Interrupters of VAscular daMAge in Malignant Hypertension

The pathophysiology of malignant hypertension is poorly understood. The current dogma is based on an overwhelming renin-angiotensin-aldosterone system activation, leading to arterial hypertension that overcomes target organ auto-regulatory mechanisms and leads to subacute microvascular lesions. However, some patients present with normal or lowered renin in the acute phase of malignant hypertension, suggesting other pathophysiological pathways. Malignant hypertension was reported following anti-VEGF treatment, suggesting that this pathway may be involved. Recent unpublished animal data highlight 1/ the possibility of severe deregulation of the VEGF (vascular endothelial growth factor) system in malignant hypertension 2/ the possibility of compensation of the vasculotoxic effects of VEGF deficiency by inflammasome components. These systems have never been studied together in human hypertension.

Investigators will analyze the angiogenic, vasoactive and VEGF systems through blood and urine sampling. These samples will be collected at the time of malignant hypertension diagnosis and repeated one month later in 30 patients. The same tests will be performed in 15 patients with severe non-malignant hypertension, constituting the control group.

Inclusion criteria

Patients group :

• Patients included in the HAMA cohort
• Who is willing to take part in the IVAMA project

Control group :

• Grade 2 or 3 hypertension with office blood pressure measurement (above 160 and/or 100 mmHg for systolic and diastolic)
• Persistence of blood pressure above 160 / 100 mmHg on the average of 3 "attended" blood pressure measurements

Exclusion criteria

Patients group :

• Age < 18 years old
• Patients with chronic renal failure of stage 3 or higher.
• Patients with any type of diabetes
• Patient in per partum
• Patients who cannot freely give their consent, or patients who refuse to participate
• Chronic dialysis patient

Control group:

• Evidence of subacute involvement of one of the following target organs: brain, kidney, eye, heart, thrombotic microangiopathy. Target organ impairment is defined in the inclusion criteria for the "Patients" group.
• Presence of known chronic kidney insufficiency of grade 3 or higher
• Chronic dialysis patient
• Diabetes of any type
• Patients who cannot freely give their consent, or patients who refuse to participate