VESS23. Risk of Developing an Abdominal Aortic Aneurysm After Ectatic Aorta Detection After Initial Screening

Abstract

Current abdominal aortic aneurysm (AAA) surveillance guidelines recommend no further follow-up after initial abdominal aortic screening of greater than 3.0 cm in aortic diameter. However, recent reports have demonstrated patients with late AAA formation and late ruptures after initial ultrasound screening detection of patients with an aortic diameter of 2.5 to 2.9 cm (ectatic aorta). The purpose of this study is to determine AAA development and rupture risk in patients with detected ectatic aortas identified from an initial AAA screening. A retrospective chart review of all patients screened for AAA from January 1, 2007, to December 31, 2016, within a regional healthcare system was conducted. Screening criteria were men 65 to 75 years of age who smoked a minimum of 100 cigarettes in their lifetime. An ectatic aorta was defined as a maximum aortic diameter from 2.5 to 2.9 cm. An AAA was defined as an aortic diameter of 3 cm or greater. Patients screened with ectatic aortas that had subsequent follow-up imaging of the aorta from either a computed tomography scan or ultrasound examination were analyzed for associated clinical and cardiovascular risk factors. Univariate and χ2 analyses were performed to identify risks associated with the development of AAA from an initially diagnosed ectatic aorta. A total of 3205 patients (mean ± standard deviation of 72.1 ± 5.3 years of age) with ectatic aortas were detected from January 1, 2007, to December 31, 2016. The average ectatic aortic diameter from screening was 2.6 ± 0.1 cm. A total of 852 of 3205 patients (26.6%) had received subsequent imaging for other clinical indications, with an average time between scans of 5.4 ± 2.9 years. There were 90 of the 852 patients (10.6%) with ectatic aortas who developed into an AAA from the last follow-up scan. Two patients had aortic growth to 5.5 cm or greater (0.2%). Older age, longer time interval between scans, larger initial screening diameter, active smoking status, chronic obstructive pulmonary disease, and a low body mass index were associated with AAA development (Table). Of all patients with detected ectatic aortas who had a subsequent imaging for other clinical indications, 10.6% developed a subsequent AAA and 0.2% developed an AAA of 5.5 cm or greater. Given that only 26.6% of patients with an ectatic aorta had a subsequent imaging study, these numbers may underestimate the true conversion to AAA. Consideration for follow-up imaging studies at 5 years should be targeted in patients with ectatic aortas who are active smokers and have chronic obstructive pulmonary disease.TableClinical and Risk Factor DataClinical dataTotal (n = 3205)Normal aorta (n = 762)AAA (n = 90)P valueAge, years72.1 ± 5.372.6 ± 5.574.2 ± 6.6.01Follow-up, years5.4 ± 2.95.9 ± 2.97.2 ± 2.9<.01Initial aortic screening diameter, cm2.6 ± 0.12.6 ± 0.12.7 ± 0.1<.01Body mass index, kg/m229.7 ± 6.029.1 ± 6.327.5 ± 5.1.02Total cholesterol, mg/dL163.6 ± 40.0159.8 ± 40.7155.2 ± 37.9.31Hemoglobin A1c, %6.5 ± 11.46.3 ± 2.56.1 ± 0.9.45Active smoking status671 (20.9)142 (18.6)25 (27.8).04Chronic obstructive pulmonary disease639 (20.0)164 (21.5)40 (44.4)<.01Hypertension2417 (75.4)606 (79.5)76 (84.4).27Diabetes1159 (36.1)296 (38.8)28 (31.1).15Statin use1482 (46.2)385 (50.5)48 (53.3).62Living status2716 (84.7)617 (81.0)73 (81.1).97Values are mean ± standard deviation or number (%). Open table in a new tab