Supplementary Material for: Efficacy and Safety of Endovascular Thrombectomy in Acute Ischemic Stroke Patients with ASPECTS ≤2: A Systematic Review and Meta-Analysis

Background: Acute ischemic stroke (AIS) affects approximately 11.9 million people annually, with large vessel occlusion (LVO) accounting for 10–20% of cases. While endovascular thrombectomy (EVT) is established for AIS with LVO, recent trials have expanded treatment to patients with Alberta Stroke Program Early CT Score (ASPECTS) 3–5. However, the efficacy and safety of EVT in patients with ASPECTS ≤2, representing extremely large infarcts with poor prognoses, remain uncertain due to limited evidence. This study evaluates EVT outcomes in this high-risk population.
Methods: PubMed, Embase, and Web of Science were searched (January 1, 2010–September 20, 2024) for studies comparing EVT plus best medical treatment (BMT) versus BMT alone in AIS patients with ASPECTS ≤2. Outcomes included favorable functional outcome (FFO, mRS 0–2), moderate functional outcome (MFO, mRS 0–3), modified Rankin Scale (mRS) shift, symptomatic intracranial hemorrhage (sICH), any intracranial hemorrhage (ICH), and 90-day mortality. Unadjusted odds ratios (ORs) and risk differences (RDs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was assessed with the I² statistic.
Results: Seven studies involving 718 patients (305 EVT, 413 BMT) were included. EVT significantly improved FFO (11.8% vs. 1.6%; OR 5.39, 95% CI 2.06–14.13, P=0.0002), MFO (24.2% vs. 11.5%; OR 2.50, 95% CI 1.53–4.09, P=0.0003), and mRS shift (OR 1.64, 95% CI 1.30–2.06, P<0.001). However, EVT increased sICH (16.5% vs. 2.4%; OR 5.30, 95% CI 1.03–27.39, P<0.001) and any ICH (40.7% vs. 14.9%; OR 3.91, 95% CI 2.24–6.83, P<0.001). No significant difference in 90-day mortality was observed (45.5% vs. 50.8%; OR 0.72, 95% CI 0.34–1.53, P=0.40), though EVT showed a trend toward reduced mortality.
Conclusion: EVT significantly improves functional outcomes in AIS patients with ASPECTS ≤2; however, the absolute benefits remain modest, given the poor prognosis associated with large infarcts. While EVT increases hemorrhagic complications, it does not increase mortality and may provide meaningful benefits for carefully selected patients. Further large-scale trials are needed to refine EVT guidelines.