The Correlation Between Ambulatory Blood Pressure And Cerebral Microbleeds In Ischemic Stroke Patients

Backgroud:With the clinical application of SWI,more and more brain microbleeds were detected.In recent years,researchers are increasingly aware of the importance of CMBs,because that is one of the markers of cerebrovascular disease.CMB is a brain parenchymal subclinical syndrome characterized by minimal hematopoietin deposition in the brain.Typical CMBs are defined as circular or round-shaped,low-signal lesions(generally 2-5 mm in diameter,but sometimes up tolO mm)on SWIL with clear edges and no edema around them.CMBs are currently found closely related to cerebral hemorrhage,and can predict the recurrence of stroke,also can cause cognitive dysfunction?gait disorder.depression and other central nervous system dysfunction.The incidence of CMBs are associated with a number of factors,and the most important reversible risk factor is hypertension.The incidence of CMBs will increase with increasing blood pressure.Blood pressure variability(BPV)is a vascular risk factor and closely related to the target organ damage of hypertension in recent years.However,there are scanty reports about the relationship between BPV and cerebral microbleeds.Objective:To investigate the correlation between ambulatory blood pressure and cerebral microbleeds in ischemic stroke patientsMethods:A total of 122 patients collected from July 2015 to November 2016 to Qilu Hospital Department of Neurology hospitalized were analyzed,who were suffered from acute ischemic stroke.Patients were divided into two groups.One was CMBs group(n=72),the other was non-CMBs group(n=50)according to the susceptibility weighted imaging of(SWI).The age,sex,smoking,alcohol consumption,history of hypertension,history of diabetes,history of cerebrovascular disease and history of coronary heart disease have been recorded in detail.The total biochemical indexes(total cholesterol,triglyceride,low density lipoprotein,apo lipoprotein B,homocysteine,creatinine and urea nitrogen)were measured 24 hours after admission and the head magnetic resonance imaging(MRI)and magnetic Sensitive weighted imaging(SWI),electrocardiogram,echocardiography,cervical blood pressure ultrasonography and other tests.In this study,subgroups were divided into three groups according to the location of CMBs:deep,subscapular and lumbar.And according to the number of CMBs,subgroups were divided into four groups:zero,mild,moderate,and severe.The ambulatory blood pressure monitoring was used to measure the blood pressure level parameters,including 24 h mean systolic blood pressure(24h SBP),mean daily systolic blood pressure(DSBP),24 hour systolic blood pressure-standard deviation(24h SBP-SD),24 hour diastolic blood pressure standard deviation(24h DBP-SD)?day syst-olic blood pressure(DSBP)?day systolic blood pressure-standard deviation(DSBP-SD)?day diastolic blood pressure(DDBP)?day diastolic blood pressure-standard deviation(DDBP-SD)?night systolic blood pressure(NSBP)?night systolic blood pressure-standard deviation(NSBP-SD)?night diastolic blood pressure(NDBP)?night diastolic blood pressure-standard deviation(NDBP-SD)?24 hour systolic blood pressure-coefficient of variation(24h SBP-CV)?24 hour diastolic blood pressure-coeff-icient of variation(24h DBP-CV)?day systolic blood pressure-coefficient of variation(DSBP-CV)?day diastolic blood pressure-coefficient of variation(DDBP-CV)?night systolic blood pressure-coefficient of variation(NSBP-CV)?night diastolic blood pressure-coefficient of variation(NDBP-CV),nighttime systolic blood pressure reduction rate,nighttime diastolic blood pressure reduction rate.We assessed determinants of incident microbleeds in relation to risk factors and ambulatory blood pressure.Results:1.General information comparisonThe history of diabetes mellitus.the history of drinking,total cholesterol and low density lipoprotein are not associated with CMBs The history of homocysteine,hypertension and smoking was significantly higher in those who had cerebral microbleeds(P<0.05).2.Comparison of Dynamic Blood Pressure ParametersThe levels of SBP,24h DBP,DSBP,DDBP,NSBP and NDBP in CMBs group were significantly higher than those in without CMBs group(P<0.05).In the univariate analysis,24h DBP-CV,DDBP-CV,?SBP,?DBP are associated with CMBs.Multivariate logistic regression analysis showed that only?DBP was associated with CMBs(P<0.05).3.Comparison of different numbers of brain microbleeds and ambulatory blood pressureAccording to the number of CMBs were divided into four groups,were non-CMBs group,mild CMBs group,moderate CMBs group,severe CMBs group.The results showed that 24h SBP,24h DBP,DSBP,DDBP,NSBP and NDBP increased with the increase of CMBs(P<0.05).The ?SBP of moderate CMBs group and severe CMBs group was lower than that of non-CMBs group(P<0.05).There was significant difference about ?DBP between mild CMBs group,moderate CMBs group and severe CMBs group(P<0.05).4.Comparison of brain microbleeds and blood pressure variability in different partsAccording to the different parts of CMBs,divided into brain lobe CMBs,deep CMBs.subtentorial CMBs,mixed CMBs four categories.The results showed that 24h DBP-CV,DDBP-CV and ?DBP were correlated with the different parts of CMBs,while 24h SBP-CV,DSBP-CV and ?SBP were only related to deep CMBs(P<0.05).Multivariate regression analysis showed that DDBP-CV,DDBP-CV and ?DBP were independent risk factors for deep CMBs(P<0.05),that DDBP-CV and ?DBP were independent risk for subtentorial CMBs(P<0.05),that ?DBP was an independent risk factor for mixed CMBs(P<0.05).There was no associated in the incidence of CMBs with 24h and DBP-CV,DDBP-CV and ?DBP(P<0.05).Conclusion:When the patient has a long history of high blood pressure and poor control,long history of smoking and hyperhomocysteinemia should be a highly vigilant to cerebral microbleeds and timely doing brain-sensitive magnetic resonance imaging sequence diagnosis.Blood pressure variability is an important factor in CMBs.DDBP-CV,DDBP-CV and ?DBP are independent risk factors for deep brain CMBs.DDBP-CV and ?DBP are independent risk factors for infratentorial location.