Bilateral Symmetry of Local Inflammatory Activation in Human Carotid Atherosclerotic Plaques

Introduction: Only a few studies have investigated the structural and functional characteristics of carotid arteries bilaterally. Furthermore, there is controversy as to whether inflammation in paired vascular beds is a local or systemic phenomenon. We aimed to examine, in patients with coronary artery disease, whether intra-subject left and right carotid arteries have similar inflammatory status, as determined non-invasively by microwave radiometry (MWR). Methods: Consecutive patients (n=200) with significant coronary artery disease were evaluated via an ultrasound echo-colour Doppler (US-ECD) study of both carotid arteries and temperature measurements with MWR. During thermography, thermal heterogeneity (Delta T) was defined as the maximum temperature along the carotid artery minus the minimum temperature. Results: Mean Delta T was similar between the left and right carotid arteries (0.78 +/- 0.48 vs. 0.84 +/- 0.52 degrees C, p=0.12). Mean right intima-media thickness (IMT) was greater compared to mean left IMT (2.16 +/- 1.20 vs. 1.93 +/- 0.94 mm, p<0.01). In all carotids, there was a correlation between left and right carotid plaque Delta T (R=0.38, p<0.001) and between left and right IMT (R=0.48, p<0.001). Independent predictors for the presence of bilateral carotid plaques were found to be the extent of coronary artery disease, high Delta T, and therapy with angiotensin II receptor blockers; predictors for the presence of high Delta T bilaterally were bilateral carotid plaques, male sex, diabetes mellitus, and hypertension. Conclusions: There is bilateral inflammatory activation in the carotid atherosclerotic lesions of patients with coronary artery disease. At this stage of carotid disease, arterial hypertension and diabetes mellitus are more strongly correlated with bilateral functional abnormalities in carotid plaques than with structural changes.