Abdominal aortic aneurysm (AAA) remains an important cause of morbidity and mortality in elderly men, and prevalence is predicted to increase in parallel with a global ageing population. AAA is commonly asymptomatic, and in the absence of routine screening, diagnosis is usually incidental when imaging to assess unrelated medical complaints. In the absence of approved diagnostic and prognostic markers, AAAs are monitored conservatively via medical imaging until aortic diameter approaches 50-55mm and surgical repair is performed. There is currently significant interest in identifying molecular markers of diagnostic and prognostic value for AAA. Here we outline the current guidelines for AAA management, and discuss modern scientific techniques currently employed to identify improved diagnostic and prognostic markers.
KeywordsAbdominal aortic aneurysm; diagnosis; prognosis; biomarker
INTRODUCTIONAn abdominal aortic aneurysm (AAA) is a dilation of the infra-renal aorta, which appears to result from chronic weakening of the arterial wall, increasing the risk of fatal rupture.1 -3 AAA is also associated with an increased risk of other major cardiovascular events in aneurysmal patients. For example the UK small aneurysm trial (UKSAT), demonstrated that only 16% of deaths in patients with 40-55mm AAAs was related to AAA repair or rupture while ~50% were due to other cardiovascular causes (mainly myocardial infarction and stroke).4 Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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AAA pathologyMacroscopically, an AAA can be considered a dilatation of the infrarenal aorta, giving rise to a permanent vessel diameter >30mm (typical abdominal aortic diameter ranges from 15 to 25mm). 23-27 AAA vessel dilation is commonly progressive, and is often accompanied by the formation of a laminated, non-occlusive, intraluminal thrombus.28 -29 Thrombus size and location varies between patients, and the arterial wall may be partially or completely covered by the thrombus ( Figure 1A and B). 30 The thrombus remains in permanent contact with circulating blood and is continually remodeled, 31,32 and thrombus size increases in parallel with aortic dilation. Due to constant remodeling the thrombus is a laminated structure comprising a red blood cell-rich luminal layer in contact with the flowing blood, progressing to a brown fibrinolysed layer at the aortic wall. 29 Localised hypoxia has been demonstrated in regions of the aorta covered by the thrombus and this has been suggested to contribute to physiological stresses within the arterial wall. 33 Similar to other vascular dise...
BackgroundPre-diabetes and untreated diabetes are common in patients with peripheral artery disease however their impact on outcome has not been evaluated. We examined the association of impaired fasting glucose, diabetes and their treatment with the presentation, mortality and requirement for intervention in peripheral artery disease patients.MethodsWe prospectively recruited 1637 patients with peripheral artery disease, measured fasting glucose, recorded medications for diabetes and categorised them by diabetes status. Patients were followed for a median of 1.7 years.ResultsAt entry 22.7% patients were receiving treatment for type 2 diabetes by oral hypoglycaemics alone (18.1%) or insulin (4.6%). 9.2% patients had non-medicated diabetes. 28.1% of patients had impaired fasting glucose (5.6-6.9 mM). Patients with non-medicated diabetes had increased mortality and requirement for peripheral artery intervention (hazards ratio 1.62 and 1.31 respectively). Patients with diabetes prescribed insulin had increased mortality (hazard ratio 1.97). Patients with impaired fasting glucose or diabetes prescribed oral hypoglycaemics only had similar outcomes to patients with no diabetes.ConclusionsNon-medicated diabetes is common in peripheral artery disease patients and associated with poor outcomes. Impaired fasting glucose is also common but does not increase intermediate term complications. Peripheral artery disease patients with diabetes requiring insulin are at high risk of intermediate term mortality.Electronic supplementary materialThe online version of this article (doi:10.1186/s12933-014-0147-2) contains supplementary material, which is available to authorized users.
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