Abstract T P55: Infarction Patterns Predict Differential Response to Thrombolysis in Acute Middle Cerebral Artery Stroke Patients

Abstract

Introduction: Thrombolytic treatment within 4.5 hours saves ischemic tissue at risk and is associated with improved clinical outcomes in patients with acute middle cerebral artery (MCA) ischemic stroke. Lesion pattern is one of the most important predictors for acute stroke patients’ outcome. However, the efficacy of thrombolysis in acute MCA stroke patients with different lesion patterns remains unclear. In this study, we aimed to compare response to intravenous tPA in patients with different infarction patterns. Methods: We included acute MCA ischemic stroke patients treated with intravenous tPA. All patients had DWI within 24 hours of symptom onset with 6 lesion patterns categorized as territorial, other cortical, small superficial, internal border zone, small deep, and other deep infarcts. We classified territorial infarcts and internal borderzone into Group 1 and the other four lesion patterns as Group 2. We analyzed clinical outcome after tPA based on these distinct DWI lesion patterns. Results: A total of 203 patients were included in our study. Mean age was 66.2±18.1.The percent of patients with hypertension at presentation is higher in Group 1 than in Group 2(100% VS 93.8%, p=0.049). The presenting NIHSS of Group 1 is higher than Group 2 (18.0 vs 12.0, p<0.001). After intravenous tPA therapy, the proportion of patients progressing to intra-arterial tPA and/or endovascular thrombectomy in Group 1 was similar to Group 2 (22.0% vs 22.2%, p=0.98). As to the clinical outcome, the percent of patients with discharge mRS≤2 in Group 1 is much higher than that Group 2 (33.9% vs 20.1% p=0.038). Logistic regression demonstrated that infarction patterns were independently associated with discharge outcome of these patients. Conclusion: Good response to intravenous tPA was more frequent in patients with territorial infarcts and internal border zone infarcts, indicating that particular DWI infarction patterns can predict good outcome of acute MCA patients after thrombolysis.