Association between red cell distribution width-to-lymphocyte ratio and 30-day mortality in patients with ischemic stroke: a retrospective cohort study

Ischaemic stroke (IS) has become a major health problem globally as it is one of the leading causes of long-term disability and death. This study aimed to evaluate the association between red cell distribution width (RDW) to lymphocyte (LYM) ratio (RLR) and 30-day mortality risk in patients with IS.

The present study employed a retrospectively cohort study design with the adult data extracted from the Medical Information Mart for Intensive Care (MIMIC-III, MIMIC-IV) databases between 2001 and 2019. The RLR was measured using RDW and LYM. Confounders were adjusted in Cox proportional hazards model. The outcome was 30-day mortality. Univariable and multivariable Cox proportional hazards models were establised. A further analysis was conducted on the basis of subgroup stratification by heart failure (HF) (yes or no), atrial fibrillation or flutter (yes or no), hypertension (yes or no), dyslipidemia (yes or no), sepsis (yes or no), and age (≥ 65 years and < 65 years).

In this study, 1,127 adult patients with IS were finally identified. Among them,818 patients survived (the survival group) and 309 patients died (the death group). The mean age was older in individuals from the death group than those from the survival group (70.19 years vs. 64.56 years). The elevated levels of RLR were linked to an increased risk of mortality within 30 days in patients with IS, with an HR of 1.70 (95% CI: 1.34–2.17). Subgroup analyses showed that high RLR levels was a significant risk factor for mortality at 30 days particularly in IS patients aged ≥ 65 years, HF, no atrial fibrillation or flutter, no hypertension, no dyslipidemia, and no sepsis.

Our study shows that high levels of RLR were associated with an increased risk of 30-day mortality in patients with IS, providing additional prognostic information for the treatment and supportive care of these patients.