Abdominal Aortic Aneurysms Screening Urged in Seniors

Two-thirds of deaths due to abdominal aortic aneurysm (AAA) rupture occur in people aged 75 and older and screening strategies should be updated to reflect the demographic shift, claims a new study.

Researchers at John Radcliffe Hospital (Oxford, United Kingdom) and Oxford University (United Kingdom) conducted a prospective, population‐based study to determine the incidence and outcome of acute AAA events and the impact of screening strategies in a population of 92,728 citizens of the United Kingdom. The researchers also utilized population projections to predict acute AAA incidence rates over the coming two decades, and estimate the likely impact of current and potential alternative screening programs.

The results showed that over a 12-year period (2002–2014), 103 acute AAA events occurred in the study population, representing an incidence rate of 9 per 1,000,000. Nearly 73% of the acute AAA events were in males, with 66% of all events occurring over 75 years of age. After extrapolating the results to the overall population, the researchers concluded that current United Kingdom screening program would prevent 10.7% of incident events, 5.6% of aneurysm-related deaths, and 12% of life years lost due to AAA. An alternative strategy of screening men who smoked at age 65, and then all men again (along with women) at 75 would be much more effective, they suggested.

If such a screening policy would be implemented, it would result in a three- to fourfold increase in the proportion of deaths prevented and reduction in life years lost, owing to the much higher incidence of acute AAA events at ages 75–84, and the higher case fatality at older ages. Another alternative screening strategy, based on patient risk factors, could also prevent more deaths and save more life years over the current model, while also decreasing the number of scans required each year. The study was published on August 19, 2015, in the Journal of the American Heart Association (JAHA).

“Given that two thirds of acute AAA occurred at over 75 years of age, screening older age groups should be considered. Screening nonsmokers at age 65 is likely to have very little impact on AAA event rates,” concluded lead author Dominic Howard, PhD, and colleagues. “If the national UK screening policy was modified, this could result in an almost four-fold increase in the number of deaths prevented, and a three-fold increase in the number of life-years saved compared to the current U.K. strategy.”

An AAA is a localized dilatation of the abdominal aorta exceeding the normal diameter by more than 50%, and is the most common form of aortic aneurysm; approximately 90% occur below the kidneys. The aneurysms can extend to include one or both of the pelvic iliac arteries. The major complication of AAA is rupture, which is life-threatening, as large amounts of blood spill into the abdominal cavity, and can lead to death within minutes.]Mortality of rupture repair in the hospital is 60–90%.

Related Links:
John Radcliffe Hospital
Oxford University