Among patients with acute ischemic stroke undergoing intravenous thrombolysis (IVT), a high neutrophil-to-lymphocyte ratio (NLR) may predict hemorrhagic transformation as well as poor 3-month functional outcomes, according to study results published in BMC Neurology. Results also suggested that NLR at admission, not post-IVT, was an independent risk factor for an increased risk of hemorrhagic transformation following IVT.

There is still debate surrounding the role of NLR as a prognostic tool in patients with acute ischemic stroke who receive IVT. A team of investigators conducted a systematic review and meta-analysis to determine whether NLR was associated with a poor prognosis following IVT and whether NLR at admission or post-IVT affected outcomes in this patient population.

The analysis included 12 studies with 3641 patients published between 2015 and 2020. Standard intravenous thrombolytic therapy was used in all 12 studies. The relationship between NLR and hemorrhagic transformation after IVT was reported in 6 studies, and a higher NLR was associated with an increased risk for hemorrhagic transformation (odds ratio [OR], 1.33; P <.001). Results indicated significant heterogeneity between studies (P <.001).

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Ten studies assessed the relationship between NLR and 3-month poor functional outcome following IVT, and a higher NLR was positively associated with a higher risk of poor 3-month function outcome (OR, 1.64; P <.001). The study investigators also noted significant heterogeneity between these studies (P <.001).

A total of 4 studies measured the association between NLR and 3-month mortality and found no significant associations between the two (OR, 1.14; P =.120). Heterogeneity was significant among these studies as well (P <.001).

Results from a subgroup analysis suggested that NLR at admission, not post-IVT, was linked to a greater risk for hemorrhagic transformation (OR, 1.33; P =.039).

“Our results suggest that both the NLR at admission and the NLR after IVT were associated with poor functional outcome at 3 months, but the NLR after IVT appeared to have a stronger correlation with poor outcome than the NLR at admission,” the study investigators concluded. “However, because of the small sample size, future studies are warranted to further determine the best time point of blood sampling for the NLR in predicting outcome in [patients with acute ischemic stroke] receiving IVT.”

Disclosure: Multiple authors declared affiliations with the pharmaceutical industry. Please refer to the original article for a full list of disclosures.


Wang C, Zhang Q, Ji M, Mang J, Xu Z. Prognostic value of the neutrophil-to-lymphocyte ratio in acute ischemic stroke patients treated with intravenous thrombolysis: a systematic review and meta-analysis. BMC Neurol. 2021;21(1):191. doi:10.1186/s12883-021-02222-8

This article originally appeared on Neurology Advisor