Abstract 146: Endovascular Treatment May Still Benefit Patients With Low Baseline Alberta Stroke Program Early CT Score

Introduction: We aimed to investigate the outcome of endovascular treatment (EVT) for acute ischemic stroke in patients with low Alberta Stroke Program Early CT Score (ASPECTS). Methods: This study reports on MR CLEAN Registry patients with available baseline ASPECTS (N=1423). ASPECTS was trichotomized in 0-4, 5, and 6-10 in order to create low ASPECTS groups of similar size. Primary outcome was modified Rankin Scale score (mRS) at 90 days. Secondary outcomes were symptomatic intracranial hemorrhage (sICH) and mortality. Benefit of reperfusion (defined as extended thrombolysis in cerebral infarction [eTICI] score 2B-3) was assessed by multivariable ordinal logistic regression analysis, including an interaction term of reperfusion and ASPECTS, and it was expressed as an adjusted common odds ratio (acOR). A comparison with the MR CLEAN trial control arm was made to assess benefit of EVT. Results: Higher trichotomized ASPECTS was associated with improved mRS (acOR 1.4, 95%CI 1.2-1.7). For ASPECTS 0-4 (n=93) successful reperfusion was not associated with improved mRS (acOR 1.4, 95%CI 0.6-2.9). ASPECTS 5 (n=63) and ASPECTS 6-10 subgroups (n=1267) however, did show significant benefit of reperfusion (acOR 3.9, 95%CI 1.3-11.8; acOR 2.7, 95%CI 2.2-3.3, respectively)(Fig1). Interaction between trichotomized ASPECTS and reperfusion was not significant ( p =0.13). Comparison with the MR CLEAN trial control group showed that trichotomized ASPECTS did not modify the effect of EVT ( p =0.14). Patients with lower trichotomized ASPECTS had a higher risk of mortality (aOR 0.9, 95%CI 0.9-1.0), but not of sICH (aOR 1.0, 95%CI 0.9-1.1). Conclusion: ASPECTS does not modify effect of reperfusion or EVT on functional outcome after acute ischemic stroke. Patients with ASPECTS 5 or higher seem to benefit from successful reperfusion.