Prognostic value of red blood cell distribution width in patients with left ventricular systolic dysfunction: Insights from the COMMIT-HF registry.

Background: Previous studies have reported that in patients with heart failure, an increased value of red cell distribution width (RDW) is associated with adverse outcomes. Nonetheless, data regarding the association between RDW values and long-term mortality in patients with left ventricular systolic dysfunction (LVSD) are lacking. The aim of this investigation was to examine the relationship between mortality and RDW in patients with ischemic and non-ischemic LVSD. Methods: Under analysis was 1734 patients with a left ventricular ejection fraction (LVEF) <= 35% of whom were hospitalized between 2009 and 2013. Patients were divided into three groups based on RDW tertiles. Low, medium and high tertiles were defined as RDW <= 13.4%, 13.4% < RDW <= 14.6% and RDW > 14.6%, respectively. Results: There was a stepwise relationship between RDW intervals and comorbidities. Patients with the highest RDW values were older and more often diagnosed with anemia, diabetes, atrial fibrillation and chronic kidney disease. The main finding of our analysis was the presence of an 8-fold increase in all-cause mortality in the entire cohort between high and low RDW tertile. Cox hazard analysis identified RDW as an independent predictive factor of mortality in all patients (HR 2.8; 95% CI 2.1-3.8; p < 0.0001) and in subgroups of patients with ischemic (HR 2.8; 95% CI 2.0-3.9; p < 0.0001) and non-ischemic (HR 3.3; 95% CI 2.01-5.5; p < 0.0001) LVSD. Conclusions: The highest RDW tertile was independently associated with higher long-term mortality compared with low and medium tertiles, both in all patients with a LVEF 35% and in subgroups of patients with ischemic and non-ischemic LVSD.