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 long-term 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.
Keywords: Asian population; Atherosclerosis; Coronary artery disease; Percutaneous coronary intervention.