Authors' objectives: This health technology assessment evaluates the effectiveness of automated computed tomography (CT) perfusion imaging to aid in the selection of patients for mechanical thrombectomy after acute ischemic stroke caused by large-vessel occlusion in the anterior circulation. It also evaluates the cost-effectiveness and budget impact of publicly funding automated CT perfusion imaging.

Authors' results and conclusions: RESULTS Automated CT perfusion imaging had a sensitivity of 84% for identifying the infarct core (dead tissue that does not recover despite restoring blood flow with mechanical thrombectomy), compared with diffusion-weighted MRI imaging at 24 hours. One study reported that 7% of patients were misclassified with respect to eligibility for mechanical thrombectomy (either erroneously classified as eligible or erroneously classified non-eligible). Two randomized controlled trials (DEFUSE 3 and DAWN) demonstrated the efficacy of mechanical thrombectomy up to 24 hours after stroke onset, with patient selection guided by automated CT perfusion imaging. These data showed that a significantly higher proportion of patients in the mechanical thrombectomy group achieved functional independence compared with the standard care group (DEFUSE 3: risk ratio: 2.67 [95% confidence interval 1.60–4.48]; DAWN: adjusted rate difference: 33% [95% credible interval 21%–44%]; GRADE: Moderate). A previous health technology assessment in stroke patients presenting at 0 to 6 hours after stroke symptom onset and the results from recent randomized controlled trials for patients presenting at 6 to 24 hours informed the evaluation of cost-effectiveness. Mechanical thrombectomy informed by automated CT perfusion imaging to assess eligibility is likely to be cost-effective for patients presenting at 6 to 24 hours after stroke symptom onset. The annual budget impact of publicly funding automated CT perfusion imaging in Ontario over the next 5 years would be $1.3 million in year 1 and $0.9 million each year thereafter. Some of the costs of automated CT perfusion imaging could be offset by avoiding unnecessary patient transfers between hospitals. CONCLUSIONS Automated CT perfusion imaging has an acceptable sensitivity and specificity for detecting brain areas that have been affected by stroke. In patients selected for mechanical thrombectomy using automated CT perfusion imaging, there was significant improvement in functional independence. Mechanical thrombectomy informed by automated CT perfusion imaging is likely to be cost-effective. We estimate that publicly funding automated CT perfusion imaging in Ontario would result in additional costs of $1.3 million in year 1 and $0.9 million per year thereafter.

Authors' recommendations: Ontario Health, based on guidance from the Ontario Health Technology Advisory Committee, recommends publicly funding mechanical thrombectomy within 24 hours of acute ischemic stroke, and that automated CT perfusion imaging is an important tool to facilitate patient selection

Authors' methods: We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each study using QUADAS-2 or the Cochrane risk-of-bias tool, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and approximated cost-effectiveness based on previous analyses. We also analyzed the budget impact of publicly funding automated CT perfusion imaging to evaluate people with acute ischemic stroke in Ontario.

Project Status: Completed

URL for project: https://ontariohealth.ca/system/health-innovation-pathway/reviews/hta-details?cf=automated-ct-perfusion-imaging-stroke

URL for protocol: https://www.crd.york.ac.uk/PROSPERO/view/CRD42019141465

Year Published: 2020

URL for published report: https://pmc.ncbi.nlm.nih.gov/articles/PMC7668535/

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: Canada

Province: Ontario

Pubmed ID: 33240454

Organisation Name: Ontario Health

Contact Address: 525 University Ave, Toronto, ON M5G 2L3

Contact Name: HealthInnovationPathway@ontariohealth.ca

Contact Email: HealthInnovationPathway@ontariohealth.ca

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