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Acute imaging does not improve ASTRAL score's accuracy despite having a prognostic value

Authors

  • George Ntaios,

    Corresponding author
    1. Department of Medicine, University of Thessaly, Larissa, Greece
    • Correspondence: George Ntaios*, Department of Medicine, University of Thessaly, Biopolis 41110, Larissa, Greece.

      E-mail: gntaios@med.uth.gr

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    • G. Ntaios and V. Papavasileiou have contributed equally and are co-first authors.
  • Vasileios Papavasileiou,

    1. Department of Medicine, University of Thessaly, Larissa, Greece
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    • G. Ntaios and V. Papavasileiou have contributed equally and are co-first authors.
  • Mohamed Faouzi,

    1. Institute of Social and Preventive Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
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  • Peter Vanacker,

    1. Department of Neurology, University Hospital Antwerp, Edegem, Belgium
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  • Max Wintermark,

    1. Department of Radiology, Division of Neuroradiology, University of Virginia, Charlottesville, VA, USA
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  • Patrik Michel

    1. Stroke Center, Neurology Service, Department of Neurosciences, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
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  • Funding: Dr P. Michel has received through his employer (CHUV) research grants from the Swiss National Science Foundation, the Swiss Heart Foundation, and Cardiomet-CHUV for analyses based on the ASTRAL registry. The other co-authors report no disclosure.
  • Authors' contributions: G. Ntaios: Study concept and design, analysis and interpretation, preparation of the manuscript, study supervision. V. Papavasileiou: Data acquisition, analysis and interpretation, critical revision of the manuscript for important intellectual content. M. Faouzi: Analysis and interpretation, critical revision of the manuscript for important intellectual content. P. Vanacker: Data acquisition, critical revision of the manuscript for important intellectual content. M. Wintermark: Study concept and design, critical revision of the manuscript for important intellectual content. P. Michel: Study concept and design, data acquisition, analysis and interpretation, critical revision of the manuscript for important intellectual content, study supervision.

Abstract

Background

The ASTRAL score was recently shown to reliably predict three-month functional outcome in patients with acute ischemic stroke.

Aim

The study aims to investigate whether information from multimodal imaging increases ASTRAL score's accuracy.

Methods

All patients registered in the ASTRAL registry until March 2011 were included. In multivariate logistic-regression analyses, we added covariates derived from parenchymal, vascular, and perfusion imaging to the 6-parameter model of the ASTRAL score. If a specific imaging covariate remained an independent predictor of three-month modified Rankin score > 2, the area-under-the-curve (AUC) of this new model was calculated and compared with ASTRAL score's AUC. We also performed similar logistic regression analyses in arbitrarily chosen patient subgroups.

Results

When added to the ASTRAL score, the following covariates on admission computed tomography/magnetic resonance imaging-based multimodal imaging were not significant predictors of outcome: any stroke-related acute lesion, any nonstroke-related lesions, chronic/subacute stroke, leukoaraiosis, significant arterial pathology in ischemic territory on computed tomography angiography/magnetic resonance angiography/Doppler, significant intracranial arterial pathology in ischemic territory, and focal hypoperfusion on perfusion-computed tomography. The Alberta Stroke Program Early CT score on plain imaging and any significant extracranial arterial pathology on computed tomography angiography/magnetic resonance angiography/Doppler were independent predictors of outcome (odds ratio: 0·93, 95% CI: 0·87–0·99 and odds ratio: 1·49, 95% CI: 1·08–2·05, respectively) but did not increase ASTRAL score's AUC (0·849 vs. 0·850, and 0·8563 vs. 0·8564, respectively). In exploratory analyses in subgroups of different prognosis, age or stroke severity, no covariate was found to increase ASTRAL score's AUC, either.

Conclusions

The addition of information derived from multimodal imaging does not increase ASTRAL score's accuracy to predict functional outcome despite having an independent prognostic value. More selected radiological parameters applied in specific subgroups of stroke patients may add prognostic value of multimodal imaging.

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