Additional screening criteria suggested for abdominal aortic aneurysm

A new study suggests using additional criteria to expand routine screening for abdominal aortic aneurysm (AAA).

Currently, the U.S. Preventive Services Task Force recommends screening for AAA in men 65 to 75 years of age who have a history of smoking and does not recommend it in women or nonsmokers. However, approximately 41% and 22% of AAA deaths, respectively, occur in the latter two groups. Researchers analyzed retrospective data obtained from Life Line Screening on 3.1 million patients who filled out a medical and lifestyle questionnaire and had ultrasound screening for AAA from 2003 to 2008. Patients were self-referred for screening and paid for the tests themselves. The aim of the study was to identify risk factors associated with AAA. The study results will appear in the September Journal of Vascular Surgery.

The data showed that smoking was associated with AAA, as was excess weight. People who exercised at least once a week and incorporated nuts, fruits and vegetables into their diets at least three times a week were at lower risk, as were blacks, Hispanics and Asians compared with whites and Native Americans. Male sex, age, cardiovascular disease and family history were reaffirmed as known risk factors.

Based on these findings, the authors created a predictive scoring system to identify AAA in a population including women, nonsmokers and those less than 65 years old. They applied their scoring system to data from the National Health and Nutrition Examination Survey and thereby estimated a prevalence of 1.1 million AAAs in the U.S., 569,000 in the latter three lower-risk groups not included in current screening recommendations.

The authors noted that expanding the screening criteria for AAA will increase ultrasound costs, and that the threshold score used with their system must be chosen carefully. In addition, they acknowledged that their study was limited by its self-referred population and its reliance on self-reporting of medical and lifestyle factors. Nonetheless, they concluded that their findings provide new information on risk factors for AAA and could offer a way for primary care physicians to stratify an individual patient's risk. However, they wrote, "Before being considered useful in clinical practice, the scoring system will need to be tested and validated in other well-defined populations."