Abstract Body: Background: The efficacy and safety of thrombectomy compared to medical therapy in patients with acute ischemic stroke irrespective of the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) has been debated.

Method: We systematically searched EMBASE, PubMed and Scopus for randomized controlled trials (RCTs) and observational studies evaluating the efficacy and safety of thrombectomy compared to medical therapy in patients with acute ischemic stroke irrespective of the ASPECTS score with primary outcomes of modified rankin scale (mRS) score 0-3 at 90 days, functional independence mRS score 0-2 at 90 days and symptomatic intracranial hemorrhage (sICH).

Results: We included 20 RCTs and 6 observational studies containing 6580 patients comparing thrombectomy with medical therapy in patients with acute ischemic stroke irrespective of the ASPECTS scores. The pooled results showed that mRS score 0-3 at 90days (RR = 2.10; 95% CI [1.59; 2.77]; I² = 71%; p < 0.001; Figure 1A) and mRS score 0-2 at 90 days (OR = 2.48; 95% CI [1.97; 3.12]; I² = 64%; p < 0.001; Figure 1B) were significantly improved by thrombectomy compared to the medical therapy. Early neurologic worsening (RR = 0.93; 95% CI [0.57; 1.51]; I² = 63%; p = 0.770; Figure 1C) was not significantly different between groups. The safety outcome, sICH within 48hrs (RR = 1.82; 95% CI [1.25; 2.64]; I² = 50%; p = 0.002; Figure 2A) was significantly higher in thrombectomy group. The National Institutes of Health Stroke Scale (NIHSS) score at 24hrs (MD = -2.84; 95% CI [-4.11; -1.58]; I² = 65%; p < 0.001; Figure 2B) and mean change in infarct volume from baseline at 24hrs (MD = -26.10; 95% CI [-40.18; -12.02]; I² = 97%; p < 0.001; Figure 2C) were significantly reduced by thrombectomy. However, decompressive craniotomy (RR = 1.17; 95% CI [0.78; 1.75]; I² = 20%; p = 0.453; Figure 2D) did not show any difference between groups. Death within 90 days (OR = 0.71; 95% CI [0.61; 0.81]; I² = 22%; p < 0.001; Figure 3A) was significantly reduced by thrombectomy. The early neurologic improvement (SMD = 3.43; 95% CI [2.39; 4.93]; I² = 37%; p < 0.001) and median EuroQol Group 5 Dimension (EQ-5D) index at 90days (MD = 0.15; 95% CI [0.07; 0.23]; I² = 84%; p < 0.001; Figure 3C) were also improved by thrombectomy.

Conclusion: Compared with medical therapy, thrombectomy may improve functional outcomes in patients with acute ischemic stroke irrespective of the ASPECTS scores, despite associated with an increased risk of sICH.