Association of Statin Treatment and Dose With the Clinical Course of Small Abdominal Aortic Aneurysms in Men: A 5-Year Prospective Cohort Study From 2 Population-Based Screening Trials

BACKGROUND: Abdominal aortic aneurysms (AAA) present with high morbidity and mortality when they occasionally rupture. No medical therapy has successfully been proven to reduce AAA growth, though both metformin and statins have been identified as potential treatments in multiple meta-analysis. This study aimed to investigate a potential relationship between statin use and AAA growth rates and risk of undergoing repair, rupture, or death. METHODS: The study population included all men with screening-detected AAAs (30–55 mm) from the 2 large, population-based, randomized screening trials; the Viborg Vascular Screening trial (inclusion, 2008–2011) and the Danish Cardiovascular Screening trial (inclusion, 2014–2018). The clinical database was supplemented with data from the nationwide Danish Healthcare Registries, including prescription and outcome data. Statin exposure was quantified by defined daily doses (DDD). The primary outcome was AAA growth rate, whereas secondary outcomes included the need for repair and a composite of repair, rupture, and all-cause death. Growth rates were calculated using linear regression. To evaluate the risk of repair, patients were followed from inclusion until surgery, rupture, death, 5-year follow-up, or December 31, 2021. RESULTS: A total of 998 aneurysmal men (median age, 69.5 [interquartile range (IQR), 67–72] years; median AAA diameter, 35.4 [IQR, 32–41.2] mm) were included. Statin use was significantly associated with reduced AAA growth rate; an increase of 1 DDD statin per day was associated with an adjusted change in growth rate of −0.22 mm/year [95% CI, −0.39 to −0.06]; P =0.009). The 5-year adjusted hazard ratio for undergoing repair per doubling of statin dose presented a significantly reduced adjusted hazard ratio (HR) of 0.82 ([95% CI, 0.70–0.97]; P= 0.023), which was significant after 2.5 years. Statin use was associated with a significantly lower risk of the composite outcome (surgery, rupture, and death) in a dose-dependent manner, with an adjusted HR of 0.83 ([95% CI, 0.73–0.94]; P =0.003) per doubling of statin dose. Findings were robust in a variety of sensitivity analyses. CONCLUSIONS: High-dose statin use was associated with decreased AAA growth rates and lowered risk of undergoing repair, rupture, and death. This nonrandomized study suggests that patients with AAA could benefit from high-dose statin use, beyond only targeting associated risk factors.