Clinical Research About Intracranial Atherosclerotic Plaque,Inflammatory Biomarkers And Ischemic Stroke

Background:Atherosclerotic disease is a major cause of ischemic stroke.About 8-10%of strokes in the United States are caused by intracranial atherosclerotic disease,and in Asia is about 20-30%.There are several studies suggest that strong contrast enhancement of plaque in magnetic resonance imaging maybe relate to greater neovascularization and increased endothelial permeability,both of which ficilitate the delivery and accumulation of the gadolinium-containing contrast agents into plaque.The development of technology has made it possible to observe intracranial plaques in vivo.Many studies of vascular wall imaging on HR-MRI have demonstrated that HR-MRI can distinguish different intracranial arterial diseases such as atherosclerosis,arteritis,vasospasm,dissection or moyamoya disease.As a new emerging technology HR-MRI can clearly show the components of carotid and intracranial atherosclerotic plaques such as lipids,fibrous caps,and calcification,and has good consistency with pathological findings.HR-MRI is the ideal way to observe intracranial plaque in vivo.Studies have shown that the development of symptomatic intracranial atherosclerotic stenosis(ICAS)is associated with inflammatory factors,such as C-reactive protein,E-selectin,intercellular adhesion molecule,matrix metalloprotein-9,Plasminogen activator inhibitor-1(PAI-1)and lipoprotein a,whereas only CRP and PAI-1 are the independent risk factors.Elevated inflammatory markers are associated with poor clinical outcomes.Objective:This study was to investigate the relationship between atherosclerotic plaque enhancement,vascular stenosis and blood inflammatory markers in acute ischemic stroke.Methods:A retrospective analysis was performed on the fifty-two patients with intracranial atherosclerotic artery stenosis(ICAS)who had underwent HR-MRI examination at Province Hospital Affiliated to Shandong University from January 2015 to December 2016.Each stenosis was classified as either mild stenosis(when the stenosis of the artery was less than 50%)or moderate-severe stenosis(when the stenosis of the artery was more than 50%).Each identified plaque was classified as acute stroke plaque(the only or most stenotic lesion upstream from a acute stroke),chronic stroke plaque(the only or most stenotic lesion upstream from a chronic stroke),or asymptomatic plaque(not within the territory of a stroke).Plaque contrast enhancement was categorized on HR-MRI(non-enhancement,no significant changes after contrast;mild enhancement,enhancement greater than non-enhancement but less than great enhancement;great enhancement,enhancement greater than or equal to that of pituitary infundibulum),and the degree of contrast enhancement of each plaque was calculated.Association of the likelyhood of being a acute stroke plaque with both plaque enhancement and vascular stenosis were estimated with logistic regression.Collect the results of blood level of C-reactive protein,peripheral leukocyte count and neutrophils ratio.The relationships between these inflammatory biomarkers and acute stroke were analyzed.Results:A total of 52 patients(36 men;mean age,59.2 10.8 years old;range from 28 to 78 years old)with ICAS were studied.Statistical analysis showed that there was no significant difference in the peripheral leukocyte count and neutrophils ratio between the acute stroke patients and the non-acute stroke patients.But the level of C-reaction protein was associated with acute stroke.Plaque contrast enhancement were compared between acute stroke groups,chronic stroke groups,and asymptomatic groups by using the Kruskal-Wallis test and the results showed significant differences(P<0.05).In these patients,moderate-severe stenosis was associated with acute stroke(P=0.01,odd ratio 16.616;95%confidence interval:1.963-140.619)when adjusted for plaque enhancement.Summary and conclusions:C-reaction protein is associated with acute ischemic stroke.Moderate-severe stenosis is an independent risk factor for acute ischemic stroke when adjusts for plaque enhancement,while plaque enhancement was not an independent risk factor when adjusts for stenosis.