We appreciate the interest expressed by Dr Yavuzer Koza in our recently published article.1 Acute coronary syndrome is one of the major causes of mortality, morbidity, and health care costs.2 In our study, we demonstrate the value of red cell distribution width (RDW) as a predictor of major bleeding after hospital discharge in patients with non–ST-segment elevation acute coronary syndrome.
As we point out in the article, all of the bleeding events were recorded, including in-hospital episodes (27% of the total number). As in other studies,3,4 the patients with the highest RDW values at admission were older and had a higher prevalence of comorbidities. They also had lower hemoglobin concentrations and mean corpuscular volume. However, when baseline hematocrit was included in the multivariate analysis, RDW continued to be an independent predictor of major bleeding. Moreover, our findings demonstrate that RDW improves the prognostic accuracy of the CRUSADE bleeding score, which also includes the hematocrit level as a variable. These results, in agreement previously reported results demonstrating that the predictive value of RDW is independent of the hemoglobin concentration or anemia,4 indicate that its ability to predict major bleeding goes beyond its pathophysiological relationship to anemia.5
As has been pointed out, given the relationship between RDW and ferrokinetics, an analysis of absolute or functional iron deficiency would have enabled a study of the pathophysiological relationship between RDW and major bleeding. Unfortunately, such analyses are is rarely available at admission. We also completely agree that serial sampling would permit evaluation of changes in the RDW value and their relationship to major bleeding over time. These samples are now available and this study is in the process of being analyzed.
It is true that the exact cutoff point of the RDW value to be considered in the risk stratification of these patients is still unknown. Future studies will need to establish a universally accepted cutoff, although, in light of the available results, it would be reasonable to consider reference values ranging between 14.5% and 15.5%.1,3,4
In short, we consider RDW to be a promising marker in the management of non–ST-segment elevation acute coronary syndrome as it is inexpensive, readily available, and improves the widely validated CRUSADE bleeding score.