ObjectiveTo evaluate the non-inferiority of endovascular treatment (EVT) alone versus intravenous thrombolysis (IVT) followed by EVT and to assess its heterogeneity across prespecified subgroups.MethodsWe pooled data from two trials (SKIP in Japan; DEVT in China). Individual patient data were pooled to assess outcomes and heterogeneity of treatment effect. The primary outcome was functional independence (modified Rankin Scale score 0–2) at 90 days. Safety outcomes included symptomatic intracranial hemorrhage (sICH) and 90-day mortality.ResultsWe included 438 patients (217 EVT alone; 221 combined IVT+EVT). The meta-analysis failed to demonstrate the non-inferiority of EVT alone over combined IVT+EVT in achieving 90-day functional independence (56.7% vs 51.6%; adjusted common odds ratio (cOR)=1.27, 95% CI 0.84 to 1.92, p_{non-inferiority}=0.06). Effect sizes favoring EVT alone were present with stroke onset to puncture time longer than 180 min (cOR=2.28, 95% CI 1.18 to 4.38, p_{interaction ≤180 vs >180 min}=0.02) and intracranial internal carotid artery ICA occlusions (for ICA cOR=3.04, 95% CI 1.10 to 8.43, p_{interaction ICA vs MCA}=0.08). The rates of sICH (6.5% vs 9.0%; cOR=0.77, 95% CI 0.37 to 1.61) and 90-day mortality (12.9% vs 13.6%; cOR=1.05, 95% CI 0.58 to 1.89) were comparable.ConclusionsThe cumulative data of these two recent Asian trials failed to unequivocally demonstrate the non-inferiority of EVT alone over combined IVT+EVT. However, our study suggests a potential role for more individualized decision-making. Specifically, Asian patients with stroke onset to EVT longer than 180 min, as well as those with intracranial ICA occlusions and those with atrial fibrillation might have better outcomes with EVT alone than with combined IVT+EVT.