The purpose of this study was to determine the predictive value of RDW, NLR, and NPR in the 3-month mortality of patients with intracerebral hemorrhage. The findings of the present study showed that hemoglobin has a significant positive correlation with RDW, while MCHC and neutrophil count has a negative one. Moreover, RDW, RBC, platelet count, and NIHSS scores are independent predictors of 3-month mortality in patients with ICH.
RDW as an available laboratory factor, which is a marker of the variation in volume of red blood cells (3), can be used as prognostic factor in various health conditions (17). Moreover, it is associated with chronic inflammation and oxidative stress (5). Thus, it is reasonable that high RDW values can be known as an integrated risk factor for sub-optimal general health condition which is accompanied by a reduction in correction, improvement and systemic defense capability (5, 9). In our study the role of RDW factor in the prognosis and mortality of stroke patients with ICH in a period for 3 months was assessed and was shown that RDW value is significantly higher in deceased patients in comparison to alive patients with ICH. The results of the study conducted by Lorente et al. among 117 patients with spontaneous ICH showed that RDW during the first week was higher in deceased than surviving patients (p≤0.001), which is in accordance to our findings (18). Furthermore, the article by Kaya et al. conducted on 153 participants concluded that RDW is an important hematopoiesis indicator for occurrence of stroke in patients with heart failure which reveals that high RDW is associated with the development of stroke and is strongly associated with cardiovascular causes (10). A study by Moreno et al. also showed that RDW is a strong indicator for stroke (19). Moreover, another study by Kara et al. concluded that RDW, an easily accessible and inexpensive test, is potentially an important parameter in diagnosing stroke and may predict prognosis. Also, in this study also NIHSS was used to determine the severity of stroke and it was found that the increase in stroke severity is associated with higher RDW and RDW is a strong predictor of stroke severity (20).
Of note, a wide range of diseases and even physiological conditions lead to changes in the level of RDW in the human body. For example, different types of anemia inflammatory diseases and cancers can cause changes in the size of red blood cells (21). Thus, RDW may not be specific enough to screen for stroke in many patients. One of the most appropriate scales to assess the severity of stroke is NIHSS which measures the severity of a neurological deficit. The NIHSS is a common diagnostic tool for quickly assessing the severity of a stroke and related neurologic deficits which is used in determining the prognosis. NIHSS had the highest association with mortality rate in stroke patients, so this variable was significantly higher among the deceased group. Also, the area under the ROC curve for this variable shows the meaningful power of predicting the death of patients by this variable (22). In addition to RDW and NIHSS, NLR, platelets and neutrophils were significantly effective in determining the prognosis of the intracerebral hemorrhage (23).
The NLR is simply calculated as a ratio by division the number of neutrophils to the number of lymphocytes in peripheral blood and measures the inflammatory response (24). Acute inflammatory response occurs in some serious conditions such as ischemic stroke, cerebral hemorrhage, and acute coronary syndrome. Therefore, this marker can be used to determine the prognosis and evaluation of disease outcome in the mentioned diseases (11, 24, 25). In this regard, our results also showed that higher RDW, NIHSS, RBC, and platelet count increases the risk of short-term and long-term mortality in patients with stroke.
Numerous studies have shown that high levels of neutrophils are sensitive markers for determining mortality (23). Jickling et al. and Maestrini et al. showed that high neutrophil level is associated with high infarct volume and poor prognosis (26, 27). In addition to its function in the homeostasis, platelets also play a role in the inflammatory responses. In fact, platelets can facilitate neutrophil entry into the brain parenchyma and higher neutrophil counts will lead to the more severe damage (28).
We acknowledge that our study had several limitations. First, since it was a retrospective study, restrictions in data collection, participant inclusion, and lack of a control group exist. Second, it was conducted in a single hospital. Third, the variables were only measured in two time points in 28-days and 3-months and they did not be remeasured during the period of hospitalization. Fourth, the follow-up was limited to 3 months and no ling-term follow-up was conducted.