This present study is the first aimed to assess the prognostic impact of symptomatic aortitis in a large cohort of GCA patients with well documented aortitis at diagnosis.
Patients with symptomatic aortitis had significantly more cardiovascular risk factors (smoking, hypertension) than asymptomatic patients, suggesting a potential additional effect leading to severe aortic involvement. In accordance to the literature, the aorta was mostly affected in its thoracic segment, especially the ascending thoracic aorta [1, 17]. Aortic aneurysms may be present at the time of diagnosis of GCA, concerning between 4 and 23% of patients [1, 17]. In our present study, exclusively including patients with well-documented aortitis, this frequency was quiet high (19%). At diagnosis or during follow-up, De Boysson et al. reported the discovery of aortic aneurysms in 11% of patients with aortitis, but also in 7% of GCA patients without aortitis [11]. In this study, an aortic aneurysm or dissection was inaugural in 23.4% of patients, with a need for surgery at diagnosis in 5.8% of all patients. These data support the interest of performing aorta imaging at diagnosis of GCA [4].
In our experience, patients with non-symptomatic aortitis received more frequently Methylprednisolone pulses. This is in part due to a higher frequency of ocular involvement in these patients. The use of immunosuppressive treatment during follow-up remained infrequent (18.1% of all cases), and mainly used for severe or resistant forms.
In case of aortitis, control imaging should be used to assess evolution and detect structural complications. The lack of systematic monitoring probably leads to an underestimation of the actual number of aortic complications. In the presence of aortitis, imaging at one and two years from the diagnosis may be considered to assess wall inflammation and screen for aortic aneurysms; later imaging can be discussed in case of multiple relapse or corticosteroid dependence.
During GCA, possible predictive factors of aortic complication (aneurysm, dissection) have already been suggested : coronary artery disease and hypercholesterolemia [7, 12], arterial hypertension and PMR at diagnosis [18], presence of aneurysms of the subclavian arteries [19] but prospective studies are lacking to assess this important issue. In a study including 549 patients, aortic inflammation has been described as the best predictor of aortic dilation [11]. In our own previous study, aortitis at the diagnosis of GCA was associated to higher corticosteroid dependence and higher cardiovascular mortality [8].
In this study, 23,5% of patients (14,8% of noS-Ao patients and 34,1% of S-Ao patients) developed an aortic complication after a median delay of 27 months, which is quiet similar to the 2.5 years found in the historical study by Evans et al. [5]. Moreover, we found that symptomatic aortitis at diagnosis was associated to a significantly higher risk of developing aortic complications, with hazard ratio at 3.78. The presence of aortitis symptoms could therefore reflect a disease with locally more severe inflammation that is the basis for structural damage. The interpretation of the prognosis of symptomatic aortitis must be careful because it also can be explain that advanced aortic disease at GCA diagnosis has unfavorable prognosis due to a significant diagnostic delay or a prior aortic disease.
This study presents an original concept with the search for clinical signs of aortitis at GCA diagnosis. If these results are confirmed, examination and auscultation associated with imaging could help identify patients with more aggressive aortitis.
Our study has several limitations: with the potential data capture errors and missing data that are inherently an issue with all retrospective data collection and short median follow-up. Although the initial dose of corticosteroid therapy was the same in both groups, tapering schedules were not standardized, the use of immunosuppressive therapy was not standardized. Moreover, for most patients, control modalities and blood pressure objectives were not clearly indicated. Only 18.1% of the cohort were treated with additional immunosuppression despite recent EULAR recommendations [20] since this is a cohort with patients included over a long period with some patients exclusively managed with steroids. The follow-up time limited the ability to capture aortic complication that can occur 5–10 years after diagnosis.
In addition, clinical signs associated with symptomatic aortitis are non-specific : pain or dyspnea are very frequently in elderly population, however in this study, symptomatic aortitis was retained after exclusion of musculoskeletal degenerative disease, atherosclerotic or other aortic disease that could explain these symptoms.
Several aortic CT scans performed were not synchronized to the heart rate (limiting the analysis of the ascending thoracic aorta) and some had no late arterial phase to evaluate aortic parietal contrast; follow-up imaging was not systematic and was performed at widely varying times.
If these data are confirmed in prospective studies, a more intensive initial treatment for symptomatic aortitis at diagnosis -with initial corticosteroid therapy combined with immunosuppressive therapy- could be evaluated.
The management of cardiovascular risk factors is also fundamental, including blood pressure monitoring with self-measures, a strict goal for LDL cholesterol level, smoking cessation, and regular physical activity.