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Routine Aortic Aneurysm Screening Questioned

— No mortality benefit in recent years, according to Swedish registry

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Recent survival improvements in patients with abdominal aortic aneurysms (AAAs) may make screening for them "outdated," one group suggested.

From the early 2000s to 2015, AAA deaths fell from 36 to 10 deaths per 100,000 younger men (age 65-74 years), and from 90 to 60 deaths per 100,000 older men (age 75-99 years) in Sweden. This drop in mortality was visible across all Swedish counties, the downward turn occurring even before routine AAA screening started being offered in the country in 2006, according to investigators led by Minna Johansson, MD, of the University of Gothenburg.

Over 6 years of screening, there was only a nonsignificant reduction in AAA mortality among men asked to get AAA screening at age 65 (3.7 fewer deaths per 100,000 years compared to an unscreened age-matched cohort, adjusted OR 0.76, 95% CI 0.38-1.51), Johansson and colleagues reported in the June 16 issue of .

What's more, screening was associated with increased odds of AAA diagnosis (50 more diagnoses per 100,000 years, adjusted OR 1.52, 95% CI 1.16-1.99) and increased odds of elective surgery (36 more surgeries per 100,000 years, adjusted OR 1.59, 95% CI 1.20-2.10).

"We estimated that if 10,000 men are invited to AAA screening, two men might avoid death from AAA after 6 years (non-significant). At the same time, 49 men will probably be overdiagnosed, and 19 men will probably be overtreated because of screening," according to Johansson's group.

"Our results call the continued justification of AAA screening into question," the authors said, suggesting that the drop in AAA deaths instead be attributed to reduced smoking.

Following four randomized trials in the 1980s and 1990s that suggested a benefit from screening, programs were implemented or urged in countries including Great Britain and the U.S. as well as Sweden.

For the current study, Johansson and colleagues analyzed Swedish registry data on men screened for AAAs at age 65 in 2006-2009 (n=25,265) and for a contemporaneous cohort that was not asked to get screened (n=106,087).

Their retrospective study precluded any causative statements from their analyses, and the investigators also acknowledged that they didn't have enough data to assess longer-term outcomes. An accompanying commentary argued that the latter was indeed an important limitation.

"The article would have benefited from including the important , who showed that at least 10 years of implementation of AAA screening might be needed to have solid data on changes in AAA mortality," wrote Stefan Acosta, MD, PhD, of Sweden's Lund University in Malmö.

"By contrast with the study findings presented by Johansson and colleagues, Wanhainen and colleagues, in the stepped-wedge cluster randomised trial, found that AAA-specific mortality was lower in the screened population than in the non-screened group," he recalled.

The editorialist also suggested that routine screening has some value when CT angiography of the whole aorta and an ultrasound of the popliteal arteries can help detect other types of aneurysms.

But Acosta agreed with Johansson's group that smoking plays a major role in AAA.

"Smoking is eight times more common in individuals with AAA than in healthy controls and is implicated in 75% of AAA cases," he said. "Primary prevention programmes to reduce the prevalence of tobacco smoking is a top priority, whereas screening for AAA is not."

  • author['full_name']

    Nicole Lou is a reporter for MedPage Today, where she covers cardiology news and other developments in medicine.

Disclosures

Johansson and Acosta disclosed no relevant conflicts of interest.

Primary Source

The Lancet

Johansson M, et al "Benefits and harms of screening men for abdominal aortic aneurysm in Sweden: a registry-based cohort study" Lancet 2018; 391(10138): 2441-2447.

Secondary Source

The Lancet

Acosta S "Screening men for AAA under magnification loupe in Sweden" Lancet 2018; 391(10138): 2394-2395.