Fibromuscular dysplasia of cervicocephalic arteries: Prevalence of multisite involvement and prognosis.

BACKGROUND: Fibromuscular dysplasia (FMD) is a noninflammatory nonatherosclerotic disease of small- to medium-sized arteries. The frequency of multisite involvement and its influence on prognosis has not been systematically assessed in patients with cervicocephalic FMD, and little is known about their mid-term clinical and arterial prognosis. The aim of our study was to assess the prevalence of renal involvement and clinical and arterial prognosis in patients with cervicocephalic FMD. METHODS: We reviewed clinical and radiological data of consecutive patients with a diagnosis of cervicocephalic FMD, admitted to our hospital between January 2000 and March 2010. Patients were identified retrospectively until December 2008, and prospectively from January 2009. For each cervical and intracranial artery, we recorded the presence and type (unifocal or multifocal) of FMD. We classified each FMD-related stenosis into four categories:<50%, 50-80%,>80% and occlusion. During the first six months of 2012, patients were scheduled for follow-up visit, including cervicocephalic follow-up imaging, and renal artery imaging, if not already available. On follow-up imaging, FMD-related stenosis was classified according to the same method used at baseline. Renal artery FMD was defined as the presence of the typical string of beads appearance, or as the presence of a unique stenosis of renal artery. Primary endpoints were stroke (ischemic or hemorrhagic), death, and progression of FMD lesions, defined by any increase in category of stenosis on follow-up imaging. RESULTS: Out of the 36 patients included (32 women), all with carotid artery involvement and 17 with associated vertebral artery involvement, 28 (78%) had ischemic symptoms and/or cervical artery dissection at the time of the diagnosis of FMD. Among the 30 patients who had renal artery imaging, 13 (43%) had renal FMD. Patients with renal artery disease did not differ from those without renal artery disease. After a median follow-up of 3.5 years, three patients had four strokes, one recurrent cervical dissection, one brain hemorrhage, and one fatal cardiac arrhythmia. Among the 31 patients who had follow-up imaging, two showed progression of cervicocephalic FMD (occlusion of carotid artery). Patients with renal involvement showed a non-significant trend toward a higher rate of stroke (P=0.17). CONCLUSIONS: In patients with cervicocephalic FMD, renal involvement is common. The risk of stroke, death or FMD progression was high in our cohort, suggesting that prognosis may not be as good as expected. This underlines the need for larger prospective studies to define the best treatment options.