The predictive value of cystatin C in patients with acute coronary syndrome after percutaneous coronary intervention

To investigate the predictive value of plasma cystatin C (CysC) in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI) . Methods A total of 660 patients with ACS admitted to cardiovascular department were enrolled in this study from January 2009 to June 2010.The enrollment criteria were; (1) the stenosis degree was above 75% in at least one coronary artery checked by coronary angiography and successful PCI; (2) normal renal function or mild dysfunction with glomerular filtration rate (GFR) >60 ml/ (min . 1.73 m ²). Exclusion criteria were severe liver and renal insufficiency, malignancies and valvular heart diseases. The plasma CysC levels were examined by the latex enhanced immune turbidity method within 24 hours after admission. The relevant clinical data were recorded. The patients were followed up by out-patient interview or telephone from March to June 2011 and adverse cardiovascular events were recorded. The patients were divided into four groups according to CysC level; Q1 (CysC <1.02 mg/L) , Q2 (1.02 mg/Ls≤CysC <1. 17 mg/L) , Q3 (1.17 mg/L ≤ CysC < 1.35 mg/L) and Q4 (CysC 13 1. 35 mg/L). Univariate and multivariate Cox hazards regressions were established to analyze the factors related to prognosis. The proportion differences between four groups were tested by \2. The survival ratio was estimated using the Kaplan-Meier method. Statistical significance was established at a P value of less than 0.05. Results (J1. A total of 606 (91.7%) patients successfully accepted follow-up. Mean follow-up time was (14.3 ±1.7) months. Of them, 95 patients were subjected to adverse cardiovascular events (15.7%). 2. The incidences of adverse cardiovascular events in Q2, Q3, Q4 were significantly higher than those in Q1 (P <0.001). The rates of mortality, nonfatal myocardial infarction and target lesion revascularization in Q4 were higher than those in Q1 (P < 0.05). The incidences of heart failure in Q3 and Q4 were higher than that in Q1 (P <0.05). 3. Univariate analysis demonstrated that CysC, creatinine, LVEF, age, history of PCI and NYHA grade >3 were the risk factors of poor prognosis (P < 0.05). 4. Multivarite cox hazards regression revealed that the elevation of CysC level remained an independent predictor of adverse cardiovascular events. The relative risk of Q3 and Q4 were 3.930 (95% C/1.306 -11.829, P=0.015) and 6.380 (95%C/2. 171-18.751, P=0.001) compared with Ql. 5. The cumulative rates of survival without adverse cardiovascular events in Q2, Q3 and Q4 decreased compared with Ql (P < 0.001). Conclusions High plasma CysC concentration is an independent predictor of adverse cardiovascular events in patients with ACS after PCI.