Reproducibility of the carotid artery vasoreactivity test

Cardiovascular disease remains the world's leading cause of mortality and
morbidity. In the development of cardiovascular disease, the presence of
endothelial dysfunction plays a crucial step. It has been demonstrated that the
presence of endothelial dysfunction precedes the development of
artherosclerosis. Identification of the presence of endothelial dysfunction,
therefore, has important clinical implications.

A few years ago, the carotid artery vasoreactivity (CAV) test was introduced.
The CAV demonstrates distinct responses between healthy subjects and those with
cardiovascular risk. During the CAV-test, the carotid artery diameter response
is measured in response to a strong activation of the sympathetic nervous
system by putting a hand in a bucket of ice water. In analogy with coronary
arteries (but not peripheral arteries), this test causes a strong dilation of
the carotid artery (of ~10%) in healthy subjects. Interestingly, subjects with
cardiovascular risk factors or those with cardiovascular disease demonstrate a
small or even absent dilation, or even a constriction. The assumption is that
this simple, non-invasive test provides information about the endothelial
function and may possess prognostic value. However, currently little is known
about the reproducibility of this test in young or older humans. This
information is important to appropriately design future studies that adopt the
CAV.

To examine the hour-to-hour and day-to-day reproducibility of the CAV-test in
young and older humans

Observational cohort study

Assessment of the CAV takes 5 minutes, which is preceded by a 20 minute resting
period. The CAV-test is non-invasive and associated with minimal burden.
Therefore, our experiments only places a minimal burden on the subjects, in
time as well as physically.