Prevalence of aortic findings among patients with multifocal fibromuscular dysplasia (FMD) seen at a specialised referral centre.

BACKGROUND

Fibromuscular dysplasia (FMD) is a non-atherosclerotic vascular disease that affects medium-sized arteries with multifocal (beaded) or focal stenotic lesions, aneurysms, dissections and tortuosity. The extent of aortic involvement in FMD is uncertain. This study evaluates the prevalence and characteristics of aortic findings in patients with multifocal FMD.

METHODS

Single-centre, retrospective chart review of patients with multifocal FMD seen from January 2019 to July 2024. Patients ≥18 years with complete aortic cross-sectional imaging were included. Demographic, medical history, family history and vascular phenotype were collected. Aortic pathologies were characterised: aneurysms (thoracic diameter ≥4 cm, abdominal diameter ≥3 cm), ectasia, dissection, stenosis and anatomical anomalies.

RESULTS

Of 360 patients (353 female, 98.1%), aortic involvement was identified in 36 patients (10.0%; 95% CI 7.3% to 13.5%): three acute aortic syndromes (<1%), eight aneurysms (2.2%), 17 ectasias (4.7%) and nine congenital anomalies (2.5%). Among those with aortic involvement (n=36), three (8.3%) were male, four (11.1%) had a family history of aneurysm, two (5.6%) had a family history of dissection and nine underwent clinical genetic testing for aortopathies, all of which were negative. All aortic aneurysms and ectasias were in the proximal thoracic aorta (eight aortic root, 17 ascending aorta). No aortic stenosis was found. Of the nine congenital anomalies, seven had an aberrant right subclavian artery, one had ductus diverticulum and one had coarctation. Compared with patients without aortic involvement, those with aortic involvement were more likely to be male and have non-aortic arterial aneurysms.

CONCLUSION

Aortic findings, predominantly presenting as thoracic ectasia or aneurysm, were identified in 10% of patients with multifocal FMD and complete aortic imaging seen at a single specialised referral centre. These findings support recommendations for head-to-pelvis imaging for patients with FMD and highlight the need for further research into the genetic and systemic aspects of this disease.