International Journal of Neuroscience, 2015; 125(1): 50–55 Copyright © 2015 Informa Healthcare USA, Inc. ISSN: 0020-7454 print / 1543-5245 online DOI: 10.3109/00207454.2014.905777

RESEARCH ARTICLE

The ABCD2 score is better for stroke risk prediction after anterior circulation TIA compared to posterior circulation TIA Junjun Wang,1 Jimin Wu,2 Rongyi Liu,2 Feng Gao,2 Haitao Hu,2 and Xinzhen Yin2 Int J Neurosci Downloaded from informahealthcare.com by Nyu Medical Center on 06/16/15 For personal use only.

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Department of Neurology, Zhejiang Hospital, Hangzhou, China and 2 Department of Neurology, The Second Affiliated Hospital of Zhejiang University, Hangzhou, China Objective: Transient ischemic attacks (TIAs) are divided into anterior and posterior circulation types (AC-TIA, PC-TIA, respectively). In the present study, we sought to evaluate the ABCD2 score for predicting stroke in either AC-TIA or PC-TIA. Methods: We prospectively studied 369 consecutive patients who presented with TIA between June 2009 and December 2012. The 7 d occurrence of stroke after TIA was recorded and correlated with the ABCD2 score with regards to AC-TIA or PC-TIA. Results: Overall, 273 AC-TIA and 96 PC-TIA patients were recruited. Twenty-one patients with AC-TIA and seven with PC-TIA developed a stroke within the subsequent 7 d (7.7% vs. 7.3%, p = 0.899). The ABCD2 score had a higher predictive value of stroke occurrence in AC-TIA (the AUC was 0.790; 95% CI, 0.677–0.903) than in PC-TIA (the AUC was 0.535; 95% CI, 0.350–0.727) and the z-value of two receiver operating characteristic (ROC) curves was 2.24 (p = 0.025). AC-TIA resulted in a higher incidence of both unilateral weakness and speech disturbance and longer durations of the symptoms. Inversely, PC-TIA was associated with a higher incidence of diabetes mellitus (19.8% vs. 10.6%, p = 0.022). Evaluating each component of scores, age ≥ 60 yr (OR = 7.010, 95% CI 1.599–30.743), unilateral weakness (OR = 3.455, 95% CI 1.131–10.559), and blood pressure (OR = 9.652, 95% CI 2.202–42.308) were associated with stroke in AC-TIA, while in PC-TIA, diabetes mellitus (OR = 9.990, 95% CI 1.895–52.650) was associated with stroke. Conclusion: In our study, the ABCD2 score could predict the short-term risk of stroke after AC-TIA, but might have limitation for PC-TIA. KEYWORDS: ABCD2 score, anterior circulation, posterior circulation, stroke, transient ischemic attack

Introduction Transient ischemic attack (TIA), as a type of cerebrovascular disease, is also an early warning signal of a subsequent cerebral infarction. In both population- or hospital-based studies, the pooled risks of stroke after TIA were 3.1% at 2 d and 5.2% (range, 0 to 12.8%) at 7 d [1]. Therefore, it is important to identify the highrisk patients. Several systems, including the ABCD2 score, have been developed to triage TIA patients in recent years. Although Ghia et al. [2] reported that moderate-to-high ABCD2 scores did not predict early stroke risk, most published data have confirmed the ability of ABCD2 scoring systems to identify patients with Received 16 January 2014; revised 14 March 2014; accepted 14 March 2014. Correspondence: Professor Jimin Wu, Department of Neurology, The Second Affiliated Hospital of Zhejiang University, #88 Jiefang Road, Hangzhou 310000, China. Fax: 086-571-87784751. E-mail: [email protected]

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a high risk of stroke in the short-term period after a TIA [3–7] no matter there was lesion on MR diffusionweighted imaging (MR-DWI) or not [8]. The brain derives its vascular supply from the internal carotid artery (anterior circulation) and vertebrobasilar artery (posterior circulation), and strokes are clinically divided into anterior or posterior types. A previous study revealed that 81.8% of strokes occurred in the anterior circulation, with the remaining 18.2% in the posterior circulation [9]. Clinical differences exist between these two subtypes. Sato reported that the baseline NIHSS score was lower in posterior circulation strokes compared with anterior circulation strokes [10]. Moreover, patients presenting with TIA or minor stroke in posterior circulation were at a higher risk for subsequent stroke in the acute phase than anterior circulation from cohort studies [11]. In recent years, ABCD2 score has been proved to have a high degree of validity in the stratification in TIA

Validation of the ABCD2 Score in AC- and PC-TIAs

patients. The American Heart Association/American Stroke Association (AHA/ASA) recommends that TIA patients with an ABCD2 score ≥3 should be hospitalized [12]. However, regarding the differences that have already been found between anterior and posterior TIA (AC-TIA and PC-TIA, respectively), we propose that this scoring system may have different predictive capacities in these two types of TIA. We thus conducted the current study to assess the value of the ABCD2 system for predicting stroke risk after either AC-TIA or PC-TIA.

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Methods We prospectively enrolled a total of 521 consecutive patients who were admitted with a TIA to The Second Affiliated Hospital of Zhejiang University between June 2009 and December 2012. All patients attended hospital within 72 h after the onset of symptoms. The patients were all recruited from the emergency department or neurological clinic, and all had developed a sudden onset of the neurological deficits. The diagnosis was made by attending neurologists before patient selection. TIA was defined as a transient episode of neurological dysfunction caused by focal brain ischemia without acute infarction [12]. Anterior and posterior territories were defined by the following clinical criteria by two senior experienced neurologists [13–15]: Anterior circulation: (1) motor deficits (one extremity or of both extremities on the same side); (2) sensory deficits (one or both extremities on the same side); (3) aphasia (speech and/or language disturbance); (4) loss of vision in one eye or in part of one eye; (5) homonymous hemianopia and (6) any combinations of the above. Posterior circulation: (1) motor deficits (any combination of extremities up to quadriplegia, sometimes changing from one side to another in different attacks); (2) sensory deficits (any combination of extremities including all four or involving both sides of the face or mouth. This is frequently bilateral or may change from side to side in different attacks); (3) loss of vision complete or partial in both homonymous fields; (4) homonymous hemianopia; (5) ataxia not associated with vertigo; (6) vertigo, diplopia, dysphagia and dysarthria are not considered to indicate a TIA when any of these symptoms occur alone, but are if they occur in combination with one another or with any of the above (1–4) and (7) any combinations of the above. The following 152 patients were ineligible and were excluded from the study: (1) TIA-mimics such as epilepsy, hypoglycemia, hysteria and so on, was confirmed by electroencephalography, vascular imaging and  C

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other examinations, with a history of cerebrovascular risk factors and treatments; (2) those who presented with a single symptom or sign, such as dizziness, vertigo, diplopia, dysphagia and dysarthria; (3) those who were diagnosed with benign paroxysmal positional vertigo through either Dix-Hallpike test or Rollover test; (4) an MRI or CT scan showed hemorrhagic or ischemia lesions; (5) those with incomplete clinical data or in whom the ABCD2 score could not be calculated correctly and (6) those were difficult to classify clinical episodes into AC- or PC-TIA. The Regional Ethics and Hospital Management Committees approved the study. All patients enrolled were evaluated with the ABCD2 score by a neurologist at the time of admission to the emergency department or neurological clinic. The score was based on five factors: age ≥60 years (1 point); systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg (1 point); clinical features: unilateral weakness (2 points), speech impairment without weakness (1 point); duration ≥60 min (2 points) or 10–59 min (1 point) and diabetes mellitus (1 point) [5]. The first blood pressure recording after the TIA during the consultation was used for the ABCD2 score. Baseline data were collected for all eligible patients, including gender, age and risk factors; the latter included hypertension, diabetes mellitus, hypercholesterolemia, previous stroke, coronary disease, atrial fibrillation (AF) and a history of smoking. Hypertension was defined as systolic blood pressure ≥140 mmHg, or diastolic blood pressure ≥90 mmHg, or the current use of antihypertensive agents based on the WHO hypertension definition; diabetes mellitus was set as a fasting plasma glucose level >126 mg/dl (7.0 mmol/l), a random plasma glucose >200 mg/dl (11.1 mmol/l) or the current use of anti-diabetic agents based on the ADA guidelines; hypercholesterolemia was defined as a total cholesterol >240 mg/dl or the current use of a lipid-lowering medication; previous stroke was defined as a history of stroke with neurological deficits; coronary disease was defined as a history of myocardial infarction or acute coronary syndrome; AF was defined as pre-existing AF or that was newly detected on an electrocardiogram or by continuous cardiac rhythm monitoring; smoking was defined as a history of current or former regular smoking. All patients were recommended to be hospitalized and underwent the following examinations: blood routine test, serum biochemistry, myocardial enzyme and coagulation assays, electrocardiogram, dynamic electrocardiogram (DCG), transthoracic echocardiography (TTE) and brain and vascular imaging (either CT or MRI). According to the pathogenesis of TIA, patients were immediately treated according to the guidelines of the European Stroke Organization [16] with an antiplatelet agent (aspirin or clopidogrel), and statins if needed. Low molecular weight heparin was commenced

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J. Wang et al.

immediately after the detection of AF, or if symptoms progressed. Patients were followed-up to assess for a subsequent stroke within 7 d after TIA onset during the period of hospitalization. Stroke was defined as a rapidly developing focal or global disturbance of cerebral function, which lasted for more than 24 h and was confirmed by brain imaging [17], and it was confirmed by two neurologists using neurological examinations and brain imaging if necessary. Statistical analysis was performed using an SPSS statistical software package, SPSS version 17.0 (SPSS Inc., Chicago, IL). Chi-squared (χ 2 ) tests or Fisher’s exact tests were used for categorical variables. Continuous variables were compared using t-tests. The predictive ability of the ABCD2 scores was evaluated by the receiver operating characteristic curves (ROCs). Areas under the ROC curves (AUC) and 95% confidence intervals (CIs) were calculated as a measure of predictive ability with ideal prediction producing a value of 1.00, whereas no better than chance prediction was represented by 0.50. Logistic regression model was used to identify variables associated with the occurrence of the stroke. Associations were presented as the odds ratios (ORs) with corresponding 95% CIs. A p-value of

The ABCD2 score is better for stroke risk prediction after anterior circulation TIA compared to posterior circulation TIA.

Transient ischemic attacks (TIAs) are divided into anterior and posterior circulation types (AC-TIA, PC-TIA, respectively). In the present study, we s...
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