Alexandre Persu

Renal sympathetic denervation in patients with treatment-resistant hypertension (The Symplicity HTN-2 Trial): a randomised controlled trial.

BACKGROUNDnActivation of renal sympathetic nerves is key to pathogenesis of essential hypertension. We aimed to assess effectiveness and safety of catheter-based renal denervation for reduction of blood pressure in patients with treatment-resistant hypertension.nnnMETHODSnIn this multicentre, prospective, randomised trial, patients who had a baseline systolic blood pressure of 160 mmu2008Hg or more (≥150 mmu2008Hg for patients with type 2 diabetes), despite taking three or more antihypertensive drugs, were randomly allocated in a one-to-one ratio to undergo renal denervation with previous treatment or to maintain previous treatment alone (control group) at 24 participating centres. Randomisation was done with sealed envelopes. Data analysers were not masked to treatment assignment. The primary effectiveness endpoint was change in seated office-based measurement of systolic blood pressure at 6 months. Primary analysis included all patients remaining in follow-up at 6 months. This trial is registered with ClinicalTrials.gov, number NCT00888433.nnnFINDINGSn106 (56%) of 190 patients screened for eligibility were randomly allocated to renal denervation (n=52) or control (n=54) groups between June 9, 2009, and Jan 15, 2010. 49 (94%) of 52 patients who underwent renal denervation and 51 (94%) of 54 controls were assessed for the primary endpoint at 6 months. Office-based blood pressure measurements in the renal denervation group reduced by 32/12 mmu2008Hg (SD 23/11, baseline of 178/96 mmu2008Hg, p<0·0001), whereas they did not differ from baseline in the control group (change of 1/0 mmu2008Hg [21/10], baseline of 178/97 mmu2008Hg, p=0·77 systolic and p=0·83 diastolic). Between-group differences in blood pressure at 6 months were 33/11 mmu2008Hg (p<0·0001). At 6 months, 41 (84%) of 49 patients who underwent renal denervation had a reduction in systolic blood pressure of 10 mmu2008Hg or more, compared with 18 (35%) of 51 controls (p<0·0001). We noted no serious procedure-related or device-related complications and occurrence of adverse events did not differ between groups; one patient who had renal denervation had possible progression of an underlying atherosclerotic lesion, but required no treatment.nnnINTERPRETATIONnCatheter-based renal denervation can safely be used to substantially reduce blood pressure in treatment-resistant hypertensive patients.nnnFUNDINGnArdian.

Blood pressure changes after renal denervation at 10 European expert centers

We did a subject-level meta-analysis of the changes (Δ) in blood pressure (BP) observed 3 and 6 months after renal denervation (RDN) at 10 European centers. Recruited patients (n=109; 46.8% women; mean age 58.2 years) had essential hypertension confirmed by ambulatory BP. From baseline to 6 months, treatment score declined slightly from 4.7 to 4.4 drugs per day. Systolic/diastolic BP fell by 17.6/7.1u2009mmu2009Hg for office BP, and by 5.9/3.5, 6.2/3.4, and 4.4/2.5u2009mmu2009Hg for 24-h, daytime and nighttime BP (P⩽0.03 for all). In 47 patients with 3- and 6-month ambulatory measurements, systolic BP did not change between these two time points (P⩾0.08). Normalization was a systolic BP of <140u2009mmu2009Hg on office measurement or <130u2009mmu2009Hg on 24-h monitoring and improvement was a fall of ⩾10u2009mmu2009Hg, irrespective of measurement technique. For office BP, at 6 months, normalization, improvement or no decrease occurred in 22.9, 59.6 and 22.9% of patients, respectively; for 24-h BP, these proportions were 14.7, 31.2 and 34.9%, respectively. Higher baseline BP predicted greater BP fall at follow-up; higher baseline serum creatinine was associated with lower probability of improvement of 24-h BP (odds ratio for 20-μmolu2009l−1 increase, 0.60; P=0.05) and higher probability of experiencing no BP decrease (OR, 1.66; P=0.01). In conclusion, BP responses to RDN include regression-to-the-mean and remain to be consolidated in randomized trials based on ambulatory BP monitoring. For now, RDN should remain the last resort in patients in whom all other ways to control BP failed, and it must be cautiously used in patients with renal impairment.

Renal Denervation Ultima Ratio or Standard in Treatment-Resistant Hypertension

The term “ultima ratio” has multiple, though related, meanings. The motto “ultima ratio regum,” cast on the cannons of the French army of King Louis XIV, meant that war is the last argument of kings, that is, the one to be used after all diplomatic arguments have failed. Along similar lines, we propose that, given the current evidence, renal denervation should be used as a last resort, after state-of-the-art drug treatment optimized at expert centers failed to control blood pressure.

Eligibility for Renal Denervation: Experience at 11 European Expert Centers

Based on the SYMPLICITY studies and CE (Conformité Européenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after a thorough work-up and treatment adjustment remains scarce. The aim of this study was to investigate the proportion of patients eligible for renal denervation and the reasons for noneligibility at 11 expert centers participating in the European Network COordinating Research on renal Denervation in treatment-resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure–lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according to the SYMPLICITY HTN-2 criteria and each center’s criteria was 42.5% (95% confidence interval, 38.0%–47.0%) and 39.7% (36.2%–43.2%), respectively. The main reasons of noneligibility were normalization of blood pressure after treatment adjustment (46.9%), unsuitable renal arterial anatomy (17.0%), and previously undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility (approximately half of cases) was blood pressure normalization after treatment adjustment by a hypertension specialist. Our findings highlight that hypertension centers with a record in clinical experience and research should remain the gatekeepers before renal denervation is considered.Based on the SYMPLICITY studies and CE (Conformite Europeenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after a thorough work-up and treatment adjustment remains scarce. The aim of this study was to investigate the proportion of patients eligible for renal denervation and the reasons for noneligibility at 11 expert centers participating in the European Network COordinating Research on renal Denervation in treatment-resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure–lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according to the SYMPLICITY HTN-2 criteria and each center’s criteria was 42.5% (95% confidence interval, 38.0%–47.0%) and 39.7% (36.2%–43.2%), respectively. The main reasons of noneligibility were normalization of blood pressure after treatment adjustment (46.9%), unsuitable renal arterial anatomy (17.0%), and previously undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility (approximately half of cases) was blood pressure normalization after treatment adjustment by a hypertension specialist. Our findings highlight that hypertension centers with a record in clinical experience and research should remain the gatekeepers before renal denervation is considered.nn# Novelty and Significance {#article-title-32}

Meta-analysis of randomized controlled trials of renal denervation in treatment-resistant hypertension

Abstract Objective. The blood pressure (BP)-lowering effect of renal sympathetic nervous denervation (RDN) in resistant hypertension (rHT) shows large variation among studies. Methods. We meta-analyzed summary statistics of randomized clinical trials on RDN in rHT. For continuous outcomes, we assessed heterogeneity by Cochrans Q test and used random-effect models weighted for the inverse of the variance. We assessed safety by assessing the risk of major adverse events from stratified contingency tables. Results. Of 5652 patients screened in seven trials, 985 (17.4%) qualified and were randomized to control (n = 397) or RDN with SYMPLICITY™ catheters (n = 588). Follow-up was 6 months. In both control and RDN patients, antihypertensive treatment was continued or optimized. At enrolment, age averaged 58.1 years, systolic/diastolic office and 24 h BP 168.5/93.3 mmHg and 151.8/86.1 mmHg, respectively, and estimated glomerular filtration rate (eGFR) 79.3 ml/min/1.73 m². For BP outcomes, there was heterogeneity among trials. Pooled effects (control minus RDN) were −4.9/−3.5 mmHg (95% confidence interval, −20.9 to 11.1/−8.9 to 1.9) for office BP, −2.8/−1.5 mmHg (−6.5 to 0.8/−3.3 to 0.4) for 24 h BP and 0.81 ml/min/1.73 m² (−1.69 to 3.30) for eGFR. Removing one trial at a time produced confirmatory results. Adverse events occurred in 7.4% and 9.9% of control and RDN patients, respectively (p = 0.24). Conclusion. In selected rHT patients maintained on antihypertensive drugs, RDN with the SYMPLICITY systems does not significantly decrease BP but is safe. Future trials with next-generation catheters should aim at identifying responders in patients with evidence of sympathetic nervous overactivity.

Evaluation of Adherence Should Become an Integral Part of Assessment of Patients With Apparently Treatment-Resistant Hypertension.

Since the publication of the first Symplicity studies in 2009 to 2010, renal sympathetic denervation gained acceptance as a novel treatment of drug-resistant hypertension. The latter has been defined as a blood pressure (BP) >140/90 mmu2009Hg, despite appropriate lifestyle measures plus a diuretic and 2 other antihypertensive drugs belonging to different classes at adequate doses.1 According to the US definition, patients with controlled BP on ≥4 antihypertensive drugs are also considered as resistant hypertensives.2 However, a substantial proportion of patients with apparently resistant hypertension are in fact poorly adherents to drug treatment. The highly variable BP response to renal denervation (RDN)3–5 prompted to a more rigorous evaluation of eligible patients, with the goal to exclude false resistant hypertension, because of poor adherence to drug treatment.6–8 In particular, several publications documented a high proportion of low drug adherence in patients with apparently resistant hypertension (23%–66%), using witnessed drug intake9 or plasma/urine drug determinations10–18 (Figure 1).nnnnFigure 1. nProportion of poor or nonadherence according to drug monitoring in different cohorts of patients with apparently resistant hypertension. Black indicates total nonadherence, whereas gray indicates partial adherence. Partial adherence was defined as the presence of at least one undetectable drug10–12,14,16–18 or as the presence of fewer medications than prescribed.13,15nnnnFurthermore, RDN studies shed the light on the dynamic character of drug adherence. Inclusion in RDN trials may influence drug adherence in various, unpredictable directions.6 In some patients, close follow-up and massive attention devoted to them may lead to improved adherence to lifestyle measures and drug treatment, particularly in the RDN arm (Hawthorne effect). Other patients may stop their medications after RDN according to their perception that the intervention cured their …

Hyperresponders vs. nonresponder patients after renal denervation: do they differ?

Background: Blood pressure (BP) response after renal denervation (RDN) is highly variable. Besides baseline BP, no reliable predictors of response have been consistently identified. The differences between patients showing a major BP decrease after RDN vs. nonresponders have not been studied so far. Aim and methods: We identified extreme BP responders (first quintile) and nonresponders (fifth quintile) to RDN defined according to office or 24-h ambulatory BP in the European Network COordinating research on Renal Denervation database (nu200a=u200a109) and compared the baseline characteristics and BP changes 6 months after RDN in both subsets. Results: In extreme responders defined according to ambulatory BP, baseline BP and BP changes 6 months after RDN were similar for office and out-of-the office BP. In contrast, extreme responders defined according to office BP were characterized by a huge white-coat effect at baseline, with dramatic shrinkage at 6 months. Compared with nonresponders, extreme responders defined according to office BP were more frequently women, had higher baseline office – but not ambulatory – BP, and higher estimated glomerular filtration rate (eGFR). In contrast, when considering ambulatory BP decrease to define extreme responders and nonresponders, the single relevant difference between both subsets was baseline ambulatory BP. Conclusion: This study suggests a major overestimation of BP response after RDN in extreme responders defined according to office, but not ambulatory BP. The association of lower eGFR with poor response to RDN is consistent with our previous analysis. The increased proportion of women in extreme responders may reflect sex differences in drug adherence.

Renal Denervation for Treatment of Hypertension: a Second Start and New Challenges.

Following the publication of the randomized controlled but open-label trial Symplicity HTN-2, catheter-based renal sympathetic denervation was proposed as a novel treatment for drug-resistant hypertension. Thousands of procedures were routinely performed in Europe, Australia and Asia, and many observational studies were published. A sudden shift from overoptimistic views to radical scepticism occurred later, when the large US randomized sham-controlled trial Symplicity HTN-3 failed to meet its primary blood pressure lowering efficacy endpoint. Experts are divided on the reasons accounting for the large discrepancy between the results of initial studies and those of Symplicity HTN-3. Indeed, the blood pressure lowering effect associated with renal denervation was overestimated in initial trials due to various patient and physician-related biases, whereas it could have been underestimated in Symplicity HTN-3, which was well designed but not rigorously executed. Still, there is a large consensus on the need to further study catheter-based renal denervation in more controlled conditions, with particular emphasis on identification of predictors of blood pressure response. US and European experts have recently issued very similar recommendations on design of upcoming trials, procedural aspects, drug treatment, patient population and inclusion–exclusion criteria. Application of these new standards may represent a second chance for renal denervation to demonstrate—or not—its efficacy and safety in various patient populations. With its highly standardized treatment regimen, the French trial DENERHTN paved the way for this new approach and may inspire upcoming studies testing novel renal denervation systems in different populations.

Persistent Increase in Blood Pressure After Renal Nerve Stimulation in Accessory Renal Arteries After Sympathetic Renal Denervation

Blood pressure response to renal denervation is highly variable, and the proportion of responders is disappointing. This may be partly because of accessory renal arteries too small for denervation, causing incomplete ablation. Renal nerve stimulation before and after renal denervation is a promising approach to assess completeness of renal denervation and may predict blood pressure response to renal denervation. The objective of the current study was to assess renal nerve stimulation–induced blood pressure increase before and after renal sympathetic denervation in main and accessory renal arteries of anaesthetized patients with drug-resistant hypertension. The study included 21 patients. Nine patients had at least 1 accessory renal artery in which renal denervation was not feasible. Renal nerve stimulation was performed in the main arteries of all patients and in accessory renal arteries of 6 of 9 patients with accessory arteries, both before and after renal sympathetic denervation. Renal nerve stimulation before renal denervation elicited a substantial increase in systolic blood pressure, both in main (25.6±2.9 mm Hg; P<0.001) and accessory (24.3±7.4 mm Hg; P=0.047) renal arteries. After renal denervation, renal nerve stimulation–induced systolic blood pressure increase was blunted in the main renal arteries (&Dgr; systolic blood pressure, 8.6±3.7 mm Hg; P=0.020), but not in the nondenervated renal accessory renal arteries (&Dgr; systolic blood pressure, 27.1±7.6 mm Hg; P=0.917). This residual source of renal sympathetic tone may result in persistent hypertension after ablation and partly account for the large response variability.

Sham or no sham control: that is the question in trials of renal denervation for resistant hypertension. A systematic meta-analysis

Abstract Background: Studies of renal denervation (RDN) in patients with apparent treatment resistant hypertension have been hampered by a number of patient and physician related confounders on blood pressure (BP) including poor drug adherence. It remains uncertain whether RDN lowers BP. We aimed to investigate whether the use of sham control is essential in RDN studies or whether systematic use of 24-hour ambulatory BP provides enough information thereby making an invasive sham control redundant. Methods: We meta-analyzed randomized controlled trials of the BP response to RDN on top of continued or optimized antihypertensive drugs in patients with resistant hypertension. On top of the randomized trials reviewed earlier, we additionally included three studies, one conducted in Spain (24 patients, RDN vs. spironolactone), one conducted in Denmark (69 patients, sham controlled) and one conducted in Netherlands (139 patients, RDN vs. continued treatment). We analyzed 24-hour ambulatory BP in 3 sham controlled studies vs. 7 no sham controlled studies. Results: The updated meta-analysis of 10 studies showed 3.6u2009mmHg (pu2009=u2009.45) and 1.0u2009mmHg (pu2009=u2009.54) reductions in office and in 24-hour systolic BP, respectively. Meta-analysis of 24-hour systolic BP in the 3 sham-controlled studies showed a reduction of 2.18u2009mmHg (95% confidence intervals (CIs) −4.70 to 0.33u2009mmHg, nu2009=u2009396 vs. 230, pu2009=u2009.07). For the 7 no sham controlled studies there was no difference in 24-hour systolic BP (+0.38u2009mmHg; 95% CIs −5.29 to 6.04u2009mmHg, nu2009=u2009215 vs. 245, pu2009=u2009.90). The test for sub-group heterogeneity showed no significant interaction (pu2009=u2009.69). Removing one trial at a time produced confirmatory results. Conclusion: The overall meta-analysis of 10 randomized and controlled studies showed no significant effect on BP of RDN in resistant hypertension. Moreover, our analysis does not support the use of sham control but rather suggests extensive use of 24-hour ambulatory BP in studies of RDN in resistant hypertension