Cystatin C as a predictor of all-cause mortality and myocardial infarction in patients with non-ST-elevation acute coronary syndrome

Objectives: To investigate the predictive value of cystatin C among patients diagnosed with non-ST-elevation acute coronary syndrome (nSTE-ACS). Design and methods: Admission serum samples from 245 nSTE-ACS patients were measured with a novel cystatin C immunoassay based on a dry-reagent, double monoclonal design. Creatinine concentrations, estimated glomerular filtration rates (eGFR) and one-year follow-up data were available for these patients. Results: During the follow-up period, 34 (14%) of patients had myocardial infarction (MI) and 25 (11%) died. Increased serum cystatin C was an independent predictor of all-cause mortality and combined events (all-cause mortality and MI) after adjustment to non-biomarker baseline factors, hazard ratio (HR) 2.19 (per increase of 1 tertile; 95% CI 1.28-3.78, p = 0.0046) and 1.75 (1.22-2.51, p = 0.0024), respectively. Corresponding values for eGFR were 2.56 (1.43-4.59, p = 0.0016) and 1.76 (1.23-2.53, p = 0.0022), respectively. Creatinine was not an independent predictor of endpoints (p > 0.05). Conclusions: Cystatin C was associated with an increased risk of death and combined events in patients with nSTE-ACS. (C) 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.