Predicting the One-Year Prognosis and Mortality of Patients with Acute Ischemic Stroke Using Red Blood Cell Distribution Width Before Intravenous Thrombolysis

Abstract

Purpose: Red blood cell (RBC) distribution width (RDW) is known to reflect the heterogeneity of RBC volume, which may be associated with cardiovascular events or mortality after myocardial infarction. However, the association between RDW and stroke, especially regarding endpoints such as death, remains ambiguous. This study aimed to explore the prognostic value of RDW and its effect on mortality among patients with acute ischemic stroke (AIS) undergoing intravenous thrombolysis (IVT) after one year.

Patients and methods: We retrospectively reviewed patients with AIS treated with IVT between January 2016 and March 2018. We grouped the patients according to modified ranking scale (MRS) scores as follows:0-2, favorable functional outcome group; and 3-6, unfavorable functional outcome. Predictors were determined using multivariate logistic regression (MVLR). The area under receiver-operating characteristic curve (AUC) was used to evaluate the predictive capability of variables. Furthermore, the Cox proportional hazard model was used to assess the contribution of risk factors to the outcome of death at one year later.

Results: MVLR analysis showed that RDW (odds ratio [OR], 1.179; 95% confidence interval [CI], 0.900-1.545; p = 0.232) was not an independent predictor of unfavorable functional outcome, but it (OR 1.371; 95% CI 1.109-1.696; p = 0.004) was an independent biomarker for all-cause mortality. The optimal RDW cut-off value to predict mortality was 14.65% (sensitivity: 42%, specificity: 88.3%, AUC: 0.649, p < 0.001). Furthermore, higher RDW (hazard ratio, 2.860; 95% CI, 1.724-4.745; p < 0.001) indicated a greater risk of death.

Conclusion: The baseline RDW is a potential predictor of mortality in patients with AIS undergoing IVT, but RDW might not be associated with worse survival function among stroke survivors, which will help us to improve treatments and the management of patients with AIS.

Keywords: cerebrovascular accident; death; fibrinolytic therapy; inflammatory; predictor; red blood cells.

Figure 1

Receiver-operating characteristic (ROC) curve displayed of multivariate model features The receiver-operating characteristic (ROC) curve based on the classic risk factors (NIHSS+Age) and multivariable model enriched with RDW. After adding RDW, there were higher significant correlations with mortality (AUC =0.813; 95% CI 0.767–0.859; p<0.001). Abbreviations: RDW, red blood cell distribution width; NIHSS, The NIH Stroke Scale; AUC, area under the ROC curve.

Figure 2

Death risk assessment using multivariate cox regression model analyses. Using cox survival curves after adjusting confounding effect. As shown in the figure, higher RDW indicated greater risk of death (HR 2.860; 95% CI 1.724–4.745; p <0.001). Abbreviation: RDW, Red blood cell distribution width.