Subverting common sense, BMJ confirms that this scale better predicts the risk of stroke after TIA

*Only for medical professionals to read for reference.
A more reasonable score means a more reasonable diagnosis and treatment strategy.

Recently, a multi-center, prospective, cohort study published in BMJ to prospectively validate the Canadian Transient Ischemic Attack (TIA) score and compare it with ABCD2 and ABCD2i to assess the risk of subsequent stroke after TIA The results show that the Canadian TIA score is more accurate than ABCD2 and ABCD2i in distinguishing the risk of stroke within 7 days and the follow-up, and carotid endarterectomy/carotid stenting.

Figure 1: Screenshot of the paper.
Research background.
We know that TIA patients have a high risk of stroke in the short term.

Historically, studies have estimated that the overall risk of stroke within 7 days after TIA is 4%-10%, and will increase to 8%-12% by 90 days [1-9].

However, in the past 10 years, the treatment of TIA has changed significantly [4,10-11], and the subsequent stroke rate is lower [4-9,12].

The point is that the highest risk of stroke is the first few days after the visit [4,9].

 Nevertheless, for most patients presenting to the emergency department with TIA symptoms, comprehensive examination, active treatment, and/or admission are inefficient and challenging for most hospitals, so priority is given to the most likely to benefit It is necessary for the patients to have a high risk.
At the same time, identifying low-risk patients is beneficial to both the patient and the hospital.

 The clinical decision rules or scores derived from the original research can help clinicians make diagnosis or treatment decisions at the bedside, but they need to be verified before implementation [13-15].

 For the stratification of TIA patients, the most famous score is the ABCD2 score.

However, during the prospective validation period, the tool cannot distinguish between low-risk and high-risk populations [16-19].

Several variants of the ABCD2 score are now available, including neuroimaging, more recent TIA, and angiography [20], which are often used to classify risk as low and high.

 In order to better evaluate, the research team prospectively derived the Canadian TIA score (Table 1) from nearly 4000 patients in the emergency department of eight large Canadian hospitals in the past [16].

The score contains 13 predictors from medical history, physical examination, and examinations routinely performed during emergency department visits.

The assigned score ranges from -3 to 23, which can be used to assign a stroke grading probability for the following week, ranging from 0.
01% to 28%.

Or, it can be divided into three risk levels, namely low, medium and high risk, so that when visiting the emergency department, priority is given to specialists for investigation, admission and follow-up.

 Therefore, in order to ensure that this score can be safely introduced into clinical practice, the researchers’ goal is to validate the Canadian TIA score previously obtained, stratify the risk of stroke in the new emergency department patient cohort, and compare it to the existing risk Compare stratified scores.

Table 1: Validation of the Canadian TIA score began.
Researchers conducted this prospective multicenter cohort study in the emergency departments of 13 Canadian hospitals.
Patients were enrolled from October 31, 2012 to December 30, 2017, prospectively Patients who entered the emergency room continuously were recruited at all sites 24 hours a day, 7 days a week.

Patients who are 18 years of age or older, have a TIA or a mild stroke when they are discharged from the hospital or consulted by a specialist doctor are their final emergency department diagnosis.

 During the period, neurological deficits for more than 24 hours (that is, stroke according to the World Health Organization definition), a lower level of consciousness than the baseline level (that is, the Glasgow Coma Scale of patients with normal cognition <15), and after the onset of neurological symptoms were excluded.
Patients with other diagnoses (for example, hypoglycemia, seizures, electrolyte imbalance, or migraine) more than 7 days.

 The attending physician, neurologist, or supervised resident physician completed all evaluations.

Physicians use a formal one-hour lecture to direct research and standardized data collection forms, as well as personal positioning of research forms (including definitions and procedures for local researchers).

The physician completed the data form to clearly record each element of the Canadian TIA score, ABCD2 score, and ABCD2i score (ABCD2 score plus 3 points for neuroimaging infarction examination).

 The main outcome indicators are the combined results of stroke or carotid revascularization within 7 days and subsequent visits to the emergency department.

 Enrolled 7,607 patients, accounting for 80.
6% of all potentially eligible patients who participated in emergency department visits during the study.

The follow-up by telephone and/or clinical evaluation was almost completed, and by day 7, only 34 (0.
4%) patients had lost the follow-up (that is, they had not arrived by telephone and had no subsequent hospitalization experience).

108 (1.
4%) patients subsequently developed a stroke, while 83 (1.
1%) patients underwent carotid revascularization within 7 days of their index visit (a total of 182 results, of which 9 patients had both ).

In terms of age, gender, and diagnostic tests, the missed patients who were not included in the group were similar to those in the group, but the admission rate was higher (18.
4% vs 5.
8%).

 The Canadian TIA score effectively divided the patients into 3 groups (Table 2), of which one-sixth of the patients were at low risk (<1% risk of the main outcome; Interval likelihood ratio 0.
20, 95% CI 0.
09-0.
44), high The risk (>5% risk; interval likelihood ratio 2.
56, 2.
02-3.
25) is one-eighth.

The rest are at medium risk, with an event rate of 2.
3% in the subsequent 7 days and an interval likelihood ratio of 0.
94 (0.
85-1.
04).

In addition to the 2-day and 90-day risk stratification, the Canadian TIA score is similar to the actual results.

 Table 2: The Canadian TIA score effectively divides the patients into 3 groups.
Results and conclusions The Canadian TIA score is significantly better than the ABCD2 score.

When the researchers used a pre-set risk threshold, almost all patients were classified as moderate risk based on the ABCD2 score (low risk <1%, medium risk 1% to 5%, high risk> 5%).

 Therefore, high-risk patients classified according to the Canadian TIA score are higher than those who pass the ABCD2 score.

This also resulted in more patients without subsequent events being classified as low risk.

However, according to the Canadian TIA score, patients considered at high risk have higher scores than both ABCD2 (the threshold for using ABCD2 is 6, and the threshold for ABCD2i is 9).

Both ABCD2 and ABCD2i are designed as dichotomous scores.

 Therefore, in practice, through the corresponding ABCD2 score, many patients at medium risk will be considered at high risk.

This dichotomy is limited to practicing physicians.
Researchers believe that having three risk levels provides clinicians with more management options.

When the researcher compares two ABCD2 scores, the ABCD2i score is better than the ABCD2 score.

It determined that many patients have a low secondary risk of secondary stroke, but at the cost of losing many patients who underwent early carotid revascularization.

 Although the Canadian TIA score is more complicated and not easy to remember, it only requires routine information from medical history, clinical evaluation, and examination results to stratify patients.

Since it does not require advanced neuroimaging, emergency doctors can easily use and apply it.

 It allows people to customize emergency situations, such as advanced neuroimaging tests, or inform decisions about inpatient admissions and outpatient specialist consultations based on local preferences or combined with patient preferences.

Many hospitals cannot provide 24/7 magnetic resonance imaging and/or specialist consultations for patients who need to be transferred.

Stratification of patient risk can achieve more standardized management, more equitable distribution of constrained resources, and may lead to better results.

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n49 article source: Neurology medical profession channel author: This article nine miles audit: Ming Li Tu, deputy director of physicians editor: Mr.
Lu Li original copyright notice for reprint this article, please contact your authorized - End -Contributions are welcome to submit to the editor’s mailbox: yxjsjbx@yxj.
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Edit WeChat: chenaFF0911488-94.
doi:10.
1001/jama.
1997.
03540300056034 pmid:9020274[14] McGinn TG, Guyatt GH, Wyer PC, Naylor CD, Stiell IG, Richardson WS, Evidence-Based Medicine Working Group.
Users' guides to the medical literature: XXII: how to use articles about clinical decision rules.
JAMA2000;284:79-84.
doi:10.
1001/jama.
284.
1.
79 pmid:10872017[15] Stiell IG, Wells GA.
Methodologic standards for the development of clinical decision rules in emergency medicine.
Ann Emerg Med1999;33:437-47.
doi:10.
1016/S0196-0644(99)70309-4 pmid:10092723[16] https:// source: Neurology medical profession channel author: This article nine miles audit: Ming Li Tu, deputy director of physicians editor: Mr.
Lu Li original copyright notice for reprint this article, please contact your authorized - End - Call for Papers Call for Papers to edit E-mail: yxjsjbx@yxj.
org .
cn Please indicate: [Submission] Hospital + Department + Name Contributions are in the form of word files, and the remuneration is favorable.
Edit WeChat: chenaFF0911488-94.
doi:10.
1001/jama.
1997.
03540300056034 pmid:9020274[14] McGinn TG, Guyatt GH, Wyer PC, Naylor CD, Stiell IG, Richardson WS, Evidence-Based Medicine Working Group.
Users' guides to the medical literature: XXII: how to use articles about clinical decision rules.
JAMA2000;284:79-84.
doi:10.
1001/jama.
284.
1.
79 pmid:10872017[15] Stiell IG, Wells GA.
Methodologic standards for the development of clinical decision rules in emergency medicine.
Ann Emerg Med1999;33:437-47.
doi:10.
1016/S0196-0644(99)70309-4 pmid:10092723[16] https:// source: Neurology medical profession channel author: This article nine miles audit: Ming Li Tu, deputy director of physicians editor: Mr.
Lu Li original copyright notice for reprint this article, please contact your authorized - End - Call for Papers Call for Papers to edit E-mail: yxjsjbx@yxj.
org .
cn Please indicate: [Submission] Hospital + Department + Name Contributions are in the form of word files, and the remuneration is favorable.
Edit WeChat: chenaFF0911Evidence-Based Medicine Working Group.
Users' guides to the medical literature: XXII: how to use articles about clinical decision rules.
JAMA2000;284:79-84.
doi:10.
1001/jama.
284.
1.
79 pmid:10872017[15] Stiell IG, Wells GA.
Methodologic standards for the development of clinical decision rules in emergency medicine.
Ann Emerg Med1999;33:437-47.
doi:10.
1016/S0196-0644(99)70309-4 pmid:10092723[16] https:/ / article source: Neurology medical profession channel author: This article nine miles audit: Ming Li Tu, deputy director of physicians editor: Mr.
Lu Li original copyright notice for reprint this article, please contact an authorized -End-Call for papers, welcome to submit papers to the editor’s mailbox: yxjsjbx@yxj.
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cn, please specify: [Submission] Hospital + department + name The manuscript is in the form of a word document, and the remuneration is favorable.
Edit WeChat: chenaFF0911Evidence-Based Medicine Working Group.
Users' guides to the medical literature: XXII: how to use articles about clinical decision rules.
JAMA2000;284:79-84.
doi:10.
1001/jama.
284.
1.
79 pmid:10872017[15] Stiell IG, Wells GA.
Methodologic standards for the development of clinical decision rules in emergency medicine.
Ann Emerg Med1999;33:437-47.
doi:10.
1016/S0196-0644(99)70309-4 pmid:10092723[16] https:/ / article source: Neurology medical profession channel author: This article nine miles audit: Ming Li Tu, deputy director of physicians editor: Mr.
Lu Li original copyright notice for reprint this article, please contact an authorized -End-Call for papers, welcome to submit papers to the editor’s mailbox: yxjsjbx@yxj.
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cn, please specify: [Submission] Hospital + department + name The manuscript is in the form of a word document, and the remuneration is favorable.
Edit WeChat: chenaFF0911Methodologic standards for the development of clinical decision rules in emergency medicine.
Ann Emerg Med1999;33:437-47.
doi:10.
1016/S0196-0644(99)70309-4 pmid:10092723[16] https:// com / content / 372 / bmj.
n49 article source: Neurology medical profession channel author: This article nine miles audit: Ming Li Tu, deputy director of physicians editor: Mr.
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Ann Emerg Med1999;33:437-47.
doi:10.
1016/S0196-0644(99)70309-4 pmid:10092723[16] https:// com / content / 372 / bmj.
n49 article source: Neurology medical profession channel author: This article nine miles audit: Ming Li Tu, deputy director of physicians editor: Mr.
Lu Li original copyright notice for reprint this article, please contact your authorized - End - Welcome Call for Papers Submit the manuscript to the editor’s mailbox: yxjsjbx@yxj.
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