Impact of drug adherence on blood pressure response to alcohol-mediated renal denervation.

PURPOSE: While poor drug adherence is frequent in patients with resistant hypertension, detailed analyses of the impact of drug adherence on the success of renal denervation are scarce. We report drug adherence at baseline, changes in drug adherence, and the influence of these parameters on blood pressure changes at 6 and 12 months in patients treated with alcohol-mediated renal denervation as part of the Peregrine study. MATERIALS AND METHODS: Urinary detection of antihypertensive drugs was performed using high-performance liquid chromatography-tandem mass spectrometry. Full adherence, partial adherence, and complete non-adherence were defined as 0, 1, or ≥2 drugs not detected, respectively. RESULTS: Renal denervation was performed in 45 patients with uncontrolled hypertension on ≥3 antihypertensive medications (62% men, age 55 ± 10 years). At baseline, the proportion of fully, partially, and non-adherent patients was 62% (n = 28), 16% (n = 7), and 22% (n = 10), respectively. At 6 months, adherence improved by 21% (n = 9), remained unchanged at 49% (n = 21), and worsened by 30% (n = 13). Mean 24-h systolic blood pressure decreased by 10 ± 13, 10 ± 4, and 14 ± 19 mmHg in fully, partially, and non-adherent patients (p = 0.77), and by 14 ± 14, 8 ± 11, and 14 ± 18 mmHg in patients who improved, maintained, or decreased adherence, respectively (p = 0.35). The results at 12 months were similar. CONCLUSION: About 40% of patients with apparently treatment-resistant hypertension were not fully adherent at baseline, and adherence decreased further in 30%. Nevertheless, mean blood pressure changes after renal denervation were similar irrespective of drug adherence. Our results suggest that such patients may benefit from alcohol-mediated renal denervation, irrespective of drug adherence. These findings are hypothesis-generating and need to be confirmed in ongoing sham-controlled trials.

Alcohol-Mediated Renal Sympathetic Neurolysis for the Treatment of Hypertension: The Peregrine™ Infusion Catheter.

Renal sympathetic denervation using conventional non-irrigated radiofrequency catheters has potential technical shortcomings, including limited penetration depth and incomplete circumferential nerve damage, potentially impacting therapeutic efficacy. Against this background, second generation multi-electrode, radiofrequency and ultrasound renal denervation systems have been developed to provide more consistent circumferential nerve ablation. Irrigated catheters may allow deeper penetration while minimizing arterial injury. In this context, catheter-based chemical denervation, with selective infusion of alcohol, a potent neurolytic agent, into the perivascular space, may minimize endothelial, intimal and medial injury while providing circumferential neurolysis. Animal studies demonstrate pronounced renal norepinephrine level reductions and consistent renal nerve injury after perivascular alcohol infusion using the Peregrine Catheter. Early clinical studies demonstrated significant blood pressure reductions and a reasonable safety profile. Randomized sham-controlled trials (NCT03503773, NCT02910414) are underway to examine whether the aforementioned theoretical advantages of alcohol-medicated denervation with the Peregrine System™ Kit translate into clinical benefits.

Evaluation of Transcatheter Alcohol-Mediated Perivascular Renal Denervation to Treat Resistant Hypertension.

Catheter-based renal denervation (RDN) has been investigated for hypertension (HTN) treatment with variable success. One of the novel approaches to RDN is the delivery of micro-doses of dehydrated alcohol to the adventitial space of the renal artery to perform perivascular ablation of the sympathetic nerves. We sought to assess the safety and efficiency of transcatheter alcohol-mediated perivascular renal denervation in patients with resistant hypertension. Fifty adult patients who had been referred for resistant HTN were screened. To qualify for the study, the patients had to have a mean 24 h systolic pressure ≥ 135 mmHg based upon ambulatory blood pressure monitoring (ABPM) and acceptable renal artery anatomy confirmed by the contrast computer tomography (AngioCT) and nephrologist consultation. Ten patients were eligible for chemical RND. There were no safety issues throughout the 24 months of follow-ups. The mean decrease in the office BP (OBP) was significant during 24 months of follow-up (p < 0.01). The difference in the BP in the ABPM was statistically significant in the 1st, 3rd and 12th months (p < 0.01), whereas during the 3-month follow-up, a trend was observed. The modifications of anti-hypertension drugs throughout the follow-up period were minimal. This study has shown that transcatheter alcohol-mediated renal denervation in patients with resistant hypertension is feasible and safe. Nevertheless, it is a hypothesis-generating study.

Alcohol-Mediated Renal Denervation Using the Peregrine System Infusion Catheter for Treatment of Hypertension.

OBJECTIVES: The aim of this multicenter, open-label trial was to evaluate the safety and efficacy of alcohol-mediated renal denervation using a novel catheter system (the Peregrine System Infusion Catheter) for the infusion of dehydrated alcohol as a neurolytic agent into the renal periarterial space. BACKGROUND: The number of hypertensive patients with uncontrolled blood pressure (BP) remains unacceptably low. The renal sympathetic nervous system has been identified as an attractive therapeutic target. METHODS: Forty-five patients with uncontrolled hypertension on ≥3 antihypertensive medications underwent bilateral renal denervation using the Peregrine Catheter with 0.6 ml alcohol infused per renal artery. RESULTS: All patients were treated as intended. Mean 24-h ambulatory BP reduction at 6 months versus baseline was -11 mm Hg (95% confidence interval [CI]: -15 to -7 mm Hg) for systolic BP and -7 mm Hg (95% CI: -9 to -4 mm Hg) for diastolic BP (p < 0.001 for both). Office systolic BP was reduced by -18/-10 mm Hg (95% CI: -25 to -12/-13 to -6 mm Hg) at 6 months. Antihypertensive medications were reduced in 23% and increased in 5% of patients at 6 months. Adherence to the antihypertensive regimen remained stable over time. The primary safety endpoint, defined as the absence of periprocedural major vascular complications, major bleeding, acute kidney injury, or death within 1 month, was met in 96% of patients (95% CI: 85% to 99%). Two patients had major adverse events of periprocedural access-site pseudoaneurysms, with major bleeding in one. There were no deaths or instances of myocardial infarction, stroke, transient ischemic attack, or renal artery stenosis. Transient microleaks were noted in 42% and 49% of the left and right main renal arteries, respectively. There were 2 cases of minor vessel dissection that resolved without treatment. CONCLUSIONS: Primary results from this trial suggest that alcohol-mediated renal denervation using the Peregrine Catheter safely reduces blood pressure and as such may represent a novel approach for the treatment of hypertension.

Transcatheter Alcohol-Mediated Perivascular Renal Denervation With the Peregrine System: First-in-Human Experience.

OBJECTIVES: This study evaluated the first clinical use of a new endovascular approach to renal denervation, using chemical neurolysis, via periadventitial infusion of dehydrated alcohol (ethanol) to perform "perivascular" renal artery sympathetic denervation. BACKGROUND: Renal denervation remains a promising technology for the treatment of hypertension and other disorders. METHODS: A novel 3-needle delivery device (Peregrine System Infusion Catheter, Ablative Solutions, Inc., Kalamazoo, Michigan) was introduced into the renal arteries of 18 subjects with refractory hypertension. Microdoses of alcohol were infused bilaterally via the 3 needles into to the adventitial space (0.30 ml/artery, 37 arteries). Renal artery angiography was performed at the time of the procedure and at 6 months (n = 16). The primary safety endpoints were complications associated with the catheter insertion and delivery of the neurolytic agent or any major vascular access complications. The secondary performance endpoint was a reduction in office-based systolic blood pressure at 6 months compared with baseline. RESULTS: Procedural success was achieved in 100% of subjects (N = 18) and arteries (N = 37). There were no study-related adverse clinical events at follow-up. One death of a subject was recorded but determined by the investigator and an independent medical monitor to be non-study related. There were no angiographic observations of renal artery stenosis, aneurysms, or other renal artery abnormalities at 6 months (32 renal arteries). Sixteen of the 18 subjects had a 6-month follow-up. The mean office systolic blood pressure decreased from 175 ± 17 mm Hg to 151 ± 26 mm Hg (-24 mm Hg). There was an average reduction of antihypertensive medications from 3.4 (baseline) to 2.0 per subject at 6 months. CONCLUSIONS: Chemical renal denervation using the infusion of very low doses of alcohol directly into the adventitial space appears to be feasible and safe. This approach may be a promising alternative approach to perform catheter-based renal denervation. These results need to be confirmed in larger scale clinical studies.

Transfemoral aortic valve replacement with the repositionable Lotus Valve System in high surgical risk patients: the REPRISE I study.

AIMS: To assess outcomes with a new fully repositionable and retrievable valve for transcatheter aortic valve replacement (TAVR). METHODS AND RESULTS: The Lotus Aortic Valve System is designed to facilitate precise positioning and minimise paravalvular regurgitation. REPRISE I enrolled symptomatic, high-surgical-risk patients with severe aortic stenosis. The primary endpoint (clinical procedural success) included successful implantation without major adverse cardiovascular or cerebrovascular events (MACCE). In all patients (N=11) the first Lotus Valve was successfully deployed. Partial resheathing to facilitate accurate placement was attempted and successfully performed in four patients; none required full retrieval. The primary endpoint was achieved in 9/11 with no in-hospital MACCE in 10/11. There was one major stroke; in another patient, discharge mean aortic gradient was 22 mmHg (above the primary endpoint threshold of 20 mmHg), but improved to 15 mmHg at 30 days. The cohort's mean aortic gradient decreased from 53.9±20.9 mmHg at baseline to 15.4±4.6 mmHg (p<0.001) at one year; valve area increased from 0.7±0.2 cm2 to 1.5±0.2 cm2 (p<0.001). Discharge paravalvular aortic regurgitation, adjudicated by an independent core laboratory, was mild (n=2), trivial (n=1), or absent (n=8). Four patients required a permanent pacemaker post-procedure. There were no deaths, myocardial infarctions or new strokes through one year. CONCLUSIONS: Initial results support proof-of-concept with the Lotus Valve for TAVR.

Boston Scientific Lotus valve.

As a result of recent randomised controlled trials and registry observations, transcatheter aortic valve replacement (TAVR) enjoys growing appeal for the treatment of patients at high or extreme risk from surgical aortic valve replacement. However, the current technologies and techniques have important limitations, including risk of stroke, vascular complications and paravalvular aortic regurgitation, which may in turn influence survival. While careful patient selection and screening may improve outcomes, new valve designs and iterations are required. The Lotus aortic valve replacement system is a new fully repositionable device designed to facilitate more precise delivery and minimise paravalvular regurgitation. The safety and efficacy of the Lotus valve are being studied systematically in the REPRISE clinical trial programme.