1Department of Internal Medicine and Cardiology, Osaka City University Graduate School of Medicine, 2Department of Cardiology, Osaka City General Hospital, 3Department of Pathology, Osaka City University Graduate School of Medicine
In the case of atherosclerotic plaques, irregular surface plaques, ulcerated plaques, and mobile plaques are classified as complex plaques. Complex plaques in the aortic arch and carotid arteries detected by vascular ultrasound imaging such as transesophageal echocardiography and carotid ultrasound have been shown to contribute to an increased risk of stroke. On the other hand, several inflammatory biomarkers such as C-reactive protein (CRP) have been reported to be associated with atherosclerosis and plaque destabilization. Neopterin has been reported to be an activation marker for monocytes/macrophages. It has been shown that neopterin is closely associated with unstable coronary plaques in patients with unstable angina pectoris. Furthermore, we recently demonstrated that the complex carotid plaques detected by carotid ultrasound were related to increased circulating levels of high-sensitivity CRP and neopterin, and immunohistochemical localization of neopterin was observed in the complex carotid plaques obtained from carotid endarterectomy in patients with stable angina pectoris. These observations suggest that the complex plaques detected by vascular ultrasound may be associated with plaque instability. Therefore, plaque complexities assessed by vascular ultrasound should be considered in the evaluation of plaque destabilization.