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

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Neurovascular imaging for patients with high-risk transient ischemic attack (TIA) or minor stroke in the emergency department (ED) with computed tomography angiography (CTA) of the head and neck is the guideline-recommended standard of care, but it is underutilized in routine practice. We conducted a quality initiative to improve adherence to guidelines.


Between January 2017 and March 2019, we implemented a decision support tool integrated into the electronic ordering system to guide ED physicians to order a CTA on patients with high-risk TIA or minor stroke defined as ongoing neurological deficits in the ED or resolved motor or speech deficits in the preceding 48 h. Data were collected retrospectively pre-intervention and prospectively post-intervention. We used an interrupted time-series analysis for the before–after comparison of the use of CTA among patients who met criteria (main process measure) and those who did not meet criteria (balancing measure).


Among 861 patients with TIA or minor stroke, the proportion of patients with high-risk events imaged with a CTA in the ED increased from 12.0% pre-intervention to 77.0% post-intervention and this shift was sustained over 11 months. CTA use in those without high-risk events increased to a lesser extent (15.3% versus 42.9%). The interrupted time-series analysis showed a step change immediately post-intervention where the increase in CTA use in patients with high-risk events was 51.7% higher than its use in those without high-risk events (p < 0.001). Compared to pre-intervention, the median ED length of stay increased by 2 h and neurology consultation in the ED was more frequent (5.8% versus 19.5%) post-intervention.


We provide a detailed framework that improved adherence to acute imaging guidelines for patients with TIA or minor stroke and anticipate that our approach could improve acute imaging for such patients in most EDs.



L'imagerie neurovasculaire pour les patients présentant un risque élevé d'accident ischémique transitoire (AIT) ou d'accident vasculaire cérébral mineur aux services d'urgence, avec une angiographie par tomodensitométrie (CTA) de la tête et du cou, est la norme de soins recommandée par les directives, mais elle est sous-utilisée dans la pratique courante. Nous avons mené une initiative de qualité pour améliorer le respect des lignes directrices.


Entre janvier 2017 et mars 2019, nous avons mis en place un outil d'aide à la décision intégré au système de commande électronique pour guider les médecins du service d'urgence à prescrire un CTA sur des patients atteints d'un AIT à haut risque ou d'un AVC mineur défini comme des déficits neurologiques en cours au service des urgences ou une résolution de la motricité ou des troubles de la parole dans les 48 heures précédentes. Les données ont été recueillies rétrospectivement avant l'intervention et prospectivement après l'intervention. Nous avons utilisé une analyse de séries chronologiques interrompues pour la comparaison avant-après de l'utilisation du CTA chez les patients qui répondaient aux critères (mesure principale du processus) et ceux qui ne répondaient pas aux critères (mesure d'équilibrage).


Parmi les 861 patients atteints d'un AIT ou d'un AVC mineur, la proportion de patients présentant des événements à haut risque imagés avec un CTA au service d'urgence est passé de 12,0 % avant l'intervention à 77,0 % après l'intervention et ce changement s'est maintenu pendant 11 mois. L'utilisation de CTA chez les personnes sans événements à haut risque a augmenté dans une moindre mesure (15,3 % contre 42,9 %). L'analyse des séries chronologiques interrompues a montré un changement d'étape immédiatement après l'intervention où l'augmentation de l'utilisation du CTA chez les patients présentant des événements à haut risque était 51,7 % plus élevée que son utilisation chez ceux sans événements à haut risque (p < 0,001). Par rapport à la pré-intervention, la durée médiane du séjour au SU a augmenté de deux heures et les consultations de neurologie au SU étaient plus fréquentes (5,8 % contre 19,5 %) après l'intervention.


Nous fournissons un cadre détaillé qui a amélioré le respect des lignes directrices en matière d'imagerie aiguë pour les patients souffrant d'AIT ou d'AVC mineur et nous prévoyons que notre approche pourrait améliorer l'imagerie aiguë pour ces patients dans la plupart des urgences.

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This study was supported by ICES, formally Institute for Clinical Evaluative Sciences, which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement by ICES or the Ontario MOHLTC is intended or should be inferred. Parts of this material are based on data and/or information compiled and provided by CIHI. However, the analyses, conclusions, opinions and statements expressed in the material are those of the author(s), and not necessarily those of CIHI.


This study is funded by a grant from the Academic Health Sciences Centres of Ontario Alternative Funding Plan Innovation Fund. AYXY is supported by a New Investigator Award and the HJ Barnett Award from Heart and Stroke. RHS is supported by a clinician-scientist phase II award from the Heart and Stroke Foundation of Canada. MKK is supported by a mid-career investigator award from the Heart and Stroke Foundation of Canada and holds the Lillian Love Chair in Women’s Health at the University Health Network.

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Authors and Affiliations



AK: study design, data collection, analysis, drafting manuscript, AV: study design, data collection, analysis, drafting manuscript, IJK: data collection, reviewing 3 manuscript, NK: data collection, reviewing manuscript, KS: data collection, reviewing manuscript, LKC: study design, reviewing manuscript, MKK: study design, reviewing manuscript, JF: analysis, reviewing manuscript, SS: study design, reviewing manuscript, RHS: study design, reviewing manuscript, AYXY: study design, data collection, analysis, drafting manuscript, funding.

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Correspondence to Amy Y. X. Yu.

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The authors report no disclosure related to this study.

Ethics approval

This study was approved by the Sunnybrook Health Sciences Centre Research Ethics Board with a waiver of individual patient consent.

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Kapoor, A., Verma, A., Kim, I.J. et al. Multidisciplinary quality improvement initiative to optimize acute neurovascular imaging for transient ischemic attack or minor stroke. Can J Emerg Med 23, 820–827 (2021).

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