Enlarging Red Blood Cell Distribution Width During Hospitalization Identifies a Very High-Risk Subset of Acutely Decompensated Heart Failure Patients and Adds Valuable Prognostic Information on Top of Hemoconcentration

Red blood cell distribution width (RDW) may serve as an integrative marker of pathological processes that portend worse prognosis in heart failure (HF). The prognostic value of RDW variation (ΔRDW) during hospitalization for acute heart failure (AHF) has yet to be studied. We retrospectively analyzed 2 independent cohorts: Centro Hospitalar do Porto (derivation cohort) and Lariboisière hospital (validation cohort). In the derivation cohort a total of 170 patients (age 76.2 ± 10.3 years) were included and in the validation cohort 332 patients were included (age 76.4 ± 12.2 years). In the derivation cohort the primary composite outcome of HF admission and/or cardiovascular death occurred in 78 (45.9%) patients during the 180-day follow-up period. Discharge RDW and ΔRDW were both increased when hemoglobin levels were lower; peripheral edema was also associated with increased discharge RDW (all P < 0.05). Discharge RDW value was significantly associated with adverse events: RDW > 15% at discharge was associated with a 2-fold increase in event rate, HR = 1.95 (1.05–3.62), P = 0.04, while a ΔRDW >0 also had a strong association with outcome, HR = 2.47 (1.35–4.51), P = 0.003. The addition of both discharge RDW > 15% and ΔRDW > 0 to hemoconcentration was associated with a significant improvement in the net reclassification index, NRI = 18.3 (4.3–43.7), P = 0.012. Overlapping results were found in the validation cohort. As validated in 2 independent AHF cohorts, an in-hospital RDW enlargement and an elevated RDW at discharge are associated with increased rates of mid-term events. RDW variables improve the risk stratification of these patients on top of well-established prognostic markers.