Aortitis in Horton disease. Review of the literature

First described in 1937, giant cell aortitis (aortitis associated with giant cell arteritis) occurs in 20 to 40% of patients with giant cell arteritis and is often clinically silent. Temporal involvement usually precedes aortic involvement. The process may involve the entire aorta, but complications are usually related to thoracic involvement. Patients with giant cell aortitis may be asymptomatic, or present with aortic arch syndrome, dilation of the aorta, aortic aneurysm, aortic dissection, sudden rupture of the aorta, or aortic valve incompetence. Thoracic aneurysms are usually fusiform and can be complicated by dissection in up to 50% of patients. Aortic involvement may be the presenting feature of giant cell arteritis: it may also occur in patients with preexisting temporal arteritis, often when corticosteroid therapy is reduced or discontinued. Aortic rupture complicating aortitis may be the cause of death in 3-12% of patients with giant cell arteritis. Clinical follow-up with assessment of disease activity by chest X-ray and biological markers of inflammation should be performed yearly in giant cell arteritis. Aortic involvement should be suspected if cardiac or vascular echo-Doppler shows evidence of an aortic arch syndrome, aortic dilation, aneurysm, or of aortic valve incompetence. Corticosteroid therapy, beginning with a dose of 1 mg/kg/day remains the key point of therapy. The dose is subsequently adjusted based on the clinical course and the results of ancillary tests. This treatment might prevent fatal outcome with aortic rupture. Long-term follow-up of all patients with giant cell arteritis or polymyalgia rheumatica is essential, as complications may develop late in the course of the disease.