Prognostic value of RDW alone and in combination with NT-proBNP in patients with heart failure

Abstract

Background: Red blood cell distribution width (RDW) and N-terminal pro brain natriuretic peptide (NT-proBNP) may predict the prognosis of heart failure (HF). However, the impact of combined RDW and NT-proBNP levels as a prognostic marker of HF remains unclear and the significance of this combination at various time-points has not been sufficiently studied.

Hypothesis: RDW can predict prognosis in HF at various time-points and combination with NT-proBNP improves the prognostic value.

Methods: Patients admitted to HF care unit of Fuwai Hospital CAMS&PUMC (Beijing, China) with a diagnosis of HF from November 2008 to November 2018 were analyzed retrospectively.

Results: In total, 3231 patients with available RDW data at admission were evaluated (median age 58 years, 71.9% males, 39.7% coronary heart disease, 68.6% New York Heart Association [NYHA] III or IV). Median RDW and NT-proBNP at admission were 13.4% (interquartile range [IQR]: 12.7%-14.5%), and 1723.00 pg/ml (IQR: 754.00-4006.25 pg/ml), respectively. During 2.9-year median follow-up, all-cause death occurred in 1075 (33.27%) patients. Kaplan-Meier survival curve and Cox proportional-hazard models, showed patients in the top quarter RDW had a 32.0% increased mortality compared to the bottom quarter (hazard ratio: 4.39, 95% confidence interval: 3.59-5.38; p <.001). The top quarter RDW retained independent prognostic value across HF with reduced ejection fraction [HFrEF], HF with mid-range ejection fraction [HFmrEF], and HF with preserved ejection fraction [HFpEF] subgroups. Patients were subsequently divided into four groups by median RDW and NT-proBNP. Comparison of Kaplan-Meier survival curves for various groups showed good risk stratification (p < .001).

Conclusions: RDW is an independent predictor of mortality among patients with HF in the short-, medium-, and long-term. Combination of RDW and NT-proBNP improves the prognostic value. This is true across all clinical subtypes of heart failure (HFrEF, HFmrEF, HFpEF), and among most subgroups of patients with various comorbidities (infection, diabetes, hypertension).

Keywords: NT-proBNP; biomarkers; heart failure; prognosis; red cell distribution width.