The following are key points to remember from a state-of-the-art review about pathogenesis and management of abdominal aortic aneurysm (AAA):

1. Caucasians have a higher AAA prevalence compared with Black and Asian races, although racial inequality to health care access and screening may limit the prevalence reported.
2. Older age, male sex, hypertension, smoking >10 pack/years, diabetes, coronary artery disease, peripheral vascular disease, family history of AAA, men with low serum testosterone, and women with premature menopause have an increased risk of AAA.
3. Currently asymptomatic, small aneurysms (30-50 mm in women and 30-55 mm in men) are managed by imaging surveillance, and the recommendation for surgical repair in larger, symptomatic, or ruptured aneurysms. This is supported by randomized controlled trials suggesting that early elective open surgical repair of asymptomatic 40-55 mm AAA does not reduce mortality.
4. No large placebo-controlled randomized trials using antibiotics, blood pressure–lowering, anti-inflammatory, immunosuppression, antiplatelet, antithrombotic, or lipid-modifying drugs have shown convincing evidence for significant slowing of AAA growth or the risk of rupture.
5. Some large observational trials suggest that blood pressure reduction using angiotensin-converting enzyme (ACE) inhibitors may reduce the risk of aneurysm rupture. However, among the cohorts with small AAA, there was no evidence that neither ACE nor angiotensin-receptor blockers (ARBs) limit progressive AAA growth.
6. Although a few animal and small human studies found that antiplatelet drugs may significantly reduce an established AAA diameter, the effect on aneurysm rupture was nonsignificant.
7. Despite a placebo-controlled trial testing fenofibrate in the management of AAA stabilization, large prospective studies found that lipid-modifying drugs did not significantly limit AAA growth or rupture, nor reduce aortic inflammation or wall concentrations.
8. A large meta-analysis found that diabetic patients treated with metformin versus those who were not had a significant reduction in aneurysm growth and a 40% reduced risk of AAA repair or rupture. However, the heterogeneity of the observational studies in the meta-analysis limits the level of certainty evidence for general AAA management.
9. The risk factors and mechanisms for AAA growth and rupture differ, so the potential favorable effects of a drug based on small animal or human studies cannot be generalized to a larger diverse population until further large placebo-controlled studies are evident.

Clinical Topics: Cardiac Surgery, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Prevention, Vascular Medicine, Atherosclerotic Disease (CAD/PAD), Aortic Surgery, Cardiac Surgery and Arrhythmias, Lipid Metabolism, Nonstatins, Interventions and Coronary Artery Disease, Interventions and Vascular Medicine, Hypertension, Smoking

Keywords: Aneurysm, Ruptured, Aortic Rupture, Angiotensin Receptor Antagonists, Angiotensin-Converting Enzyme Inhibitors, Aortic Aneurysm, Abdominal, Blood Pressure, Cardiac Surgical Procedures, Coronary Artery Disease, Diabetes Mellitus, Fenofibrate, Fibrinolytic Agents, Hypertension, Immunosuppression, Inflammation, Lipids, Menopause, Metformin, Patient Care Team, Peripheral Vascular Diseases, Platelet Aggregation Inhibitors, Risk Factors, Secondary Prevention, Smoking, Testosterone, Vascular Diseases

< Back to Listings