Abstract WP70: Novel Weighted FANG-D Scale Scoring to Detect Large Vessel Occlusion

Abstract

Objective: To determine if a novel weighted FANG-D scoring scale (NWFSS) increases sensitivity and specificity rates of large vessel occlusion (LVO) as compared to those reported with the original FANG-D scale scoring. Methodology: The present study used an observational, descriptive design to identify the important variables (field cut, aphasia, neglect, gaze preference, and dense hemiparesis) associated with the likelihood of detecting LVO. We used the FANG-D scale in patients admitted through the emergency department (ED) of a comprehensive stroke center (CSC), from December 2022 through April 2023. The NIHSS was performed and compared with the NWFSS for analysis. Each component was required to have a score ≥ 2(moderate to severe deficits) except dense hemiparesis which required a score ≥3 (significant weakness) to receive one point on the FANG-D scale. A total score of 2 or higher on FANG-D indicated a positive result suggesting LVO. If aphasia or neglect were present with a NIHSS of≥2, it was considered a positive FANG-D score. Results: A total of 311 patients were included in the study for analysis with a mean age of 67 ±16.4 years of whom 56.6% were female. The sensitivity and specificity rates were 85.7% (Confidence Interval (CI) =72.8%-94.1%) and 90.5% (CI= 86.2%-93.7%) respectively for positive predictive value of NWFSS to identify LVO. The sensitivity and specificity of the NIHSS has been reported as 86% and 60% respectively for LVO detection. The previous FANG-D study group used lower values in calculating the FANG-D scores and reported a sensitivity rate of 98% and specificity of 76.7%. Conclusion: The NWFSS has high specificity and is reliable for LVO prediction. While the NIHSS assesses eleven items sensitive for stroke diagnosis, it may take up to 10 minutes to complete and is not specific for LVO, whereas the FANG-D assesses 5items critical to LVO detection and is simple and fast with completion in <1 minute, minimizing time to intervention. Our study occurred in the ED, but this scale scoring method could be tested in the prehospital setting. The use of a scale with higher specificity for LVO could improve patient outcomes and resource utilization by faster routing of patients to CSCs capable of performing mechanical thrombectomy.