Long term outcomes in men screened for abdominal aortic aneurysm: prospective cohort study

Abstract

Objective To determine whether there is a relation between aortic diameter and morbidity and mortality in men screened for abdominal aortic aneurysm.Design Prospective cohort study.Setting Highland and Western Isles (a large, sparsely populated area of Scotland).Participants 8146 men aged 65-74. Main outcome measuresMorbidity and mortality in relation to presence of abdominal aortic aneurysm and three categories of aortic diameter (≤24 mm, 25-29 mm, and ≥30 mm).Results When screened, 414 men (5.1%) had an aneurysm (diameter ≥30 mm), 669 (8.2%) an aortic diameter of 25-29 mm, and 7063 (86.7%) an aortic diameter of ≤24 mm. The cohort was followed up for a median of 7.4 (interquartile range 6.9-8.2) years. Mortality was significantly associated with aortic diameter: 512 (7.2%) men in the ≤24 mm group died compared with 69 (10.3%) in the 25-29 mm group and 73 (17.6%) in the ≥30 mm group. The mortality risk in men with an aneurysm or with an aorta measuring 25-29 mm was significantly higher than in men with an aorta of ≤24 mm. The increased mortality risk in the 25-29 mm group was reduced when taking confounders such as smoking and known heart disease into account. After adjustment, compared with men with an aortic diameter of ≤24 mm, the risk of hospital admission for cardiovascular disease and chronic obstructive pulmonary disease was significantly higher in men with aneurysm and those with aortas measuring 25-29 mm. Men with an aneurysm also had an increased risk of hospital admission for cerebrovascular disease, atherosclerosis, peripheral arterial disease, and respiratory disease. In men with aortas measuring 25-29 mm, the risk of hospital admission with abdominal aortic aneurysm was significantly higher than in men with an aorta of ≤24 mm (adjusted hazard ratio 6.7, 99% confidence interval 3.4 to 13.2) and this increased risk became apparent two years after screening. ConclusionsMen with abdominal aortic aneurysm and those with aortic diameters measuring 25-29 mm have an increased risk of mortality and subsequent hospital admissions compared with men with an aorta diameter of ≤24 mm. Consideration should be given to control of risk factors and to rescreening men with aortas measuring 25-29 mm at index scanning.

Increased Aortic Diameters on Multidetector Computed Tomographic Scan Are Independent Predictors of Incident Adverse Cardiovascular Events

“…The study by Duncan et al was limited by exclusion of women (on the assumption that aortic dilation is more common among men). 22 …”

International Update on Screening for Abdominal Aortic Aneurysms: Issues and Opportunities

“…24 People with sub-aneurysmal aortic dilatation or AAA are at higher risk of cardiovascular death than those with normal infrarenal aortic diameter. 25 It should also be noted that the relationship between aortic diameter and cardiovascular mortality is not linear and individuals with both small and large aortic diameters are at higher risk of cardiovascular mortality and morbidity. 26 The increased risk in patients with AAA is partly due to common risk factors for both AAA and other cardiovascular traits.…”

The role of diameter versus volume as the best prognostic measurement of abdominal aortic aneurysms

“…Duncan et al conducted the prospective cohort study of long-term outcomes in men (n ¼ 8146, aged 65-74 years) for AAAs in relation between aortic diameter, morbidity, and mortality. 26 All-cause mortality was significantly associated with aortic diameter: 512 (7.2%) men in the #24-mm group died compared with 69 (10.3%) in the 25-to 29-mm group and 73 (17.6%) in the $30-mm group. The mortality risk in men with an aneurysm or with an aorta measuring 25 to 29 mm was significantly higher than in men with an aorta of #24 mm.…”

“…Despite the widespread use of diameter measurements in clinical trials and its ease of ascertainment in clinical practice, several studies have also concluded that the diameter may not be reliable as rupture risk criterion and that it should be replaced by a more specific criterion. [27][28][29] Therefore, multiple studies have focused on patient-specific issues such as peak wall stress [25][26][27] or intraluminal thrombus in AAAs. [33][34][35][36] In the current era, these determinants of AAA progression and cardiovascular events are still poorly understood, and thus have proven to have limited clinical applicability over diameter measurement at the present time.…”