AB0777 Computed tomodensitometric (CT) angiographic imaging characteristics of idiopathic aortitis: A case control study
Authors: V.R. Chowdhary, C.S. Crowson, K.J. Warrington, T.J. Vrtiska
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Idiopathic aortitis is a rare condition characterized by giant cell or lymphoplasmacytic inflammation of aorta in absence of a secondary cause. No information is available on pre-operative imaging findings in these patients. <h3>Objectives</h3> We undertook a retrospective case-control study to identify characteristic computed tomodensitometric (CT) -angiographic findings in thoracic aorta of these patients and correlate them with known atherosclerotic risk factors. <h3>Methods</h3> Cases and controls, with non-infectious thoracic aortic aneurysms, older than 18 years of age, were identified using a pathologic database from January 1, 2000 to December 31, 2008. All patients with secondary causes for the aortic aneurysms were excluded. Pre-operative CT-angiographic images were uploaded on Advantage workstation with 3-D rendering capabilities (GE Healthsystems®) and reviewed by an expert vascular radiologist in a blinded fashion. Diameter of thoracic aorta, wall thickness and calcification were measured at various sites. Presence of calcification was scored as none (grade 0), involving 25-50% of the wall circumference (grade 1), involving 50-75% (grade 2) and more than 75% of wall circumference (grade 3). Presence or absence of traditional atherosclerotic risk factors was identified from patient case record and included hypertension, hyperlipidemia, diabetes mellitus and smoking (current, former and never). <h3>Results</h3> 63 cases were identified with idiopathic giant cell or lymphoplasmacytic inflammation in their aortic specimen and 20 cases had pre-operative CT images available for review. These were randomly matched to controls on age, gender and year of surgery and 18 (out of 20) controls had pre-operative images. The median age of cases was 73.5 years (range 56-82 y) and that of controls was 71 years (range 53-85 y, p=0.429). The median duration of symptoms prior to surgery was 104 days (range 0-3000) in cases and 76 days (range 0-2995) in controls (p=0.737). Aortic diameter was significantly larger in cases from mid-ascending level to the level of diaphragmatic hiatus in spite of similar duration of symptoms. There were no differences in wall thickness between cases and controls. Controls had significantly more calcification at aortic arch and at aorta distal to the left subclavian artery and aorta distal to the left subclavian (grade 1 versus grade 0, p=0.04 and 0.03). There were no differences in prevalence of hypertension between the groups. No patient had diabetes mellitus. Hyperlipidemia was more prevalent in controls (72% versus 35%, p=0.002) and current smoking was more prevalent in cases (20% versus 6% in controls, p=0.20). Luminal aortic diameter correlated positively with active smoking (r =0.51, p=0.02) at mid-ascending aortic levels but not at other sites whereas presence of hypertension and hyperlipidemia had no effect. <h3>Conclusions</h3> Idiopathic aortitis patients have significantly greater dilatation of thoracic aorta and lower prevalence of calcification. No differences in aortic wall thickening were seen between cases and controls. The combination of smoking and inflammation with consequent aortic wall destruction from elastolytic enzymes may lead to larger luminal diameters in idiopathic aortitis. <h3>Disclosure of Interest</h3> None Declared