Risk Factors And Risk Of Ischemic Stroke In Asymptomatic Intracranial Arterial Stenosis

Objective The aim of this study was to investigate the Risk factors and risk of ischemic stroke in asymptomatic intracranial arterial stenosis（ICAS）,and to provide guidance for the management of risk factors for clinical asymptomatic ICAS and primary prevention of ischemic stroke.Methods A total of 588 patients admitted to the Department of Neurology of Minda Hospital affiliated to Hubei Minzu University from January 2015 to December 2019 were collected,and all of them had completed the head MRA examination.All the patients were divided into asymptomatic ICAS group and non-ICAS group according to the existence of ICAS.The risk factors of asymptomatic ICAS were analyzed by collecting the general information,medical history information and laboratory data of the patients.Clinical follow-up was performed in all patients.The risk of ischemic stroke in the two groups during the follow-up period was analyzed.Results（1）According to inclusion criteria and exclusion criteria,a total of 205 asymptomatic ICAS patients and 383 non-ICAS patients were collected.In all 205 asymptomatic ICAS patients,a total of 334 arterial stenosis were found,including 121cases（59.02%）with single stenosis and 84 cases（40.98%）with multiple stenosis.There were 246（73.65%）mild stenosis,53（15.87%）moderate stenosis and35（10.48%）severe stenosis.The incidence of mild stenosis was significantly higher than that of moderate and severe stenosis.According to the distribution of stenosis,there were 224（67.07%）stenoses in the anterior circulation and 110（32.93%）in the posterior circulation.Asymptomatic ICAS mainly occurred in anterior circulation.（2）Univariate analysis showed that there were statistically significant differences in age,gender,hypertension,diabetes,smoking history,drinking history,serum creatinine and uric acid between the two groups（P<0.05）.Multivariate logistic regression analysis showed that older age（OR=1.076,95%CI[1.056-1.095]）,male（OR=1.775,95%CI[1.059-2.974]）,hypertension（OR=2.050,95%CI[1.355-3.102]）and diabetes mellitus（OR=2.661,95%CI[1.266-5.592]）were independent risk factors for asymptomatic ICAS.（3）During a mean follow-up period of 45.35 months in 588 patients,a total of 21 patients had ischemic stroke,including 16 cases（7.8%）in the asymptomatic ICAS group and 5 cases（1.3%）in the non-ICAS group.According to COX proportional hazard regression analysis,after adjusting for age and hypertension,asymptomatic ICAS were independent risk factors for ischemic stroke（HR=3.640,95%CI[1.217-10.888]）.Conclusion（1）Asymptomatic ICAS is mainly characterized by mild stenosis,and the incidence of anterior circulation stenosis is higher than that of posterior circulation.（2）Older age,male,hypertension and diabetes were independent risk factors for asymptomatic ICAS.（3）Patients with asymptomatic ICAS have a higher risk of ischemic stroke than those without ICAS.