Predictive value of hemoglobin level on early neurological outcomes in acute ischemic stroke

Few studies have examined the association between hemoglobin (Hb) levels and early neurological changes following acute ischemic stroke (AIS). The present research investigated whether higher or lower Hb level on admission was associated with early neurological deterioration (END) in AIS patients. Furthermore, we evaluated the predictive effect of Hb concentration on stable or improving outcome.

In this prospective cohort study, a total of 1330 patients admitted within 24 hours after AIS onset were finally involved in the analysis. We classified participants into four groups according to baseline Hb levels: ≤120, 121-140, 141-160, and >160 g/L. The risk of END was accessed by means of logistic regression analysis, and tendency of improvement and stability by multinomial logit analysis. We further evaluated the pattern and magnitude of association of Hb as a continuous variable and END by multivariate logistic regression analysis of restricted cubic spline.

Compared with the reference group, hemoglobin >160 g/L was associated with END (OR, 95%CI; 2.149, 1.314-3.512) and severe END (OR, 95% CI as 2.317, 1.351-3.976 and 2.810,1.589-4.968, respectively). Comparatively, higher Hb level also independently predicted improving (OR, 95% CI; 0.322, 0.170-0.609) and stable (OR, 95% CI; 0.371, 0.205-0.673) outcome. Similar results were found when restricted to anterior circulation ischemic stroke after adjustment of variables including large vessel disease.

We concluded that patients with higher baseline Hb level are at significantly higher risk for END, and less likely to reach stable or improving status at the early stage of stroke.