Abstract: Objective To evaluate the impact of serum cystatin C (Cys C) level on short term prognosis in elderly patients with unstableangina (UA). Methods 167 patients with US were involved in this study. The serum Cys C level was measured by immunonephelometric assay.The patients were divided into normal group (Cys C<1.5 mg/L, n=102) and high Cys C group (Cys C≥1.5 mg/L, n=65) according totheir baseline of the first Cys C level within 24 hours. The clinical outcomes, including major cardiac events, mortality and readmission duringhospitalization and 6 months in the follow-up period were observed and evaluated. Results The major cardiac events, mortality and readmissionrate were higher in the high Cys C group than in the normal group (χ²=4.16, P=0.042). Conclusion The serum of Cys C level isclosely related to the short term prognosis of UA, it could be a risk factor to predict major cardiac events in patients with UA.

Key words: unstable angina, cystatin C, brain natriuretic peptide, prognosis