An Observation And Analysis Of The Risk Factors For Silent Brain Infarction In Patients With Internal Carotid Artery Stenosis

ObjectiveSilent brain infarction(SBI)is associated with an increased risk of symptomatic stroke,post-stroke depression,vascular dementia,and perioperative death after carotid endarterectomy.It would be beneficial for the decrease of SBI prevalence to recognize the risk factors of SBI.We aimed to investigate the possible risk factors of SBI in patients with unilateral internal carotid artery(ICA)stenosis.MethodsWe enrolled the patients with unilateral ICA stenosis admitted to our hospital from September 2018 to December 2019 retrospectively and continuously.SBI was evaluated separately ipsilateral and contralateral to the stenosed ICA on the sequence of T1-weighted,T2-weighted,fluid attenuated inversion recovery(FLAIR)of magnetic resonance imaging(MRI).According to the presence of SBI on the side ipsilateral to stenosed ICA,the enrolled patients were divided into SBI group and non-SBI group,between whom the following items were compared: patients’ age,sex,medical history(hypertension,diabetes,coronary heart disease,atrial fibrillation),smoking history,medication history,body mass index,systolic pressure,diastolic pressure,total cholesterol(TC),triglycerides,low density lipoprotein cholesterol(LDL-C),high density lipoprotein cholesterol(HDL-C),fasting blood glucose,glycated hemoglobin,uric acid,creatinine,homocysteine,completeness of the circle of Willis,subcortical and periventricular white matter hyperintensities(WMHs),plaque morphology and echo characteristics and degree of ICA stenosis.Meanwhile,according to the presence of SBI on the side ipsilateral to the stenosed ICA,the enrolled patients with acute cerebral infarction and those without were divided into SBI group and non-SBI group respectively,between whom the above items were also compared.Results1.We enrolled 274 patients with unilateral ICA stenosis ≥50%,with mean age of 70.00 ± 10.31 years old.There were 133 patients had ipsilateral SBI(48.54%)and and 141 patients(51.46%)did not have ipsilateral SBI.Multivariate logistic regression analysis showed that male(OR=1.87,P=0.016),hypertension(OR=2.14,P=0.004),elevated serum creatinine level(OR=1.84,P=0.021),subcortical WMHs(OR=1.88,P<0.001),periventricular WMHs(OR=1.17,P=0.017),irregular/ulcerative plaques(OR=10.71,P<0.001),hypoecho plaques(OR=1.47,P=0.041)and mixed echo plaques(OR=1.35,P=0.041)were independent risk factors for ipsilateral SBI in patients with ICA stenosis.ICA stenosis patients with increased level of HDL-C(OR=0.60,P=0.045)and completeness of the circle of Willis(OR=0.27,P<0.001)had a lower risk of ipsilateral SBI.2.In all the enrolled patients,there were 137 patients(50.00%)with acute cerebral infarction.Among them,73 patients(53.28%)had SBI ipsilateral to the stenosed ICA and 64 patients(46.72%)did not.Multivariate logistic regression analysis showed that male(OR=1.87,P=0.016),hypertension(OR=2.25,P=0.031),elevated serum creatinine level(OR=2.75,P=0.004),subcortical WMHs(OR=2.47,P<0.001),periventricular WMHs(OR=1.64,P=0.007),irregular/ulcerative plaques(OR=7.69,P=0.002),hypoecho plaques(OR=1.12,P=0.036)and mixed echo plaques(OR=3.39,P=0.036)were independent risk factors for ipsilateral SBI in patients with ICA stenosis and acute cerebral infarction.ICA stenosis patients with increased level of HDL-C(OR=0.41,P=0.012)and completeness of the circle of Willis(OR=0.31,P=0.002)had a lower risk of ipsilateral SBI.3.In all the enrolled patients,there were 137 patients(50.00%)without acute cerebral infarction.Among them,60 patients(43.80%)had SBI ipsilateral to the stenosed ICA and 77 patients(56.20%)did not.Multivariate logistic regression analysis showed that male(OR=2.22,P=0.029),hypertension(OR=2.25,P=0.031),elevated serum creatinine level(OR=1.12,P=0.043),subcortical WMHs(OR=1.64,P=0.004),periventricular WMHs(OR=1.71,P=0.005),irregular/ulcerative plaques(OR=7.69,P<0.001),hypoecho plaques(OR=2.10,P=0.038)and mixed echo plaques(OR=2.72,P=0.038)were independent risk factors for ipsilateral SBI in patients with ICA stenosis and without acute cerebral infarction.ICA stenosis patients with increased level of HDLC(OR=0.42,P=0.031)and completeness of the circle of Willis(OR=0.24,P=0.004)had a lower risk of ipsilateral SBI.Conclusions1.In patients with unilateral ICA stenosis,male,hypertension,reduced HDL-C,elevated creatinine,irregular/ulcerative plaques,hypoecho plaques,mixed echo plaques,subcortical and periventricular WMHs,and incompleteness of the circle of Willis are independent risk factors for SBI.2.The independent risk factors for SBI were similar in patients with unilateral ICA stenosis with or without acute cerebral infarction.