Introduction: Immune dysregulation has long been implicated in the development of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH). The neutrophil–lymphocyte ratio (NLR) is an established prognostic marker in patients with cancer, cardiac disease, or sepsis. This study sought to determine whether there is a relationship between NLR and DCI in SAH patients.
Methods: We evaluated 1045 aneurysmal SAH patients between 2006 and 2015 enrolled into a single center, prospective, observational cohort study. Admission WBC differentials (NLR) were analyzed using a =5.9 cutoff. DCI from cerebral vasospasm was defined as (1) clinical deterioration (i.e., a new focal deficit, decrease in level of consciousness, or both), and/or (2) a new infarct on CT that was not visible on the admission or immediate postoperative scan, when the cause was thought by the research team to be vasospasm. Logistic regression models were generated.
Results: We found that 749 (72%) patients had an admission NLR =5.9. In a multivariable model elevated NLR was associated with poor admission Hunt Hess grade (OR:1.6, 95%-CI:1.2-2.6, p= 0.005), Caucasian ethnicity (OR:2.6, 95%-CI:1.9-3.7, p< 0.001), anterior aneurysm location (OR:1.7, 95%-CI:1.2- 2.4, p= 0.004), loss of consciousness at ictus (OR:1.4, 95%-CI:1.0-2.0, p=0.055), and thick SAH (modified Fisher =3)(OR:1.8, 95%-CI:1.3-2.4, p< 0.001). Admission NLR predicted development of DCI (OR: 1.7; 95% CI: 1.1- 2.5, p=0.008) after controlling known predictors including age, poor admission clinical grade, thick SAH blood, and elevated admission MAP
Conclusions: This study shows that the admission NLR provides further evidence to the association between inflammation and DCI. Admission NLR is a readily available biomarker that may be a clinically useful tool for prognostication when evaluating SAH.
Patient Care: Our research introduces a readily available biomarker that may be a clinically useful tool for prognostication when evaluating SAH.
Learning Objectives: Admission NLR is a readily available biomarker that may be a clinically useful tool for prognostication when evaluating SAH.