Abdominal aortic aneurysm (AAA) is a common vascular disease and associated with risk of rupture, but also with a high cardiovascular (CV) event rate. A key difficulty in AAA is predicting these life-threatening complications. Recent studies suggest that the endothelial function of the abdominal aorta might have a correlation with the disease development. A novel, easy to perform, non-invasive test can assess central artery endothelial function (i.e. the carotid artery reactivity (CAR)). The CAR test is based on the cold pressure test (CPT), which induces sympathetic stimulation by placing one hand in cold water. Using duplex ultrasound, central artery blood flow and diameter responses can be examined.
Previous work has demonstrated that the CPT is associated with an increase in abdominal aortic diameter, whilst others found that the carotid and coronary artery diameter also shows dilation. Interestingly, a previous study found a strong correlation between carotid and coronary artery diameter responses to the CPT, whilst these artery responses show independent prognostic value for future cardiovascular events in patients with peripheral arterial disease. Possibly, similarity may be present in central artery reactivity to the CPT. To date, no study examined whether carotid and aorta responses are in agreement during the CPT. Given the potential importance of central artery vasoreactivity for AAA, the CAR-test may have potential in this group, especially given the relative simplicity of measuring the carotid artery.
The aim of this explorative study is to investigate the correlation between the magnitude of the abdominal aorta and the carotid artery diameter and blood flow responses during the sympathetic stimulation (using the cold pressor test) between healthy young, healthy older and individuals with AAA.
