Background/Purpose:  

The clinical and radiographic features of giant cell arteritis (GCA) with extracranial (large-vessel) involvement can be similar to those of Takayasu arteritis (TAK) with age often being used to differentiate these two forms of large-vessel vasculitis. The aim of this study was to compare clinical and imaging characteristics of GCA and upper extremity (UE) arterial involvement with TAK.

Methods:

A cohort of patients with TAK diagnosed between 1984 and 2009, and, a cohort of patients with GCA and UE arterial involvement (based on imaging) diagnosed between 1999 and 2008 have been assembled. Comparisons were performed using Kruskal-Wallis and Chi-square tests.

Results:

 The TAK cohort consisted of 125 patients (91% female); mean age (±SD) at diagnosis 30.9 (±10) years. The cohort of patients with GCA and UE involvement comprised of 120 patients (80% female); mean age (±SD) at diagnosis 67.8 (±7.5) years. Mean onset of symptoms prior to diagnosis was significantly longer in TAK (3.2 years) compared to GCA (0.5 years), p<0.001.  Fever was more common in patients with TAK (29% compared to 15% with GCA, p=0.01). Headache frequency was similar in both groups (33% GCA versus 45% TAK, p=0.06). UE claudication was present in 63 patients (53%) with GCA compared to 49 patients (40%) with TAK, p=0.04. Lower extremity claudication was reported in 11 patients (9%) with GCA compared to 22 patients (18%) with TAK, p=0.05. UE blood pressure discrepancy was present in 65% with TAK versus 28% with GCA, p<0.001. Absent pulses were noted in 72% of the TAK cohort compared to 53% of the GCA cohort, p=0.002; while any bruit was present in 74% TAK and 38% GCA, p<0.001.

Imaging findings are in the Table. Involvement of the thoracic aorta, abdominal aorta, carotid arteries, innominate artery, mesenteric artery and left renal artery was more frequently observed in TAK (Table). Among patients with luminal changes of the thoracic aorta, stenotic/occlusive lesions were predominant in TAK (81% compared to 0% in GCA), whereas aneurysmal disease was more common in GCA (100% compared with 19% in TAK p<0.001). Similar findings were noted in the abdominal aorta. In other arterial beds, stenotic or occlusive changes were the most frequent type of lesion observed in both GCA and TAK (p>0.05).

Conclusion:

Despite some similarities, patients with UE involvement from GCA differ from TAK in clinical and imaging characteristics. Stenotic/occlusive disease was the most frequent type of arterial lesion in both groups at the primary branches of the aorta. However, the type of aortic involvement differed between the two forms of large-vessel vasculitis. Aortic aneurysms were more common in GCA while stenotic changes of the aorta were more common in TAK suggesting different pathophysiologic mechanisms or vascular response to injury.