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| Name | Class |
|---|---|
| Ecole Polytechnique Fédérale de Lausanne | OTHER |
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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.
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.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| 1: control | 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. |
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| 2: untreated hypertensive | 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. |
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| 3. resistant hypertensive | 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. |
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| 4. renal denervation | 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. |
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| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Cold Pressor test | Diagnostic Test | Both feet in icy waterbath alternated with body temperature water |
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| Measure | Description | Time Frame |
|---|---|---|
| Change in brain BOLD signal intensity | Changes in the brain BOLD fMRI signal of the brainstem in response to a cold pressor test | 1.5 hours |
| Measure | Description | Time Frame |
|---|---|---|
| Functional connectivity (resting state and effective connectivity) | Activation patterns in spatially separated brain regions tending to have synchronous activity in resting state and activation pattern changes during a cold pressor test | 1.5 hours |
| Structural connectivity |
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Inclusion Criteria:
Exclusion Criteria:
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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
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| Name | Affiliation | Role |
|---|---|---|
| Gregoire Wuerzner, MD | Centre Hospitalier Universitaire Vaudois | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| CHUV, nephrology service | Lausanne | Canton of Vaud | 1011 | Switzerland |
Anonymized data of participants that have signed the consent allowing their anonymized data to be shared, will be made available via the repository Zenodo
Once data are published
available at zenodo :https://zenodo.org/
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| ID | Term |
|---|---|
| D000075222 | Essential Hypertension |
| D006973 | Hypertension |
| ID | Term |
|---|---|
| D014652 | Vascular Diseases |
| D002318 | Cardiovascular Diseases |
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plasma: cathecholamines, plasma renin activity (PRA), Aldosterone, Neuropeptide Y (NPY)
| PinPrick test | Diagnostic Test | Pricking both feet with a needle using gravity (without penetrating) alternated with cotton swap |
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Map of anatomical (neural) connections within the brain in normotensive subjects and hypertensive patients |
| 30 minutes |
| Correlation between brain BOLD fMRI and renal ultrasound | Correlation between changes in brain BOLD signal and renal (contrast-enhanced) ultrasound endpoints | 2 hours |