Abstract 205: Optimizing Prediction Scores for Poor Outcome After Intra-arterial Therapy for Anterior Circulation Acute Ischemic Stroke

Abstract

Background: Intra-arterial therapy (IAT) is an approach to promote recanalization of large artery occlusions (LAO) in acute ischemic stroke (AIS) but is resource intensive. Previous studies evaluated different variables that affect clinical outcome after IAT. To better identify patients who have poor outcomes despite IAT, we compared the performance of previous predictive scoring systems that relied either on clinical or imaging variables in patients undergoing IAT. We then combined imaging and clinical variables to optimize a score that would better predict poor outcome after IAT for AIS. Methods: We studied consecutive AIS patients undergoing IAT at UT-Houston for LAO (MCA or ICA) from 01/03 to 05/11. We collected demographics and clinical variables and analyzed CT head scans using the ASPECTS scores by raters blinded to outcomes. Independent predictors of poor outcome (mRS 4–6) with p values ≤0.1 were evaluated as score variables using sensitivity analysis and logistic regression. Spearman’s correlation and ROC curves were used to evaluate the final score. Houston Intra-arterial Therapy 2 (HIAT2) score ranged from 0–10 with points for: age (≤59=0, 60–79=2, ≥80 years=4), Glucose (<150=0, ≥150=1), NIHSS (≤10=0), 11–20=1, ≥21=2), ASPECTS (8–10=0, ≤ 7=3). The score was created using 75% of the dataset (build group) and tested on the remaining 25% (test group). Previously published prediction scores (HIAT, THRIVE, ASPECTS) were compared against HIAT2. Results: Table 1 shows the clinical features for the 163 patients collected. Fig 1 shows the proportion of poor outcome based on HIAT-2. Patients with HIAT2 ≥ 5 were more likely to have a poor outcome at discharge (OR 6.43, 95% CI 2.75–15.02, p<.001). After adjusting for reperfusion (TICI≥2b, p=.7) and time from symptom onset to recanalization (p=.4), HIAT2 remained a significant independent predictor of poor outcome (OR 5.88, 95% CI 1.96–17.64, p=.02). Fig 2 shows the performance of HIAT2 against THRIVE, HIAT and ASPECTS as well as the validation of HIAT-2. Conclusions: Clinical prediction scores for patients undergoing IAT (HIAT, THRIVE) proved superior to the ASPECTS score. The HIAT2 score, which combines clinical and imaging variables, performed better than all previous scores in predicting the chance of poor outcome after IAT for anterior circulation LAO.