Background and Objectives:
The systemic exposure of contrast agent is strongly associated with risk of contrast induced nephropathy (CIN). To avoid the risks of CIN, patients should be subjected to a minimal necessary dose of contrast medium (CM-dose). However, it is not easy to determine the safe CM-dose. The arm of this study was to determine the safe CM-dose using a index based on the ratio of CM-dose and cystatin C (CysC) based estimated glomerular filtration rate(eGFR) in who underwent elective percutaneous coronary intervention (PCI) according to individual CysC level.
Methods:
We prospectively enrolled a total of 1004 patients who underwent PCI in this study. GFR was calculated as creatinine clearance by CysC based equation (CysC_eGFR), and systemic exposure of contrast media was defined as novel index, CM-dose/eGFR_cysC. CIN was defined as an absolute increase of > 0.5mg/dL in the serum creatinine level compared to baseline within 72hrs. Results: Overall, there were 43 cases (4.3%) of CIN. In multivariate regression analysis, LVEF (HR 0.97, p<0.05), Hb (HR 0.67, p<0.001) and CM-dose/CysC_eGFR (HR 4.00, p<0.001) were found to be an independent predictor of CIN. In ROC analysis, fair discrimination for CIN was found at a CM-dose/CysC_eGFR (C statics = 0.765), and at this value, the sensitivity and specificity were 78% and 71%, respectively. According to the result of this study, the individual acceptable CM dose can be represented by this simple equation. "Safe contrast dose < 260/CysC (ml of iodixanol)."
Conclusions:
CM-dose/CysC_eGFR can be a simple, useful indicator for determining the safe CM-dose based on the preprocedural CysC value.