Angiotensin II Receptor Blockade in Vascular Ehlers Danlos Syndrome (ARCADE)

Inclusion Criteria: * Patients with genetically-proven vEDS (presence of a pathogenic mutation at the COL3A1 gene); * Age ≥18 years and \<70 years; * Men and women with reliable contraception or negative beta-HCG at screening; * Celiprolol at the optimal tolerated dose since at least 12 weeks; * vEDS patient fully intolerant to celiprolol but not treated with any other drug active on the vascular system, except another beta-blocker; * No compelling indication for ARB therapy (renal infarction, hypertension, proteinuric nephropathy, chronic heart failure, myocardial infarction, stroke); * Estimated glomerular filtration rate (GFR) ≥ 30ml/min/1,73m2 (MDRD Formula); * Normal or clinically acceptable 12-lead ECG; * Written informed consent to participate in the study. Exclusion Criteria: General criteria * Unlikely to co-operate in the study and/or poor compliance anticipated by the investigator, e.g., uncooperative attitude, inability to return for follow-up visit, and unlikelihood of completing the study; * Participation in another interventional therapeutic study at the same time or within 3 months prior to the beginning of the present study; * Participant not affiliated to the French social security; * No written informed consent; * Severe contrast media allergy, not amenable to pre-treatment Medical and therapeutic criteria * History of previous symptomatic visceral complication (any CV event, pulmonary or digestive event) in the 3 months preceding the inclusion; * Formal indication for an antihypertensive medication (office BP ≥140/90 mmHg on celiprolol on at least two separated visits, confirmed by daytime ambulatory BP or home BP ≥ 135/85 mmHg); * Concomitant treatment with renin-angiotensin-aldosterone system blocking agents apart from the study drug, e.g. ACEI, ARB or aldosterone-antagonist or any renin inhibitor, if given for an elective indication (heart failure, renal infarction, chronic kidney disease, proteinuria, myocardial infarction, stroke); * Any cardiac condition that justifies a specific medical care (i.e. second or third degree auriculo-ventricular block, potentially life threatening arrhythmia or other uncontrolled arrhythmia or persistent arrhythmia, clinically significant valvular heart disease); * Known significant renal artery stenosis with evidence of renal ischemia (on Duplex ultrasound, CTA, or other exam); * Any concurrent life threatening condition other than vEDS with a life expectancy less than 2 years; * Likely allergy or hypersensitivity to irbesartan, based on known allergies to drugs of the same class, or which in the opinion of the investigator suggests an increased potential for an adverse hypersensitivity as well as known or suspected contraindications to the study drug; * Any condition that in the opinion of the investigator would jeopardize the evaluation of efficacy or safety; * Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive Human Chorionic Gonadotropin (hCG) laboratory test (\>5 mIU/ml); * Women of child-bearing potential (WOCBP) without reliable contraception.