Brain BOLD fMRI in Hypertensive and Normotensive Participants

Completed

• Conditions: Hypertension,Essential

• Registration Number: NCT03473275
• Lead Sponsor: Centre Hospitalier Universitaire Vaudois

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.

Study Timeline

• Study First Submitted: 2018-03-15
• Study First Submitted QC: 2018-03-15
• Study First Posted: 2018-03-22
• Study Start: 2018-08-16
• Primary Completion: 2022-08-12
• Study Completion: 2022-08-12
• Status Verified: 2023-02
• Last Update Submitted: 2023-02-20
• Last Update Posted: 2023-02-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 84

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Change in brain BOLD signal intensity	1.5 hours	Changes in the brain BOLD fMRI signal of the brainstem in response to a cold pressor test

Secondary Outcome Measures

Name	Time	Method
Functional connectivity (resting state and effective connectivity)	1.5 hours	Activation patterns in spatially separated brain regions tending to have synchronous activity in resting state and activation pattern changes during a cold pressor test
Structural connectivity	30 minutes	Map of anatomical (neural) connections within the brain in normotensive subjects and hypertensive patients
Correlation between brain BOLD fMRI and renal ultrasound	2 hours	Correlation between changes in brain BOLD signal and renal (contrast-enhanced) ultrasound endpoints

Trial Locations

Locations (1)

CHUV, nephrology service; 🇨🇭 Lausanne, Vaud, Switzerland