We read the article ‘‘Relationship Between Red Cell Distribution Width and Stroke in Patients With Stable Chronic Heart Failure: A Propensity Score Matching Analysis’’ by Kaya et al with interest. They aimed to investigate the association between baseline red cell distribution width (RDW) level and the risk of stroke in patients with heart failure (HF). They concluded that RDW may be important hematological indices for stroke in patients with HF using propensity score analysis. Thank to the authors for their contribution. We think that further studies should be made to enlighten the role of RDW as a prognostic indicator in patients with HF. The RDW is a novel inflammatory marker in clinical practice. It has been recently proposed as an independent predictor of all-cause, long-term mortality in patients with HF. Recently, a number of studies have reported that elevated RDW levels are associated with poor prognosis in the setting of stable angina, acute coronary syndrome, coronary bypass surgery, HF, stroke, peripheral arterial disease, and older age. However, RDW can reflect ethnicity, neurohumoral activation, renal dysfunction, thyroid disease, hepatic dysfunction, nutritional deficiencies (ie, iron, vitamin B12, and folic acid), bone marrow dysfunction, inflammatory diseases, chronic, or acute systemic inflammation. Also, the value of RDW is instrument dependent forcing each laboratory to establish its own reference values. Furthermore, HF is closely related to renal dysfunction. Glomerular filtration rate (GFR) was estimated using the simplified Modification of Diet in Renal Disease (MDRD) formula in the current study. The Cockcroft-Gault equation (CGE) is another method for calculating the GFR. However, the CGE may estimate lower GFR than that of the MDRD formula in younger age groups, but it can measure higher GFR in older individuals compared with the MDRD formula. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) recently published an equation for GFR using the same variables (serum creatinine level, age, sex, and race) as the MDRD formula. However, the CKD-EPI equation more precisely categorized individuals with respect to long-term clinical risk of incident end-stage renal disease, all-cause mortality, coronary heart disease, and stroke compared with the MDRD formula. After that, not only RDW but also neutrophil–lymphocyte ratio, a g-glutamyltransferase, and uric acid are easy methods to assess the the risk of stroke in patients with HF. These might be useful in clinical practice. The RDW alone without other inflammatory markers may not give information to clinicians about the inflammatory condition and prognostic indication of the patient. So, we think that it should be evaluated together with other serum inflammatory markers.