Risk of developing an abdominal aortic aneurysm after ectatic aorta detection from initial screening.

OBJECTIVE: Current abdominal aortic aneurysm (AAA) surveillance guidelines lack any follow-up recommendations after initial abdominal aortic screening diameter of less than 3.0 cm. Some 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 was to determine ectatic aorta prevalence, AAA development, rupture risk, and risk factor profile in patients with detected ectatic aortas in a AAA screening program. METHODS: A retrospective chart review of all patients screened for AAA from January 1, 2007, to December 31, 2016, within a regional health care system was conducted. Screening criteria were men 65 to 75 years of age that 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 who had subsequent follow-up imaging of the aorta with a minimum of 1-year follow-up were analyzed for associated clinical and cardiovascular risk factors. All data were collected through December 3,/2018. A logistic regression of statistically significant variables from univariate and χ2 analyses were performed to identify risks associated with the development of AAA from an initially diagnosed ectatic aorta. A Cox proportional hazard model was used to assess survival data. A P value of less than .05 was considered statistically significant. RESULTS: From a screening pool of 19,649 patients, 3205 (16.3%) with a mean age of 72.1 ± 5.3 years were identified to have an ectatic aorta from January 1, 2007, to December 31, 2016. The average screening ectatic aortic diameter was 2.6 ± 0.1 cm. There were 672 patients (21.0%) with a mean age of 73.0 ± 5.7 years who received subsequent imaging for other clinical indications and 193 of these patients (28.7%) with ectatic aortas developed an AAA from the last follow-up scan (4.2 ± 2.5 years). The average observation length of all patients was 6.4 ± 2.9 years. No ruptures were reported, but 27.8% of deaths were of unknown cause. One patient had aortic growth to 5.5 cm or greater (0.15%). Larger initial screening diameter (P < .01), presence of chronic obstructive pulmonary disease (P < .01), and active smoking (P = .01) were associated with AAA development. CONCLUSIONS: Patients with diagnosed ectatic aortas from screening who are active smokers or have chronic obstructive pulmonary disease are likely to develop an AAA.

The 10-year outcomes of a regional abdominal aortic aneurysm screening program.

OBJECTIVE: In 2007, Medicare established ultrasound screening guidelines to identify patients at risk for abdominal aortic aneurysm (AAA). The purpose of this study was to evaluate AAA diagnosis rates and compliance with screening during 10 years (2007-2016) of the Screen for Abdominal Aortic Aneurysms Very Efficiently Act implementation within a regional health care system. METHODS: A retrospective chart review of all patients screened for AAA from 2007 to 2016 within a regional Veterans Affairs health care system was conducted. Screening criteria were men 65 to 75 years of age who smoked a minimum of 100 cigarettes in their lifetime. An AAA was defined as a maximum aortic diameter ≥3 cm. A comparison was made of the AAA diagnosis rate and clinical adherence rate of screening criteria between the first 5 years and total years evaluated. AAA-related mortality was identified by using terminal diagnosis notes or autopsy reports. All data were recorded by August 31, 2017. RESULTS: A total of 19,649 patients (70.7 ± 4.8 years of age, mean ± standard deviation) were screened from January 1, 2007, to December 31, 2016. There were 9916 new patients screened from 2012 to 2016. A total of 1232 aneurysms (6.3% total patients) were identified during the 10-year period. The overall AAA diagnosis rate has declined from 7.2% in the first 5 years to 6.3% in 10 years (13.5% decrease; P < .01). There were 66 patients found with AAA ≥5.5 cm (5.3% of AAAs), and 54 of these patients received successful elective repair. A total of 2321 patients died (11.8%) and 6 deaths were suspected AAA ruptures (0.03%) within the analysis period. A total of 3680 patients screened (18.7%) did not meet screening criteria: 593 patients were <65 years of age, 3087 patients were >75 years of age, and 59 patients were women. This rate has declined from 28.2% within the first 5 years to 18.7% overall in 10 years (33.7% decrease; P < .01). The compliance of screened patients using screening criteria improved significantly from 61.7% in 2007 to 92.4% in 2016 (P < .01). The overall compliance rate since implementation of the screening program during the past 10 years is 81.3%. CONCLUSIONS: The overall 10-year rate of AAA diagnosis is 6.3%. There are more smaller aneurysms (3.0-4.4 cm) detected and fewer large AAAs ≥5.5 cm in the last 5 years compared with the first 5 years of the screening program. The overall AAA-related mortality rate of all screened patients is 0.03%. There were 54 patients with AAA ≥5.5 cm who underwent successful elective repair resulting from the AAA screening program. The overall compliance of screened patients using screening criteria improved significantly from 61.7% in 2007 to 81.3% since implementation of the screening program during the past 10 years.