Social-biological misalignment modulates the prognostic impact of infarct volume after endovascular thrombectomy

Objective Endovascular thrombectomy (EVT) achieves high rates of reperfusion, yet functional recovery remains heterogeneous. We investigated whether social-biological time misalignment modifies the association between final infarct volume and 90-day functional outcome. Methods This retrospective cohort study included 160 patients with large vessel occlusion treated with EVT. Misalignment was quantified using a composite score incorporating occupational shift exposure and symptom onset timing. Multivariable logistic regression assessed the interaction between misalignment and final infarct volume on favorable 90-day outcome (modified Rankin Scale 0–2). Results Misalignment was not independently associated with favorable outcome. However, a significant interaction was observed (OR = 9.70, 95% CI 1.74–54.10, LRT p = 0.008), remaining significant after FDR correction ( q = 0.034), stable across profile likelihood and Firth penalized regression. The interaction improved model fit (AIC 124.35 → 119.38) and provided modest incremental net benefit. Exploratory threshold analysis suggested a potential inflection point approximating 25 mL, but this is hypothesis-generating and requires validation. Conclusion Misalignment does not exert a uniform adverse effect but acts as a state-dependent modifier, modifying the association between final infarct volume and favorable outcome. The interaction between chronobiological state and infarct burden offers a novel framework for understanding outcome heterogeneity.