|Title:||P2-46 - Carotid Artery Thickness and Plaque Quantified by Carotid Ultrasound is Associated With Angiographic Coronary Stenosis|
|Authors:||Pearl Behl, M. Matangi, P. Malik, P. Mousavi, Chris Simpson, Amer Johri. Queens University, Kingston, ON, Canada|
Background: Due to increasing prevalence of cardiac risk factors, the development of better non-invasive tools for early detection of coronary artery disease (CAD) is of considerable interest. Carotid intima-media thickness (CIMT) measured by ultrasound is an inexpensive and established approach to predict risk of future cardiovascular events. Although CIMT has been shown to predict risk, use of this measure with carotid plaque quantification to predict severity of coronary atherosclerosis is unknown. We investigated the relationship between CIMT and carotid plaque, and significant coronary stenosis.
Methods: Three hundred and twenty consecutive outpatients for clinically indicated coronary angiography were prospectively recruited. All patients underwent angiography and carotid ultrasounds on the same day; each test interpreted by an investigator blinded to results of the other study in that patient. Patients were divided into 2 groups: Group 1 (N=79) without a critical coronary lesion and Group 2 (N=241) (significant CAD) with at least 1 major epicardial coronary lesion (more than 50% luminal narrowing). Chi-square tests were used for categorical variables (diabetes, smoking, HTN, hyperlipidemia, gender) and independent T tests for continuous variables (age, CIMT, plaque height).
Results: The mean right and left common carotid distal wall CIMT (Group 1= 0.82±0.21mm; Group 2=0.90±0.24mm) (p=0.017) and the mean plaque height (Group 1=1.75±1.07mm; Group 2=2.60±0.93mm) (p<0.001) were significantly higher in Group 2 compared to Group 1. When analyzed by the number of vessels, the General Linear Model was statistically significant (p<0.001). Post hoc analysis with Bonferroni correction showed that the mean CIMT was higher in the groups with multi-vessel disease (greater than 2) compared to Group 1 (p=0.003). There was an increase in CIMT with the number of coronary vessels involved. The mean plaque height was significantly higher in the groups with single, double, triple and quadruple vessel disease compared to Group 1 (p<0.001). Logistic regression identified CIMT (p=0.04) and plaque height (p=0.003) as the important factors for predicting CAD.
Conclusion: Increased CIMT and carotid plaque height are associated with the presence and extent of epicardial coronary stenosis. CIMT may be useful in estimating atherosclerotic burden in multi-vessel disease whereas plaque burden may be more sensitive to detect disease early on in mild CAD (single vessel disease). Carotid ultrasound with plaque quantification may serve as a useful screening tool for the detection of clinically significant CAD.