[Calcified plaque of the extracranial carotid arteries in comparison with traditional risk factors as a predictor for relevant coronary artery stenoses].

BACKGROUND

Intima-media thickness (IMT) of carotid arteries, measured by vascular ultrasound, has widely been used as a surrogate marker for coronary atherosclerosis. As recent studies showed significant but only weak correlation between IMT and coronary artery stenoses, this study evaluated calcified plaques in the extracranial carotid arteries as a reasonable marker for coronary artery disease.

PATIENTS AND METHOD

139 patients underwent cardiac catheterization with selective coronary angiography and ultrasound examination (B-mode, standard Doppler, color Doppler) of the carotid arteries. In case of calcified plaques number and distribution among the extracranial cerebral arteries were determined (Figure 1). Coronary angiograms were analyzed for disease severity and extent (number of main vessels with > 50% stenosis). Besides the traditional vascular risk factors hypertension, diabetes, smoking and hypercholesterolemia as well as body mass index, age and sex were analyzed.

RESULTS

Calcified plaques of carotid arteries were significantly correlated (r = 0.502, p < 0.001) with coronary artery stenoses as well as hypercholesterolemia (r = 0.410, p < 0.001), increasing age (r = 0.406, p < 0.001) and diabetes (r = 0.290, p < 0.001) in contrast to hypertension (r = 0.125, p = 0.075), smoking status (r = -0.043, p = 0.311), body mass index (r = -0.122, p = 0.083) and male sex (r = -0.103, p = 0.114) (Table 1). The number of calcified plaques was significantly correlated (r = 0.568, p < 0.001) with severity and extent of coronary artery disease, too (Figure 2). For two and more calcified plaques sensitivity concerning coronary artery stenoses was 80%, specificity 75%, positive predictive value 83%, negative predictive value 73% (Table 2). Multiple stepwise regression analysis was performed for all eight variables (calcified plaques, hypercholestrolemia, diabetes, hypertension, smoking status, age, sex, body mass index). Including calcified plaques the predictive value of all factors was higher (r = 0.644 to r = 0.607).

CONCLUSIONS

Determination of calcified carotid plaques by ultrasound is useful to improve the predictive value of risk factor-based multivariate models based on traditional risk factors.