Renal Artery Fibromuscular Dysplasia Registry

• Study name: A Prospective Study of the Renal artery fibromuscular dysplasia Registry in China
• Rationale: Fibromuscular dysplasia (FMD) is an idiopathic systemic noninflammatory arterial disease resulting in narrowing of medium-sized arteries and causes stenosis, aneurysm, occlusion, or dissection. Renal arteries are most commonly involved vessels, although it can also affect arteries in other vascular territories. Renal artery FMD is the second frequent cause of renovascular hypertension (RVH), especially in adolescents. FMD often affects two or more arterial beds (prevalence of multivessel FMD: 57 to 66%). Despite traditional views on the role of female hormones, mechanical factors and, more recently, smoking, the pathophysiology of FMD is still not well understood. There were little Asians in the United States and the European/International FMD registry.
• Objective: 1) To describe the characteristics of renal artery FMD in men and women, older and younger patients and according to different arterial manifestations, ethnic origin in order to individualize management and prevent complications; 2) To identify environmental/ hormonal factors and exposures (for example smoking) associated with the onset and progression of renal artery FMD;3)To identify baseline characteristics of the disease associated with an increased risk of complications such as dissections, aneurysms, stroke or myocardial infarction; 4) To provide evidence-based algorithms for the optimal management and follow-up of patients with renal artery FMD; 5) To establish a comprehensive imaging resource including a wide range of presentations of renal artery FMD, which may be used to improve knowledge and raise awareness in the medical community.
• Study design: Prospective, multi-center, observational study.
• Study population: patients with renal artery fibromuscular dysplasia who signed the informed consent will be eligible. The following patients are eligible for inclusion: 1) Patients with established renal artery FMD, at least one string-of-beads (multifocal FMD) or focal stenosis (focal FMD). 2) Patients with so-called "atypical FMD" or "FMD-like presentation", i.e. patients presenting with at least one dissection or 2 aneurysms < 60-year-old, in the absence string-of-beads, focal stenosis or evidence of inherited arteriopathy. 3) Children with renal artery FMD may be also included, provided they meet the inclusion criteria and there is no evidence of underlying syndromes such as Williams syndrome, Alagille syndrome or type 1 Neurofibromatosis.
• Data Collections: 1) Data on demographic characteristics (age, gender, height, and ethnicity), clinical characteristics [seated office systolic and diastolic blood pressure (BP), smoking, family history on hypertension or FMD, concomitant diseases, current medications, age at diagnosis of renal artery FMD, angiographic subtype of renal artery FMD, symptoms of renal artery FMD at diagnosis and associated atheroma lesions], blood routine, biochemical and plasmic electrolytes and vascular imaging (arterial beds explored, imaging modality, type, and site of lesions for each vascular bed) were collected using a questionnaire; 2) The diagnosis of renal artery FMD was based on the identification of focal or multifocal FMD lesions in at least one arterial bed by computed tomography angiography (CTA), magnetic resonance angiography(MRA) and/or digital subtraction angiographies (DSA), as recommended in the first international FMD Consensus; 3) For the patients with renal artery FMD, screening was performed to assess all arteries (for example: cerebrovascular, mesenteric, aorta, renal, coronary, visceral, upper and lower extremity arteries) and multivessel FMD would be collected. 4) All patients would be followed up and data ( for example: the blood pressure and restenosis) would be evaluated again.
• Treatment: Standardized diagnosis and treatment procedure as recommended in the International Consensus on the diagnosis and management of fibromuscular dysplasia.
• Follow up: 3, 6, 12 months after diagnosis and every year after enrolled.
• Sample size estimation: About 5 hundred.
• Timeline: Start of subjects' enrollment: Jan 2021; End of subjects enrollment: December 2026; End of study: December 2036.
• Organization: The Centre for Epidemiological Studies and Clinical Trials, Ruijin Hospital, Shanghai, China.

Inclusion criteria

• Informed consent;
• Patients diagnosed with renal artery fibromuscular dysplasia (FMD), i.e. at least one string-of-beads (multifocal FMD) or focal stenosis (focal FMD). The diagnosis needs to be confirmed by at least one of the following imaging modalities: CT-angiography, MR-angiography or catheter-based angiography;
• Patients with so-called "atypical renal artery FMD" or "renal artery FMD-like presentation", i.e. patients presenting with at least one dissection or 2 aneurysms < 60-year-old, in the absence string-of-beads, focal stenosis or evidence of inherited arteriopathy;
• Patients with established renal artery FMD younger than 18 years, without evidence of underlying syndromes such as Williams syndrome, Alagille syndrome or type 1 Neurofibromatosis;

Exclusion criteria

• Not eligible for inclusion or in situations considered unqualified for the study by the investigator;