trial is the change in peak walking time at 12 weeks compared with baseline. The sample size is expected to provide an 80% power to detect a difference of 1.5 minutes between any of the 2 treatment groups and the placebo group. Secondary efficacy parameters include claudication onset time, hemodynamic effects of therapy assessed with ankle-brachial index, assessment of physical impairment, and health-related quality of life as measured with the Walking Impairment Questionnaire and SF-36 Health Survey. All randomized patients will also be evaluated for safety.

Does complete renal denervation translate into superior clinical outcomes? Lessons learned from denervation of accessory renal arteries.

Pre-clinical studies of renal denervation would suggest that the extent of renal nerve injury correlates with outcomes. The "completeness" of renal nerve injury following renal denervation correlates with treatment-based variables such as the depth of ablation, the number of ablations along the length of the artery, and the number of renal arteries successfully ablated. Renal denervation techniques targeting only main renal arteries may lead to suboptimal results in patients with accessory renal artery anatomy. Technological differences among the different systems may make some more suited for this common anatomical variant. The early clinical experience with renal denervation of accessory renal arteries highlights the importance of complete renal denervation for clinical success.

Evaluation of renal nerve morphological changes and norepinephrine levels following treatment with novel bipolar radiofrequency delivery systems in a porcine model.

OBJECTIVE: To evaluate the safety and effectiveness of different bipolar radiofrequency system algorithms in interrupting the renal sympathetic nerves and reducing renal norepinephrine in a healthy porcine model. METHODS: A porcine model (N = 46) was used to investigate renal norepinephrine levels and changes to renal artery tissues and nerves following percutaneous renal denervation with radiofrequency bipolar electrodes mounted on a balloon catheter. Parameters of the radiofrequency system (i.e. electrode length and energy delivery algorithm), and the effects of single and longitudinal treatments along the artery were studied with a 7-day model in which swine received unilateral radiofrequency treatments. Additional sets of animals were used to examine norepinephrine and histological changes 28 days following bilateral percutaneous radiofrequency treatment or surgical denervation; untreated swine were used for comparison of renal norepinephrine levels. RESULTS: Seven days postprocedure, norepinephrine concentrations decreased proportionally to electrode length, with 81, 60 and 38% reductions (vs. contralateral control) using 16, 4 and 2-mm electrodes, respectively. Applying a temperature-control algorithm with the 4-mm electrodes increased efficacy, with a mean 89.5% norepinephrine reduction following a 30-s treatment at 68°C. Applying this treatment along the entire artery length affected more nerves vs. a single treatment, resulting in superior norepinephrine reduction 28 days following bilateral treatment. CONCLUSION: Percutaneous renal artery application of bipolar radiofrequency energy demonstrated safety and resulted in a significant renal norepinephrine content reduction and renal nerve injury compared with untreated controls in porcine models.

Hyperperfusion syndrome following carotid artery stenting: the largest single-operator series to date.

BACKGROUND: Cerebral hyperperfusion syndrome (HPS) results from autoregulatory failure of cerebral blood flow following carotid endarterectomy (CEA) or carotid artery stenting (CAS) and encompasses a range of neurological findings including headache, seizure, intracranial hemorrhage (ICH), altered mental status and focal neurological changes. This report is the largest single-operator series evaluating the incidence and predictors of HPS following CAS. METHODS: A retrospective review was conducted on 482 consecutive patients who underwent CAS between August 1999 and December 2007 at Baptist Medical Center--Princeton, Birmingham, Alabama. All interventions were performed by a single operator (FM). The mean patient age was 70.4 +/- 10.3 years and 36% were symptomatic. All patients were high-risk for CEA. After cerebral protection catheters were routinely available, they were used in all but 6 cases (98.1%) where the anatomy precluded delivery. Brain computed tomography (CT) was performed immediately for any neurological change or significant headache following CAS. After neurological consultation and imaging, HPS was diagnosed if: 1) a neurological change occurred (not simply a headache); 2) CT revealed ipsilateral sulcal effacement/cerebral edema; and 3) stroke or transient ischemic attack (TIA) was excluded. RESULTS: Seven patients (1.45%) developed HPS following CAS. All patients achieved complete neurological recovery 6-24 hours following the procedure. Patients who developed HPS were significantly more likely to have had recent transient ischemic attack (TIA) symptoms than patients without HPS (p = 0.04). Unlike previous reports, there were no significant differences in procedural details, lesion characteristics and post-procedure blood pressure between the HPS and non-HPS patients, although the number of cases was small. Overall, the HPS cohort had a higher prevalence of comorbidities, though these differences did not reach statistical significance. Hypertension was present in all 7 HPS patients. Other complications in the series were death (0.83%), stroke (1.87%) and TIA (1.45%). CONCLUSIONS: The incidence of HPS is low (1.45%) following CAS, but it is an important complication to distinguish from stroke and TIA. Patients with a recent TIA may be predisposed to HPS. This report may underestimate the incidence of HPS, since patients with an isolated headache did not meet our diagnostic criteria and routine post-procedure brain CT imaging was not performed. The clinical predictors of HPS and its optimum management remain to be determined.

Therapeutic angiogenesis with recombinant fibroblast growth factor-2 for intermittent claudication (the TRAFFIC study): a randomised trial.

BACKGROUND: Recombinant fibroblast growth factor-2 (rFGF-2) improves perfusion in models of myocardial and hindlimb ischaemia. We investigated whether one or two doses of intra-arterial rFGF-2 improves exercise capacity in patients with moderate-to-severe intermittent claudication. METHODS: 190 patients with intermittent claudication caused by infra-inguinal atherosclerosis were randomly assigned (1:1:1) bilateral intra-arterial infusions of placebo on days 1 and 30 (n=63); rFGF-2 (30 microg/kg) on day 1 and placebo on day 30 (single-dose, n=66); or rFGF-2 (30 microg/kg) on days 1 and 30 (double-dose, n=61). Primary outcome was 90-day change in peak walking time. Secondary outcomes included ankle-brachial pressure index and safety. The main analysis was per protocol. FINDINGS: Before 90 days, six patients had undergone peripheral revascularisation and were excluded, and ten withdrew or had missing data. 174 were therefore assessed for primary outcome. Peak walking time at 90 days was increased by 0.60 min with placebo, by 1.77 min with single-dose, and by 1.54 min with double-dose. By ANOVA, the difference between groups was p=0.075. In a secondary intention-to-treat analysis, in which all 190 patients were included, the difference was p=0.034. Pairwise comparison showed a significant difference between placebo and single-dose (p=0.026) but placebo and double-dose did not differ by much (p=0.45). Serious adverse events were similar in all groups. INTERPRETATION: Intra-arterial rFGF-2 resulted in a significant increase in peak walking time at 90 days; repeat infusion at 30 days was no better than one infusion. The findings of TRAFFIC provide evidence of clinical therapeutic angiogenesis by intra-arterial infusion of an angiogenic protein.