Overall and gender-specific reduction in abdominal aortic aneurysm (AAA) related mortality with screening and endovascular therapy have been reported. The impact of these improvements at a population level have not been systematically evaluated and was the aim of this study.

A population-based cohort study was conducted (1980-2017) of all patients with AAA based on identification using ICD 9/10 and CPT codes. Review of medical records, imaging and death certificates was undertaken to confirm diagnosis and late events. Age- and sex-adjusted incidence rates were estimated adjusted to the US white 2010 census figures. Late events were assessed with Kaplan-Meier estimates.

The study included 1537 patients (75% male; median age 74 years). Overall age and sex-adjusted incidence of AAA was 59/ 100,000 patient-years, 4.5 times higher in men than women. Age and sex-adjusted incidence of ruptured AAA (rAAA) was 4/100,000 patient years (7:1, M: F), with a sharp decline from 12/100,000 patient years before 2000 to 0.4/100,000 patient years after (p< 0.001). Diagnosis of AAA was made at presentation with rupture in 95 patients, of which 75% presenting before and 66% after 2007 satisfied current Medicare established ultrasound screening criteria. Only 16% AAAs during the entire study period were detected on screening, 23% after 2007, with no significant change per year (p=0.1981). Patients with incidentally detected AAAs were older, had larger AAAs, more likely female and to present with rupture, but had similar incidence of progression to and type of repair (Table 1). Median follow-up was 18 years. Overall survival in AAA patients was 94%, 72% and 34% at 1, 5 and 15 years, significantly lower than age and sex-matched controls (median survival 7.5 vs 11.9 years, p <0.001). (Figure 1) Cause of death was unknown in 5.6% patients. Cumulative probability of aortic aneurysm related death at 10 years was 7.3%, with a 5-fold decrease from the 1st to last decade of the study, (p<0.001). On multivariable regression, older age (HR 3.1), higher Charlson index >7 (HR 2.9) and incidental detection (HR 1.5) were associated with higher risk of overall mortality (p<.001). Median age at diagnosis was higher in women (81 vs 74 years, p<0.001); age adjusted survival was similar to men, (HR=0.93, p =0.26).

Incidence of ruptured AAAs and aortic related mortality have decreased significantly in the population over time. Aneurysms are diagnosed and repaired in women almost a decade later than men, with similar age adjusted mortality.