Background. Carotid artery intima media thickness (IMT) is a non-invasive reliable predictor of the extent and severity of CVD. There is difficulty acquiring all measurements for validated three-site carotid IMT. More accessible one-site common carotid artery (CCA) IMT has not yet been validated with CVD events.

Purpose. This study will evaluate the diagnostic accuracy of one-site CCA IMT compared to three-site IMT in predicting cardiovascular disease (CVD) events. Assessment of whether the association of incremental one-site CCA IMT to a CVD event is significant with and without adjustment for traditional cardiac risk factors was made.

Methodology. Data from The Atherosclerosis Risk in Communities (ARIC) Study was analyzed for this secondary analysis research study. The study sample utilized only participants for whom raw values were obtained (n=4974). A second sample with raw values which excluded all values <.5 mm IMT was also used (n=4366).

Analysis. Receiver Operator Characteristic (ROC) curves were used to determine diagnostic accuracy of one-site CCA vs. three-site IMT in predicting CVD events. Age and gender-specific logistic regression analysis were used to compare the relative incidence of CVD for incrementally different levels of one-site CCA IMT and three-site IMT, with and without adjustment for risk factors.

Major Findings. ROC curve AUCs demonstrated CCA one-site and three-site IMT to be similarly predictive of CVD event. Odds ratio comparisons of one-site IMT to CVD event showed no association for women, however, for three-site IMT there was a strong association, and this value was profoundly affected by exclusion of values <.5mm and by risk factor adjustment. For men, both one-site and three-site IMT were associated with CVD event similarly.

Other Findings. Only IMT measures and diabetes for women were found to have association to CVD events in final sample.

Significance to the Field of Preventive Care. The common carotid artery mean IMT is easier to analyze than other carotid IMT sites but this site alone was not shown to be an adequately robust predictor of CVD event risk. Further study must be done to find a robust predictor of CVD events, so that preventive care specialists may clinically use this tool.