Background: Contrast induced nephropathy (CIN) is a common complication of cardiac catheterization procedures such as percutaneous coronary intervention (PCI). The ratio of the volume of contrast medium used and creatinine clearance (V/CrCl) has been shown to predict the incidence of CIN in patients undergoing PCI. This study aims to determine the accuracy of V/CrCl ratio in predicting contrast induced nephropathy in patients undergoing PCI.
Methods: This is a prospective cohort study done in the Philippine Heart Center among patients who underwent PCI from October 2016 to January 2017. Calculation of the baseline creatinine clearance among eligible patients was done using the Cockroft-Gault equation prior to the procedure and a repeat serum creatinine was done 24 hours post-PCI for the calculation of the V/CrC1 ratio. An increase serum creatinine of ≥1.5 times the baseline OR ≥26.5μmol increase was considered abnormal. The predictive value of V/CrCl ratio for CIN was then assessed using logistic regression analysis.
Results: A total of 112 patients were included in the study, with the mean V/Crc1 ratio at baseline of 2.34. Twenty-one patients out of the 112 (18.8%) developed CIN. Using receiver-operator curves, a V/CrCl ratio of 1.75 was determined to be the optimal cut-off value predictive of CIN, with a sensitivity of 47.62%, specificity of 40.66%, and odds ratio of 0.622 (p-value: 0.33).
Conclusion: V/CrCl ratio is affected by several variables and is highly dependent to the population studied. Though it was found not to be a significant predictor of CIN in this study, alonger observation period with a more delayed determination of repeat serum creatinine can provide more conclusive and significant results that can show the association of the V/CrCl ratioand development of CIN.