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Prediction of 90 day home time among patients with low baseline ASPECTS undergoing endovascular thrombectomy: results from Alberta’s Provincial Stroke Registry (QuICR)
  1. Nishita Singh1,
  2. Jessalyn K Holodinsky1,
  3. Nima Kashani2,3,
  4. Rosalie V McDonough2,
  5. Fouzi Bala1,
  6. MacKenzie Horn1,
  7. Jillian Stang1,4,
  8. Andrew M Demchuk1,
  9. Michael D Hill1,
  10. Mohammed A Almekhlafi1,2
  1. 1Department of Clinical Neurosciences, Calgary Stroke Program, Calgary, Alberta, Canada
  2. 2Department of Radiology, University of Calgary, Calgary, Alberta, Canada
  3. 3Department of Neurosurgery, Royal University Hospital, Saskatoon, Saskatchewan, Canada
  4. 4Alberta Health Services, Foothills Medical CEnter, Calgary, Alberta, Canada
  1. Correspondence to Dr Nishita Singh, Clinical Neurosciences, University of Calgary, Calgary, AB T2N 4M1, Canada; nishitaneurology{at}


Background The benefit of endovascular thrombectomy (EVT) in stroke patients with a low baseline Alberta Stroke Program Early CT Score (ASPECTS, ≤5) is uncertain. We aim to use random forest regression modeling to predict 90 day home time in patients with low ASPECTS.

Methods We used the Quality Improvement and Clinical Research (QuICR) provincial stroke registry and administrative data from southern Alberta to identify patients who underwent EVT in our center from July 2015 to November 2020. Baseline ASPECTS on non-contrast CT and CT angiography data were scored by a two physician consensus. The primary outcome was the predicted 90 day home time (the number of nights a patient is back at their premorbid living situation without an increase in level of care within 90 days of the stroke) using random forests regression. Estimates were generated using 200 bootstrapped datasets. Covariate contribution to home time was determined using partial dependence plots.

Results Of 657 EVT patients, 85 (12.9%) had baseline ASPECTS ≤5 (mean age 70.9 years, 44.7% women, 93.9% good–moderate collaterals, 60% M1–middle cerebral artery occlusion). Using partial dependence estimates, mean predicted home times were similar in the low ASPECTS (44.3 days) versus higher ASPECTS (43.1) groups. Factors predicting lower 90 day home time in this population were diabetes mellitus (−8.8 days), hypertension (−5.7 days), and atrial fibrillation (−3.6 days). There was no meaningful difference in predicted 90 day home time by sex, baseline National Institutes of Health Stroke Severity Scale score, occlusion site, tandem lesion, collateral grade or thrombolysis.

Conclusions Patients with low ASPECTS who are selected for EVT using demographic and clinical profiles similar to higher ASPECTS patients achieved comparable outcomes.

  • Stroke
  • Thrombectomy

Data availability statement

Data are available upon reasonable request.

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Data availability statement

Data are available upon reasonable request.

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  • Twitter @nishita_singh3, @nimakashani, @rosevmcd, @FouziBala, @mihill68, @AlmekhlafiMa

  • Contributors NS: collected the data and wrote the paper. JKH: designed and performed the analysis, and provided critical inputs to the manuscript. NK, FB, RVM, and MH: collected the data. JS: helped in providing the registry data. AMD and MDH: provided critical inputs to the manuscript. MAA: conceived the idea and provided critical inputs to the manuscript. NS is responsible for the overall content as the guarantor.

  • Funding FB is supported by La Société Française de Neuroradiologie et La Société Française de Radiologie.

  • Competing interests None declared.

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

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