Identification and characterization of new candidates for abdominal aortic aneurysm screening in patients outside of current accepted guidelines.

BACKGROUND: Previous studies have identified groups of patients with abdominal aortic aneurysm (AAA) that fall outside of currently accepted screening guidelines. Population-based studies have found AAA screening would be cost-effective at a prevalence of 0.5-1%. The goal of this study was to determine the prevalence of AAA in patients that fall outside of the current screening guidelines. In addition, we analyzed outcomes of the groups with a prevalence of greater than 1%.

METHODS: Using the TriNetX Analytics Network, several patient cohorts were abstracted with a diagnosis of ruptured or unruptured AAA based on previously identified groups with potential high risk for AAA that fall outside of currently accepted screening guidelines. Groups were also stratified by sex. For groups found to have a prevalence of greater than 1%, the unruptured patients were further analyzed for long term rates of rupture and included male ever-smokers aged 45-65, male never-smokers aged 65-75, male never-smokers aged >75, and female ever-smokers aged 65 or greater. Long-term mortality, stroke, and myocardial infarction rates were compared in patients with treated and untreated AAA after propensity score matching.

RESULTS: 148,279 patients were identified across the four groups with prevalence of AAA greater than 1% with female ever smokers aged 65 or older being the most prevalent (2.73%). In each of the four groups, the rate of AAA rupture increased every five years and all had rupture rates greater than 1% at 10 years. Meanwhile, controls for each of these four subgroups without a previous AAA diagnosis had rupture rates between 0.09% and 0.013% at 10 years. Those who underwent repair of their AAA had decreased incidence of mortality, stroke, and MI. Specifically, male ever-smokers 45-64 had a significant difference in incidence of mortality and MI at 5-years and stroke at 1- and 5-years.

CONCLUSIONS: Our analysis suggests male ever-smokers aged 45-65, male never-smokers aged 65-75, male never-smokers aged >75, and female ever-smokers aged 65 or greater have a >1% prevalence of AAA, and therefore may benefit from screening. Outcomes were significantly worse compared to well-matched controls in these groups.