Case Study 1

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Introduction

The SymplicityTM renal denervation system is specifically designed to deliver low-level radio frequency (RF) energy through the wall of the renal artery to achieve renal denervation (RDN). In this case study, renal denervation is used to achieve marked blood pressure (BP) reductions in a patient with treatment-resistant hypertension. In addition, microneurography was used to measure muscle sympathetic nerve activity (MNSA).

Case Study 1

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Background

A 59-year-old male with essential hypertension resistant to treatment with 7 different antihypertensive medications was evaluated for treatment with catheter-based RDN. At baseline, the patient’s in-office mean BP was 161/107 mm Hg, with a heart rate of 76 beats/min. Baseline kidney function was normal, with a creatinine level of 57 µmol/L, and estimated glomerlular filtration rate (eGFR) >60 ml/min/1.73m2.

Case Study 1

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Technique

Using a standard interventional catheter technique, the catheter was advanced into the vasculature adjacent to the target neural site. Once the intended location was achieved, RF energy was delivered through the catheter to the target nerves (Figure 1). Treating distal to proximal with ≥5 mm between locations with circumferential coverage, 5 treatments in stable, unique locations were delivered to each renal artery.

Figure 1. The Location of the Renal Nerves and Target Sites for the RDN Procedure

rdn case-study fig 1

Case Study 1

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Results

Within 1 month, the patient’s BP had decreased from 161/107 at baseline to 141/90 mm Hg (Figure 2). The BP reduction was maintained through 12 months, reaching 127/81 mm Hg. The BP reduction resulted in the discontinuation of 2 antihypertensive medications.

Figure 2. Blood Pressure (Systolic BP/Diastolic BP) Measurements Over Time

Renal denervation hypertension case study patient

Microneurography can be used to measure excess central sympathetic nerve activity by recording postganglionic nerve traffic in subcutaneous sympathetic nerves in the skin and skeletal muscle vasculature. In this patient, microneurography was used to record muscle sympathetic-nerve activity (MSNA) in the peroneal nerve. At baseline, the level of MSNA was 56 bursts/min. At 1 month follow-up, MSNA was reduced to 41 bursts/min; at 12-month follow-up, MSNA was reduced to normal levels of 19 bursts/min (Figure 3). The gradual reduction in MSNA after bilateral RDN points to the possibility that inhibition of afferent renal nerve activity may contribute to decreased central sympathetic drive.

In addition, kidney function was unaffected following the procedure. At 12 months post-procedure, the patient’s creatinine level and eGFR were normal, at 67 μmol/L and >60 ml/min/1.73m2, respectively.

Figure 3. Microneurography Before and After Renal Denervation

Renal denervation hypertension case study patient

Case Study 1

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Conclusion

  • The 33-minute, one-time, catheter-based procedure resulted in a substantial and persistent reduction in BP of 34/26 mm Hg at 12 months in a patient resistant to multiple antihypertensive drug classes
  • The patient’s BP, which was previously uncontrolled on 7 antihypertensive medications, reached target level within 1 month following the RDN procedure, which was maintained through 12-month follow-up. The patient was able to reduce his treatment burden by discontinuing 2 of his 7 medications
  • In addition to the marked reduction in BP, the RDN procedure gradually reduced muscle sympathetic-nerve activity, with normal sympathetic-nerve firing rates (19 bursts/min) at 1-year follow-up
  • Kidney function, as measured by creatinine level and eGFR, remained normal at 1-year follow-up
  • Results in this patient have been durable to at least 12 months

Portions of this case were published previously in Schlaich MP, Sobotka PA, Krum H, Lambert E, Esler MD. N Engl J Med. 2009;361:932-934.

This patient case was provided courtesy of Markus P. Schlaich, MD, Baker IDI Heart and Diabetes Institute, Melbourne, VIC, Australia.

Case Study 2

Case Study 2 - Patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Introduction

The SymplicityTM renal denervation system is specifically designed to deliver low-level radio frequency (RF) energy through the wall of the renal artery to achieve renal denervation. This case study demonstrates its use to achieve dramatic blood pressure (BP) reductions in a patient with treatment-resistant hypertension who has already shown intolerance to certain medications.

Case Study 2

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Background

A 47-year-old female with a history of hypercholesterolemia and hypertension resistant to multiple medications was evaluated for treatment with catheter-based RDN by her treating physician, a cardiologist with expertise in the management of hypertension. At baseline, the patient’s in-office BP was 169/100 mm Hg despite compliance with the maximum tolerated doses of antihypertensive drugs from 4 different classes:

  • β-blocker (metoprolol 50 mg once daily)
  • Angiotensin-converting-enzyme (ACE) inhibitor (ramipril 10 mg once daily)
  • Calcium channel blocker (nitrendipine 10 mg once daily)
  • Diuretic (indapamide)

Prior treatment with the centrally acting agent, clonidine, was unsuccessful due to intolerance. Additionally, previous aldosterone blockade with spironolactone was associated with persistent hyperkalemia, precluding the use of this agent. A work-up for identifiable causes of hypertension was negative and white-coat hypertension was ruled out with ambulatory BP monitoring. Contributing lifestyle factors were mitigated to the extent possible over the 6-months prior with a low-salt diet, increased physical activity, and moderation of alcohol intake. After a baseline renal arteriogram revealed no renal artery stenosis or other major abnormalities, the patient underwent catheter-based RDN with the SymplicityTM renal denervation system.

Case Study 2

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Technique

The catheter was placed in the vasculature adjacent to the target neural site using standard interventional catheter techniques. RF energy was then delivered through the catheter to the target nerves. Four treatments in stable, unique locations were delivered to each renal artery, distal to proximal, requiring approximately 2 minutes each. Cines immediately prior to each treatment were taken to identify the location of the catheter, show the previous treatment location, and assist with positioning for the next treatment (Figure 1).

Pain management was obtained with morphine. The total time from first RF application to last RF application was 30 minutes. There were no complications associated with the procedure.

Figure 1.  Renal Arteriograms Showing the Platinum Electrode at the Distal Tip of the SymplicityTM Catheter in Contact with the Renal Artery Wall

rdn case-study2 fig 1

Case Study 2

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Results

Within 1 month of the procedure, the patient’s BP had successfully dropped below target, decreasing to 136/83 mm Hg. Additionally, 2 weeks post-procedur, the calcium channel blocker and diuretic were discontinued (Figure 2). BP reduction was maintained through 12 months.

Figure 2. Blood Pressure (SBP/DBP) Measurements Over Time

Renal denervation hypertension case study patient

Case Study 2

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Conclusion

  • This patient was ideally suited for RDN, having been evaluated and optimally managed by a hypertension expert prior to referral to a trained interventionist
  • This 30-minute, one-time, catheter-based procedure led to a dramatic reduction in BP of 26/18 mm Hg through 12 months
  • Previously uncontrolled on 4 antihypertensive medications, her BP was successfully controlled to target following the procedure. Although the primary goal of RDN is to reduce cardiovascular (CV) risk by helping patients achieve their BP goals, this patient was able to discontinue 2 of her 4 medications, thus reducing her treatment burden
  • Results in this patient have been durable to at least 12 months

This patient case was provided courtesy of Jacek Godlewski, MD, The John Paul II Hospital, Jagiellonian University, Krakow, Poland.

Case Study 3

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Introduction

The SymplicityTM renal denervation system is specifically designed to deliver low-level radio frequency (RF) energy through the wall of the renal artery to achieve renal denervation. This case study demonstrates its use to achieve dramatic blood pressure (BP) reductions in a patient with treatment-resistant hypertension.

Case Study 3

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Background

A 51-year-old male, with treatment-resistant primary hypertension, was evaluated for treatment with catheter-based renal denervation. The patient was fit, with a body mass index of 25, but had a family history of cardiovascular and cerebrovascular disease, and mild dyslipidemia (on treatment with simvastatin 20 mg once daily and ezetimibe 10 mg once daily). He was a former heavy smoker, with a habit of 20 to 40 cigarettes a day until 4 years prior to the procedure. He led an active lifestyle, doing gymnastics and weight lifting 3 times a week. At baseline, the patient’s in-office mean blood pressure was 180/100 mm Hg, despite treatment with antihypertensive drugs from 3 different classes:

  • Angiotensin-converting-enzyme ACE inhibitor (ramipril 5 mg twice daily)
  • α-blocker (doxazosin 2 mg twice daily)
  • Diuretic (hydrochlorothiazide 25 mg once daily)

He had previously been treated with β-blockers and calcium channel blockers, but these were discontinued due to side effects.

The patient underwent an extensive diagnostic workup. Echocardiography found left ventricle hypertrophy and mild dilatation with normal ejection fraction, mild diastolic dysfunction, mild dilatation of the left atrium, and no significant valvular disease. Doppler ultrasound of supra-aortic trunks showed only mild thickening of the medio-intimal complex. Repeated exercise stress tests showed no signs of stress-induced myocardial ischemia but a hypertensive response to exercise of up to 260 mm Hg systolic blood pressure (SBP). Cerebral magnetic resonance imaging (MRI) with angio sequences for intracranial vessels showed some minor ischemic lacunae in the white substance of both hemispheres and a normal intracranial vessel anatomy. Blood and urine testing showed no signs of ongoing nephropathy. Fundus oculi examination was negative for signs of hypertensive retinopathy.

Secondary hypertension was ruled out by means of Doppler ultrasound of the renal arteries and laboratory testing for catecholamine blood and urine levels. Home BP self-measurement confirmed the hypertensive values and ruled out white-coat hypertension.

After a baseline renal arteriogram revealed no renal artery stenosis or other major abnormalities (Figure 1), the patient underwent catheter-based renal denervation with the SymplicityTM renal denervation system.

Figure 1: Renal Arteriogram Showing Appropriate Anatomy for the Renal Denervation Procedure

Renal denervation hypertension case study patient

Case Study 3

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Technique

The patient was prepared for the renal denervation procedure with intravenous saline and N-acetylcysteine infusion starting 12 hours before the procedure. The patient was sedated with propofol (4 mg/kg/h) and pain management was obtained with remifentanil (0.1 mcg/kg/min).

The catheter was placed in the vasculature adjacent to the target neural site using standard interventional catheter techniques. RF energy was then delivered through the catheter to the target nerves. A series of 4 treatments, lasting approximately 2 minutes each, was delivered to each renal artery in a spiral pattern.

Following the treatment, an angiographic control showed no signs of renal artery dissection or leak of contrast medium. The formation of denervation notches, a marker of effective contact between the tip of the catheter and the artery wall, was observed (Figure 2).

The time for patient preparation, application of RF energy, and post-cardiac care was 85 minutes. There were no procedural complications associated with the procedure.

Figure 2: Renal Arteriogram Showing Denervation Notches Following Procedure, Suggestive of Good Contact Between the Tip of the Catheter and the Artery Wall

Renal denervation hypertension case study patient

Case Study 3

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Results

The patient had a significant pressure reduction while sedated, which is consistent with a major role of adrenergic drive in the hypertensive mechanism. This also explains why the procedure had an almost immediate positive effect, allowing for dosage reduction of doxazosin (2 mg once daily) at the time of discharge. Within one month, the patient’s BP was reduced to 142/78 mm Hg. The benefit was maintained at 6 months, with an office BP value of 145/85 mm Hg (Figure 3).

Figure 3: Blood Pressure (SBP/DBP) Measurements Over Time

Renal denervation hypertension case study patient

Case Study 3

Renal denervation hypertension case study patient

This photograph is not representative of the real patient. It is for illustrative purposes only.

Conclusion

  • The patient was a good candidate for renal denervation due to his young age, high BP values despite ongoing treatment with multiple drugs, no apparent causes for secondary hypertension, and no significant comorbidities
  • This one-time, catheter-based procedure resulted in a substantial and persistent reduction in BP in this patient
  • The patient’s BP, previously uncontrolled on 3 antihypertensive medications, with intolerance to 2 other drug classes, was substantially reduced following the procedure. Although the primary goal of renal denervation is to reduce cardiovascular (CV) risk by helping patients achieve their BP goals, this patient was also able to reduce his dosage of antihypertensive medications
  • Results in this patient have been durable to at least 6 months

This patient case was provided courtesy of Marco Panfili, MD and Filippo Marzot, MD, University of Padua, Padua, Italy.

Next: Resource Center

Trademarks may be registered and are the property of their respective owners.