In patients with acute ischaemic stroke, baseline infarct size may not alter the impact of alteplase prior to endovascular thrombectomy regarding favorable functional outcomes and adverse events.

• In the DIRECT-MT, endovascular thrombectomy was shown to be non-inferior to thrombectomy preceded by intravenous alteplase regarding functional outcome in patients with acute ischaemic stroke.

• This post-hoc analysis was conducted to determine if infarct size altered the impact of alteplase.

• All patients with baseline Alberta Stroke Program Early Computed Tomography Score (ASPECTS) grade were included; Of 649 cases, 323 (49.8%) were in the thrombectomy-alone group and 326 (50.2%) in the combination-therapy group.

• For the primary endpoint of ordinal modified Rankin Scale (mRS), there was no significant treatment-by-trichotomized ASPECTS interaction with alteplase prior to endovascular treatment (p-value interaction term compared to ASPECTS 8-10: ASPECTS 0-4, p=0.386; ASPECTS 5-7, p=0.936).

• Adjusted common odds ratio for improvement in the 90-day mRS with thrombectomy alone vs combination therapy was estimated to be 1.99 for ASPECTS 0-4, 1.07 for ASPECTS 5-7, and 1.03 for ASPECTS 8-10.

• The two groups did not differ significantly in terms of safety outcomes.