Evaluation of the significance of cystatin C levels in patients suffering from coronary artery disease.

OBJECTIVES

Cystatin C is a novel marker used in the diagnosis of preclinical chronic kidney disease (CKD). The aim of the study was to assess the role of cystatin C in the diagnosis of coronary artery disease.

MATERIAL AND METHODS

The study involved 63 patients of a mean age of 62.7 ± 9.5 years. The population was divided into two groups: Group I were patients with angiographically diagnosed coronary artery disease (CAD) with their first acute coronary syndrome (ACS, n = 45); Group II were patients who had clinically diagnosed coronary disease but were negative on angiography (n = 18). Cystatin C levels were measured before angiography in both groups; in Group I they were also measured 6 months after discharge.

RESULTS

Cystatin C levels were significantly higher in Group I (p = 0.01), and this depended on the type of CAD: non-ACS, non-ST elevated myocardial infarction (NSTEMI) or ST elevated myocardial infarction (STEMI) (p = 0.01). Cystatin C levels correlated inversely with the left ventricular ejection fraction in the whole study population (p = 0.003) and in patients with NSTEMI (p = 0.03). A high cystatin C level was found to be a risk factor for ACS (OR: 1.002 95% CI [1.00029-1.004], p = 0.02) and STEMI (OR: 1.0009 95% CI [0.99-1.002], p = 0.04) but not for NSTEMI (OR: 0.99 95% CI [0.99-1.0], p = 0.21. A ROC analysis revealed that there is a significantly higher risk of ACS above a cystatin C level of 727.85 ng/mL (OR: 5.5 CI [1.65-18.3], p = 0.004) and a significantly higher risk of STEMI above 915.22 ng/mL (OR: 5.9 CI [1.7-19.7], p = 0.003).

CONCLUSIONS

The available data suggest that a high cystatin C level is a risk factor for ACS and STEMI. This could play an important role in the early diagnosis and prevention of adverse cardiovascular events.