Both Low and High Postprocedural hsCRP Associate with Increased Risk of Death in Acute Coronary Syndrome Patients Treated by Percutaneous Coronary Intervention

Background. Inflammation poses dual effects after myocardial infarction, but robust evidence shows that high-sensitivity C-reactive protein (hsCRP), as an inflammatory marker, is constantly associated with worse outcomes. This study is aimed at investigating the probable nonlinear association between postprocedural hsCRP and mortality in patients with acute coronary syndromes (ACS) treated by percutaneous coronary intervention (PCI). Methods. A total of 3940 consecutive ACS patients treated by PCI with postprocedural hsCRP measurements were retrospectively recruited. Patients were stratified into 5 groups according to quintiles of hsCRP. Cox regression with adjustments for multiple covariates was used for outcome analysis. Restricted cubic spline (RCS) analysis was used to allow possible nonlinear associations. The primary outcome was all-cause death. Results. During a median follow-up of 727 days, mortality occurred in 207 (5.3%) patients. Adjusted hazard ratio (HR) was higher in the lowest (<2.26 mg/L, HR: 1.90, 95% confidence interval (CI): 1.08-3.33; P=0.025), second highest (10.16-12.56 mg/L, HR: 1.86, 95% CI: 1.09-3.16; P=0.023), and highest quintiles (>= 12.56 mg/L, HR: 2.02, 95% CI: 1.21-3.36; P=0.007) of postprocedural hsCRP, compared to the second lowest quintile (2.26-4.85 mg/L). RCS analysis depicted a J-shaped association between postprocedural hsCRP and mortality (P for nonlinearity=0.004). Similar association was observed between hsCRP and cardiac death (P for nonlinearity=0.014), but not for noncardiac mortality (P for nonlinearity=0.228). Conclusions. Both low and high postprocedural hsCRP were associated with higher risk of death in ACS patients treated by PCI.