Prediction of Contrast-induced Nephropathy in Diabetic Patients undergoing Elective Cardiac Catheterization or PCI: Role of Volume-to-Creatinine Clearance Ratio and Iodine dose-to-Creatinine Clearance Ratio
Surapong Worasuwannarak MD*, Suwatchai Pornratanarangsi MD*
Affiliation : *Division of Cardiology, Department of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To assess a role of volume-to-creatinine clearance ratio (V/CrCl) and iodine dose-to-creatinine clearance ratio (I-
dose/CrCl) in predicting contrast- induced nephropathy (CIN) in diabetic patients undergoing elective cardiac catheterization
or percutaneous coronary intervention (PCI).
Background : In diabetic patients undergoing cardiac catheterization or PCI, the incidence of CIN is higher than in non-
diabetic patients. High doses of contrast media also increase the likelihood of renal dysfunction. The ratio of the volume of
contrast media to creatinine clearance (V/CrCl) and iodine dose-to-creatinine clearance (I-dose/CrCl) has been shown to
correlate with the area under the curve of contrast media concentration over time and was used to predict the occurrence of
CIN in unselected patients. No study has been conducted specifically in diabetic patients undergoing cardiac catheterization
or PCI before.
Material and Method: We conducted a prospective, single center study. The V/CrCl and I-dose/CrCl were calculated in
diabetic patients undergoing elective cardiac catheterization or PCI. An increase in serum creatinine of > 0.5 mg/dl or > 25%
by 7 days from baseline was considered CIN. The incidence of CIN was determined. The predictive value of V/CrCl and I-
dose/CrCl for CIN were assessed using multivariable logistic regression.
Results : The total number of patients that had been enrolled in the study was 248; Male 50.8%. The overall incidence of CIN
was 5.2%. The mean age for the entire population was 65 + 9 years; the mean body mass index was 25.6 + 4.0 kg/m(cid:31); and
the mean creatinine clearance was 60.6 + 27.4 ml/min. The mean values of V/CrCl for patients with and without CIN were 3.7
+ 2.9 and 2.2 + 1.7 (p = 0.041). The mean values of I-dose/CrCl for patients with and without CIN were 1.31 + 0.94 and 0.82
+ 0.63 (p = 0.042). The receiver-operator characteristic curve analysis indicated that a V/CrCl ratio of 2.60 and I-dose/CrCl
of 0.98 were fair predictors of CIN. After adjusting for other known predictors of CIN, a V/CrCl ratio > 2.60 remained the
only significant predictor of CIN (Odds ratio 5.8; 95% confidence interval 1.7-19.4, p = 0.005)
Conclusions: A V/CrCl ratio > 2.60 was a significant predictor of CIN in diabetic patients undergoing elective cardiac
catheterization or PCI.
Keywords : Contrast induced nephropathy, Coronary angiography, Diabetes mellitus
