A prospective study on patients with transient ischemic attack and minor ischemic stroke presenting to a tertiary care emergency department

Jubin Merin Jacob; Aparna Lohanathan; Sanjith Aaron

doi:10.4103/cmi.cmi_2_20

ORIGINAL ARTICLE

Year : 2020 | Volume : 18 | Issue : 2 | Page : 130-135

A prospective study on patients with transient ischemic attack and minor ischemic stroke presenting to a tertiary care emergency department

Jubin Merin Jacob¹, Aparna Lohanathan¹, Sanjith Aaron²
¹ Department of Emergency Medicine, Christian Medical College, Vellore, Tamil Nadu, India
² Department of Neurology, Christian Medical College, Vellore, Tamil Nadu, India

Date of Submission	02-Jan-2020
Date of Decision	20-Jan-2020
Date of Acceptance	02-Mar-2020
Date of Web Publication	17-Apr-2020

Correspondence Address:
Dr. Aparna Lohanathan
Department of Emergency Medicine, Christian Medical College, Vellore - 632 004, Tamil Nadu
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/cmi.cmi_2_20

Abstract

Background: The incidence of stroke after transient ischemic attack (TIA) has been observed to be high in the first 90 days. There are very few studies conducted in India to assess the risk of stroke in patients presenting with TIA. Hence, the primary aim of our study is to assess the risk of stroke in patients presenting to the emergency department (ED) with TIA or minor ischemic stroke (MIS) and the various risk factors associated with it. Materials and Methods: This was a prospective observational study done on consecutive patients who presented to our ED with neurovascular deficits suggestive of TIA or MIS within 16 h. Results: During the study period, a total of 71 patients were recruited. The mean age of the study group was 58.07 (standard deviation: 13.15) years. There was a male predominance of 70.4%. The incidence of TIA during the study period was 56 (78.9%) and that of MIS was 6 (8.5%) in our ED. Based on the magnetic resonance imaging stroke protocol finding, it was observed that among the TIA patients, about half of them had an infarct and 8.45% had a minor stroke with acute infarct. Overall, we observed that 19.7% of the recruited patients with TIA or MIS developed stroke within 3 months and majority of the clinical deterioration were in the 1^st week post index event. Conclusion: TIA and MIS should be considered as a major ischemic event and should be treated aggressively with effective collaboration of various departments. Early diagnosis and proper treatment will help prevent further grave neurological deterioration.

Keywords: Cerebrovascular accident, minor ischemic stroke, stroke, transient ischemic attack

How to cite this article:
Jacob JM, Lohanathan A, Aaron S. A prospective study on patients with transient ischemic attack and minor ischemic stroke presenting to a tertiary care emergency department. Curr Med Issues 2020;18:130-5

How to cite this URL:
Jacob JM, Lohanathan A, Aaron S. A prospective study on patients with transient ischemic attack and minor ischemic stroke presenting to a tertiary care emergency department. Curr Med Issues [serial online] 2020 [cited 2023 Mar 30];18:130-5. Available from: https://www.cmijournal.org/text.asp?2020/18/2/130/282778

Introduction

The classic definition of transient ischemic attack (TIA) is a sudden, focal neurologic deficit that lasts for <24 h. It is presumed to be of vascular origin and is confined to an area of the brain or retina perfused by a specific artery.^[1] The term “TIAs” implies warning symptoms of stroke usually lasting up to 30 min–1 h and complete recovery within 24 h.^[2] A stroke was defined as minor by the National Institute of Neurological Disorders and Stroke when the symptoms were believed at the discretion of the local investigator to be mild and cause very minimal or no disability.^[3] The incidence of TIA in the US is 300,000/year, and according to a retrospective study done among patients with the diagnosis of TIA in the emergency department (ED), the incidence of stroke was 10.5% in the first 90 days out of which half of them occurred within the first 48 h.^[4]

A recent prospective study done in India on risk factors and predictors for TIA and minor ischemic stroke (MIS) enrolled 118 patients with TIA, out of which 15.3% developed new cerebrovascular or cardiovascular event in the 90-day follow-up and more than half of which occurred within the first 7 days.^[5] The ultimate aim of doing an evaluation of risk factors of TIA is to prevent repeated events leading to permanent disability and death. No single medicine or intervention can prevent another episode with 100% certainty, but experts suggest that the immediate initiation of antiplatelet agents and risk factor modifications is beneficial. Patients often tend to ignore the symptoms of TIA or MIS due to their transitory nature and also oversights by emergency physicians due to the unpredictability in presentation leading to underdiagnosis. There are various scoring systems used worldwide to triage patients with TIA among which the most commonly used score is ABCD3I.

The primary aim of this study was to determine the risk of stroke in patients presenting with TIA or MIS with the National Institutes of Health Stroke Scale (NIHSS) ≤5 in ED. For the study purpose, we have included all patients with NIHSS <5 in the MIS group. Our secondary objectives were to determine the number of patients presenting with TIA with and without infarction, respectively, based on magnetic resonance imaging (MRI) stroke protocol findings and the proportion of patients who underwent carotid endarterectomy.

Materials and Methods

Study design

This was a prospective observational study done between October 2015 and October 2017.

Setting

The study was conducted in the ED of Christian Medical College Hospital, Vellore, which is a tertiary care hospital in South India.

Participants

All patients presenting to ED with symptoms suggestive of TIA or MIS with an NIHSS score ≤5 within 16 h of symptom onset were included.

Variables

Relevant details in history, comorbidities, ABCD3I score, and NIHSS score were documented in the data capture sheet. Relevant investigations including blood investigations such as homocysteine levels, lipid levels, random blood sugar levels, carotid Doppler, and MRI stroke protocol findings were documented in the same form. The management in ED, either conservative or surgical, was noted. The outcome of the patients with regard to neurological deterioration within 3 months was documented after reviewing the patients when they come to a stroke prevention clinic.

Outcome variable

The percentage of risk of stroke in patients presenting with TIA and MIS with an NIHSS score ≤5.

Bias

Recall bias is inherent due to variation in history because of the transient nature of TIA events.

Sample size

A total sample size of 196 was needed to estimate the prevalence of 15% stroke in TIA patients with a 95% confidence interval and a 5% precision.

Laboratory tests and radiological imaging

All patients had relevant blood investigations such as homocysteine levels, lipid levels, random blood sugar levels, carotid Doppler, and MRI stroke protocol (T1/T2/fluid-attenuated inversion recovery/diffusion-weighted imaging [DWI]/apparent diffusion coefficient).

Statistical analysis

The data were analyzed using the Statistical Package for the Social Sciences (IBM Corp. Released 2015. IBM SPSS, Version 23.0, Armonk, NY, USA). All categorical variables were expressed as frequencies and percentages. Data were summarized using mean along with standard deviation (SD) for continuous variables, and frequencies along with percentages were calculated.

Ethical considerations

This study was approved by the institutional review board (IRB) before the commencement of the study (IRB Min no: 9738 dated November 10, 2015). All the participants' identification data and information were kept confidential. All the data sheets were number coded, and names were not mentioned and were stored in a password-protected PC.

Results

A total of 71 patients were enrolled during the study period between October 2015 and October 2017. The basic outline of the results is shown in [Figure 1].

Figure 1: STROBE diagram

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The mean age of presentation was 58.07 (SD: 13.2) years, with a male predominance of 70.4%. About 16.9% of the patients received primary first aid in local hospitals before the presentation and were referred to our institution for further management. Majority of the patients were from a mean distance of 11 (SD 6.5) km and more than half presented to ED within a time interval of 4 ± 2.8 h. The average ABCD3I score assessed in ED was 7.24 ± 2.46. Among the study population, 39.5% already had carotid stenosis, 31% had a previous history of cerebrovascular accident, 15.5% were known ischemic heart disease, and 15.5% were known alcohol consumers. The baseline characteristics are shown in [Table 1].

Table 1: Baseline characteristics (n=71)

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Among the 71 patients included in this study, 19.7% of the patients developed stroke, as shown in [Figure 2]. Out of these, 11.3% of the patients developed stroke within the first 7 days, 1.4% developed stroke in 2-week to 1-month time duration, and 7% developed stroke within 2–3 months. Among the 8 patients who developed stroke within 7 days, 5 had TIA and 3 had MIS at initial presentation. Among the 5 patients who developed stroke within 2–3 months, 4 had TIA and 1 had MIS [Figure 3].

Figure 2: Overall incidence of stroke among the study population

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Figure 3: Time period of development of stroke after transient ischemic attack with or without infarct and minor ischemic stroke

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Based on the findings observed in the MRI of 56 patients with TIA, 35 (49.3%) had TIA with infarct, 21 (29.6%) had TIA without infarct, and the rest had minor stroke with acute infarct [Figure 1]. All the recruited patients were referred to neurology for their expert opinion after preliminary investigations including MRI stroke protocol. In the TIA group, majority of the patients, i.e., 83%, were conservatively managed with dual antiplatelets and regular outpatient department (OPD) follow-up, 12.5% underwent carotid endarterectomy within 3 months, 1.7% underwent thrombolysis, and the rest were discharged against medical advice [Table 2]. In the MIS group, out of the six patients, five were managed conservatively and one patient underwent carotid endarterectomy. Among the 14 patients who developed stroke, 12 were conservatively managed with dual antiplatelets and the remaining 2 patients underwent thrombolysis and carotid endarterectomy, respectively. In patients with recurrent stroke, it was observed that 92.86% had hypertension and 71% had diabetes. Out of the total patients, 9 were categorized into the TIA mimic group, who at presentation were thought to be TIA but later during detailed evaluation found to have focal abscesses in the brain, arteriovenous malformation, multiple sclerosis, and labyrinthine disorders.

Table 2: Treatment advocated

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Discussion

Stroke is one of the leading causes of death and disability worldwide. In developing countries such as India, lack of awareness and inadequate knowledge among the public are major factors contributing to delay in seeking treatment and leading to increase in the incidence. Based on a study done in India regarding early predictors and risk factors of stroke by Kate et al., it was observed that 15.3% developed new ischemic events during their 90-day follow-up which is similar to the risk estimated from our study.^[5] The Indian Council of Medical Research conducted a multicentric prospective case–control study of ischemic strokes, which showed that hypertension, raised blood sugar, tobacco use, and low hemoglobin are the most important risk factors.^[6] Majority of the patients who developed stroke in our study had hypertension and diabetes. The most likely etiology was observed to be large artery atherosclerosis which correlates with the inference from other studies.

The ABCD3I score in majority of the patients who developed stroke later was between 8 and 12, thereby making it a sensitive predictor for detecting early neurological deterioration in people presenting with TIA. The ASPIRE approach also proved the ABCD2 score to be a perfect triage tool to determine early neurological deterioration in patients with TIA.^[7] It had a very high negative predictive value making it a highly sensitive triage tool.

Among both the TIA and MIS groups, the maximum incidence of stroke was observed in the 1^st week though all were managed with dual antiplatelets and regular follow-up, which is similar to other Indian and international studies.^[5] This claims for aggressive management and close monitoring of these patients in the first 7 days. Similar to ischemic strokes, TIA occurs due to the reduced blood supply to the brain either by embolism or in situ occlusion of small vessels. The symptoms resolve due to either lysis of the thrombus spontaneously or distal movement of the thrombus or formation of collaterals. The diagnosis of TIA rests entirely on the clinical expertise of the physician, but with the emergence of imaging modalities, TIA diagnosis is made easier to an extent with the help of DWI. The likelihood of a DWI-detected lesion increases with symptom duration. The risk of stroke after TIA in patients with evidence of acute infarction ranged between 3- and 18-fold higher than TIA patients without acute infarction detected by MRI.^[8] Hence, we can infer that MRI DWI findings can predict early deterioration in patients with TIA and have to be used as a diagnostic tool.

The management of TIA requires equal input from an ED physician as well as a neurologist along with the help of an expert radiologist and a vascular surgeon. All the patients who presented to ED with neurovascular deficit are referred to an on-call neurologist who after assessment decides on management. Among the patients with TIA, majority received conservative management and a very few underwent carotid endarterectomy. The use of dual antiplatelets remains the mainstay of conservative management.^[9] Aspirin in doses ranging from 50 to 1300 mg/dl is efficacious for preventing ischemic stroke after stroke or TIA.^[9] The CHANCE trial demonstrated that the combination of aspirin/clopidogrel for 21 days followed by clopidogrel monotherapy was superior to single-agent aspirin for reducing stroke recurrence at 90 days, without a difference in bleeding rate between the two groups.^[10] According to another study, the absolute benefit of clopidogrel is amplified over aspirin in patients with a history of ischemic events, but the relative benefit is similar across endpoints related to ischemia.^[11] The point demonstrates that 90 days of dual antiplatelet therapy reduces the rate of recurrent stroke and increases the rates of major bleeding among patients with MIS and high-risk TIA.^[12] Clopidogrel is more expensive compared to aspirin, which may affect the long-term compliance in a developing country like India.

The primary objective of this study was to emphasize the fact that majority of the patients with TIA/MIS if diagnosed early and treated with aggressive management, especially in the first 7 days the risk of 90-day stroke, can be decreased significantly. The use of MRI DWI as a diagnostic tool finding to predict early deterioration in patients with TIA along with aggressive management and close monitoring of these patients in the first 7 days significantly decreases the risk of early recurrent stoke. The EXPRESS study proved that early initiation of existing treatments after TIA or minor stroke was associated with an 80% reduction in the risk of early recurrent stroke.^[13]

The strength of our study is the early inclusion of the patient directly from ED within 16 h of index event and prospective follow-up through telephonic calls and during OPD visits in the next 90 days. The main limitation of this study was that a large percentage of population presented post 16 hours of the index event hence could not be included in the study. The other limitation was that our patients preferred following up in a primary or secondary care center and were thus lost to follow up.

Conclusion

TIA implies that acute brain ischemia has occurred and must be treated as a medical emergency. Its severity is often underestimated by the common population due to its transient nature. The aftermath of this negligence is leading to significant morbidity and mortality. At presentation to ED urgent assessment, early use of diagnostic tools (MRI) for risk assessment, aggressive treatment, and close monitoring, especially in the first 7 days, is very essential in preventing recurrent stroke in these cases. Further neurological deterioration can be reduced significantly with an effective collaboration of an emergency physician, a neurologist and a radiologist.

Research quality and ethics statement

The authors of this manuscript declare that this scientific work complies with reporting quality, formatting, and reproducibility guidelines set forth by the EQUATOR Network. The authors also attest that this clinical investigation was determined to require IRB/ethics committee review, and the corresponding protocol/approval number is IRB Min no: 9738 dated November 10, 2015. We also certify that we have not plagiarized the contents in this submission and have done a plagiarism check.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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