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Original research
Imaging criteria across pivotal randomized controlled trials for late window thrombectomy patient selection
  1. Bijoy K Menon1,2,
  2. Johanna Maria Ospel1,3,
  3. Ryan A McTaggart4,
  4. Raul G Nogueira5,
  5. Andrew M Demchuk1,2,
  6. Alexandre Poppe6,
  7. Jeremy L Rempel7,
  8. Charlotte Zerna2,
  9. Manish Joshi8,
  10. Mohammed A Almekhlafi1,2,
  11. Thalia S Field9,
  12. Dariush Dowlatshahi10,
  13. Brian Anthony van Adel11,
  14. Eric Sauvageau12,
  15. Jason Tarpley13,
  16. Tiago Moreira14,
  17. Oh Young Bang15,
  18. Don Heck16,
  19. Marios N Psychogios3,
  20. Michael Tymianski17,
  21. Michael D Hill1,2,
  22. Mayank Goyal1,2,8
  23. on behalf of the ESCAPE-NA1 investigators
  1. 1Calgary Stroke Program, University of Calgary, Calgary, Alberta, Canada
  2. 2Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
  3. 3Department of Neuroradiology, Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland
  4. 4Warren Alpert School of Medicine & Brown University, Providence, Rhode Island, USA
  5. 5Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
  6. 6Department of Neurology/ Neurosciences, Universite de Montreal, Montreal, Quebec, Canada
  7. 7Department of Radiology, University of Alberta, Edmonton, Alberta, Canada
  8. 8Diagnostic Imaging, University of Calgary, Calgary, Alberta, Canada
  9. 9Neurology, University of British Columbia, Vancouver, British Columbia, Canada
  10. 10Neurology, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
  11. 11Clinical Neurological Sciences, London Health Sciences Centre, London, Ontario, Canada
  12. 12Lyerly Neurosurgery, Baptist Hospital, Jacksonville, Florida, USA
  13. 13Vascular Neurology, Providence Saint John’s Health Center and The Pacific Neuroscience Institute, Torrance, California, USA
  14. 14Neurology, Karolinska University Hospital, Stockholm, Sweden
  15. 15Department of Neurology, Samsung Medical Center, Seoul, Republic of Korea
  16. 16Radiology, Forsyth Medical Center, Winston Salem, North Carolina, USA
  17. 17NoNo Inc, Toronto, Ontario, Canada
  1. Correspondence to Dr Mayank Goyal, Diagnostic Imaging, University of Calgary, Calgary, Canada; mgoyal2412{at}


Background The DAWN and DEFUSE-3 trials showed the benefit of endovascular treatment (EVT) in acute ischemic stroke patients presenting beyond 6 hours from last known well (LKW) and selected by perfusion imaging criteria. The ESCAPE NA1-trial selected patients based on non-contrast CT (NCCT) Alberta Stroke Program Early CT Score (ASPECTS) and multiphase CT angiography (CTA) collateral status. This study compares baseline characteristics, workflow, and outcomes in the EVT arms of DAWN and DEFUSE-3 with late-window patients from the EVT-only arm of ESCAPE-NA1.

Methods Aggregate data on baseline characteristics, workflow, reperfusion quality, final infarct volume, and clinical outcomes (modified Rankin Score [mRS] at 90 days) in subjects enrolled in the DAWN and DEFUSE-3 EVT arms were compared with similar data from the ESCAPE-NA1 control arm (EVT-only arm) presenting beyond 6 hours from LKW using descriptive statistics.

Results Baseline characteristics among late-window patients in the ESCAPE NA1 trial were similar to those in the DAWN and DEFUSE-3 EVT arms. Median time from LKW-to-puncture in subjects enrolled in the ESCAPE NA1 trial was 9 hrs (IQR: 7.5–11 hours) when compared with DAWN (n=107; 12.8 hours, IQR: 10.6–16.7 hours) and DEFUSE-3 (n=92; 11.5 hours, IQR: 9.2–12.8 hours). Median post-treatment infarct-volume was largest in the ESCAPE NA1-patients (47 mL [IQR: 19–146] vs median 8 mL [IQR: 0–48] in the DAWN group and 35 mL [IQR: 18–82] in DEFUSE-3), while % mRS 0–2 at 90 days were similar across the three trials (ESCAPE NA1: 50/111 [45%], DAWN: 52/107 [49%], DEFUSE-3: 41/92 [45%]).

Conclusion Patients enrolled beyond 6 hours from LKW in the ESCAPE-NA1 trial based on NCCT-ASPECTS and mCTA had similar clinical outcomes when compared with patients selected by perfusion imaging in the DAWN and DEFUSE-3 trials.

  • stroke
  • CT
  • CT angiography
  • CT perfusion
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  • Twitter @johanna_ospel, @CharlotteZerna, @AlmekhlafiMa, @mihill68

  • Contributors BM, JO: conceptualization, analysis, drafting, and critical revision of the manuscript and figures. MG, MH, MT: conceptualization, drafting, and critical revision of the manuscript. Remaining authors: data curation and critical revision of the manuscript.

  • Funding This study was funded by Canadian Institutes for Health Research, Alberta Innovates, and NoNO Inc. (Grant number: 389143).

  • Competing interests BM holds a patent on systems of triage in acute stroke and stock ownership in Circle Neurovascular Inc. MG is a consultant for Medtronic, Stryker, Microvention, GE Healthcare, and Mentice. MH reports grants from CIHR during the conduct of the study, grants from Medtronic, and grants from NoNO Inc. outside the submitted work. In addition, he has a patent to US Patent office Number: 62/086,077 issued and licensed, and Director, Board of Circle Neurovascular, Director, Board of the Canadian Neuroscience Federation, and Director, Board of the Canadian Stroke Consortium.

  • Patient consent for publication Not required.

  • Ethics approval This study was approved by the local ethics committee of the University of Calgary (ID: ESCAPE-NA1, REB-19-3029).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request. The data underlying the analyses in this manuscript will be made available by the corresponding author upon reasonable request and after approval by the ESCAPE NA1 investigators.

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