Preadmission use of renin-angiotensin blockers and rupture of abdominal aortic aneurysm: A nationwide, population-based study

Purpose: Rupture of abdominal aortic aneurysms (rAAA) is associated with high mortality. Use of angiotensin converting enzyme inhibitors (ACE-inhibitors) and angiotensin receptor blockers (ARBs) has been suggested to reduce the risk of rAAA. This nationwide, combined case-control and follow-up study aims to examine the possible impact of preadmission renin-angiotensin system blockade on the risk of rAAA and case fatality following rAAA. Methods: Using Danish healthcare registries, a combined case-control and follow-up study was conducted among all patients with a first-time hospital admission for rAAA and AAA controls without rupture in Denmark from 1996 to 2012. Individual-level data were obtained on preadmission drug use, comorbidity, socioeconomic factors, healthcare services use, and death. Results: The adjusted age-matched and sex-matched odds ratios (adj. OR) were 0.96 (95% confidence interval (CI): 0.85; 1.07) for rAAA for current ACE-inhibitor users and 0.93 (95%CI: 0.79; 1.09) for current ARB users compared with never users. Propensity score-matched analyses yielded similar results for current ACE-inhibitor users (adj. OR: 1.02, 95%CI: 0.88; 1.19) and current ARB users (adj. OR: 1.02, 95%CI: 0.83; 1.26). The total 30-day mortality rate after hospital admission was 61.0% in current ACE-inhibitor users compared with 59.4% in non-ACE-inhibitor users (adjusted mortality rate ratio (adj. MRR) 1.06, 95%CI: 0.94; 1.20) and 58.6% in current ARB users compared with 59.9% in non-ARB users (adj. MRR: 0.96, 95%CI: 0.82; 1.14). Conclusion: Use of renin-angiotensin system blockade was not associated with a lower risk of rAAA or lower case fatality following rAAA.