Background/Aims: Endovascular thrombectomy (EVT) enhances clinical outcomes across various infarct volumes and time windows1-2. This study aimed to assess whether EVT provides similar benefits across different lesion ages using quantitative lesion net water uptake (NWU)3 in large infarcts.
Methods: A secondary analysis of the ANGEL-ASPECT trial4 involved patients with large ischaemic cores, randomised to EVT or medical management. Patients with available baseline CT or CTP for NWU measurement were included. The primary outcome was 90-day functional independence. EVT benefits versus medical management were evaluated across NWU levels.
Results: Of 389 patients (median age 68 years; 38.3% women), the relationship between NWU and functional outcomes showed a non-linear pattern after medical management and no correlation after EVT. An inflection point at 10% NWU categorised patients into low NWU (<10%, n=194) and high NWU (≥10%, n=195) groups. Patients with NWU ≥10% benefited more from EVT compared to those with NWU <10%, with a significant interaction between NWU and treatment groups in achieving functional independence (adjusted OR 16.48 [95% CI 5.18–52.49] vs. 2.41 [95% CI 1.11–5.21], P for interaction=0.03). Patients with NWU <10% had higher rates of spontaneous recanalisation than those with higher NWU (50.63% vs. 23.75%) in the medical management group.
Conclusion: EVT improved clinical outcomes across different lesion ages by NWU in large infarcts. Patients with later lesion age and large ischaemic stroke within 24 hours had a lower chance of spontaneous recanalisation without EVT, and therefore, showed more pronounced benefits from EVT than those with early lesion age.