Effect of blood pressure lowering drugs and antibiotics on abdominal aortic aneurysm growth: a systematic review and meta-analysis

Objective There is currently no medical treatment proven to limit abdominal aortic aneurysm (AAA) progression. The aim of this systematic review and meta-analysis was to pool data from previous randomised controlled trials assessing the efficacy of blood pressure-lowering and antibiotic medications in limiting AAA growth and AAA-related events, that is, rupture or repair. Methods A systematic literature search was performed to identify randomised controlled trials that examined the efficacy of blood pressure-lowering medications or antibiotics in reducing AAA growth and AAA-related events. AAA growth (mm/year) was measured by ultrasound or computed tomography imaging. Meta-analyses were performed using random effects models. A subanalysis was conducted including trials that investigated tetracycline or macrolide antibiotics. Results Ten randomised controlled trials including 2045 participants with an asymptomatic AAA were included. Follow-up was between 18 and 63 months. Neither blood pressure-lowering medications (mean growth +/- SD 2.0 +/- 2.4 vs 2.3 +/- 2.7 mm/year; standardised mean difference (SMD) -0.07, 95% CI -0.19 to 0.06; p=0.288) or antibiotics (mean growth +/- SD 2.6 +/- 2.1 vs 2.6 +/- 2.5 mm/year; SMD -0.11, 95% CI -0.38 to 0.16; p=0.418) reduced AAA growth or AAA-related events (blood pressure-lowering medications: 92 vs 95 events; risk ratio (RR) 0.86, 95% CI 0.66 to 1.11; p=0.244; and antibiotics: 69 vs 73 events; RR 0.93, 95% CI 0.69 to 1.25; p=0.614). The subanalysis of antibiotics showed similar results. Conclusions This meta-analysis suggests that neither blood pressure-lowering medications or antibiotics limit growth or clinically relevant events in people with AAAs.