AbstractStatin Use and Rupture of Abdominal Aortic Aneurysm

There have been studies suggesting that statins may reduce AAA growth rates and rupture risk by enhancing endothelial function and attenuating oxidative stress and inflammation of the vessel wall (Liao JK. Am J Cardiol 2005;96:24F-33F). Meta-analyses also suggests decreased growth rate of AAAs with the use of statins (Sweeting MJ et al, Br J Surg 2012;99:655-65). In addition there have been small, single-center observational studies suggesting an association between prehospital statin therapy and lower mortality following surgery for ruptured (rAAA) (Feeney JM et al, J Am Coll Surg 2009;209:41-6). In the current study the authors use the Danish National Registry of Patients, to examine incident rAAA cases and AAA control patients with a focus on the risk and prognosis of rAAA. This was a nationwide, population-based, combined case-control and follow-up study that included all patients (aged at least 50 years) with a first-time hospital admission for rAAA and 1:1 matched AAA controls without rupture in Denmark, from 1996 to 2008. Individual-level data on preadmission drug use, comorbidities, socioeconomic markers, healthcare contacts and death were obtained from nationwide registries. The study included 3584 cases and 3584 match controls. Current statin use was registered for 418 patients with rAAA (11.7%) and 539 AAA controls (15.0%), corresponding to an age- and sex-matched odds ratio of 0.7 (95% CI, 0.60-0.81) for rAAA in current statin users vs never users. The decreased risk of rAAA remained after adjustment for potential confounding factors (adjusted OR, 0.73; 95% CI, 0.61-0.86). Overall, 30-day mortality rate from time of hospital admission among patients with rAAA was 46.1% in current statin users compared with 59.3% in never users (adjusted mortality rate [MRR], 0.80, 95% CI, 0.68-0.95). Patients who had formerly used statins did not have reduced mortality (adjusted MRR, 0.98; 95% CI, 0.78-1.22).