Red blood cell distribution width predicts long-term outcome regardless of anaemia status in acute heart failure patients

To study the long-term prognostic value of red blood cell distribution width (RDW) in patients hospitalized with acute heart failure (AHF) and to compare the value of this measurement with haemoglobin levels and anaemia status. During a 2-year period, we studied 628 consecutive patients (aged 71 years [interquartile range, IQR: 61-77], 68% male) hospitalized with AHF. Demographic, clinical, echocardiographic, and laboratory characteristics were registered at discharge and patients were closely followed-up for 38.1 months [16.5-49.1]. Median RDW was 14.4% [13.5-15.5] and was higher among decedents (15.0% [13.8-16.1] vs. 14.2 [13.3-15.3], P < 0.001). After adjustment for other prognostic factors in a multivariable Cox proportional-hazards model, RDW remained a significant predictor (P = 0.004, HR 1.072, 95% CI 1.023-1.124); whereas, haemoglobin or anaemia status did not add prognostic information. RDW levels above the median were associated with a significantly lower survival rate on long-term follow-up (log rank < 0.001). These levels were predictive of death in anaemic patients (n = 263, P = 0.029) and especially in non-anaemic patients (n = 365) (P < 0.001, HR 1.287, 95% CI 1.147-1.445), even after adjustment in the multivariable model. Higher RDW levels at discharge were associated with a worse long-term outcome, regardless of haemoglobin levels and anaemia status.