Direct Intra-arterial Thrombectomy in Order to Revascularize AIS Patients With Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals

Background: Intravenous thrombolysis (IVT) combined with mechanical thrombectomy (MT) has been proven safe and effective in patients with acute ischemic stroke (AIS) of anterior circulation large vessel occlusion (LVO). Despite recanalization, a considerable proportion of patients do not recover. The incidence of symptomatic intracerebral hemorrhage (sICH) was similar between combined IVT plus MT and IVT, suggesting that this complication could not be attributed to the MT, but rather to pre-treatment with IVT. Meanwhile, the incidence of intracranial atherosclerosis stenosis (ICAS) is higher in Asians. It is not clear whether patients with ICAS benefit from pretreatment with alteplase or not and how ICAS modifies treatment effect. Objective: To assess whether direct MT is non-inferior compared to combined IVT plus MT in patients with AIS due to an anterior circulation LVO, and to assess treatment effect modification by presence of ICAD. Study design: This is a parallel group, RCT of direct MT compared to combined IVT plus MT, using a non-inferiority design. The trial has observer blinded assessment of the primary outcome and of neuro-imaging at baseline and follow up. The trial will be executed in collaboration with MRCLEAN NO-IV investigators. Study population: Patients with AIS of anterior circulation VLO confirmed by CTA. Initiation of IVT must be feasible within 4.5 hours from symptom onset. Age must be 18 or over and NIHSS 2 or more. Main outcomes: The full distribution of the mRS at 3 months. Secondary outcomes: 1. death within 90 +/- 14 days; 2. pre-interventional reperfusion assessed on first intracranial DSA; 3. eTICI19 score on final angiography of MT; 4. score on the NIHSS at 24 +/- 6 hours and 5-7 days, or at discharge; 5. recanalization rate at 24-72h by CTA; 6. Final lesion volume at 5-7 days on NCCT20; 7. score on the EuroQoL 5-dimensions 5-level (EQ5D-5L)21 and Barthel index22 at 90 +/- 14 days; 8. dichotomous clinical outcome on the mRS at 90 +/