US Screening for AAA More Effective in Older Patients

October 5, 2015

Ultrasound screening for abdominal aortic aneurysm would save more lives of people aged 75 or older, rather than nonsmoking 65-year-olds.

Ultrasound screening for abdominal aortic aneurysm (AAA) among nonsmokers at age 65 has little impact on AAA event rates, but screening people aged 75 or older could save more lives, according to a study published in the Journal of the American Heart Association.

In an effort to address the lack of population-based studies of event rates and outcomes of acute AAA, researchers from the United Kingdom performed a prospective, population-based study to determine if current screening guidelines for AAA among older men is having a significant impact on AAA death rates.

The study population comprised 92,728 subjects. All patients with acute vascular events that affected the aorta from April 1, 2002 to March 31, 2014 were assessed. The researchers noted that there were 103 incident acute AAA events, a rate of 9/100 000 per year, and the number of incidents was highest among males (72.8%), particularly those between age 75 and 84:

AgeMaleFemale
55–645/100,0002/100,000
65–7423/100,0005/100,000
75–8428/100,00010/100,000
85 or older19/100,00011/100,000

Thirty-one (30.1%) of the AAAs resulted in sudden deaths in the community and six (5.8%) died during transit to the hospital or shortly after arrival. [[{"type":"media","view_mode":"media_crop","fid":"42022","attributes":{"alt":"ultrasound","class":"media-image media-image-right","id":"media_crop_87981877732","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"4509","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"height: 107px; width: 160px; border-width: 0px; border-style: solid; margin: 1px; float: right;","title":"©Bork/Shutterstock.com","typeof":"foaf:Image"}}]]

“Incidence at ages 65 to 74 was highest in male smokers (274), with 96.4 percent of events in men younger than 75 years occurring in ever-smokers,” the authors wrote. “Extrapolating rates to the UK population, using trial evidence of screening efficacy, the current UK screening program would prevent 5.6 percent of aneurysm-related deaths (315 200 scans/year: 1426/death prevented, 121/year-of-life saved).”

If only male smokers were screened at age 65, and all men at age 75, the researchers calculated that 21.1% of deaths from AAA would be prevented. “By 2030, 91.0 percent of deaths will occur at age 75 or older, 61.6 percent at 85 or older, and 28.6 percent in women,” the authors wrote.

With the results showing that the majority of acute AAA affected people were 75 years or older, the authors suggested that screening older groups should be considered and that screening nonsmokers at age 65 had little impact on AAA event rates.