Cystatin C predicts mortality in patients with coronary artery disease both among subjects with and among those without the metabolic syndrome

Introduction Cystatin C is an established biomarker for renal function and, given the strong impact of chronic kidney disease on life expectancy, might indicate overall mortality. However, evidence for cystatin C as a predictor of mortality in coronary artery disease (CAD) patients is limited and controversial. Purpose The purpose of this study was to investigate whether Cystatin C can be used as a predictor of mortality in CAD patients. Methods We prospectively recorded mortality in 1115 patients with angiographically verified CAD over a mean follow-up of 11.5±5.0 years. Results At baseline, 514 patients had the metabolic syndrome (MetS) and 601 did not have the MetS. During follow-up, 627 (56.5%) of our patients died. Cystatin C proved to be a strong and independent predictor for mortality in the total study cohort (standardized adjusted HR 1.20 [1.13-1.28], p<0.001). When MetS status was taken into account, cystatin C significantly predicted mortality both in patients with the MetS (HR 1.20 [1.10-1.30], p<0.001) and in non-MetS patients (HR 1.20 [1.10-1.32], p<0.001). Conclusion We conclude that cystatin C predicts overall mortality in patients with coronary artery disease both among patients with the MetS and in non-MetS individuals.