Relationship of cystatin C with coronary artery disease and its severity.

Objective: Cystatin C, which is an endogenous marker for renal function, is reported to be a novel marker for coronary atherosclerosis. In this study, we aimed to evaluate its role in determining the presence and also the severity of coronary atherosclerosis in patients with coronary artery disease (CAD).

Materials And Methods: Eighty-eight patients who underwent elective coronary angiography were enrolled in the study. Patients with heart failure, renal failure, diabetes, and thyroid disease were excluded from the study. The study population was divided into three groups: individuals with normal coronary arteries, patients with critical CAD, and patients with noncritical CAD. We also analyzed the relationship of cystatin C levels with the presence and the severity of CAD and the number of vessels involved.

Results: The mean age of the study group was 51.73±9.21 years, and the majority were men (n=71, 80.7%). Cystatin C levels were significantly lower in patients with CAD (1334.86±93.45 vs. 836.49±411.29, P<0.001). It was significantly lower in patients with critical CAD compared with those with noncritical CAD and normal individuals (656.60±346.35, 1016.38±396.54, and 1334.86±393.45, P<0.001, respectively). Serum levels of cystatin C according to the numbers of coronary vessels such as none, single-vessel, two-vessel, three-vessel, and four-vessel disease were as follows: 1334.86±393.45, 801.67±418.70, 993.90±457.34, 744.09±354.53, and 682.30±294.43, respectively.

Conclusion: Lower cystatin C levels may be associated with increased severity of CAD in clinically stable patients, whereas higher levels may indicate the presence of any vulnerable plaque. It may also guide the diagnostic and therapeutic options for the clinical scene on the presentation.