C-Reactive Protein and the Risk of Stent Thrombosis and Cardiovascular Events After Drug-Eluting Stent Implantation

Abstract

Background— Although C-reactive protein (CRP) has been proposed as a useful biomarker for predicting atherothrombosis, the association between CRP and stent thrombosis after drug-eluting stent implantation has not been defined. Methods and Results— We prospectively evaluated 2691 patients treated with drug-eluting stents who had a baseline CRP measurement. The primary outcome was stent thrombosis; secondary outcomes were death, myocardial infarction (MI), death or MI, and target vessel revascularization. During follow-up (median, 3.9 years), 32 patients had definite or probable stent thrombosis, 137 patients died, 227 had an MI, and 195 underwent target vessel revascularization. In multivariable Cox proportional-hazards models, elevated levels of CRP were significantly associated with increased risk of stent thrombosis (hazard ratio, 3.86; 95% confidence interval, 1.82 to 8.18; P <0.001). Elevated CRP levels also significantly predicted the risks of death (hazard ratio, 1.61; 95% confidence interval, 1.13 to 2.28; P =0.008), MI (hazard ratio, 1.63; 95% confidence interval, 1.25 to 2.12; P =0.001), and death or MI (hazard ratio, 1.61; 95% confidence interval, 1.29 to 2.00; P <0.001) but not target vessel revascularization (hazard ratio, 1.20; 95% confidence interval, 0.90 to 1.61; P =0.21). The incorporation of CRP into a model with patient, lesion, and procedural factors resulted in a significant increase in the C statistic for the prediction of stent thrombosis, MI, and the composite of death or MI. Conclusions— Elevated CRP levels were significantly associated with increased risks of stent thrombosis, death, and MI in patients receiving drug-eluting stents, suggesting the usefulness of inflammatory risk assessment with CRP. Given the relatively infrequent occurrence of stent thrombosis, death, and MI, larger studies with longer-term follow-up are required to confirm the novel relationship.