Red blood cell distribution width and its relation to cardiac function and biomarkers in a prospective hospital cohort referred for echocardiography

BackgroundRed blood cell distribution width (RDW), a measure of anisocytosis, is a prognostic biomarker for heart failure (HF). However it is still unclear how RDW is associated with heart function and established cardiac biomarkers.Methods and resultsIn a prospective hospital cohort of 296 patients referred for echocardiography because of suspected HF, blood sampling and clinical examination were performed within 24 h after echocardiography. The patients were divided into four HF groups, including one group where the HF diagnosis was uncertain (gray zone). In the patients the mean age was 70 ± 11 years, 44% with systolic HF (SHF), 18% with heart failure with normal ejection fraction (HFNEF), 17% with gray zone and 21% without HF (non-HF). RDW was higher among patients with SHF and HFNEF, compared with gray zone and non-HF patients. The distribution of different variables over the RDW quartiles showed an inverse correlation between RDW levels and LVEF and a positive correlation between RDW and NT-proBNP levels. Further analysis with stepwise multiple linear regression demonstrated that NT-proBNP levels, but not LVEF, were independently correlated with RDW.ConclusionIn patients referred for echocardiography because of suspected HF, RDW levels were higher in patients with SHF and HFNEF. Moreover, NT-proBNP levels were independently linked with elevated RDW.