Analysis Of The Risk Factors For Cerebral Infarction Secondary To TIA And Prediction Of Early Stroke Risk

Objective: Transient Ischemic Attack（TIA） is a harbinger of cerebralinfarction, and it’s a super early warning signal. Therefore，clarifying the riskfactors which affect TIA development to stroke and predicting the risk ofinfarction which occurs early after TIA are common focuses of clinicians andpatients. And the identification of high-risk groups of cerebral infarction anddrawing up the individualized treatment plan have important clinicalsignificances to reduce the incidence of cerebral infarction. The purpose ofthis study is a clinically prospective follow-up study of181patients with TIA,to explore the relationship between the risk factors and secondary stroke, andthen provide the basis for clinical treatment and prognosis of TIA. And antherpurpose is to evaluate four methods: ABCD~2, ABCD~2L (ABCD~2+LDL),ABCD~3L and ABCD~3(ABCD~3+LDL) in forecasting early risk of stroke afterTIA, so as to screen out a more reliable method.Methods: Choose181TIA patients as study objects and make detailedrecords of their basic information, including age, gender, past history(hypertension, diabetes, Cardiac insufficiency, atrial fibrillation,hyperlipidemia, previous history of stroke or TIA), family history ofcerebrovascular disease, smoking history, drinking history, clinical features(duration of initial symptoms, seizure frequency, onset times, onset totreatment time, the internal carotid artery system or vertebrobasilar system), aswell as the imaging data (CT or MRI), ultrasound examination of the neckvessels, EKG, blood routine, blood sugar, blood lipids, liver and kidneyfunction, etc. Then conduct follow-ups through phone calls or outpatientservices on the first, the third and the twelfth month respectively after they arechosen as objects, and ask them about their medicine use situation, whetherthey have gotten rid of smoking and drinking, as well as whether there is any occurrence of cerebral infarction and the time of the event. This project will beterminated when new cerebrovascular diseases show up or the death ofpatients occurs.First, the relationship between the risk factors and secondary cerebralinfarction after TIA is analyzed, using the chi-square test and P <0.05wasconsidered to indicate a statistically significant difference, which can screenout significant single factors serving as covariate, stroke as the dependentvariable in a multivariate logistic regression analysis, to get relatedindependent risk factors for TIA prognosis. Second, compare the accuracy ofthe four scoring methods: ABCD~2, ABCD~2L, ABCD~3, and ABCD~3L inpredicting the incidence of stroke within2days or7days after a TIA, andfilter out the most reliable method. Then a linear regression analysis is used tovalidate the predictive value of the most reliable method in predictingsecondary cerebral infarction after TIA within2days or7days. And we canmake use of this method in risk stratification for patients with TIA, andcompare the differences in the incidence of stroke among groups. All of theabove data is analysed with SPSS20.0software.Results: There are181patients satisfying requirements during thisproject, Statistical analysis of the181patients are as follows: all the patientsare at the age of22~80(average59.12±11.692);60out of the181patientsdevelop into cerebral infarction within1year; the cerebral infarction rate onthe first month, the third month and the twelfth month after TIA is18.78%,23.76%and33.15%respectively. There are2cases of acute coronarysyndrome, not cerebral hemorrhage or cerebral infarction. And cerebralinfarction in2days is8.29%, and14.92%within7days.As for clinical manifestation,142have problems in internal carotidsystem. There are53cases of cerebral infarction, accounting for88.33%. Outof this142patients,113of them have symptoms of single paralysis orhemiplegia;55of them dysarthria or aphasia;38of them hemisensoryobstacles;8of them blurred vision or visual defect;1of them transientamaurosis. The rest39patients have problems of vertebrobasilar system. There are7cases of cerebral infarction, accounting for1.67%, which includevertigo38cases, disturbance of consciousness4cases, falls attack3cases,balance disorder2cases and diplopia4cases.Analysis has been conducted on the relationship between incidence ofstroke after TIA within1year and the duration of initial symptoms, seizurefrequency, onset times, onset to treatment time. The results are as follows:1Compared to duration time <10min group, the group with duration10~29min and>30min have higher incidence of cerebral infarction withinone year, with a statistically significant difference (P <0.05), while the groupswith duration time10~29min and>30min have no significant statisticaldifference (P>0.05).2One time before treatment,2~3times before treatment and>3times,pairwise comparison of these three groups are statistically significant (P <0.05). The more times TIA happens before the treatment, the higher incidenceof cerebral infarction may be.3Seizure frequency <1/d, seizure frequency1~3times/d and>3times/d, pairwise comparison of these three groups were statisticallysignificant (P <0.05). The more seizure frequency, the greater the probabilityof the occurrence of cerebral infarction.4Compared to onset to treatment time <6h group, onset to treatmenttime6~24h group and24h group have higher incidence of cerebralinfarction within one year, the differences are statistically significant (P <0.05), while onset to treatment time6~24h group and>24h group have nostatistically significant difference (P>0.05).Analysis has been conducted on the comparison of incidence of cerebralinfarction1-year after TIA in patients with carotid stenosis or obliteration invarious degree.The results are as follows:There is a statistically significant difference between ICA stenosis orobliteration in various degree and incidence of cerebral infarction.Comparedto ICA Stenosis (<50%) group, ICA Stenosis (50%~75%) group and ICAStenosis (>75%) group have higher incidence of cerebral infarction within one year, the differences are statistically significant (P <0.05), while ICA Stenosis(50%~75%) group and ICA Stenosis (>75%) group have no statisticallysignificant difference (P>0.05).Analysis has been conducted on relationship between incidence ofcerebral infarction of TIA patients within1year and risk factors such asgender, age, hypertension, diabetes, hyperlipidemia, cardiac insufficiency,artery systems involved, family history of cerebrovascular disease, previoushistory of stroke or TIA, atrial fibrillation, smoking history and drinkinghistory. Single factor analysis shows that meaningful influencing factors ofincidence of cerebral infarction on TIA patients within1year include age≥60,medical history of hypertension and diabetes, hyperlipidemia, cardiacinsufficiency, artery systems involved, family history of cerebrovasculardisease, as well as previous history of stroke or TIA (P <0.05).To exclude mutual interference between the factors and control theconfounding factors, significant factors are put in the multivariateunconditional Logistic regression analysis. Bounded by levels of α=0.05,multi-factor logistic regression analysis shows that the four factors ofhypertension, diabetes, hyperlipidemia, and onset times>3are the dangerousfactors in TIA patients’ development into cerebral infarction within1year (P<0.05).There is a significant correlation between the level of LDL and incidenceof cerebral infarction after TIA in2days and7days.When predicting stroke risk within two days, the AUCs (95%CI) ofABCD~2, ABCD~2L, ABCD~3, ABCD~3L are0.783(0.679~0.887),0.841(0.750~0.931),0.908(0.859~0.958) and0.912(0.862~0.961) separately.When predicting stroke risk within seven days, the AUCs (95%CI) of ABCD~2,ABCD~2L, ABCD~3, ABCD~3L are0.814(0.732~0.894),0.872(0.809~0.935),0.915(0.872~0.959) and0.924(0.884~0.963) separately. As can be seen, areaunder the curve of ABCD~3L is the biggest.Linear correlation exists between ABCD~3L scoring and short-term risk ofcerebral infarction in TIA patients (P <0.05)．The higher the score is，the higher the incidence is.According to ABCD~3L scoring，the patients are divided into threegroups：low-risk group (score0~3)，moderate-risk group (score4~7) andhigh-risk group (score8~10)．The2-day risk of stroke are0％,9.41％,38.89％in there groups separately (P <0.05)．The7-day risk of stroke are0％,17.65％,66.67％in there groups separately (P <0.05).The ABCD~3Lscore of5is the best cut-off.Conclusions:1Cerebral infarction incidence rate on the second day, the seventh day,the first month, the third month and the twelfth month after TIA are8.29%,14.92%,18.78%,23.76.4%,33.15%respectively.2Risk factors that make TIA develop into cerebral infarction within1year include: hypertension, diabetes, hyperlipidemia, as well as onset times>3.3The LDL level in the cerebral infarction group is higher than thecontrol group (P <0.05). The level of LDL is related to the prognosis of TIA.4ABCD~2scoring and ABCD~3scoring are both effective to predict risk ofshort-term stroke after TIA，while the ABCD~3scoring is more reliable. Evenafter the combination with the LDL, which can improve the predictiveaccuracy, finding shows that the ABCD~3L is the most sensitive. Andaccording to the risk stratification of ABCD~3L scoring，the higher the score is,the higher the risk of secondary cerebral infarction is. We can identifyindividuals at high early risk of stroke after TIA．It can aid the clinicians in themanagement of patients with TIA．...