Assessment Of Ischemic Stroke Recurrence Risk

Purpose: Ischemic stroke is a kind of highly heterogeneous disease. Different causes, pathophysiology and risk factors affect different treatment and prevention measures of stroke patients, also determine different recurrence risk of patients with stroke. Therefore, stratification of patients with acute ischemic stroke by risk of recurrent stroke can contribute to optimized treatment and secondary prevention.Prediction scores could help to identify those patients with ischemic stroke at high risk of recurrent stroke, so as to raise awareness of recurrent stroke risk in both patients and physicians and select rational secondary prevention. The Essen Stroke Risk Score is a simple and convenient 9-point scale for clinical use. The ESRS was derived from the data subset of 6431 patients with ischemic stroke in the large-scale the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial. It is a predictive scale for recurrence stroke in non-AF stroke patients. It takes the patients′age, HT, DM, smoking history, myocardial infarction history etc vascular risk factors as score index. It stratifies patients according to the future risk of cerebrovascular events. Already the ESRS has been validated in large cohort patients with stroke to predict stroke and combined cerebrovascular events effectively and valuably. Several studies show that recurrence risk of stroke patients of ESRS below 3 points is less than 4% , for low risk crowd, 3-6 is divided into high risk, in stroke risk of recurrence of 7% - 9%, six points above for extremely high risk, the risks of stroke recurrences in 11%.The modified TOAST classification system defined five causes of stroke after referring the clinical information and test, which includes: Atherothrombosis (AT), Small Artery Disease (SAD), Cardioembolism (CE), Other Determined Etiology and Undetermined Etiology. This classification system had high accuracy and reliability based on the modified diagnostic criteria of stroke subtype of the Trial of ORG 10172 in the Acute Stroke Treatment (TOAST), it especially enhanced screening rates of AT. AT is the most common subtype of acute ischemic stroke in Asian population, more than half of patients with stroke in our coutry belong to Atherothrombosis. AT is as the main type of non-AF-type stroke. There are great difference of the clinical manifestations, pathogenesis, clinical outcomes and risk of recurrence between AT and SAD, especially the patients of AT with an artery - artery embolization mechanism, received endovascular interventional treatment, and accompanied by DM, coronary heart disease, metabolic syndrome, smoking or atherosclerosis risk factors. As the very high-risk recurrent groups of stroke, they should give separately different levels of antithrombotic, lipid-lowering treatment to prevent stroke recurrence according to risk classification. There are reports of AT recurrence risk in more than 19%, and SAD less than 4%.Current due to lack of large sample sizes to evaluate the validity and accuracy of various assessment scales of the risk of ischemic stroke recurrence, this research takes the AT and SAD subtypes patients as research subjects, and compares ESRS of them according to modified TOAST etiology classification, then to observe that whether it is different to identify patients at high risk of stroke recurrence by TOAST etiology classification and ESRS.In this research, ESRS mainly evaluates recurrence risk of stroke between AT and SAD. There is short of a large sample clinical research to evaluate whether it could accurately evaluate recurrence risk of patients with different etiology. Therefore, this research verifies the accuracy of ESRS based on modified TOAST classification.Methods:Review data from the consecutive patients admitted acute ischemic stroke cases in Neurology department of the Third Hospital of Hebei Medical University from January 2007 to October 2010. The patients of the AT and SAD subtypes were evaluated by the ESRS. At last compare whether there are difference between two methods of identifying patients at high risk recurrence of stroke. Results:1 A total of 725 patients with acute ischemic stroke (59.6% men) with a mean age of 65.1 years were included in this study. 72.1% of patients have a history of hypertension; patients with hyperlipidemia 49.0%; history of TIA or ischemic stroke 43.2%; diabetes 40.9%; smoking 35.1%; coronary heart disease 20.7%; peripheral arterial disease 3.1%. The risk factors in the distribution of different populations are different.2 Classified by the modified TOAST etiology classification, the result shows that AT subtype patients 533 cases, SAD subtype ones 192 cases. We scored the patients by Essen stroke risk score, there are 398 (55.6%) patients belonging to high risk crowd with the ESRS≥3, 327 (44.4%) patients belonging to low risk crowd with the score <3. The result shows that in AT subtypes:<3 points 211 cases (38.9%), 3-6 points 318 cases (60.47%) , >6 points 4 cases (0.7%); in SAD subtypes:<3 points 116 cases (59.7%), 3-6 points 76 cases (40.3%), >6 points 0 case. Age<65 years, AT 257 cases (48.3%), patients of ESRS≥3 points 187 cases (46.6%); 65-75 years crowd, AT 164 cases (30.6%), patients of ESRS≥3 points 105 cases (26.5%); >75 years crowd, AT 111 cases (21.1%), patients of ESRS≥3 points 106 cases (26.9%).3 It is inconsistent to identify high-risk group by TOAST classification and the ESRS evaluation (P<0.05). Considered the age factor, we discovered that in the groups of age≤75 it is inconsistent to identify high-risk group by the methods (P<0.05), but in the age>75 group it is not obvious difference (P>0.05).Conclusion:1 In this study, all patients are evaluated by the ESRS, only 61.10% of AT subtype patients were classified as high-risk group of stroke recurrence, while 38.9% is less than 3 points as the low-risk ones. And more than 40% of SAD subtype patients were classified as high-risk group of stroke recurrence. It shows that the two assessment methods for the assessment of high recurrence risk of stroke were significantly different, and relative to the modified TOAST classification, ESRS can not be a good assessment of patients of high recurrence risk.2 Divided all patients into 3 groups according to the age<65, 65-75, >75, the result shows that following age the proportion of high risk patients is increasing according to the ESRS, this existing good consistency with AT subtype patients; and following age, the low risk patients in SAD also displays a progressive trend to decrease. For patient of age>75 year-old, ESRS could evaluate recurrence high-risk of stroke well; but for age≤75 years patients, on the high recurrence risk of stroke population screening ESRS is flawed. These results show age factor is very important for the ESRS. ESRS is only a kind of method for evaluating recurrence risk of ischemic stroke.3 As a tool of clinical prognostic evaluation, the modified TOAST classification has better clinical significance. It can guide clinicians to take scientifically risk stratification, effective secondary prevention and treatment, reasonable treatment to minimize the recurrences risk of ischemic stroke.