Abstract 541: Association Of Influenza Pneumonia With Abdominal Aortic Aneurysm (aaa) Disease

Abstract

Objectives: Renin-angiotensin system contributes to AAA pathogenesis. The pulmonary system regulates circulating angiotensin II and 1-7 via angiotensin converting enzyme (ACE) and ACE2 activity. Pulmonary diseases including COPD and sleep apnea are associated with increased AAA risk. This study examined whether a similar association exists with influenza pneumonia (IP). Methods: Using a cohort discovery tool with IRB approval for informed consent waive, electronic health records from Stanford health system were retrospectively queried to identify patients ≥ 50 years of age with a history of IP or non-influenza pneumonia (NIP). After controlling for gender, race, and cigarette smoking, AAA prevalence and odds ratios (ORs) were calculated for patients with IP or NIP as a function of age and diabetes status. Results: We identified 935 and 6145 AAA patients in the IP (45,110) and NIP (1,993,760) cohorts, respectively. IP was associated with increased AAA prevalence regardless of sex, age, smoking, diabetic status or racial classification (excepting Native Americans, Table 1 ). After controlling for white race and male sex, AAA prevalence remained higher in IP smoking patients in most age groups regardless of diabetic status. OR for IP-associated AAA risk ranged from 1.48 to 2.31 ( Table 2 ). In white male non-smokers, AAA prevalence was also higher in IP than NIP patients, particularly in non-diabetics (OR 10.10 to 228.86, Table 3 ). Conclusions: This study suggests that influenza pneumonia is positively associated with AAA disease prevalence in older patients. Additional study is needed to determine whether this association is causal and, ultimately, whether AAA screening and surveillance protocols should be adjusted accordingly.