Carotid artery reactivity may help assess cardiovascular risk
Lower carotid artery reactivity (CAR%) correlates with older age and cardiovascular risk factors, whereas CAR% demonstrates positive association with coronary artery responses to the cold pressor test (CPT), a recent study has found.
Researchers used ultrasound to measure both resting and peak carotid artery diameters during the CPT, with CAR% being calculated as the relative change from baseline (%). CAR% was compared between young (n=50; 24 ±3 years) and older participants (n=44; 61 ±8 years); the relationships between CAR% and traditional cardiovascular risk factors in 50 participants (44 ±21 years) were also evaluated.
Using transthoracic Doppler echocardiography, a fundamental instrument to understand heart damage during essential arterial hypertension, researchers then compared the left anterior descending (LAD) artery velocity with carotid artery diameter (ie, CAR%) during the CPT (n=33; 37 ±17 years). [J Cardiovasc Med (Hagerstown) 2007;8:997-1006]
CAR% was significantly larger in young compared with older healthy participants (4.1 vs 1.8; p<0.001). Participants with no cardiovascular risk factors showed greater CAR% than those with at least two risk factors (2.9 vs 0.5; p=0.019).
During CPT, both the carotid artery diameter and LAD velocity increased (p<0.001). Carotid diameter (r=0.486; p<0.004) and change in velocity (r=0.402; p<0.02) were both associated with LAD velocity.
“Therefore, CAR% may represent a valuable technique to assess cardiovascular risk, while CAR% seems to reflect coronary artery vasodilator function,” according to researchers.
CAR%, which involves carotid artery diameter responses to a CPT, is a noninvasive measure of conduit artery function in humans, they added.