Prognostic value of red blood cell distribution width in prediction of in-hospital mortality in patients with acute myocardial infarction.

Abstract

Red blood cell indices may add important prognostic information to risk stratification scores, such as Global Registry of Acute Coronary Events (GRACE) risk score. However, the incremental predictive value of red blood cell distribution width (RDW) on this score has not been assessed. Therefore, the aim of this study was to assess whether the RDW has additional prognostic value on the GRACE risk score in prediction of in-hospital mortality in patients with acute myocardial infarction (AMI). A historic cohort was investigated at the University Hospital in Santa Maria city, Brazil. The laboratory database and medical registry were used to identify patients with AMI. A total of 109 patients were eligible for the present study. Cox regression models were calculated including GRACE risk score variables plus RDW. Moreover, measures of discrimination and calibration were also calculated. The primary outcome evaluated was all-cause in-hospital mortality. When included in a predictive model based on the GRACE risk score, RDW became an independent predictor of in-hospital mortality (HR 1.358, 95% CI 1.04 - 1.77; p = 0.023). The addition of RDW to the original model showed adequate calibration (Hosmer-Lemeshow p-value 0.174) and produced a slight improvement in its discriminatory power (AUC 0.769, 95% CI 0.677 - 0.847; p = < 0.0001). We suggest that RDW might provide additional information over the GRACE risk score in patients with AMI.