Usefulness of Red Cells Distribution Width to Predict Worse Outcomes in Patients With Atrial Fibrillation

Red cells distribution width (RDW) is a measure of red cell size variability, but little is known about the relation between RDW and outcomes in atrial fibrillation (AF).The aims of our study were to evaluate the association between RDW values, AF patients' profile and outcomes. Consecutive patients with ECG-confirmed AF were divided in 3 groups according to tertiles of RDW values (≤13.5%, 13.6% to 14.6%, >14.6%).We enrolled 457 patients, 61.9% males, median (interquartile range) age 74 (66 to 80). Both CHA₂DS₂-VASc and HAS-BLED scores increased progressively according to RDW tertiles. During follow-up, there was an increased risk for all-cause death and the composite end point in the highest RDW tertile (p <0.001 for both outcomes). On multivariate Cox regression analysis, the highest RDW tertile was independently associated with all-cause death (hazard ratio [HR] 3.23, 95% confidence interval [CI] 1.04 to 10.00) and the composite end point (HR 2.04, 95% CI 1.12 to 3.70). RDW as a continuous variable was also independently associated with all cause death and the composite outcome (HR 1.16, 95% CI 1.02 to 1.31 and HR 1.16, 95% CI 1.05 to 1.27, respectively). In conclusion, in a real-life AF population, RDW is associated with clinical factors indicating a worse profile and is independently associated with increased risks of all-cause death and other clinical events.