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Posts Tagged ‘SYMPLICITY’


Reporter: Aviva Lev-Ari, PhD, RN

UPDATED on 5/29, 2013

Renal Denervation Safe in Real-World Setting

By Todd Neale, Senior Staff Writer, MedPage Today

Published: May 25, 2013

Reviewed by F. Perry Wilson, MD, MSCE; Instructor of Medicine, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

Action Points:

PARIS — May 21-24, 2013

Out in everyday practice, renal denervation with the Symplicity device safely lowers blood pressure in patients with hypertension, preliminary results from the Global SYMPLICITY registry showed.

The Global SYMPLICITY registry is part of the clinical program evaluating the Symplicity device. It has been approved for use in Europe and elsewhere but remains restricted to investigational use in the U.S. Medtronic, which makes the Symplicity device, announced on Thursday that it has completed enrollment in Symplicity HTN-3, the pivotal U.S. trial.

The registry has a targeted enrollment of about 5,000 patients from about 200 centers worldwide; 149 sites spread throughout Canada, Mexico, South America, Europe, Africa, the Middle East, Asia, and Australia have already started collecting data.

Any patient who receives renal denervation can be included in the registry, and thus the study will include patients with hypertension and other conditions associated with increased sympathetic activity, including heart failure, insulin resistance, atrial fibrillation, sleep apnea, and chronic kidney disease.

European Society of Cardiology‘s recently published consensus paper on renal denervation, which recommended treatment in patients with a systolic blood pressure of 160 mm Hg or higher (or at least 150 mm Hg for type 2 diabetics) who were taking at least three antihypertensive medications, including a diuretic.

SOURCE:

Expert consensus document from the European Society of Cardiology on catheter-based renal denervation

http://eurheartj.oxfordjournals.org/content/early/2013/04/25/eurheartj.eht154.extract

Most of the first 617 patients included the registry (60%) were treated in accordance with the European Society of Cardiology’s recently published consensus paper on renal denervation, above.

About one-fifth of the patients (22%) started with a systolic blood pressure of at least 180 mm Hg, which was the average baseline blood pressure in the Symplicity HTN-1 and HTN-2 trials.

The average starting blood pressure overall was 164/89 mm Hg, and patients were taking an average of 4.35 medications. Common comorbidities included diabetes (38.2%), renal disease (30.1%), sleep apnea (16.3%), a history of cardiac disease (49%), heart failure (9.3%), and atrial fibrillation (11.9%).

The registry data showed significant drops in blood pressure measured both in the office and with 24-hour ambulatory monitoring, although the reductions were smaller than those seen in the clinical trials.

That’s not surprising, according to Mahfoud, because out in everyday practice blood pressure is not recorded as appropriately as in a clinical trial setting and poor compliance to medication becomes more of an issue. In fact, he said, a recent study showed that 47% of patients with resistant hypertension were not adherent to their medication regimens.

Also contributing to the smaller reductions in the real-world population is the fact that the average starting blood pressure was lower than in the clinical trials, Mahfoud said, adding that it is known that renal denervation induces greater reductions in blood pressure among those with the highest readings initially.

Mahfoud reported receiving institutional grant/research support from Medtronic, St. Jude, Recor, and serving as a consultant for St. Jude, Medtronic, Boston Scientific, and Cordis. Medtronic makes the Symplicity renal denervation device.

 Primary source: European Association of Percutaneous Cardiovascular Interventions

SOURCE REFERENCE:

Mahfoud F, et al “Early results following renal denervation for treatment of hypertension in a real-world population: the Global SYMPLICITY registry” EuroPCR 2013.

Adverse Events:
Of the first 617 patients included in the registry, only two had vascular complications related to access during the procedure, and none had serious events stemming from delivery of the radiofrequency energy to the renal artery; the rate of vasospasm was 9%, according to Felix Mahfoud, MD, of Saarland University Medical Center in Homburg/Saar, Germany.Through 6 months of follow-up, there were two hospitalizations for hypertensive crisis, two myocardial infarctions, one new case of end-stage renal disease from nephrotoxic overdose, and one death that was not considered to be related to the procedure, he reported at the EuroPCR meeting here.The procedure was not only safe, but also effective at lowering blood pressure, with reductions in office-based readings ranging from 13/6 mm Hg among patients with a baseline systolic blood pressure of 140 mm Hg or higher to 28/18 mm Hg among those with a baseline systolic pressure of 180 mm Hg or higher at 3 months. The findings were similar at 6 months.

“The take-home message will be hopefully … that renal denervation is a safe procedure providing blood pressure lowering in patients with high blood pressure at baseline and that that procedure might have an impact on clinical outcomes,” Mahfoud said in an interview.

Positive Effects of Renal Denervation Ablation for Hypertension in Controlled Randomized SYMPLICITY HTN-2 Trial

Renal Nerve Ablation Effects on BP Lasting

Download Complimentary Source PDF 

By Chris Kaiser, Cardiology Editor, MedPage Today

Published: January 08, 2013
Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

Late-term results from a study of the safety and effectiveness of renal denervation to reduce hypertension mirrored positive results seen earlier in the randomized SYMPLICITY HTN-2 trial, researchers found.

The mean reduction in systolic blood pressure at 1 year post procedure was a significant 28.1 mmHg (P<0.001), similar to the mean 31.7 mmHg drop at 6 months (P=0.16 for the comparison), according to Murray Esler, MD, of the Baker IDI Heart and Diabetes Institute in Melbourne, Australia, and colleagues.

Those in the control group who crossed over to the intervention at 6 months also had a significant fall in systolic blood pressure from a mean 190 to 166 mmHg (P<0.001), researchers reported in the January issue of Circulation: Journal of the American Heart Association.

The increasing prevalence of hypertension is a worldwide phenomenon, with an estimated 1.56 billion predicted to be affected in 2025, the authors noted. Yet, many of these patients cannot control their blood pressure (with control being defined as a pressure <140/90 mmHg) even when taking three or more antihypertensive medications.

Esler and colleagues cited a 2005 study that found a range of 47% to 87% of people in North America and Europe whose blood pressure is not under control (Lancet 2005; 365: 217-223).

Renal denervation has shown promise in these patients who are refractory to medication. The percutaneous procedure uses energy such as radiofrequency waves to scar the renal artery in an attempt to disrupt the sympathetic nerves, thereby affecting blood pressure.

Three-year data from the nonrandomized SYMPLICITY HTN-1 study were in line with 2- and 1-year results, showing a mean drop of 33/19 mmHg associated with the intervention.

In the current study, researchers from the multi-center randomized controlled SYMPLICITY HTN-2 trial enrolled 106 patients with essential hypertension (systolic blood pressure ≥160 mmHg, or ≥150 mmHg for diabetics). Patients were taking at least three antihypertensive medications.

The initial 1-year data from the SYMPLICITY HTN-2 trial were reported at the 2012 American College of Cardiology meeting. The primary endpoint was a change in systolic blood pressure at 6 months. Also at the 6-month mark, patients in the control group were allowed to cross over and receive the treatment; they were then followed for 6 more months.

The 6-month data were based on 101 patients (49 in the treatment group versus 51 controls). The 1-year data were based on 47 patients in the primary treatment group and 35 per-protocol controls who crossed over. The crossover patients also had to have a systolic blood pressure of ≥160 mmHg.

The significant decrease of 28.1 mmHg in systolic blood pressure in the treatment arm at 1 year was matched by significant drops in diastolic blood pressure at 6 and 12 months, as well as in the crossover group at 6 months (P<0.001 for all).

The authors reported that 84% of initial denervation patients had a decrease of at least 10 mmHg at 6 months; at 1 year, the number was 79%. In the crossover group, that rate was 63% at 6 months.

Interestingly, there was no significant difference in the changes in medication — reduced dosage or fewer drugs — between the treatment arm and controls, despite the reduction in blood pressure for the treatment arm.

“These data further substantiate the safety of renal sympathetic denervation via delivery of controlled radiofrequency energy bursts,” Esler and colleagues concluded.

They also noted that renal function remained unchanged at both 6 and 12 months. A pilot study by the Melbourne group looking specifically at patients with chronic kidney disease found renal denervation to be safe in this population.

The limitations to the current study include the lack of 24-hour blood pressure monitoring and the lack of blinding among the staff measuring blood pressure. The investigators noted that the ongoing SYMPLICITY HTN-3 trial addresses these limitations.

This study was funded by Medtronic Ardian.

Esler and three co-authors reported receiving research support from Medtronic Ardian. During the conduct of the trial, senior author Sobotka was chief medical officer of Ardian, and was a medical adviser to Medtronic.

From the American Heart Association:

 SOURCE:

Other articles on this topic on this Open Access Online Scientific Journal:

Lev-Ari, A. (2012aa). Renal Sympathetic Denervation: Updates on the State of Medicine

https://pharmaceuticalintelligence.com/2012/12/31/renal-sympathetic-denervation-updates-on-the-state-of-medicine/

 

Lev-Ari, A. (2012U). Imbalance of Autonomic Tone: The Promise of Intravascular Stimulation of Autonomics

https://pharmaceuticalintelligence.com/2012/09/02/imbalance-of-autonomic-tone-the-promise-of-intravascular-stimulation-of-autonomics/

Lev-Ari, A. (2012C). Treatment of Refractory Hypertension via Percutaneous Renal Denervation

https://pharmaceuticalintelligence.com/2012/06/13/treatment-of-refractory-hypertension-via-percutaneous-renal-denervation/

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Curator: Aviva Lev-Ari, PhD, RN

Intravascular Stimulation/Ablation of Autonomics are procedures, aka Renal Arterial Denervation, that since 1999 has greater promise for treatment of a diseases assumed to be related to an imbalance of autonomic tone.  Dr. Scherlag prefers the name “cardiac sympathetic denervation”.  As he has outlined, the ablation of autonomics in the renal artery has more of an effect on the heart than it does on the kidneys. I do agree that the procedure has  a cardiac effect obtained by autonomic modulation in essence.

https://pharmaceuticalintelligence.com/2012/09/02/intravascular-stimulation-of-autonomics-a-letter-from-dr-michael-scherlag/

Pioneering work in this field, the first to stimulate/ablate autonomic nerves effecting the heart from the intravascular space was accomplished by Dr. Scherlag and others. The greatest accomplishment was “Method and apparatus for  transvascular treatment of tachycardia and fibrillation. US Patent 6,292,695. Filed June 17, 1999.

Dr. Scherlag writes, [T]he possibility that parasympathetic or sympathetic nerves running on blood vessels  could be stimulated or ablated from inside the vasculature was initially demonstrated using basket electrode catheters in a series of experimental studies (1-6) and formally patented in 1999 (7).

Treatment of Hypertension by renal arterial denervation from inside the vasculature using a basket electrode catheters by ultra sound or by RF energy is fully documented in my post Treatment of Refractory Hypertension via Percutaneous Renal Denervation

https://pharmaceuticalintelligence.com/2012/06/13/treatment-of-refractory-hypertension-via-percutaneous-renal-denervation/

Clinical Trials and the Ecosystem of all leading manufacturers of Medical Devices for Renal Arterial Denervation, including videos for demonstration of the procedure are presented in my post, link above.

Benefits and New Indications for Usage of Intravascular Stimulation/Ablation of Autonomics

1. Reduction in Heart Rate and Heart Rate Variability

Dr. Scherlag experiments noted changes in heart rate which have also been reported in SYMPLICITY HTN-1 and SYMPLICITY HTN-2 (8-9).  The SYMPLICITY HTN-2 study demonstrated profound bradycardia in 13% of patients that was treated with atropine.

The intra-procedure effect on heart rate during renal artery denervation documented in the  SYMPLICITY trials is also manifest long term by measuring heart rate variability (10). Indeed, cardiac effects would be expected with autonomic modulation.  Besides the two example above showing that cardiac sympathetic denervation effects heart rate, there are many more that are just beginning to be reported in the literature.

These articles shows the effects of renal denervation on heart rate.

http://www.ncbi.nlm.nih.gov/pubmed/1735574
http://www.ncbi.nlm.nih.gov/pubmed/8777835

A Cleveland Clinic review article states: “Additionally, the resting heart rate was lower and heart rate recovery after exercise improved after the procedure, particularly in patients without diabetes.”
http://www.ccjm.org/content/79/7/501.full

2. Renal Sympathetic Denervation lowers Atrial Fibrillation

This article discusses the effect of renal sympathetic denervation on atrial fibrillation.

http://www.ncbi.nlm.nih.gov/pubmed/22585944

3. Regression of Left Ventricular Hypertrophy, Increase in Ejection Fraction (EF) and improved Diastolic Dysfunction

“Brandt reported regression of left ventricular hypertrophy and significantly improved cardiac functional parameters, including increase in ejection fraction and improved diastolic dysfunction, in a study of 46 patients who underwent renal denervation. This findings suggests a potential beneficial effect on cardiac remodeling.” (Brandt MC, Mahfoud F, Reda S, et al. Renal sympathetic denervation reduces left ventricular hypertrophy and improves cardiac function in patients with resistant hypertension. J Am Coll Cardiol 2012; 59:901–909)

4. Reduction in Ventricular Tachyarrhythmias (VT)

“Ukena reported reduction in ventricular tachyarrhythmias in two patients with congestive heart failure who had therapy-resistant electrical storm.” (Ukena C, Bauer A, Mahfoud F, et al. Renal sympathetic denervation for treatment of electrical storm: first-inman experience. Clin Res Cardiol 2012; 101:63–67)

5. Intravascular Stimulation of Autonomics Effects on Heart Failure

The most recent data from Europe shows the following effects on heart failure:

http://www.eurekalert.org/pub_releases/2012-08/esoc-rdg082712.php
http://www.theheart.org/article/1364267.do

Dr. Scherlag, writes, [N]early ten examples of the effects of “CARDIAC SYMPATHETIC DENERVATION” and what are the effects on the kidney?

No change in GFR.  No change in creatinine.

Medical Debate on the Procedure – The candidates are hypertensive patients receiving blood-pressure-lowering medication that are truly “resistant.”

The Symplicity system (Medtronic) is the far-and-away front runner, having demonstrated average office-based BP drops of 32/12 mm Hg at six months in the SYMPLICITY HTN 2 trial, as reported by heartwire, with 84% of patients having had a >10-mm-Hg drop in systolic blood pressure from baseline.

Upwards of 20 other companies, according to Dr Ron Waksman (Washington Hospital, DC), are busy developing competing systems, some of which were featured in a EuroPCR session devoted to emerging technologies in May 2012 in Paris.

Leading this pack is St Jude’s EnligHTN system, which received CE Mark on the opening day of the meeting. Dr Stephen Worthley (Royal Adelaide Hospital, Australia) presented 30-day results in 47 resistant-hypertension patients treated with the multielectrode, RF-ablation-based system. Mean office BP changes at one month in EnligHTN 1 were -28 systolic and -10 diastolic (p<0.0001 from baseline), with 78% of patients having systolic BP drops of >10 mm Hg.

https://www.massdevice.com/news/europcr-st-judes-enlightn-lowers-blood-pressure-faster-rival-systems

In terms of safety, no serious complications were seen in the renal artery or at the access site in the EnligHTN study; minor procedure-related events included four hematomas, three vasovagal responses to sheath removal, and two postprocedure transient bradycardias.

Other devices featured in the session included a second RF-energy system and two ultrasound systems, see below technology description by supplier.

The risk of cardiovascular death doubles with every 20 point increase in systolic blood pressure, so an average blood pressure reduction of 28 points is quite significant and demonstrates just how effective the technology is. Principal investigator Prof. Stephen Worthley said in prepared remarks. “From other clinical trials studying the impact of renal denervation we have learned that blood pressure continues to be reduced over time, so I would not be surprised to see this trend continue and see an even greater benefit for patients.” St. Jude’s study included 47 patients with high blood pressure that wasn’t managed with drug therapy. Participants had an average of 176/96 mmHg baseline blood pressure, despite taking multiple medications, before the denervation procedure and an average of 148/87 mmHg after. More than 40% had systolic rates below 140 mmHg.

http://investors.sjm.com/phoenix.zhtml?c=73836&p=irol-newsArticle&ID=1695802

Interventionalists who spoke with heartwire were unvaryingly excited about the potential of renal denervation, with some caveats.

“You need enthusiasm to develop new things, and in hypertension we haven’t seen an innovation in decades,” Dr Thomas Lüscher (University Hospital Zürich, Switzerland) told heartwire. “So just the possibility that you would be able to have a persistent treatment effect by a procedure that helps severe hypertension patients and maybe in the future even the option to cure hypertension is very exciting indeed. But I agree it’s a dream at this point. I think we need the SYMPLICITY HTN 3 trial, which hopefully will confirm what the other studies have shown.”

Now enrolling at as many as 90 US centers, SYMPLICITY HTN 3, Lüscher pointed out, has design characteristics addressing two concerns with the earlier trials, namely a sham procedure for the control group and ambulatory blood-pressure monitoring in all patients.

During the same emerging-technologies session, Lüscher explored the albeit-scant data supporting a role for renal denervation in other conditions: everything from metabolic syndrome and obstructive sleep apnea to heart failure, atrial fibrillation, and polycystic-ovary syndrome.

But his counterpoint, Dr Jean Renkin (UCL St Luc University Hospital, Brussels, Belgium), was skeptical, pointing to the myriad unanswered questions with the technology.

“Currently, reasonably solid data are available only for patients with hypertension resistant to pharmacotherapy, which cannot necessarily be extrapolated to other forms of hypertension or conditions referred to [by Dr Lüscher]. However, at this point in time, no clouds have appeared in the sky, so let us dream on.”

Dr Renkin had one staggering number for the audience to consider: of 5000 patients who have undergone renal denervation, only 250 were actually treated as part of clinical studies. While no device has US approval, five denervation systems already hold CE Mark in Europe and are being used with increasing frequency.

Treating the Truly Medication Treatment “Resistant”

For a comprehensive presentation of Triple Antihypertensive Combination Therapy Significantly Lowers Blood Pressure in Hard-to-Treat Patients with Hypertension and Diabetes, refer to

https://pharmaceuticalintelligence.com/2012/05/29/445/

Another talking point is the proportion of patients who are truly “resistant.” The number agreed on by Lüscher, Waksman, and session comoderator Dr Robert Whitbourn (St Vincent’s Hospital, Fitzroy, Australia) was that just 3% of all hypertensive patients receiving blood-pressure-lowering medication are truly “resistant.” Numbers as high as 30% have been suggested in other reports, he noted.

“Interestingly, when we’ve been involved in various trials, every cardiologist says they have hundreds of these patients, but when we actually go to get them, no one actually has any,” Whitbourn quipped. “I think it should be a sobering thought—the numbers are actually quite small.”

Dr William Wijns (Cardiovascular Center Aalst, Belgium), also speaking with heartwire, agreed that the subset was “small” but argued it was “still big numbers, millions of people,” and “a massive unmet need.”

Waksman, insisting he was “excited” by what he called “robust reductions in blood pressure,” nevertheless urged eager interventionalists to work with hypertension experts and resist the urge “to jump on patients before we truly verify that they are resistant to medical treatment.”

In the vast majority of people even for whom renal denervation is appropriate, it “won’t be a cure,” Waksman said. “Most of these patients will have to continue on medical treatment—this is not replacing medical treatment, it is just getting [patients] more in control.”

http://www.theheart.org/article/1402321/print.do

REFERENCES

1. Schauerte P, Scherlag BJ, Scherlag MA, Goli S, Jackman WM, Lazzara R. Transvenous parasympathetic cardiac nerve stimulation: an approach for stable sinus rate control. J Electrophysiol. 1999 Nov;10(11):1517-24.

2. Schauerte P, Scherlag BJ, Scherlag MA, Goli S, Jackman WM, Lazzara R. Ventricular rate control during atrial fibrillation by cardiac parasympathetic nerve stimulation: a transvenous approach. J Am Coll Cardiol. 1999 Dec;34(7):2043-50.

3. Schauerte P, Scherlag BJ, Pitha J, Scherlag MA, Reynolds D, Lazzara R, Jackman WM. Catheter ablation of cardiac autonomic nerves for prevention of vagal atrial fibrillation. Circulation. 2000 Nov 28;102(22):2774-80.

4. Scherlag MA, Scherlag BJ, Yamanashi W, Schauerte P, Goli S, Jackman WM, Reynolds D, Lazzara R. Endovascular neural stimulation via a novel basket electrode catheter: comparison of electrode configurations. J Interv Card Electrophysiol. 2000 Apr;4(1):219-24.

5. Scherlag BJ, Yamanashi WS, Schauerte P, Scherlag M, Sun YX, Hou Y, Jackman WM, Lazzara R. Endovascular stimulation within the left pulmonary artery to induce slowing of heart rate and paroxysmal atrial fibrillation. Cardiovasc Res. 2002 May; 54(2):470-5.

6. Hasdemir C, Scherlag BJ, Yamanashi WS, Lazzara R, Jackman WM. Endovascular stimulation of autonomic neural elements in the superior vena cava using a flexible loop catheter. Jpn Heart J. 2003 May;44(3):417-27.

7. Webster W Jr, Scherlag BJ, Scherlag MA, Schauerte P. Method and apparatus for   transvascular treatment of tachycardia and fibrillation. US Patent 6,292,695. Filed June 17, 1999.

8. Krum H, Schlaich M, Whitbourn R, Sobotka PA, Sadowski J, Bartus K, Kapelak B, Walton A, Sievert H, Thambar S, Abraham WT, Esler M. Catheter-based renal sympathetic denervation for resistant hypertension: a multicentre safety and proof-of-principle cohort study. Lancet. 2009;373(9671):1275-1281.

9. Symplicity HTN-2 Investigators. Renal sympathetic denervation in patients with treatment-resistant hypertension (The Symplicity HTN-2 Trial): a randomised controlled trial. Lancet. 2010;376:1903-1909.

10. Frank Himmel MD, Joachim Weil MD, Michael Reppel MD, Kai Mortensen MD, Klaas Franzen, Leidinger Ansgar MD, Heribert Schunkert MD, Frank Bode MD.  Improved Heart Rate Dynamics in Patients Undergoing Percutaneous Renal Denervation. Letter to the Editor. JCH. 31 MAY 2012.1751-7176.

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