[Clinical, laboratory, radiological features, and outcome in 26 patients with aortic involvement amongst a case series of 63 patients with giant cell arteritis]. / Caractéristiques cliniques, paracliniques et profil évolutif de l'atteinte aortique de la maladie de Horton : à propos de 26 cas d'aortite parmi 63 cas de maladie de Horton.

PURPOSE: Aortic involvement that occurs in temporal arteritis is probably underestimated because it is usually asymptomatic. The characteristics of giant cell arteritis with aortic involvement are still poorly described and the relationship between aortitis and vascular outcome of the disease has not been clearly delineated. The objective of this retrospective study of 63 patients with giant cell arteritis, including 26 with aortic involvement, was to compare the features of patients with and without aortitis, and to assess the contribution of CT-scan and FDG-PET-scan in screening for vascular disease, monitoring, and therapeutic management of patients. METHODS: This retrospective study was conducted in the internal medicine department of the university hospital in Marseille, France, from January 1, 2005 to September 30, 2011. Patients had at least three out of the five American College of Rheumatology criteria for temporal arteritis and aortic involvement was investigated in all patients using CT-scan. Aortic wall thickness greater or equal to 3mm was considered to be abnormal. RESULTS: Of 63 patients diagnosed with giant cell arteritis, 26 (41.3%) had aortic involvement diagnosed by aortic CT-scan. Age at diagnosis was significantly younger (66.8 vs 73.8 years; P=0.002) in the group with aortitis. Inflammatory dorsal and low back pain, signs of vascular disease of the upper limbs (P=0.009), and higher level of acute phase reactants were associated with aortitis. Aneurysmal lesions of the aorta were significantly more frequent in the group with aortitis. Twenty patients had both aortic CT-scan and FDG-PET-scan. For patients in whom aortic involvement was not demonstrated with CT-scan, FDG-PET-scan was always non-contributive. With corticosteroids, aortitis resolved within 6 months in all patients as evaluated by aortic CT-scan. However, aortitis persisted in 80% of cases at 6 months when evaluated with FDG-PET-scan, and in 66% of cases at 12 months, without influencing the treatment. CONCLUSION: This case series shows no specific features of aorta and its main roots involvement in giant cell arteritis, justifying a systematic screening by CT-scan. The high frequency of this arterial involvement could help physicians in the diagnosis of giant cell arteritis. Aortitis seems to be associated with vascular complications as highlighted by the frequency of aortic aneurysm and a case of early aortic dissection. Finally, the role of PET-CT-scan for screening vascular disease and therapeutic monitoring remains to be clarified.