Exploring the Limits of Endovascular Therapy for Large Core Patients: Where Do We Need More Data?

Endovascular therapy; large core; stroke imaging; CT perfusionThe six randomized large core stroke trials reported or published between 2022 and 2024 have expanded the selection criteria for endovascular therapy (EVT) demonstrating that patients with lower Alberta Stroke Program Early CT (ASPECT) scores and larger CTperfusion (CTP) or diffusion-weighted imaging (DWI) core volumes benefit from EVT [1-6].There are, however, several patient subgroups that were underrepresented in the randomized trials, as well as heterogeneity in study designs and treatment responses.This brings into question which subgroups of patients with large cores benefit from EVT.Some trials focused on MRI-based selection (DWI-ASPECTS), others included patients who had both non-contrast CT (NCCT) and CTP, while others required only a NCCT and enrolled based on ASPECTS criteria (see Table 1).Some studies were restricted to early time windows, while others treated patients up to 24 hours after last know well.Subgroups with an uncertain response to EVT include CT ASPECT or DWI-ASPECT scores between 0-3 in in the early time window, large core volumes on CTP or MRI (especially in later treatment windows), and those with no perfusion imaging mismatch in any time window.Patients with baseline disability were not represented as a premorbid modified Rankin Score (mRS) 1 was required for all trials except TENSION, which allowed mRS 0-2.Those of age greater than 80 years were also under-represented as the mean ages of the patients enrolled was in the mid-late 60s in TESLA, SELECT2, and ANGEL-ASPECT and in the mid 70s in the other three studies.