(IP007) Factors associated with AAA rupture among patients under 65 years of age in the Vascular Quality Initiative

Objectives: Screening for AAA is not covered for individuals under 65. Yet, studies have shown that 21% of ruptured aneurysms occur in this group of patients. Therefore, we aimed to investigate the characteristics of young patients with ruptured AAA in the VQI to identify a subset that could potentially benefit from early screening.

Methods: All patients in the VQI between 18-65 years undergoing AAA repair between 2003-2024 were examined. Patients were stratified by repair type as ruptured vs. non-ruptured, and univariate analysis was performed comparing the characteristics of these groups. Logistic regression was performed to identify variables associated with rupture.

Results: A total of 16,166 patients were included. Of those, 1,607 (10%) were repaired for rupture (Table 1). Ruptured patients were more commonly male (87% vs 85%, p=.030), and current smokers (69% vs. 56%, p<.0001). Ruptured patients were less likely to have hypertension (70% vs. 80%, p<.0001), CAD (24% vs. 35%, p<.0001), diabetes (13% vs. 18%, p<.0001), and COPD (23% vs. 30%, p<.0001). Patients presenting with rupture were also less likely to have undergone prior aortic surgery when compared to those operated on for non-ruptured aortas (58% vs. 71%, p<.0001) or family history of AAA (7% vs. 11%, p<.0001). No difference was seen between groups regarding history of genetic aortopathy ( < 1% for both, p=0.691), however, this variable was only present for about half of the sample. Mean aneurysm size at the time of repair was significantly higher for those repaired for ruptures (75±15mm vs. 56±20mm, p<.0001). In a multivariate logistic regression (Table 2), odds of repair for rupture were significantly associated with smoking status (OR 1.25, 95%CI: 1.14-1.38), aneurysm diameter (OR 1.07, 95%CI: 1.07-1.07), hypertension (OR 0.71, 95%CI: 0.62-0.82), family history of AAA (OR 0.56, 95%CI: 0.45-0.71), diabetes (OR 0.89, 95%CI: 0.81-0.97), COPD (OR 0.84, 95%CI: 0.78-0.91), and CAD (OR 0.69, 95%CI: 0.60-0.79).

Conclusions: Patients operated on for rupture were more likely male and current smokers. Diagnosis of hypertension, CAD, diabetes, and COPD appeared protective but are likely simply a marker of patients who are connected to the healthcare system and have more frequent follow up and timely interventions. Positive family history also appears protective, and probably reflects patients that are already undergoing screening and consequent repair of AAA prior to rupture. It cannot be ruled out that other factors could be driving young patients to present with ruptured AAA which are not measured in this study, and therefore further investigations are warranted.