A Retrospective Study: Factors Associated with the Risk of Abdominal Aortic Aneurysm Rupture

Introduction: Literature regarding pharmacological manipulation of aneurysm development and progression is abundant; however studies looking at preventing rupture are sparse. Moreover, best medical therapy is ill-instituted, and continued in this high-risk cohort. This paper aims to identify factors which affect the risk of AAA-rupture.

Materials & Methods: A retrospective review of patients undergoing non-screen detected AAA-repair at a single tertiary-referral centre was performed. Age, cardiovascular history, medication use and the nature of surgical repair (elective or emergency) were converted to binary characteristics and a binomial logistic regression performed.

Results: We included 315 admissions for ruptured AAA, and 668 referrals for elective repair of large aneurysms (n=983). Multifactorial analysis showed that the cohort which was prescribed statins experienced fewer ruptured AAA ([OR] 0.50, [95% CI] 0.32-0.77). Factors associated with increased risk of rupture include female gender (2.49, 1.63-3.80), history of hypertension (3.5, 1.6-3.8) or renal failure (8.08, 4.15-15.4), age over 80 (2.77, 1.79-4.27) and current smoking (1.80, 1.09-2.96).

Discussion And Conclusions: This is the largest study, interrogating individual patient data, to suggest an association between statins and prevention of large AAA-rupture. As patients with AAA are at high risk of cardiovascular events, and statins may decrease the risk of the devastating consequence of the condition, healthcare teams should maintain pharmaco-vigilance in instituting and continuing best medical therapy, including a statin.