Prospective validation of Canadian TIA Score and comparison with ABCD2 and ABCD2i for subsequent stroke risk after transient ischaemic attack: multicentre prospective cohort study

Abstract

Objective To validate the previously derived Canadian TIA Score to stratify subsequent stroke risk in a new cohort of emergency department patients with transient ischaemic attack. Design Prospective cohort study. Setting 13 Canadian emergency departments over five years. Participants 7607 consecutively enrolled adult patients attending the emergency department with transient ischaemic attack or minor stroke. Main outcome measures The primary outcome was subsequent stroke or carotid endarterectomy/carotid artery stenting within seven days. The secondary outcome was subsequent stroke within seven days (with or without carotid endarterectomy/carotid artery stenting). Telephone follow-up used the validated Questionnaire for Verifying Stroke Free Status at seven and 90 days. All outcomes were adjudicated by panels of three stroke experts, blinded to the index emergency department visit. Results Of the 7607 patients, 108 (1.4%) had a subsequent stroke within seven days, 83 (1.1%) had carotid endarterectomy/carotid artery stenting within seven days, and nine had both. The Canadian TIA Score stratified the risk of stroke, carotid endarterectomy/carotid artery stenting, or both within seven days as low (risk ≤0.5%; interval likelihood ratio 0.20, 95% confidence interval 0.09 to 0.44), medium (risk 2.3%; interval likelihood ratio 0.94, 0.85 to 1.04), and high (risk 5.9% interval likelihood ratio 2.56, 2.02 to 3.25) more accurately (area under the curve 0.70, 95% confidence interval 0.66 to 0.73) than did the ABCD2 (0.60, 0.55 to 0.64) or ABCD2i (0.64, 0.59 to 0.68). Results were similar for subsequent stroke regardless of carotid endarterectomy/carotid artery stenting within seven days. Conclusion The Canadian TIA Score stratifies patients’ seven day risk for stroke, with or without carotid endarterectomy/carotid artery stenting, and is now ready for clinical use. Incorporating this validated risk estimate into management plans should improve early decision making at the index emergency visit regarding benefits of hospital admission, timing of investigations, and prioritisation of specialist referral.

Validation of a comprehensive diagnostic algorithm for patients with acute vertigo and dizziness

“…CVEs in the UVP group. Although, recently, some studies have found a low reliability of the ABCD2 score in identifying patients with a CVE [50][51][52], it has been suggested that it might be useful when used in combination with other clinical signs [53] This is also supported by data from the present study, since the sensitivity for the detection of a CVE decreased (87.6 vs. 93.8%) when the ABCD2 criterion was excluded. Overall, we feel that the approach used in the PoiSe diagnostic algorithm adequately considers the existing evidence of a high stroke risk in specific subgroups of patients with vertigo and…”

Multidisciplinary quality improvement initiative to optimize acute neurovascular imaging for transient ischemic attack or minor stroke

“…We found that 16.3% of the CTAs done during the post-intervention period had a clinically significant abnormality and more neurology consultations were completed in the ED. More work on using different clinical triaging tools to select high-risk patients who may benefit from CTA [21], or neurology consultation in the ED, and further effort to improve patient flow in the ED for patients with TIA or minor stroke are needed.…”

Transient ischemic attack and minor stroke: diagnosis, risk stratification and management

“…The Canadian TIA Score (Figure 2) has been derived and validated in 2 large, multicentre cohort studies to accurately stratify patients with TIA or minor stroke as low-, medium-or high-risk for a subsequent stroke within 7 days. 16,17 Low-risk patients have a risk of less than 1%, medium-risk patients have a 1%-5% risk and high-risk patients have a risk of more than 5% for a subsequent stroke within 7 days. A reasonable clinical approach is to arrange urgent vascular imaging for medium-and high-risk patients, and to discuss high-risk patients with a stroke specialist during their initial evaluation.…”

“…The Canadian TIA Score outperformed both the ABCD2 (age, blood pressure, clinical features, duration of symptoms and diabetes) and the ABCD2i (age, blood pressure, clinical features, duration of symptoms, diabetes and infarction) scores, which are relatively simple and widely recognized tools (absolute net reclassification index, which quantifies how well a new model reclassifies cases compared with an old model, of 12.0% and 8.5% over ABCD2 and ABCD2i, respectively; 16.3% of patients classified as low risk with Canadian TIA Score v. 0% classified as low risk using ABCD2 or ABCD2i). 16…”

“…Figure 2:The Canadian Transient Ischemic Attack (TIA) score 16. Note: BP = blood pressure, CT = computed tomography, ECG = electrocardiography, ED = emergency department.…”