Background: For a long time, serum cystatin C (Cys C) was only considered an indicator of renal function besides creatinine. Recently, it has been found that it is also a good biomarker showing the oxidative status of the human body. We hypothesized that serum Cys C levels are associated with in-stent restenosis (ISR) among patients receiving stent implantation.
Methods: Here, we enrolled 145 (men, 110; mean age, 59.6±11.1) consecutive patients admitted to the Fourth Affiliated Hospital of Harbin Medical University for stent implantation. At 11.2±3.2 months after stent implantation, all of the patients were administered coronary angiography to evaluate ISR. The serum levels of total bilirubin (TB), high-sensitive C-reactive protein (hs-CRP), and Cys C were obtained to determine the relationship of ISR with these oxidative-related biomarkers.
Results: A total of 163 stents were studied; patients experiencing ISR had considerably higher levels of serum hs-CRP and Cys C and lower levels of TB compared with patients without ISR (TB, 13.7±3.5 vs. 11.8±4.0 μmol/l, P=0.007; hs-CRP, 11.8±6.0 vs. 5.9±6.4 μmol/l, P=0.001; Cys C, 1.68±0.85 vs. 0.94±0.24 mg/l, P<0.001). Furthermore, the Cox proportional hazard model showed that serum TB [odds ratio (OR)=2.42, 95% confidence interval (CI), 2.21-2.68, P=0.028], hs-CRP (OR=2.89, 95% CI, 2.76-3.02, P=0.003), and Cys C (OR=80.46, 95% CI, 11.10-2977.60, P<0.001) are all independent predictors of ISR.
Conclusion: Cys C, together with TB and hs-CRP, is an independent risk factor associated with ISR.