A group of researchers is studying population-based screening interventions to reduce mortality from abdominal aortic aneurysm. This disorder develops primarily in elderly patients and is often asymptomatic until an acute rupture event, which is frequently fatal. Screening of high-risk patients for abdominal aortic aneurysm is found to reduce mortality. Which of the following risk factor combinations would likely define the highest-risk group for screening purposes?

Question

A group of researchers is studying population-based screening interventions to reduce mortality from abdominal aortic aneurysm.  This disorder develops primarily in elderly patients and is often asymptomatic until an acute rupture event, which is frequently fatal.  Screening of high-risk patients for abdominal aortic aneurysm is found to reduce mortality.  Which of the following risk factor combinations would likely define the highest-risk group for screening purposes?

Quizplus · Accepted Answer

11ec160b_3a78_0c56_9249_d99612eccd4e_MD0001_00 Focal dilation of the abdominal aorta >50% above normal (or >3 cm in diameter) is termed abdominal aortic aneurysm (AAA). AAA formation involves transmural inflammation of the aortic wall with subsequent apoptosis of smooth muscle cells and degradation of matrix proteins (eg, elastin, collagen). This causes progressive thinning of the aortic wall with secondary expansion of the lumen due to chronic hemodynamic stress. AAA is generally asymptomatic until aneurysm rupture, which typically presents with acute abdominal pain and hypotension; mortality of AAA rupture is 75%-90%. Major risk factors for development of AAA include: Smoking appears to be associated with increased inflammatory infiltrates and formation of reactive oxygen species (eg, superoxide anion) in the aortic wall. In light of this, screening for AAA with ultrasonography is recommended for men age 65-75 who have ever smoked. The risk of rupture increases with aneurysm diameter, and surgical or endovascular repair is considered for aneurysms ≥5.5 cm in diameter. (Choices A and E) Although diabetes mellitus increases the risk for atherosclerotic cardiovascular disease, the risk of AAA is lower in patients with diabetes, possibly due to the effects of glycosylation of matrix proteins in the aortic wall. (Choices B and C) Female sex is associated with a lower risk of AAA, and the benefit of screening in women (including in women who smoke) has not been shown to outweigh the risks of overdiagnosis and potential treatment complications. (Choice D) Hypertension is associated with an increased risk of aneurysm rupture, but the relation to aneurysm incidence and expansion is less clear. Although there is a broad coincidence of AAA and atherosclerosis, studies on an epidemiologic link between hyperlipidemia and AAA are mixed. Educational objective: Abdominal aortic aneurysm is focal dilation of the abdominal aorta >50% above normal (or >3 cm in diameter). It is generally asymptomatic until aneurysm rupture, which is frequently fatal. Risk factors include age >65, smoking, and male sex.

A Group of Researchers Is Studying Population-Based Screening Interventions to Reduce