REN and triple-A syndrome: In our study, the use of ACE inhibitors was associated with a lower risk of IA—perhaps explained by activation of the renin–angiotensin system.12 Previous clinical trials on AAA showed that ACE inhibitors can inhibit their growth and rupture, probably by reducing vascular inflammation, augmenting systemic collagen synthesis, and reducing the stiffness of the aortic wall.10, –12 In our analysis, beta-blockers were also related to lower IA risk.