Red cell distribution width predicts mid-term prognosis in patients hospitalized with acute heart failure: the RDW in Acute Heart Failure (RE-AHF) study

The aim of the study was to evaluate the prognostic role of red cell distribution width (RDW) in a broad population of patients hospitalized for acute heart failure (AHF). In a retrospective cohort observational study, 451 consecutive patients discharged for AHF were categorized in patients with low RDW (≤ 14.8%) and high RDW (> 14.8%). The rates of death from all causes or of hospital readmission for worsening heart failure and death were determined after a median follow-up of 18 months. The overall population has a median age of 80 years (IQR 72–85), 235 patients (52%) were males. Patients with a higher RDW have more comorbidities and a higher Charlson Index. At follow-up, 200 patients (44%) had died and 247 (54%) had died or were readmitted for HF: in the cohort with low RDW, 70 patients (36.4%) had died, whereas in the cohort with high RDW, 165 patients (63.7%) had died: the unadjusted risk ratio of patients with high RDW was 2.03 (log-rank test: p < 0.0001). In a multivariate Cox regression model, the hazard ratio for death from any cause in the ‘high RDW’ cohort is 1.73 (95% confidence interval 1.2–2.48; p = 0.003); the RDW adds prognostic information beyond that provided by conventional predictors, including age; etiology of HF; anemia; hyponatremia; estimated glomerular filtration rate; NT-proBNP levels; Charlson comorbidity score, atrial fibrillation, functional status, therapy with renin–angiotensin–aldosterone system inhibitors, beta-blockers. RDW is a powerful marker of worse long-term outcomes in patients with AHF, and its prognostic value is maintained beyond that provided by other well-established risk factors or biomarkers.