The Value Of Contrast Medium Volume To Estimated Glomerular Filtration Rate Ratio For Early Prediction Of Contrast Induced Acute Kidney Injury (CIAKI) In Elder Patients

Objective: Contrast induced acute kidney injury (CIAKI) has beenrecognized as a serious complication of coronary artery angiography (CAG) orpercutaneous coronary intervention (PCI), although the understanding ofCIAKI deeped gradually, no pharmacological approach has been demonstratedto offer consistent protection. The incidence of CIAKI has shown anincreasing trend，the elder patients undergoing CAG or PCI have a higherincidence of CIAKI than non elder patients, therefore, identifying individualswho were at increased risk becomed essential, especially for the elder. Thediagnosis of CIAKI depended on the changes in the levels of serum creatinine(SCr).However, the SCr level changes often tend to droped behind in kidneyinjury.It was more need to find a more sensitive and reliable indicators toshow the early CIAKI.This study was designed to analysis the characteristics,clinically relevant risk factors,the level of SCr changes of these elder patientsand to investigate the predictive value of the ratio of contrast media volume toestimated glomerular filtration rate ratio (V/eGFR) for early prediction ofCIAKI in elder patients undergoing elective CAG or PCI who developedCIAKI and to avoid CIAKI occurrence in elder patients.Methods: We prospective investigated clinical factors associated withthe development of CIAKI in63elder (≥60years) hospitalized patients whohad undergone elective CAG or PCI in Hebei Medical University ThirdHospital from November of2011to December of2012.The risk factors forCIAKI included age,gender,body mass index (BMI),history of smoking anddrinking, history of hypertension, diabetes, myocardial infarction andcerebrovascular disease, medication history,biochemical markers,such as levelof blood lipids, fasting plasma glucose (FPG),etc,volume of contrast medium(V), the number of narrow vessels and the number of stents used,Wealso calculated the estimated glomerular filtration rate (eGFR) and V/eGFRratios. According to the rise of SCr(an acute absolute increase in SCr by atleast0.5mg/dl or a relative increase in SCr of25%, excepted otherinterpretable factors within72h after the use of contrast medium) to determinethe CIAKI group and nonCIAKI group, the general clinical characteristics ofthe two groups were compared. Then we conducted a stepwise regressionanalysis to evaluate the predictive role of these risk factors in the incidence ofCIAKI. Receiver operator characteristic (ROC) curves were used to identifythe optimal sensitivity for the observed range of V/eGFR to predicte CIAKIoccurrence.Results:163elder patients (male/female,36/27) who had undergone CAG or PCI.The clinical features was shown:age rage from60to81years old,average age(69.19±5.91) years old, average height (163.48±7.56) cm, the mean BMI(25.95±2.50) kg/m~2, smokers in17cases (27%),23cases of myocardialinfarction (36.5%), diabetes in23patients (36.5%), cerebrovascular disease17patients (27%), FPG (5.89±1.29) mmol/L, HGB (132.31±17.76) g/L, PLT(212.90±68.41)×109/L, mean lipid levels (total cholesterol:4.50±0.86mmol/L, triglycerides:1.77±0.96mmol/L, high density lipoproteincholesterol:1.06±0.21mmol/L, low density lipoprotein cholesterol:2.88±0.72mmol/L),median baseline SCr level (76.24±44.18) umol/L, meanpreoperative eGFR (82.26±21.58) ml/min/1.73m~2.The frequency of CIAKI was9.5%(6/63).There were neither anysignificant differences in age(70.83±5.42vs.69.02±5.98，P=0.470) year old,gender (male/famale)(3/3vs.33/24, P=0.710), body mass index (BMI)(24.53±1.87vs.26.10±2.53, P=0.139)kg/m~2, smoking history (0vs.29.8,P=0.117)%, history of drinking (0vs.19.3,P=0.236)%, blood lipid levels(Total Cholesterol：3.96±0.75vs.4.56±0.86,P=0.099,Triglycerides：1.77±0.78vs.1.77±0.99,P=0.991, High density lipoprotein-Cholesterol：1.04±0.09vs.1.06±0.22,P=0.720, Low density lipoprotein-Cholesterol：2.56±0.48vs. 2.92±0.74,P=0.238) mmol/L, hypertension (83.3vs.73.7,P=0.606)%,cerebrovascular disease history (16.7vs.28.1,P=0.549)%, fasting plasmaglucose (FPG)(6.00±1.16vs.5.88±1.31,P=0.822)mmol/L,hemoglobin (HGB)(126.08±28.39vs.132.96±16.50, P=0.363)， g/L, platelet count (PLT)(226.85±69.24vs.212.43±68.78,P=0.596)×109/L,nor eGFR (71.11±31.57vs.83.43±20.30,P=0.18)ml/min/1.73m~2between the CIAKI and the non CIAKIgroup. However, β-blocker medication history was significantly lower (0vs.42.1,P=0.043)%, and angiotensin converting enzyme inhibitors/angiotensinreceptor blocker (ACEI/ARB) medication history (83.8vs.2.81, P=0.006)%,diabetes(83.3vs.31.6, P=0.043)%, baseline SCr levels (116.67±54.76vs.71.98±19.00,P=0.018) umol/L,the V/eGFR(3.10±2.37vs.1.71±1.16,P=0.015), myocardial infarction history(83.3vs.31.6,P=0.012)%wassignificantly higher in the CIAKI group.2Angiographic results showed that there was no significant difference inthe number of diseased vessels (2.17±0.75vs.1.70±1.02，P=0.275) betweenthe CIAKI and the non CIAKI group;However stents used (2.67±1.21vs.1.46±1.24，P=0.026) and use of large volume of contrast medium (≥5ml/kg/SCr (mg/ml), or≥300ml)(50vs.5.3)，P＜0.001)%in the CIAKIgroup were significantly higher than in the non CIAKI group;Volume ofcontrast tended to be higher in the CIAKI group, but not significantly(162.67±48.32vs.134.78±74.39ml，P=0.366).3Stepwise regression analysis showed that no history of the β-blockermedication and history of the ACEI/ARB medication, history of diabetes,baseline SCr levels, the V/eGFR ratio, history of myocardial infarction, use oflarge volume of contrast medium was a significant independent predictor forthe development of CIAKI ((P＜0.05).4ROC analysis showed that a area under the curve for the contrastmedium volume to estimated glomerular filtration rate (V/eGFR) ratio was(0.746), confidence interval of AUC95%was (0.576,0.915),At a cut-off levelof>1.45, the V/eGFR ratio exhibited100%sensitivity and50.9%specificityfor detecting CIAKI. Conclusion: No history of the β-blocker medication, history of theACEI/ARB medication, history of diabetes, a high baseline SCr level, theV/eGFR ratio (>1.45), history of myocardial infarction, use of large volume ofcontrast medium could be a independent predictor of CIAKI for older patientsafter CAG or PCI.The V/eGFR ratio could be more sensitive and specific forearly predictors. At a cut-off point of>1.45, the V/eGFR ratio was an optimalpredictor for the incidence of CIAKI.