目的 探讨血清胱抑素C水平与不稳定型心绞痛(unstable angina ,UA）严重程度的相关性。方法 选取本院不稳定型心绞痛患者147例作为观察组（按Braunwald分级分为三个亚组），选取同期非冠心病患者 50例作为对照组，对四组的血清胱抑素C水平进行检测，并进行比较分析。结果 观察组各亚组血清胱抑素C水平及阳性率明显高于对照组；观察组亚组中血清胱抑素C水平及阳性率，BraunwaldⅢ级组患者明显高于BraunwaldⅡ级组和Ⅰ级组患者，BraunwaldⅡ级组患者亦明显高于BraunwaldⅠ级组患者，差异均有统计学意义（P＜0.05）。结论 血清胱抑素C水平随着不稳定型心绞痛严重程度的加重而升高，检测血清胱抑素C对不稳定型心绞痛严重程度具有一定的预测价值，有助于判断病情，指导治疗。

Objective To investigate the correlation between serum levels of Cystatin C and unstable angina (UA). Methods 147 cases of patients with unstable angina were selected as the observation group and divided into three sub groups according to Braunwald classification, 50 cases of non coronary heart disease patients as control group. The serum Cystatin C levels in these four groups were detected. Results The serum Cystatin C level and the positive rate in observation group were significantly higher than that of control group. The serum cystatin C levels and positive rate in Braunwald Ⅲ group patients were higher than that of Braunwald grade II and grade I group of patients, and the serum cystatin C levels in Braunwald grade II group were also higher than that of Braunwald Ⅰ group patients (P < 0.05). Conclusion The serum Cystatin C level in patients is increased with the increasing of unstable angina severity. The detection of serum Cystatin C has some predictive value and may be helpful in the diagnosis and guiding treatment of unstable angina severity.