Abstract TP51: Does Intracranial Atherosclerotic Disease With Low NIHSS Effect Outcomes in Reperfusion Therapy Eligible Acute Stroke Patients?

Abstract

Background: Even patients with low National Institutes of Health Stroke Scale (NIHSS) benefit from reperfusion therapy due to its high efficacy and warranted safety by multimodal imaging assessment. On the other hand, having intracranial atherosclerotic disease (ICAD) could be a risk for reperfusion therapy in Asian population. We assessed the safety and efficacy of reperfusion therapy in patients with low NIHSS and ICAD. Method: Acute anterior ischemic stroke patients with baseline MRI before reperfusion therapy from National Cerebral and Cardiovascular Center stroke database between 2015-2017 were included. Outcome was assessed by modified Rankin Scale (mRS) at 90 days. DWI volume was measured by RAPID software and ICAD was measured by TOF-MRA as >50% of stenosis in the middle cerebral artery. Baseline DWI volume as a risk factor for having poor outcome (mRS 5-6 at 90 days) was assessed by ROC analysis as a malignant DWI profile and logistic regression analysis was performed to estimate the risk of low NIHSS (≤5) and presence of ICAD. Interaction of Low NIHSS and ICAD was analyzed for having unfavorable outcomes. Result: Total of 124 patients (42 women, mean age 72±13 years) were included in this study with mRS <3 before onset. Incident of ICAD was 18.5% (23/124), median (interquartile range: IQR) NIHSS was 9 (5-12) and median onset to MRI time was 109 (IQR 70-217) minutes. Mean (SD) DWI volume was 15.5 (27.3) mL. ROC analysis determined DWI volume larger than 46.0 mL to be associated with poor outcome with 94.8% specificity and 62% sensitivity (AUC 0.86, p<0.001). Interaction between ICAD and low NIHSS showed no difference in association with poor outcome between patients with and without ICAD (p=0.459) in the logistic regression analysis. Low NIHSS was associated with the lower risk of poor outcome in univariate analysis (p=0.05). However, low NIHSS was not an independent predictor of poor outcome (p=0.384) when adjusted for other significant factors (age, DWI volume, systolic blood pressure, chronic heart failure). ICAD was neither associated with outcome independently nor associated with low NIHSS. Conclusion: Low NIHSS and ICAD at baseline would not be factors for unfavorable clinical outcome in reperfusion therapy eligible patients in Asian population.