Derivation of a clinical prediction score for the diagnosis of clinically significant symptomatic carotid artery disease.

OBJECTIVES: Emergent vascular imaging identifies a subset of patients requiring immediate specialized care (i.e. carotid stenosis > 50%, dissection or free-floating thrombus). However, most TIA patients do not have these findings, so it is inefficient to image all TIA patients in crowded emergency departments (ED). Our objectives were to derive and internally validate a clinical prediction score for clinically significant carotid artery disease in TIA patients. METHODS: This was a planned secondary analysis of a prospective cohort study from 14 Canadian EDs. Among 11555 consecutive adult ED patients with TIA/minor stroke symptoms over 12 years, 9882 had vascular imaging and were included in the analysis. Our main outcome was clinically significant carotid artery disease, defined as extracranial internal carotid stenosis ≥ 50%, dissection, or thrombus in the internal carotid artery, with contralateral symptoms. RESULTS: Of 9882 patients, 888 (9.0%) had clinically significant carotid artery disease. Logistic regression was used to derive a 13-variable reduced model. We simplified the model into a score (Symcard [Symptomatic carotid artery disease] Score), with suggested cut-points for high, medium, and low-risk stratification. A substantial portion (38%) of patients were classified as low-risk, 33.8% as medium risk, and 28.2% as high risk. At the low-risk cut-point, sensitivity was 92.9%, specificity 41.1%, and diagnostic yield 1.7%. CONCLUSIONS: This simple score can predict carotid artery disease in TIA patients using readily available information. It identifies low-risk patients who can defer vascular imaging to an outpatient or specialty clinic setting. Medium-risk patients may undergo imaging immediately or with slight delay, depending on local resources. High-risk patients should undergo urgent vascular imaging.

RéSUMé: OBJECTIFS: L'imagerie vasculaire émergente permet d'identifier un sous-ensemble de patients nécessitant des soins spécialisés immédiats (c.-à-d. sténose carotidienne >50 %, dissection ou thrombus flottant). Cependant, la plupart des patients atteints de RTI ne présentent pas ces résultats, il est donc inefficace d'effectuer une imagerie de tous les patients atteints de RTI dans les services d'urgence (ER) surpeuplés. Nos objectifs étaient de calculer et de valider en interne un score de prédiction clinique pour la maladie carotide cliniquement significative chez les patients atteints d'une AIT MéTHODES: Il s'agissait d'une analyse secondaire planifiée d'une étude de cohorte prospective menée auprès de 14 DE canadiens. Parmi les 11555 patients adultes consécutifs atteints d'un EI présentant des symptômes d'AIT/AVC mineur au cours des 12 dernières années, 9882 ont reçu une imagerie vasculaire et ont été inclus dans l'analyse. Notre principal critère de jugement était la maladie carotide cliniquement significative, définie comme une sténose extracrânienne de la carotide interne à 50 %, une dissection ou un thrombus dans l'artère carotide interne, avec des symptômes contralatéraux. RéSULTATS: Sur 9882 patients, 888 (9,0 %) présentaient une maladie de l'artère carotide cliniquement significative. La régression logistique a été utilisée pour obtenir un modèle réduit à 13 variables. Nous avons simplifié le modèle en un score (Symcard [Symptomatic carotid artery disease] Score), avec des points de coupure suggérés pour la stratification à risque élevé, moyen et faible. Une proportion importante (38,0 %) des patients ont été classés à faible risque, 33,8 % à risque moyen et 28,2 % à risque élevé. Au seuil de faible risque, la sensibilité était de 92,9 %, la spécificité de 41,1 % et le rendement diagnostique de 1,7 %. CONCLUSIONS: Ce score simple permet de prédire la maladie de l'artère carotide chez les patients atteints d'AIT en utilisant des informations facilement disponibles. Il identifie les patients à faible risque qui peuvent reporter l'imagerie vasculaire à un établissement de consultation externe ou de spécialité. Les patients à risque moyen peuvent subir une imagerie immédiatement ou avec un léger délai, selon les ressources locales. Les patients à haut risque doivent subir une imagerie vasculaire urgente.

Ninety-Day Stroke or Transient Ischemic Attack Recurrence in Patients Prescribed Anticoagulation in the Emergency Department With Atrial Fibrillation and a New Transient Ischemic Attack or Minor Stroke.

Background For patients with atrial fibrillation seen in the emergency department (ED) following a transient ischemic attack (TIA) or minor stroke, the impact of initiating oral anticoagulation immediately rather than deferring the decision to outpatient follow-up is unknown. Methods and Results We conducted a planned secondary data analysis of a prospective cohort of 11 507 adults in 13 Canadian EDs between 2006 and 2018. Patients were eligible if they were aged 18 years or older, with a final diagnosis of TIA or minor stroke with previously documented or newly diagnosed atrial fibrillation. The primary outcome was subsequent stroke, recurrent TIA, or all-cause mortality within 90 days of the index TIA diagnosis. Secondary outcomes included stroke, recurrent TIA, or death and rates of major bleeding. Of 11 507 subjects with TIA/minor stroke, atrial fibrillation was identified in 11.2% (1286, mean age, 77.3 [SD 11.1] years, 52.4% male). Over half (699; 54.4%) were already taking anticoagulation, 89 (6.9%) were newly prescribed anticoagulation in the ED. By 90 days, 4.0% of the atrial fibrillation cohort had experienced a subsequent stroke, 6.5% subsequent TIA, and 2.6% died. Results of a multivariable logistic regression indicate no association between prescribed anticoagulation in the ED and these 90-day outcomes (composite odds ratio, 1.37 [95% CI, 0.74-2.52]). Major bleeding was found in 5 patients, none of whom were in the ED-initiated anticoagulation group. Conclusions Initiating oral anticoagulation in the ED following new TIA was not associated with lower recurrence rates of neurovascular events or all-cause mortality in patients with atrial fibrillation.

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

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.