• Author
    Alexander Fish
  • Discovery PI

    Jeffrey L. Saver, MD

  • Project Co-Author

    Jeffrey Gornbein, DrPH, Angshuman Saha, PhD

  • Abstract Title

    The Expanded-CASPR Scale to Identify Intracerebral Hemorrhage Patients in the Prehospital Setting: Derivation and Validation in the FAST-MAG Trial

  • Discovery AOC Petal or Dual Degree Program

    Basic, Clinical, & Translational Research

  • Abstract

    BACKGROUND AND AIMS

    Distinguishing intracerebral hemorrhage from ischemic stroke in the prehospital setting would improve destination hospital and blood pressure strategy. The California Acute Stroke Subtype Prehospital (CASPR) Scales (CASPR-B and CASPR-ACS), leveraging information available to first responders, shows moderate performance. This study aimed to evaluate whether an Expanded-CASPR (E-CASPR) Scale, augmented with select NIH Stroke Scale (NIHSS) elements, would improve ICH identification.

     

    METHODS

    In secondary analysis of data from the prehospital NIH FAST-MAG randomized clinical trial, we analyzed non-intubated patients with a final diagnosis of ischemic stroke or ICH.  Prediction models included CASPR-B (n=1302) and CASPR-ACS (n=362), enhanced using selection of six among 13 candidate NIHSS elements for CASPR-B and three of 13 for CASPR-ACS, via Akaike Information Criterion (AIC). Internal validation used a 70/30 training-testing split with ten-fold cross validation. Exploratory XGBoost models assessed feature importance.

     

    RESULTS

    In derivation, CASPR-B ICH prediction improved with addition of NIHSS elements including level of consciousness (LOC), sensory deficits gaze deviation, arm and leg weakness, while CASPR-ACS improved with leg weakness, language impairment and dysarthria. In validation analyses, CASPB-B performance improved AUC 0.759 to 0.804 (p<0.05) and CASPR-ACS improved 0.791 to 0.845 (p<0.05). NIHSS score alone as a predictor of ICH performed near chance, and XGboost identified CASPR score as the most predictive variable for ICH. E-CASPR-B showed positive likelihood ratio (LR) 3.32 and negative LR 0.30 while E-CASPR-ACS demonstrated positive LR 4.56 and negative LR 022.

     

    CONCLUSIONS

    Incorporation of select NIHSS elements improves prehospital discrimination of ICH from ischemic stroke by CASPR, specifically with rule out potential. The selected NIHSS elements are feasible for prehospital implementation alongside CASPR, improving utility in stroke triage and treatment.

     

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