Red Cell Distribution Width Predicts Long-Term Cardiovascular Outcomes in Patients with Chronic Coronary Syndrome

Red cell distribution width (RDW) has been shown to be an independent risk factor for increased cardiovascular mortality, heart failure, and cardiovascular disease. However, the association between RDW and longterm clinical outcomes in patients with chronic coronary syndrome (CCS) remains uncertain. In this study, a total of 2,881 CCS patients who underwent their first percutaneous coronary intervention (PCI) and who had available data on pre-procedural RDW between 2002 and 2016 were enrolled. Of these, 1,827 without anemia and severe renal dysfunction were divided into quartiles based on their RDW values. The primary endpoint was a composite of all-cause death and non-fatal myocardial infarction. As a result, patients in the higher RDW quartile groups were more likely to be older and have chronic kidney disease. During a median follow-up of 6.2 years, 209 (11.4%) events were identified. Kaplan-Meier curves showed the highest RDW quartile group had a clearly higher incidence of the primary endpoint (log-rank P = 0.0002). The highest RDW group had a significantly higher risk of cardiovascular events compared with the lowest RDW group, even after adjustment for other risk factors (hazard ratio 1.95, 95% confidence interval 1.04-3.67, P = 0.04). Increasing RDW as a continuous variable was also associated with the incidence of the primary endpoint (hazard ratio 1.46 per 1% increase, 95% confidence interval 1.24-1.69, P < 0.0001). In conclusion, this study demonstrated that increased RDW was associated with worse clinical outcomes after elective PCI. Assessing pre-PCI RDW may be useful for risk stratification of CCS.