Red cell distribution width: an inexpensive and powerful prognostic marker in heart failure

Aims Red cell distribution width (RDW) is prognostic in patients with heart failure (HF), but it has not been compared with N‐terminal brain natriuretic peptide (NT‐proBNP). We sought to make this comparison. Methods and results Patients referred to a specialist HF clinic between 2001 and 2008 were assessed comprehensively including medical history, echocardiogram, and blood tests. Cox‐regression was used to assess the multivariable relationship between RDW, NT‐proBNP, and all‐cause mortality. A total of 1087 patients were recruited; median (IQR) follow‐up was 52 months (29–66); age 72 years (64–78); 74% male; 70% ischaemic heart disease; 20% diabetic; 85% NYHA ≥ 2, and 63% with at least moderate LV impairment (EF < 35% equivalent). In a multivariable model, both RDW and NT‐proBNP were independently prognostic (RDW: χ 2 = 21.8 vs. 49.1 both P < 0.001). In a model using quartiles of each variable, the relative risk for each was similar for the second and third quartiles compared with the first. A larger increase in risk for NT‐proBNP is seen in the fourth quartile. Conclusion Red cell distribution width is a readily available test in the HF‐population with similar independent prognostic power to NT‐proBNP across the first to third quartiles. Prognostic models in HF should include RDW and further investigation is necessary to determine the pathological mechanism of the relationship.