The common carotid artery (CCA) is an unusual localization of fibromuscular dysplasia (FMD). However, we previously detected CCA phenotypic alterations in a small population of patients with renal FMD and validated a CCA score. We aimed to test this score in a larger population of patients with renal FMD and hypertension.

Methods: CCA score was calculated with an high resolution echotracking device as the sum of B-mode and radiofrequency score as follows: B-mode. Normal=1; discontinuous blood-intima interface=2; discontinuous additional interface within the media=3; continuous interface within the media=4. Radiofrequency signals. Constant normal two-waved (double) signal=1; alternation of double and triple signal over successive acquisitions=2; constant three-wave (triple) signal=3.

Results: 185 hypertensive patients with renal FMD (40 patients with unifocal and 145 with multifocal lesions) and a control group of 79 hypertensive patients without renal FMD were enrolled. Prevalence of CCA score>3 was higher in patients with multifocal, with or without string of beads, than unifocal FMD and controls (Figure 1). In multivariate analysis, intima-media thickness (150μm increase: OR 1.83, 95%CI 1.27–2.64; P=0.001) and FMD distribution (renal FMD alone: OR 2.97; 95%CI 1.38–6.37; P<0.01. Multisite FMD: OR 6.03; 95%CI 2.62–13.89; P<0.001.) were associated with CCA score>3.

Conclusions: Phenotypic alterations of the CCA were reported in subjects with renal FMD with a higher prevalence in those with multifocal lesions. The CCA score>3 is associated with FMD distribution and intima-media thickness.