Brain BOLD fMRI in Hypertensive and Normotensive Participants (BRAIrdN)

Vaud University Hospital Center

Status: Completed

Conditions: Hypertension,Essential

Treatments: Diagnostic Test: Cold Pressor test; Diagnostic Test: PinPrick test

Study type: Observational

Funder types: Other

Identifiers

NCT03473275

2018-00105

Details and patient eligibility

About

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.

Full 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.

Enrollment: 84 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

84 participants in 4 patient groups

1: control

Description:

Healthy normotensive participants. Cold pressor test on feet 3 times for 40 seconds during brain BOLD fMRI (2 runs), renal ultrasound and contrast-enhanced ultrasound. PinPrick test on feet 3 times for 40 seconds during brain BOLD fMRI (2 runs), renal ultrasound and contrast-enhanced ultrasound.

Treatment:

Diagnostic Test: Cold Pressor test

Diagnostic Test: PinPrick test

2: untreated hypertensive

Description:

Untreated (or off antihypertensive drugs) hypertensive patients (ABPM proven essential hypertension). Cold pressor test on feet 3 times for 40 seconds during BOLD fMRI (2 runs), renal ultrasound and contrast-enhanced ultrasound.

Treatment:

Diagnostic Test: Cold Pressor test

3. resistant hypertensive

Description:

Patients with proven resistant hypertension and not renal denervated or for whom a renal denervation is planned according to the criteria of the CHUV. Cold pressor test on feet 3 times for 40 seconds during BOLD fMRI (2 runs), renal ultrasound and contrast-enhanced ultrasound.

Treatment:

Diagnostic Test: Cold Pressor test

4. renal denervation

Description:

Patients with a renal denervation. Cold pressor test on feet 3 times for 40 seconds during BOLD fMRI (2 runs), renal ultrasound and contrast-enhanced ultrasound.

Treatment:

Diagnostic Test: Cold Pressor test