Systematic review and meta-analysis of the effects of statin therapy on abdominal aortic aneurysms

BACKGROUND: The aim was to investigate the effects of statin therapy on abdominal aortic aneurysm (AAA) disease. METHODS: PubMed, the Cochrane Library, Embase and ClinicalTrials.gov were searched for all studies on any clinical effect of statin therapy on AAA. Outcomes were selected based on their inclusion in two or more studies: AAA expansion rate, 30-day mortality, and short- and long-term postoperative mortality. The data were subjected to meta-analysis by outcome. RESULTS: Twelve cohort studies were selected for inclusion involving 11 933 individuals. Meta-analysis of four studies examining all-cause postoperative mortality showed a significant improvement with statin therapy at 1, 2 and 5 years (odds ratio (OR) at 5 years 0·57, 95 per cent confidence interval (c.i.) 0·42 to 0·79; P < 0·001) with minimal heterogeneity between the four included studies. There was no significant difference in 30-day mortality after AAA treatment in patients on statin therapy (OR 0·22, 0·02 to 2·90; P = 0·25). Sensitivity analysis including four high-quality studies examining AAA expansion rates showed no significant difference with statin therapy: standardized mean difference -0·14 (95 per cent c.i. -0·33 to -0·05) mm/year (P = 0·16). CONCLUSION: The claim of a reduction in AAA expansion rate with statin therapy is based on low-quality evidence and was not significant on meta-analysis. However, statin therapy did appear to improve all-cause survival after AAA repair.