ABSTRACT
Background: Recurrent acute myocardial infarction requiring unplanned percutaneous coronary intervention (PCI) is one of the major adverse cardiovascular events (MACEs) in patients with acute coronary syndrome (ACS) after PCI. There is a continuing controversy about the association between serum cystatin C, a biomarker for the evaluation of renal function, and the prognosis of ACS patients following PCI. The retrospective study evaluated the association between serum cystatin C level and MACE in ACS patients after PCI. Methods: Data were retrieved for 330 patients with ACS for primary PCI in a single center. Serum cystatin C levels were measured before PCI. All patients underwent regular follow-ups after PCI, and the studied endpoint was MACE, defined as the need for a repeat revascularization in the heart. The predictive value of serum cystatin C for MACE was analyzed using univariate and multivariate analysis. Restricted cubic spline (RCS) analysis was applied to evaluate the dose-response relationship between serum cystatin C level and MACE in ACS patients following PCI. Results: After a median follow-up of 63 months (range, 1-148 months), 121 of the 330 patients experienced MACE. Compared to patients who did not have MACE, patients who had MACE showed a significant decrease in serum cystatin C levels (0.99±0.32 vs. 1.15±0.78 mg/L, P=0.03). In multivariate regression analysis, serum cystatin C level was an independent risk factor for MACE. According to the serum cystatin C level, patients were divided into 4 categories, Cox regression analysis illustrated that the second quartile of serum cystatin C level indicated an increased risk of MACE in patients with PCI for primary ACS compared to the highest quartile [Q2: adjusted hazard ratio (HR) =2.109; 95% confidence interval (CI): 1.193-3.727; P=0.01]. RCS analysis showed a significant U-shaped dose-response relationship between cystatin C level and MACE in patients with PCI for ACS (P for non-linearity =0.004). Conclusions: These results indicated an association between serum cystatin C level and post-PCI MACE in ACS patients.