Serum heme oxygenase‐1 level predicts clinical outcome after acute ischemic stroke

Aims The relationship between heme oxygenase‐1 (HO‐1) and human ischemic stroke outcome remains unclear, which was investigated in this study. Methods Acute ischemic stroke patients admitted within 24 h were enrolled. Serum HO‐1 levels at baseline were measured via ELISA. Poor 3‐month functional outcome was defined as modified Rankin Scale (mRS) score 3–6. Multivariable‐adjusted binary logistic regression and restricted cubic spline models were employed to examine association between serum HO‐1 and functional outcome. HO‐1's additive prognostic utility was assessed by net reclassification index (NRI) and integrated discrimination improvement (IDI). Results Of 194 eligible patients, 79 (40.7%) developed poor functional outcomes at 3‐month follow‐up. The highest quartile of serum HO‐1 was independently associated with a lower risk of poor functional outcome (adjusted OR 0.13, 95% CI 0.04–0.45; p = 0.001) compared with the lowest HO‐1 category. The relationship between higher HO‐1 levels and reduced risk of poor functional outcome was linear and dose responsive (p = 0.002 for linearity). Incorporating HO‐1 into the analysis with conventional factors significantly improved reclassification for poor functional outcomes (NRI = 41.2%, p = 0.004; IDI = 5.0%, p = 0.004). Conclusions Elevated serum HO‐1 levels at baseline were independently associated with improved 3‐month functional outcomes post‐ischemic stroke. Serum HO‐1 measurement may enhance outcome prediction beyond conventional clinical factors. Among patients with acute ischemic stroke (AIS), those with higher serum heme oxygenase‐1 (HO‐1) levels at baseline were associated with a lower risk of poor 3‐month functional outcomes. Incorporating HO‐1 with conventional factors improved reclassification for poor functional outcomes. These findings showed the potential of HO‐1 as a prognostic biomarker after stroke.