Evidence-Based Screening and Management of Abdominal Aortic Aneurysm

Each year, approximately 10 000 Americans die of abdominal aortic aneurysm (AAA), making this condition the 14th leading cause of death in the United States. Because most of these patients die of rupture of previously undetected AAAs, many researchers advocate earlier diagnosis using screening ultrasonography. A recent meta-analysis of 4 large, randomized clinical trials suggested that population-based screening substantially reduces AAA-related mortality in selected patient groups (1–5). In light of these findings, the U.S. Preventive Services Task Force (USPSTF) and a consortium of leading professional organizations recommend 1-time screening with abdominal ultrasonography for all men age 65 to 74 years who have ever smoked (6, 7).

In this issue, late results from the Multicentre Aneurysm Screening Study (MASS) provide more compelling evidence in support of these guidelines (8). Based in the United Kingdom, this trial randomly assigned 67 770 men age 65 to 74 years to receive an invitation for screening or to not receive an invitation. At 4-year follow-up, screening was associated with a substantial reduction in AAA-related mortality (42%) but only borderline cost-effectiveness ($44 900 per life-year gained) (1). Kim and colleagues' study, based on a mean 7-year follow-up period, shows that mortality benefits continue to accrue over the longer term in screened patients. For the first time, population-based screening was found to reduce all-cause mortality, not just AAA-related mortality—a high bar given the numerous competing mortality risks in this patient population. Because much of the cost of AAA screening is incurred up front (the screening test and treatment for large aneurysms), these longer-term benefits imply much more favorable cost-effectiveness ratios ($19 500 per life-year based on AAA-related mortality and $7600 per life-year based on all-cause mortality). In effect, the investment in …