Concomitant Detection of Systemic Atherosclerotic Disease while Screening for Abdominal Aortic Aneurysm

Association of diabetes mellitus with presence, expansion, and rupture of abdominal aortic aneurysm: "Curiouser and curiouser!" cried ALICE

Both coronary artery and peripheral artery disease are representative atherosclerotic diseases that are positively associated with presence of abdominal aortic aneurysm (AAA). Diabetes mellitus, which is one of major risk factors of coronary artery and peripheral artery diseases, however, has been curiously suggested to be negatively associated with AAA, despite the positive associations of coronary artery and peripheral artery diseases with presence of AAA. In the present article, we overviewed epidemiologic evidence (meta-analyses) regarding the associations of diabetes mellitus with presence, expansion, and rupture of AAA through a systematic literature search. Our exhaustive search identified seven meta-analyses. Main results of almost all meta-analyses (except for the two earliest ones) apparently found that diabetes mellitus is negatively associated with presence, expansion, and rupture of AAA.

Diabetes and abdominal aortic aneurysms

Epidemiologic evidence suggests that patients with diabetes may have a lower incidence of abdominal aortic aneurysm (AAA); however, the link between diabetes and AAA development and expansion is unclear. The aim of this review is to analyze updated evidence to better understand the impact of diabetes on prevalence, incidence, clinical outcome, and expansion rate of AAA. A systematic review of literature published in the last 20 years using the PubMed and Cochrane databases was undertaken. Studies reporting appropriate data were identified and a meta-analysis performed using the generic inverse variance method. Sixty-four studies were identified. Methodological quality was "fair" in 16 and "good" in 44 studies according to a formal assessment checklist (Newcastle-Ottawa). In 17 large population prevalence studies there was a significant inverse association between diabetes and AAA: pooled odds ratio (OR) 0.80; 95% confidence intervals (CI) 0.70-0.90 (p = .0009). An inverse association was also confirmed by pooled analysis of data from smaller prevalence studies on selected populations (OR 0.59; 95% CI 0.35-0.99; p = .05), while no significant results were provided by case-control studies. A significant lower pooled incidence of new AAA in diabetics was found over six prospective studies: OR 0.54; 95% CI 0.31-0.91; p = .03. Diabetic patients showed increased operative (30-day/in-hospital) mortality after AAA repair: pooled OR 1.26; 95% CI 1.10-1.44; p = .0008. The increased operative risk was more evident in studies with 30-day assessment. In the long-term, diabetics showed lower survival rates at 2-5 years, while there was general evidence of lower growth rates of small AAA in patients with diabetes compared to non-diabetics. There is currently evidence to support an inverse relationship between diabetes and AAA development and enlargement, even though fair methodological quality or unclear risk of bias in many available studies decreases the strength of the finding. At the same time, operative and long-term survival is lower in diabetic patients, suggesting increased cardiovascular burden. The higher mortality in diabetics raises the question as to whether AAA repair should be individualized in selected diabetic populations at higher AAA rupture risk.

Simple adaptation of current abdominal aortic aneurysm screening programs may address all-cause cardiovascular mortality: prospective observational cohort study

BACKGROUND

Population screening for abdominal aortic aneurysm (AAA) can be cost-justified by its impact on the incidence of emergency presentations with rupture. The objective of this prospective, cohort study was to determine whether the proposed framework can be further evolved to address all-cause cardiovascular mortality in the community by integrating full risk factor assessment.

METHODS

Male volunteers aged >60 years attending for AAA screening by ultrasound also underwent full cardiovascular assessment via physician-administered health questionnaire, sphygmomanometry, anthromorphometry, and fasting phlebotomy for lipid and glucose profiling. Framingham and SCORE project evaluations were used to calculate 10-year risk of ischemic heart disease and all-cause fatal cardiovascular disease, respectively.

RESULTS

A total of 481 men were screened, and 23 (4.8%) had an AAA detected (22% of which were >4 cm). Obesity, smoking, hypertension, impaired glucose metabolism, and hypercholesterolemia were notably frequent in those without an AAA. Mean 10-year cardiovascular risk in the population without AAA (6.89 and 6.74 by SCORE and Framingham estimations, respectively) was similar to those with AAA (7.78 and 7.04, respectively). Supplementary screening increased total costs by 2.5%. Reserving concomitant atherosclerotic testing for those with elevated systolic blood pressure at presentation allowed identification of 96%/95% of those with Framingham/SCORE risks >10%, respectively, thus saving 162 (33%) individuals from additional investigation and conserving the cost increment to 1.8% overall.

CONCLUSION

The proven framework of population sifting for AAA provides a unique opportunity to also confront latent cardiovascular malady. Sphygmomanometry during ultrasonographic screening for AAA seems both cost-effective and readily incorporated within the current paradigm.