The relationship between elevated red cell distribution width and long-term outcomes among patients with atrial fibrillation

Objectives: Red cell distribution width (RDW) is associated with the incidence of atrial fibrillation (AF). The aim of this study was to evaluate the relationship between elevated RDW and long-term clinical outcomes among patients with AF. Design and methods: We prospectively observed 300 consecutive patients with AF (50.3% males, mean age 62.6 +/- 12.9 years) between February 2009 and October 2011. Baseline RDW levels and clinical data were collected. The primary clinical outcomes of interest included all-cause mortality and the incidence of major adverse events (MAEs). Results: During a median follow-up period of 3.2 years, 60 deaths and 92 MAEs were recorded. From the lowest to the highest ROW quartile, an increased risk of mortality (2.76, 3.98, 8.40 and 13.77 per 100 person-years, respectively) and an incidence of MAEs (6.46, 8.18, 13.79 and 20.27 per 100 person-years, respectively) were noted. In a multivariate Cox regression analysis, ROW was independently associated with both all-cause mortality (hazard ratio (HR): 1.024; 95% confidence interval (CI): 1.012-1.036, P < 0.001) and MAEs (HR: 1.012; 95% CI: 1.002-1.023, P = 0.023). A receiver operating characteristic (ROC) analysis revealed that ROW predicted both mortality and MAEs with areas under the ROC curves (AUCs) of 0.682 (P < 0.001) and 0.617 (P = 0.001); the best cutoff points were 13.85% and 13.55%, respectively. Conclusions: Elevated ROW is an independent predictor of long-term adverse clinical outcomes, including all-cause mortality and MAEs, among patients with AF. (C) 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.