Elevated C-reactive protein-to-albumin ratio is associated with early neurological deterioration in acute ischemic stroke: a retrospective cohort study.

Background: Early neurological deterioration (END) is a frequent complication of acute ischemic stroke (AIS) that contributes to poor clinical outcomes. The C-reactive protein-to-albumin ratio (CAR) reflects systemic inflammation relative to albumin levels and may be associated with END. We evaluated the association between log Methods: We retrospectively analyzed 1,766 patients with AIS admitted between September 2016 to September 2022. END was defined as an increase of ≥2 points in the NIHSS motor item or total score within 72 h of admission. Associations between log₂-CAR and END were assessed using a multivariable logistic regression analysis. Generalized additive and two-piecewise regression models were used as exploratory analyses to assess potential non-linearity. ROC curves were used to compare CAR with established biomarkers and the A2DS2 score. Conclusion: Higher CAR was independently associated with END in this cohort. CAR's strongest predictive advantage was observed when compared with the A2DS2 clinical score, whereas superiority over CRP alone was not demonstrated. The possible threshold at a raw CAR of approximately 0.020 is exploratory and requires independent validation.