Whether Serum Cys C Is A Easy And Sensitive Indicator To Evaluate EGRF In Patients With Coronary Heart Disease

Background：As people ’s living standards improvment, the incidence of coronaryheart disease showed a rising trend, coronary angiography (Coronary angiography,CAG) diagnosis of coronary heart disease has become the "gold standard".Percutaneous coronary intervention (percutaneous coronary intervention, PCI) clinicalapplications, can significantly improve the quality of life of patients and improve theprognosis, has become an important means of treatment in coronary heart disease.Because patients undergoing coronary angiography and PCI increasingiodine-containing contrast agent widely used, contrast-induced nephropathy(contrast-induced nephropathy, CIN) has attracted great attention. CIN is surgicaltrauma after hypotension and acute renal injury caused by iatrogenic third leadingcause, accounting for10%of iatrogenic acute renal injury incidence. CIN in patientswith prolonged hospitalization, the corresponding increase in the cost of treatment andlong-term mortality was significantly increased, in addition, can also lead to seriousrenal complications. PCI seriously affect the prognosis of patients accepted, CAREstudy found that long-term occurrence of CIN in patients with serious adverse events,including myocardial infarction, stroke, death, and the incidence of ESRD comparedwith CIN was significantly higher in patients who did not happen. Tip CIN closelyrelated to long-term serious adverse events. Therefore, preoperative using simple,sensitive, crucial indicators to assess renal function. MDRD eGFR is currently assessing the classic formula, but the calculation is relatively cumbersome, requirecomputer-aided, can not meet the timely assessment of the clinical needs of eGFR.Therefore, to find a simple method to meet the clinical needs assessment imminent.Serum cystatin C (Cystatin C, Cys C) may be a reliable early diagnosis of renal functionand prognosis markers.Objective： To evaluate serum Cystatin C(Cys C) Whether it is more sensitive andearlier in renal injury prediction while comparing with serum creatinine. Whether it isbetter to predict eGFR, and Whether it can be used as an alternative to assess eGFRsubstitute MDRD formula in clinical work.Methods：Use ELISA method to measure the serum Cys C concentration and creatinineof473patients undergoing coronary angiography for the diagnosis of coronary arterydisease. Calculate and estimate the eGFR by MDRD formula calculation according topatients’ height, weight and creatinine value. Compare the correlation of eGFR withCys C and creatinine based on the diagnose evaluation index of eGFR. Use LR toevaluate the reliability of Cys C.Results：Different eGFR groups of patients showed no significant difference (P>0.05)on gender, height; but with age increasing, eGFR showed a decreasing trend (P <0.05);Preoperative and postoperative serum different eGFR groups of patients serum Cys C,creatinine, eGFR measurement display, whether before or after surgery with decreasedeGFR, serum Cys C and gradually increased serum Cr, serum Cys C and Cr werepresented with eGFR significant negative correlation, correlation coefficients were-0.601,-0.813(P <0.01).Different eGFR group of patients serum Cys C levels andserum Cr levels abnormal and the percentage number of cases,different eGFR groupχ2CysC=119.03, χ2Cr=74.2, were statistically significant differences (P <0.001).serumCys C compared to serum creatinine in renal impairment is earlier and moresensitive.Serum Cys C positive likelihood ratio (LR+) was significantly higher than in serum creatinine,but the negative likelihood ratio (LR-) lower than serumcreatinine,showed that compared with serum creatinine serum Cys C level assessmentof renal damage is better reliability.Preoperative and postoperative serum Cys C＜1.0mg/L,1.0mg/L≤Cys C＜1.25mg/L,1.25mg/L≤Cys C＜1.5mg/L,Cys C＞1.5mg/Lin four groups, the number and percentage of patients with abnormal serum Cr andeGFR values,Preoperative different Cys C levels set χ2eGFR=68.20, χ2Cr=52.54, werestatistically significant differences (P <0.001);Postoperative different Cys C groupχ2eGFR=71.23, χ2Cr=42.29, were statistically significant differences (P <0.001).indicatewhether it is in the preoperative or postoperative,serum Cys C is a more sensitiveindicator of renal dysfunction compared with serum creatinine.Different eGFR grouphad contrast-induced nephropathy in patients with preoperative Cys C wassignificantly higher than the percentage of abnormal creatinine, indicating that Cys Cserum creatinine levels than better predict the risk of early kidney contrast agent. eGFRnormal, mild lower group, moderate lower group,95%confidence interval, serum CysC were1.02mg/L-1.07mg/L,1.18mg/L-1.24mg/L,1.61mg/L-1.81mg/L, show thatCys C≥1.25mg/L are expected to ease as the clinical assessment of eGFR indicators.Conclusion：Serum Cys C is a reliable and accurate index that reflect early kidneyfunction damage in patients with coronary artery disease. Serum Cys C is expected to beused to improve the assignment MDRD formula or alternative assessment MDRDeGFR simple formula as clinical indicators.In patients whose serum Cys C≥1.25mg/L, serum creatinine levels at this time may be in the normal range, but has started eGFRdecrease in the use of contrast agents, to be alert to the occurrence of contrast-inducednephropathy, preoperative and postoperative should be given adequate hydrationtherapy, strictly control the amount of contrast agent in surgery.