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.