Subclinical involvement of common carotid arteries in patients with fibromuscular dysplasia – a case-control study

Abstract

Summary: Background: Fibromuscular dysplasia (FMD) primarily involves medium-sized arteries, though the entire spectrum of vascular involvement is not fully understood. We hypothesized that larger arteries may also be affected, albeit sub-clinically. Patients and methods: We measured the cross-sectional diameter of the thoracic aorta, abdominal aorta, common iliac arteries (CIA) and common carotid arteries (CCA) in FMD subjects and compared them to matched controls. We retrospectively analyzed records of FMD subjects (n = 74) and of age- and sex- matched controls (n = 74) that underwent computed tomography of the neck, chest or abdomen. Cross-sectional diameters of the thoracic and abdominal aorta, CIA and CCA were measured in a standardized manner by two trained physicians. Results: The FMD group had a significantly greater diameter of the CIA and CCA bilaterally. The measurements (mm) in FMD and control groups were as follows: Right CIA: 10.85 + 1.75 vs. 10.23 + 1.36, p = 0.04, left CIA: 11.01 + 1.93 vs. 10.15 + 1.38, p = 0.007, right CCA: 7.70 + 0.81 vs. 6.80 + 1.10, p < 0.001 and left CCA: 7.70 + 1.10 vs. 6.80 + 1.0, p < 0.001). There was no difference in the diameter between the two groups in the ascending aorta, descending and the abdominal aorta. After adjusting for baseline differences, common carotid arteries (but not common iliac) were significantly larger in FMD group compared with controls. Conclusions: There is sub-clinical involvement of the common carotid arteries in patients with FMD and this manifests as a greater diameter of these arteries compared to age and sex matched controls.