Impact of red blood cell distribution width on long-term mortality in diabetic patients after percutaneous coronary intervention.

BACKGROUND Red blood cell distribution width (RDW) is a novel prognostic marker that reflects oxidative stress and chronic inflammation in patients with cardiovascular disease. Diabetes mellitus increases oxidative stress and vascular inflammation, which accelerate atherosclerosis. However, the relationship between RDW and long-term outcome in diabetic patients with coronary artery disease (CAD) is unclear. METHODS AND RESULTS Subjects comprised 560 consecutive diabetic patients (mean age, 66.6 years; male, 80%) with stable CAD who had undergone elective percutaneous coronary intervention (PCI). Patients were divided into 2 groups according to median RDW at baseline (13.1%): a high RDW group (mean RDW, 14.0%; interquartile range, 13.3-14.2%); and a low RDW group (mean RDW, 12.6%; interquartile range, 12.4-12.9%). All-cause mortality rates were compared between groups. Mean duration of follow up was 3.9 years. Patients with high RDW were more likely to be older, show dyslipidemia and have a lower ejection fraction and decreased hemoglobin level. Twenty-nine patients (5.2%) died during follow up. The cumulative incidence of all-cause death was significantly higher in the high RDW group than in the low RDW group (log-rank P=0.0015). Multivariate analysis identified high RDW as being associated with all-cause mortality (hazard ratio, 2.56; 95% confidence interval, 1.12-6.62; P=0.025). CONCLUSIONS Increased RDW was significantly associated with increased long-term all-cause mortality in diabetic patients after PCI.