How best to diagnose and manage abdominal aortic aneurysms

Although abdominal aortic aneurysms are more common in men, there is a 2- to 4-fold higher risk for rupture in women.

When assessing perioperative risk, SVS guidelines recommend clinicians employ a shared decision-making approach with patients that incorporates Vascular Quality Initiative (VQI) mortality risk score.⁴ (VQI risk calculators are available at https://qxmd.com/vascular-study-group-new-england-decision-support-tools.⁴³)

Medication management

Based on the close association of aortic aneurysm with atherosclerotic CVD (ASCVD), professional societies such as the European Society of Cardiology and European Atherosclerosis Society (ESC/EAS) have suggested aortic aneurysm is equivalent to ASCVD and should be managed medically in a similar manner to peripheral arterial disease.⁴⁴ Indeed, many patients with AAA may have concomitant CAD or other arterial vascular diseases (eg, carotid, lower extremity).

Statins. In its guidelines, the ESC/EAS consider patients with AAA at “very high risk” for adverse CV events and suggest pharmacotherapy with high-intensity statins, adding ezetimibe or proprotein convertase ­subtilisin/kexin type 9 (PCSK9) inhibitors if needed, to reduce low-density lipoprotein cholesterol ≥ 50% from baseline, with a goal of < 55 mg/dL.⁴⁴ Statin therapy additionally lowers all-cause postoperative mortality in patients undergoing AAA repair but does not affect the rate of aneurysm expansion.⁴⁵

Aspirin and other anticoagulants. Although aspirin therapy may be indicated for the secondary prevention of other cardiovascular events that may coexist with AAA, it does not appear to affect the rate of growth or prevent rupture of aneurysms.^46,47 In addition to aspirin, anticoagulants such as clopidogrel, enoxaparin, and warfarin are not recommended when the presence of AAA is the only indication.⁴

The USPSTF continues to recommend against screening in women with no smoking history and no family history of abdominal aortic aneurysm.

Other medications. Angiotensin-­converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and antibiotics (eg, doxycycline) have been studied as a treatment for AAA. However, none has shown benefit in reducing aneurysm growth or rupture and they are not recommended for that sole purpose.^4,48

Metformin. There is a negative association between diabetes and AAA expansion and rupture. Several cohort studies have indicated that this may be an independent effect driven primarily by exposure to metformin. While it is not unreasonable to consider this another important indication for metformin use in patients with diabetes, RCT evidence has yet to establish a role for metformin in patients without diabetes who have AAA.^48,49

ACKNOWLEDGEMENT
The authors thank Gwen Wilson, MLS, AHIP, for her assistance with the literature searches performed in the preparation of this manuscript.

CORRESPONDENCE
Nicholas LeFevre, MD, Family and Community Medicine, University of Missouri–Columbia School of Medicine, One Hospital Drive, M224 Medical Science Building, Columbia, MO 65212; nlefevre@health.missouri.edu