Analysis of the prognostic value of emergency blood tests in ischaemic stroke

Objectives: This study aims to evaluate the prognostic value of emergency blood test results in patients with acute ischaemic stroke.

Methods: We evaluated 592 prospectively patients with neuroimaging-confirmed ischaemic stroke admitted to our stroke unit between 2015 and 2018. We gathered emergency blood test results and calculated the neutrophil-to-lymphocyte ratio and the neutrophil-to-platelet ratio (neutrophils × 1.000/platelets). The association between blood test results and functional prognosis (as measured with the modified Rankin Scale) and such complications as haemorrhagic transformation was evaluated by logistic regression analysis. The additional predictive value of blood test parameters was assessed with receiver operating characteristic curves and the net reclassification index.

Results: An neutrophil-to-lymphocyte ratio ≥ 3 at admission was associated with a two-fold increase in the risk of functional dependence at 3 months (OR: 2.24; 95% CI: 1.35-3.71) and haemorrhagic transformation (OR: 2.11; 95% CI: 1.09-4.05), while an neutrophil-to-lymphocyte ratio ≥ 3.86 resulted in an increase of 2.4 times in the risk of mortality at 3 months (OR: 2.41; 95% CI: 1.37-4.26) after adjusting for the traditional predictors of poor outcomes. Patients with neutrophil-to-platelet ratio ≥ 32 presented 3 times more risk of haemorrhagic transformation (OR: 3.17; 95% CI: 1.70-5.92) and mortality at 3 months (OR: 3.07; 95% CI: 1.69-5.57). Adding these laboratory parameters to standard clinical-radiological models significantly improved discrimination and prognostic accuracy.

Conclusions: Basic blood test parameters provide important prognostic information for stroke patients and should therefore be analysed in combination with standard clinical and radiological parameters to optimise ischaemic stroke management.