THE RELATIONSHIP BETWEEN CAROTID PLAQUE COMPOSITION, PLAQUE MORPHOLOGY, AND NEUROLOGIC SYMPTOMS

Variations in plaque composition could make carotid artery plaques pro ne to ulceration, subintimal hemorrhage, plaque progression, or emboli zation and, thus, increase the risk of ipsilateral ischemic neurologic events. Seventy-eight carotid endarterectomy specimens from 74 patien ts (38 symptomatic and 36 asymptomatic) were analyzed. Prior to analys is, 43 of the 78 plaques were divided into sections based on disease s everity and examined by light microscopy for surface ulceration and su bintimal hemorrhage. Extracted lipid, cholesterol, collagen, and calci um content were determined in all 78 plaques and compared to clinical presentation and/or morphologic observations. Plaques removed from sym ptomatic patients contained more extracted lipid and cholesterol than those from asymptomatic patients. In addition, compared to the remaind er of the plaque, the most stenotic portion of the plaque contained mo re cholesterol, more calcium, and less collagen. Finally, irrespective of clinical presentation, plaque sections found to have surface ulcer ation and subintimal hemorrhage contained more cholesterol and less co llagen than plaques without these changes. Lipid-laden plaques with lo w levels of collagen are associated with plaque ulceration, subintimal hemorrhage, and ischemic neurologic symptoms. This suggests that plaq ue composition may be an important factor in the pathophysiology of ca rotid atherosclerosis. (C) 1995 Academic Press, Inc.