SCAD and Other Arterial Abnormalities Such as Fibromuscular Dysplasia

Abnormalities may occur in arteries other than those that deliver blood to the heart — for example, in the femoral artery in the leg or the carotid artery in the neck.

One such abnormality is fibromuscular dysplasia (FMD). The SCAD Research Program team has noted that people with SCAD are more likely than other people to have other arterial abnormalities, including FMD. But this phenomenon is poorly understood.

The Mayo Clinic SCAD Research Program uses a dedicated protocol to find other arterial abnormalities in patients with SCAD and study the links between SCAD and these other abnormalities. This research focuses on creating images of patients' veins, called vascular imaging. It includes vascular imaging of the same patients through time to look for changes. It also includes looking back through existing vascular imaging among participants with confirmed SCAD who are being reviewed as outpatients at Mayo Clinic.

Mayo Clinic SCAD researchers are working to find the best ways to screen for abnormalities of other arteries and determine how often they occur. In Mayo Clinic's SCAD CT angiogram protocol — which was created specifically for people with SCAD — participants get an outpatient exam. This exam includes a single CT angiogram of the neck with their arms down followed by another CT angiogram of the chest, abdomen and pelvis with their arms up. All exams are done with techniques to control the dose of radiation. Vascular radiologists then review these exams.

The research team has found other arterial abnormalities in more than two-thirds of scanned patients. Specific abnormalities found include FMD, aneurysms, dissection and aortic tortuosity. These abnormalities have been seen in the aorta, carotid, vertebral, iliac, renal and mesenteric arteries.

Data suggest that most patients with SCAD have other abnormalities in other arteries. This leads the research team to hypothesize that underlying disease of the entire vascular system may cause SCAD.