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|Year : 2021 | Volume
| Issue : 5 | Page : 1282-1284
Intracranial Large Artery Disease is Independently Associated with Poor Functional Outcome in a Cohort of Ethnic South Asian Ischemic Stroke Patients
Deidre A De Silva1, Chee-Keong Wee1, Fung-Peng Woon2, Hui-Meng Chang1, Meng-Cheong Wong3
1 Department of Neurology, National Neuroscience Institute, Singapore General Hospital Campus, Singapore
2 Department of Neurology, Singapore General Hospital, Singapore
3 National University Singapore, Singapore
|Date of Submission||25-Apr-2016|
|Date of Decision||31-Aug-2016|
|Date of Acceptance||05-Jan-2017|
|Date of Web Publication||30-Oct-2021|
Deidre A De Silva
Department of Neurology, National Neuroscience Institute, Singapore General Hospital Campus
Source of Support: None, Conflict of Interest: None
Background: Intracranial large artery disease (ICLAD) in ischemic stroke patients is associated with an increased risk for recurrent stroke; however, it is not known if ICLAD influences functional status following stroke. We studied the 6-month functional outcome in south Asian ischemic stroke patients and compared those with and without ICLAD.
Materials and Methods: This is a prospective cohort study of consecutive south Asian ischemic stroke patients. ICLAD was assessed with transcranial color-coded Doppler ultrasound or magnetic resonance angiography. Functional outcomes were obtained via telephone interviews with poor outcome defined as modified Rankin scale of 3–6.
Results: Of 216 ischemic stroke patients studied, 203 (93.9%) had follow-up data, of whom 50.7% (103) had ICLAD. Patients with ICLAD had a higher prevalence of hypertension (P < 0.001), hyperlipidemia (P = 0.047), ischemic heart disease (P = 0.030), and extracranial carotid disease (P = 0.005). A higher proportion of patients with ICLAD had poor functional outcome at 6 months (30.1%) versus those without ICLAD (13.0%) (P = 0.004). After adjusting for age, sex, hypertension, hyperlipidemia, diabetes, ischemic heart disease, atrial fibrillation, extracranial carotid stenosis, and recurrent vascular events, patients with ICLAD were 3.01 (95% confidence interval: 1.35–7.10) times more likely than those without ICLAD to have poor functional outcome.
Conclusions: The presence of ICLAD rendered poorer functional prognosis after stroke. These findings support the specific evaluation of the benefits of known acute stroke treatments such as thrombolysis, as well as investigation of potential novel strategies such as acute stenting.
Keywords: Functional outcome, intracranial atherosclerosis, ischemic stroke
Key Message: Ischaemic stroke patients with intracranial large artery disease (ICLAD) are 3 times more likely to have poor functional outcome compared to those without ICLAD. This association is independent of other known prognostic factors and thus provides evidence for further research to optimise hyperacute treatment of stroke due to ICLAD.
|How to cite this article:|
De Silva DA, Wee CK, Woon FP, Chang HM, Wong MC. Intracranial Large Artery Disease is Independently Associated with Poor Functional Outcome in a Cohort of Ethnic South Asian Ischemic Stroke Patients. Neurol India 2021;69:1282-4
|How to cite this URL:|
De Silva DA, Wee CK, Woon FP, Chang HM, Wong MC. Intracranial Large Artery Disease is Independently Associated with Poor Functional Outcome in a Cohort of Ethnic South Asian Ischemic Stroke Patients. Neurol India [serial online] 2021 [cited 2021 Dec 4];69:1282-4. Available from: https://www.neurologyindia.com/text.asp?2021/69/5/1282/329581
Intracranial large arteries are a common site of disease in ischemic stroke, particularly among Asian patients including ethnic south Asians., There are no proven acute treatments specific for ischemic stroke caused by intracranial large artery disease (ICLAD) and limited evidence of proven treatments such as stroke thrombolysis in subgroups with ICLAD. While ICLAD is associated with increased risk of recurrent stroke,, data regarding the influence of ICLAD on functional status following acute stroke are lacking. We studied the 6-month functional outcomes of ischemic stroke patients of south Asian ethnicity comparing those with and without ICLAD.
| » Materials and Methods|| |
This is a prospective cohort study of consecutive ethnic south Asians admitted for acute ischemic stroke from November 2003 to December 2007 to a 1400-bed tertiary care hospital in Singapore. Ischemic stroke was determined by the managing clinicians based on clinical presentation and imaging. Ethnicity was ascertained from patient interviews or as indicated in the patient's identification cards issued to all Singapore citizens and residents. Patients of mixed ethnicity were excluded. None of the patients received acute reperfusion therapy.
Assessment of ICLAD of internal carotid artery, middle cerebral artery, anterior cerebral artery, vertebrobasilar arteries, and/or posterior cerebral artery was performed with transcranial color-coded Doppler ultrasound (TCCD) or magnetic resonance angiography (MRA). ICLAD on TCCD was defined by previously established criteria. If there were poor acoustic/bone windows, we used MRA to assess ICLAD, which was defined as ≥50% luminal narrowing with or without loss of signal at the stenotic region. ICLAD was present if one or more vessels fulfilled the criteria. Extracranial carotid disease was assessed by Duplex ultrasonography; severe disease was defined as stenosis of ≥70% by the North American Symptomatic Carotid Endarterectomy Trial criteria or complete occlusion.
Telephone interviews with the patients or their caregivers were conducted by a trained research assistant at 6 months to ascertain functional status, scored with the modified Rankin scale (mRS) and incidence of recurrent vascular events (stroke, myocardial infarction, and vascular death). Poor functional outcome was defined as mRS 3–6.
Statistical analysis was performed using the Statistical Package for the Social Sciences software for Windows Version 21.0 (IBM Corp, Armonk, New York, USA). Chi-square test was used for comparison of dichotomous variables. Regression analyses were performed adjusting for covariates of age, sex, hypertension, hyperlipidemia, diabetes, ischemic heart disease (IHD); factors associated with stroke etiology, namely extracranial carotid disease and atrial fibrillation (AF); and recurrent vascular events. This study was approved by the hospital's ethics committee and written consent was obtained from all patients.
| » Results|| |
Among 240 consecutive south Asian ischemic stroke patients, 216 (90.0%) had ICLAD assessment, of whom 203 (93.9%) had follow-up data. The median age of these 203 patients was 64 years [interquartile range (IQR): 54–72); 70.4% (143) were males; 78.8% (160) had hypertension, 76.4% (155) had hyperlipidemia, 61.6% (125) had diabetes, 37.9% (77) had IHD, 4.9% (10) had AF; and 35.0% (71) were smokers.
The prevalence of ICLAD was 50.7% (103). Median age of patients with ICLAD (64, IQR: 56–72 years) was similar to those without ICLAD (62, IQR: 53–72 years) (P = 0.393). Patients with ICLAD had a higher prevalence of hypertension (91.2% vs. 66.0%; P < 0.001), hyperlipidemia (82.5% vs. 70.0%; P = 0.047), IHD (45.6% vs. 30.0%; P = 0.030), and extracranial carotid disease (16.7% vs. 4.0%; P = 0.005). Baseline National Institute of Health Stroke Scale (NIHSS) was higher in ICLAD patients (median NIHSS = 4; IQR 2–6) vs. non-ICLAD (median NIHSS = 3, IQR 1–4; P = 0.039). There were no differences in sex distribution between patients with ICLAD versus those without ICLAD (males 66.9% vs. 74.0%; P = 0.286), diabetes (66.9% vs. 56.0%; P = 0.115), prevalence of AF (5.0% vs. 4.8%; P = 1.000), or smoking (33.0% vs. 37.0%; P = 0.560).
In the overall cohort, 21.7% (44) had poor functional status and 8.9% (18) had a subsequent vascular event at six months poststroke. A higher proportion of patients with ICLAD had poor functional status (30.1% vs. 13.0%; P = 0.004). Subsequent vascular event rates were similar across both groups (ICLAD 10.6% vs. non-ICLAD 7.0%; P = 0.461). After adjusting for age, sex, hypertension, hyperlipidemia, diabetes, IHD, AF, extracranial carotid stenosis, and recurrent vascular events, the likelihood of poor functional outcome was higher for patients with ICLAD [odds ratio (OR) 3.01, 95% confidence interval 1.35–7.10; P = 0.008] compared to those without ICLAD [Table 1].
|Table 1: Regression Analysis of Prognostic Factors for Poor Outcome (modified Rankin Score 3-6) at six months following Ischemic Stroke|
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| » Discussion|| |
This study reveals the novel finding that ICLAD was associated with poor function at 6 months following stroke, independent of demographics, risk factors, other etiologies of stroke, and recurrent vascular events. The poorer functional outcome in patients with ICLAD could in part be accounted by their higher initial NIHSS, which was observed in this study and other published research.,
Based on our findings of poorer functional outcome and more severe baseline neurological deficits in stroke patients with ICLAD, the specific benefits and roles of acute reperfusion treatments including intravenous thrombolysis and mechanical thrombectomy should be investigated. There are data suggesting greater potential benefit from acute stroke reperfusion treatments in patients with ICLAD, possibly due to better collaterals and larger areas of penumbra with less severe hypoperfusion.
The main strengths of our study are the prospective consecutive recruitment of patients and the good follow-up rate. Though the sample size was relatively small, this study was sufficiently powered to show the independent association between ICLAD and poorer functional outcomes. The main limitations are that this study did not annotate if the ICLAD was related to the index stroke, asymptomatic or remotely symptomatic, and the severity of ICLAD. Other limitations are use of MRA or TCCD for ICLAD assessment instead of the gold standard digital subtraction angiography, and follow-up assessment by telephone rather than in-person visits.
| » Conclusions|| |
In conclusion, ischemic stroke patients with ICLAD have poorer functional outcome at 6 months compared to those without ICLAD.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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