Red Blood Cell Distribution Width and Long-Term Outcome in Patients Undergoing Percutaneous Coronary Intervention in the Drug-Eluting Stenting Era: A Two-Year Cohort Study

BACKGROUND: Previous studies suggest the higher the red blood cell distribution width (RDW) the greater the risk of mortality in patients with coronary artery disease (CAD). However, the relationship between RDW and long-term outcome in CAD patients undergoing percutaneous coronary intervention (PCI) with a drug-eluting stent (DES) remains unclear. This study was designed to evaluate the long-term effect of RDW in patients treated with drug-eluting stent for CAD. METHODS: In total of 2169 non-anemic patients (1468 men, mean age 60.2±10.9 years) with CAD who had undergone successful PCI and had at least one drug-eluting stent were included in this study. Patients were grouped according to their baseline RDW: Quartile 1 (RDW<12.27%), Quartile 2 (12.27%≤RDW<13%), Quartile 3 (13%≤RDW<13.5%), and Quartile 4 (RDW≥13.5). RESULTS: The incidence of in-hospital mortality and death or myocardial infarction was significantly higher in Quartiles 3 and 4 compared with Quartile 1 (P<0.05). After a follow-up of 29 months, the incidence of all-cause death and stent thrombosis in Quartile 4 was higher than in Quartiles 1, 2, and 3 (P<0.05). The incidence of death/myocardial infarction/stroke and cardiac death in Quartile 4 was higher than in Quartiles 1 and 2 (P<0.05). Multivariate Cox regression analysis showed that RDW was an independent predictor of all-cause death (hazard ratio (HR) = 1.37, 95% confidence interval (CI) = 1.15–1.62, P<0.001) and outcomes of death/myocardial infarction/stroke (HR = 1.21, 95% CI = 1.04–1.39, P = 0.013). The cumulative survival rate of Quartile 4 was lower than that of Quartiles 1, 2, and 3 (P<0.05). CONCLUSION: High RDW is an independent predictor of long-term adverse clinical outcomes in non-anemic patients with CAD treated with DES.