Clinical trial NCT03473275: Brain BOLD fMRI in Hypertensive and Normotensive Participants
Official title: Central Blood Pressure Regulation by the Brainstem and Influence by Renal Sympathetic Afference: a Functional Magnetic Resonance Imaging (MRI) Study in Hypertensive and Normotensive Participants
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Hypertension,Essential
Keywords: Sympathetic nervous system
Blood oxygen level dependent
Brainstem
Contrast enhanced ultrasound
Kidney function
Hypertension
Renal denervation
Lead sponsor: Centre Hospitalier Universitaire Vaudois
Sponsor class: OTHER
Collaborators: name: Ecole Polytechnique Fédérale de Lausanne
First posted: 2018-03-22
Enrollment: 84
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Healthy normotensive participants: university employees mainly Hypertensive patients: from the outpatient clinic of the Nephrology Service Resistant hypertensive patients (renal denervated and non-denervated): from the outpatient clinic of the Nephrology Service

Brief summary: This study will explore the brainstem activity in response to stress in hypertensive patients and normotensive subjects. In addition, it will evaluate if the response in hypertensive patients can be modulated by blocking the afferent signalling of sympathetic nervous system from the kidney to the brain achieved by renal denervation.

The investigators hypothesize that the change in BOLD signal intensity in response to stress is higher in hypertensive patients than in normotensive subjects and that in patients responsive to renal denervation the change in BOLD signal intensity in response to stress is decreased compared to non-responders or to non-denervated resistant hypertensive patients.

Detailed description: In hypertension, the overactivity of the sympathetic nervous system (SNS) has been found to be implicated in its initiation, maintenance and adverse consequences. The SNS is composed of an afferent and efferent arm, which brings sensory information to the brain (e.g. brainstem and hypothalamus) and transmits sympathetic outflow from the brain to the peripheral organs, respectively. Selective removal of the afferent renal component of the SNS can modulate central sympathetic outflow to the kidney, heart and vasculature in animals. The specific contribution of afferent nerve signalling in hypertension and in the potential antihypertensive effect of renal denervation has not been studied in humans.

Eligibility criteria: Inclusion Criteria:

* signed informed consent
* capable of discernment

Exclusion Criteria:

* having contra-indications for MRI (claustrophobia, cardiac pacemaker or other metallic or mechanical implant or device, etc.)
* pregnant women
* lower limb sensitive neuropathy
* Blood pressure \>180/110 mmHg during washout period (for hypertensive patients)
* Intolerance to Sonovue®(ultrasound contrast agent)
* Acute or chronic disease other than hypertension that influences renal function
* taking medication/drugs, except of calcium channel blockers for resistant hypertensive patients

Primary outcomes:
measure: Change in brain BOLD signal intensity
timeFrame: 1.5 hours
Secondary outcomes:
measure: Functional connectivity (resting state and effective connectivity)
timeFrame: 1.5 hours
measure: Structural connectivity
timeFrame: 30 minutes
measure: Correlation between brain BOLD fMRI and renal ultrasound
timeFrame: 2 hours
Other outcomes:
Locations:
city: Lausanne
country: Switzerland
facility: CHUV, nephrology service
state: Vaud
Study officials:
affiliation: Centre Hospitalier Universitaire Vaudois
name: Gregoire Wuerzner, MD
role: PRINCIPAL_INVESTIGATOR
References: