Association between the Lactate-to-hematocrit Ratio and the Outcomes in Ischemic Stroke Patients: Insights from...

Ischemic stroke (IS) is a leading global cause of death and disability. The lactate-to-hematocrit ratio (LHR), which potentially reflects the oxygen metabolism and tissue perfusion, has not yet been sufficiently studied for IS prognosis prediction. To investigate the association between LHR and the 28-day all-cause mortality in patients with IS.

This MIMIC-IV database-based study included 866 patients with IS. Kaplan-Meier curves were used to compare survival between the log (LHR) subgroups. Multivariate Cox regression was performed with adjustment for the Glasgow Coma Scale (GCS) score, and robustness verification was further implemented by controlling for the SOFA score. An RCS analysis was used to explore the underlying nonlinear associations, followed by subgroup and mediation analyses.

A survival analysis demonstrated a significantly higher 28-day mortality in log (LHR)≥ 2.32 than in the log (LHR) ＜2.32 groups (log-rank P = 0.017). In the Cox regression analysis with full adjustment for confounding factors, for every unit increase in log (LHR), the 28-day mortality risk increased by 38.1% (HR = 1.381, 95% CI: 1.111-1.718). The mortality risk of patients with log (LHR) ≥ 2.32 increased by 47.8% compared to those with log (LHR) ＜2.32 (HR = 1.478, 95% CI: 1.075-2.031). The RCS analysis showed no significant non-linear relationship between log (LHR) and the 28-day mortality rate (P-non-linear = 0.859). No significant interaction was observed in the subgroup analyses, and the relevant associations remained statistically significant within the severe stroke subgroup. After adjusting for the GCS and SOFA scores, the independent prognostic value of log (LHR) remained consistent. A mediation analysis showed that white blood cell count (mediation ratio, 33.54%) and blood urea nitrogen (mediation ratio, 18.69%) partially mediated the relationship between log (LHR) and mortality risk. The original LHR was also independently correlated with the mortality rate (HR = 1.018, 95% CI: 1.006-1.030).

LHR was positively correlated with 28-day mortality in patients with IS, independent of stroke severity, sepsis, and systemic organ failure, and inflammation, and renal dysfunction may jointly mediate this association. As an easily accessible composite indicator, LHR has potential clinical application value in early risk stratification.