Effect of renal denervation on Muscle Sympathetic Nerve Activity in patients with uncontrolled hypertension

Chronic elevation of sympathetic nervous system (SNS) activity has been
identified by extensive preclinical and clinical literature as a common and key
factor in disease states such as hypertension, heart failure, and chronic
kidney disease. The renal sympathetic nerves are a major contributor to the
complex pathophysiology of elevated SNS activity and hypertension. Therapeutic
renal denervation, the deliberate disruption of the nerves connecting the
kidneys with the central nervous system, has been shown to be an effective
means of modulating elevated SNS activity - both by reducing the sympathetic
control of renal function and by removing the renal afferent sympathetic
contribution to central blood pressure elevation. St. Jude Medical has
developed the EnligHTN Renal Denervation System as a minimally-invasive means
of achieving renal denervation. This system is comprised of a single-use
catheter with expandable basket with four ablation electrodes and a
radiofrequency (RF) generator. In an international multi-center study called
EnligHTN II we will study the effect of renal denervation on systolic blood
pressure and safety of denervation during five year follow up (13-096).
Furthemore, the EnligHTN catheter is recently added as device in the Sympathy
study. This proposal is a sub-study of the EnligHTN II study and Sympathy
study. The goal of this sub-study (mono-center study) is to investigate the
effect of renal denervation with the EnligHTN Renal Denervation System on
sympathetic nerve activity.
We hypothesize that MSNA will be normalized after renal denervation in this
population.

The goal of this study (mono-center study) is to study the effect of renal
denervation with the EnligHTN Renal Denervation System on sympathetic nerve
activity.

This study is a sub-study of EnligHTN II study and Sympathy study. We
prospectively collect data on MSNA before and after renal denervation. All
patients included in EnligHTN II or Sympathy may be included in this study.
However, this sub-study is not obligatory for patients included in EnligHTN II
or Sympathy. Participants of EnligHTN II or Sympathy may refuse to participate
in this sub-study. The participants will be recruited from our outpatient
clinics.

First the patient is asked to participate in the EnligHTN II or Sympathy study.
Prior to enrollment in this study, his/her eligibility to participate in the
study will be checked. A complete medical history will be reviewed, physical
examination will be performed and office blood pressure measurements will be
recorded. If the patient meets all inclusion and exclusion criteria, he/she is
eligible for the study. Secondly, the patient can be asked to participate in
this sub-study. The patient will be asked to provide written informed consent
for the MSNA measurements, once he/she has been fully informed about the
investigation, has agreed to participate, signed and dated the patient informed
consent.

This sub-study contains 2 visits:

FIRST VISIT
The first MSNA measurement will be performed, prior to the renal denervation.
This visit will take about two hours. In order to maximize the value and
standardization of the measurements, the patient has to be on a stable
medication regime for at least three months.

SECOND VISIT
This visit will take place 6 months after the renal denervation procedure. The
participant visits the day-care centre. MSNA measurements will be repeated.

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