Select wisely: the ethical challenge of defining large core with perfusion in the early time window

The pivotal stroke trials published in 2015 provided indisputable evidence of the benefit of thrombectomy in early window (0–6 hours) patients with anterior circulation emergent large vessel occlusion (ELVO) and small infarcts on non- contrast CT (NCCT), measured by ASPECTS 6–10. 1–5 Since then, endovascular treatment of this population has been standard guideline- based care. 6 Efforts, similar to the late window trials, 7 8 are now directed at further expanding thrombectomy indications. Five trials are underway inves-tigating the role of thrombectomy in patients with ELVO with ASPECTS <6, the 'large core' population for whom formal level I evidence is lacking (TENSION