Contrast medium volume to estimated glomerular filtration rate ratio as a predictor of contrast-induced nephropathy developing after elective percutaneous coronary intervention.

Background: Contrast-induced nephropathy (CIN) has been recognized as a serious complication of diagnostic coronary angiography and percutaneous coronary intervention (PCI), and has been associated with prolonged hospitalization and adverse clinical outcomes. A key step to minimize the risk for developing CIN is to identify patients at risk for CIN.

Methods And Results: We retrospectively investigated clinical factors associated with the development of CIN in 60 stable angina patients who had undergone elective PCI. The frequency of CIN was 13% (8/60). There were neither any significant differences in age, gender, baseline serum creatinine or hemoglobin levels, nor in the rate of diabetes mellitus between the CIN and the non-CIN group. However, the estimated glomerular filtration rate (eGFR) was significantly lower (40.4+/-11.4 mL/min/1.73 m(2) vs. 57.4+/-22.6 mL/min/1.73 m(2), p=0.044), and number of treated vessels (1.5+/-0.8 vs. 1.2+/-0.4, p=0.039) and stents used (2.1+/-0.6 vs. 1.4+/-0.6, p=0.007) were significantly higher in the CIN group. In addition, the amount of contrast medium was significantly larger (272+/-37 mL vs. 201+/-62 mL, p=0.003) and the contrast medium volume (CMV) to eGFR ratio (CMV/eGFR) was significantly greater (7.4+/-2.9 vs. 4.0+/-2.0, p=0.0001) in the CIN group. Stepwise regression analysis showed that the CMV/eGFR ratio was a significant independent predictor of CIN (p=0.035). At a cut-off point of >5.1, the CMV/eGFR ratio exhibited 87.5% sensitivity and 74.5% specificity for detecting CIN.

Conclusion: The CMV/eGFR ratio could be a useful predictor of CIN developing after elective PCI.