Abstract Body: Introduction:
Several clinical trials have shown the benefits of endovascular thrombectomy (EVT) for patients with large core strokes, defined as an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) < 6. However, achieving independent functional outcomes in these patients remains relatively low. Particularly in developing countries with limited resources, the effectiveness of EVT in treating large core strokes is not well validated. In this study, conducted in a lower-middle-income country, we aimed to assess the utility of EVT in managing large core strokes using a simple imaging protocol with non-contrast CT (NCCT) and CT angiography (CTA).

Method:
We conducted a prospective, single-center, observational study from May 2023 to May 2024 in Da Nang Hospital, Vietnam. Patients with large-vessel occlusion stroke in the anterior circulation, having an ASPECTS < 6 on initial NCCT, admission NIHSS ≥ 6, and received EVT within 24 hours from onset were included. A favorable outcome was defined as mRS 0-3 at 90 days. Safety outcomes included symptomatic intracranial hemorrhage (sICH) per the SITS-MOST criteria. We compared outcomes between successful (mTICI ≥2b) and unsuccessful (mTICI 0-2a) reperfusion groups. Multivariable logistic regression was used to identify independent predictors of favorable outcomes.

Results:
During the study period, 157 patients received EVT, and 52 (33.1%) had ASPECTS < 6. The median age was 62.5 (IQR 58.5-71), with 57.7% being male. Median onset-to-hospital time was 4.5 hours (IQR 3-8), median admission NIHSS 15 (IQR 13 – 19.5), and median initial ASPECTS 3.5 (IQR 3-4). Successful reperfusion was achieved in 41 (78.9%) patients. At 90 days, the median mRS was 3.5 (IQR 3-4), and 50% of patients achieved a favorable outcome. sICH occurred in 9.6%, and the mortality rate was 25%. Patients with successful reperfusion had a significantly higher rate of favorable outcome (61% vs 9.1%, p = 0.005), lower mortality (17.1% vs 54.6%, p = 0.019), and similar sICH (9.8% vs 9.1%, p = 0.99) compared to those without successful reperfusion. Multivariable analysis showed that successful recanalization was the only independent predictor of favorable outcomes (OR 14.7, 95%CI 1.6 - 134).

Conclusion:
Our findings suggest that EVT is feasible and effective for large core stroke patients in lower-income countries when using a simplified NCCT-CTA protocol, especially for patients with successful reperfusion.