Association between red cell distribution width and thromboembolic events in patients with atrial fibrillation.

Abstract

BACKGROUND: We investigated whether an increase in the value of red cell distribution width (RDW) was associated with thromboembolic outcomes in patients with atrial fibrillation (AF). METHODS: We performed a retrospective analysis of 5082 consecutive patients with non-valvular AF. Thromboembolic events (N=723, 14.2%) were recorded and analysed according to RDW value. RESULTS: The peak RDW value during follow-up was higher in patients with thromboembolic events than in those without thromboembolic events (15.1% vs. 14.2%, p<0.001). The RDW value showed similar power in predicting thromboembolic outcomes compared with the factor of age. The risk of thromboembolic events was higher in patients with a peak RDW≥13.9% than in patients with a peak RDW<13.9% (hazard ratio 1.63, p<0.001), and increased with each quartile increase of RDW. In a subgroup of 739 patients with congestive heart failure (CHF), there were 112 (15.2%) thromboembolic events. The peak RDW value of patients with CHF with thromboembolic events was also significantly higher (16.4% vs. 15.6%, p=0.019) compared to that of those without thromboembolic events. CONCLUSION: An increased RDW value during follow-up could be associated with thromboembolic events in patients with non-valvular AF. The suggested cut-off values for RDW used to predict an increased thromboembolic risk in were ≥13.9% in patients with AF in general, ≥15% in patients with co-existing AF and CHF.