Effect Of Thrombolytic Therapy On High Neutrophil-to-Lymphocyte Ratio In Predicting Stroke-Associated Pneumonia After Acute Ischemic Stroke

Abstract

Background and Purpose In patients with acute ischemic stroke (AIS) undergoing intravenous thrombolysis (IVT), there are few studies assessing the predictive effect of blood cell inflammatory markers on stroke-associated pneumonia (SAP), short-term and long-term prognosis. In this study, we evaluated whether the neutrophil-to-lymphocyte ratio (NLR) can predict SAP and functional prognosis in patients receiving IVT. Methods We assessed 388 patients undergoing IVT for acute ischemic stroke. Blood parameters were sampled before thrombolysis (within 30 mins after admission) and within 12–24 h after thrombolysis. The primary outcome measure was the occurrence of SAP as well as the prognosis after IVT. Multivariate logistic regression analysis was performed to analyze the association between NLR and the occurrence of SAP. We also used receiver operating characteristic curve analysis to assess the discriminative ability of NLR measured at different times in predicting SAP and prognosis. Further exploration of the correlation between NLR and baseline variables was conducted using Pearson correlation and multivariate linear regression analysis. Results Among the total patients, SAP occurred in 60 (15%) patients. Multivariate analysis showed that NLR was significantly associated with SAP (NLR before IVT: aOR = 1.288; 95%CI = 1.123–1.476; p < 0.001; NLR after IVT (aOR = 1.113, 95%CI = 1.007–1.23; p = 0.036). The receiver operating characteristic curve showed that the predictive ability of NLR after IVT was better than NLR before IVT (area under the curve [AUC] of NLR after IVT: 0.80, 95%CI = 0.74–0.86; p < 0.001; NLR before IVT: 0.72, 95%CI = 0.66–0.80; p < 0.001), not only in predicting the occurrence of SAP but also in predicting short-term functional outcomes and one-year mortality. Furthermore, NLR after IVT was significantly correlated with the initial NIHSS score (p < 0.001) and early neurological outcomes after IVT (p < 0.001). Conclusions We demonstrated that increased NLR has a significant predictive effect on the occurrence of SAP and can be used to predict functional dependence and one-year mortality. NLR measured within 12–24 h after IVT had better predictive validity than that measured before IVT.