The 24‑ to 48‑hour follow‑up infarct volume (FIV) is a limited surrogate outcome for late–time‑window stroke because it explains only a small fraction of the benefit seen with endovascular treatment (EVT), according to new research. In a post hoc analysis of 449 acute ischemic stroke patients from six randomized late‑window EVT trials, larger FIVs were associated with worse 90‑day functional outcomes. However, this relationship was much stronger in the EVT group than in controls, whose overall outcomes were poorer across all FIV levels. An increase in FIV lowered the probability of functional independence after EVT—from 65% at 0 mL to 4% at 200 mL—only 5.9% of EVT’s clinical benefit was mediated through FIV reduction, and EVT consistently outperformed medical management for FIVs up to 100 mL. These findings suggest that although FIV correlates with better clinical outcomes, it does not adequately capture the mechanisms through which EVT improves recovery in late‑window stroke.