The Relationship Between Cystatin C And Coronary Heart Disease

Objective:The pathologic basis of coronary heart disease(CHD) is coronary atherosclerosis and clinical coronary events by 90% are caused by coronary atherosclerosis. Current basic researches have proved that atherosc- lerosis is a chronic inflammatory process which involved the extracellular matrix degradation and vascular wall remodeling. Stimulation of inflammatory mediators promote the vascular smooth muscle cells to secret cathepsin S and K, etc, making this type of cysteine protease with the characteristics of promoting the dissociation of elastic tissue overexpression in the injuries of arterial elastin.An important function of cystatin C is to inhibit the activity of endogenous cysteine protease and it is the strongest inhibitor of cathepsin B.In this study,serum cystatin C was measured by immunoturbidimetry(ITM) to explore its relationship with the CHD and the severity of CHD.Methods:120 cases were selected by coronary angiography. The diagnostic criteria for CHD is that there is at least one epicardial vessel with the diameter stenosis≥50% by coronary angiography. Combined with cardiac enzymes and troponin,all the cases were divided into control group (26 cases),stable angina group(SAP, 26 cases),unstable angina pectoris group (UA,31 cases) and acute myocardial infarction group(AMI, 37 cases).There are not statistical differences in sex, smoking,hypertension,diabetes and hyperlipidemia in each group(P>0.05).The serum concentration of cystatin C was measured by ITM and the left ventricular ejection fraction(LVEF) was measured by echocardiography in all patients.According to the evaluation criteria of coronary artery image grading scoring published by American Heart Association,we use the Gensini score system to evaluate the stenosis of each coronary artery quantitatively. Differences in continuous variables between groups were tested by analysis of variance (ANOVA).Differences in count data were compared with Chi-Square test.The relationship between two variables were tested by Spearman correlation or Pearson correlation.P<0.05 for the difference was significant.Results: 1.Cystatin C levels and LVEF values in each group and their relevance①AMI Group: cystatin C 0.79±0.16mg/L, LVEF 45.22±4.96%②UA Group:cystatin C 0.87±0.13mg/L, LVEF 48.16±3.84%③SAPgroup:cystatin C 1.03±0.14mg/L, LVEF 50±3.09%④control group:cystatin C 1.14±0.19mg/L, LVEF 53.76±3.36%.Differences among thesegroups are statistically significant.The cystatin C levels correlate with the severity of CHD negatively and correlate with the values of LVEFpositively.2.The relationship between cystatin C levels and the numberof coronary artery disease and its severity①single-vessel disease group:cystatin C1.01±0.11mg/L, Gensini score 29.28±10.33②double-vesseldisease group:cystatin C 0.88±0.14mg/L, Gensini score 39.73±19.85③triple-vessel disease group:cystatin C 0.75±0.16mg/L, Gensini score56.85±24.08④control group:cystatin C 1.14±0.19mg/L, Gensini score 0.07±0.39. With the increase in the number of coronary artery disease,cystatin C levels decreased gradually, and the Gensini score was sign-ificantly higher. The cystatin C levels and Gensini score was negatively correlated.Conclutions:There is a close relationship between cystatin C and the development of coronary heart disease.It can reflect the sevirity of coronary heart disease and the heart function indirectly. Cystatin C may play a protective role in patients with coronary heart disease.