Large vessel occlusion prediction scale thresholds that are sensitive for DAWN Trial patients

Area of Science:

• Neurology
• Emergency Medicine
• Radiology

Background:

• Large vessel occlusion (LVO) prediction scales aid in triaging stroke patients for endovascular therapy.
• The sensitivity of these scales in the 6-to-24-hour time window is not well-established.
• Optimizing scale thresholds is crucial for accurate LVO stroke identification and timely treatment.

Purpose of the Study:

• To determine the highest scale score thresholds that maintain at least 85% sensitivity for LVO prediction.
• To investigate potential differences in sensitivity between left and right-sided LVOs within the 6-to-24-hour window.
• To inform clinical decision-making regarding the selection of appropriate LVO prediction scale thresholds.

Main Methods:

• Retrospective analysis of National Institutes of Health Stroke Scale (NIHSS) scores from the DAWN Trial.
• Calculation of LVO prediction scale scores for patients with last known well times between 6 and 24 hours.
• Identification of scale thresholds with ≥85% sensitivity and assessment of side-specific sensitivity variations.

Main Results:

• Specific highest sensitive thresholds identified: CPSS=3, C-STAT≥2, FAST-ED≥4, G-FAST≥3, RACE≥5, SAVE≥3.
• RACE≥5 demonstrated higher sensitivity for right-sided LVOs; similar minor differences observed for other scales at higher thresholds.
• All evaluated patients had confirmed LVOs, precluding specificity calculations.

Conclusions:

• The identified thresholds represent maximum sensitivities for ideal thrombectomy candidates in the 6-to-24-hour window.
• Prehospital documentation and less severe NIHSS scores (<10) or distal LVOs may reduce scale sensitivity.
• Elevating LVO triage thresholds risks a significant number of missed LVO strokes, delaying critical treatment.