Prevalence and characteristics of renal artery fibromuscular dysplasia in hypertensive women below 50 years old.

Background: Renal fibromuscular dysplasia (FMD) is typically diagnosed in young hypertensive women. The 2014 European FMD Consensus recommended screening in all hypertensive women <30 yo. However, the prevalence of renal FMD in young/middle-aged hypertensive women remains unclear. The aim of this work was to assess the prevalence and characteristics of renal FMD in hypertensive women ≤50 yo.

Methods: We retrospectively included all consecutive women aged ≤50 years referred to our Hypertension Unit from 2014 to 2017 and collected standardized information on patient characteristics and screening modalities.

Results: Of 1083 incident hypertensive patients, 157 patients fitted with inclusion criteria. The prevalence of renal FMD varied between 3.2% in the whole sample and 7.5% in patients explored by CTA and/or MRA (n = 67). In the subgroup of patients ≤30 yo (n = 32), the corresponding figures were 3.1% and 5.6%. The yearly prevalence of FMD tended to increase over time, in parallel with increased use of CTA/MRA as a first-line imaging modality. Out of 5 patients with renal FMD, 2 were revascularized and 1 had extra-renal FMD.

Conclusions: The prevalence of renal FMD in young/middle-aged hypertensive women is probably one order of magnitude higher than previously assumed, in the range of 3%-8%, depending on imaging modalities. While the diagnosis of FMD does not influence short-term management in all patients, it may allow close monitoring and prevention of complications of the disease over time. This analysis provides the rationale for a prospective, multicentre study aiming at determining the cost-effectiveness of systematic screening for renal FMD.