Contrast induced nephropathy in older patients undergoing coronary angiography and intervention: an observational study in Vietnam

Abstract Background Contrast induced nephropathy (CIN) is the third common cause of hospital-acquired renal insufficiency and can negatively impact the treatment effect and increase mortality in older patients undergoing percutaneous coronary intervention (PCI). The Mehran risk score has been the most used in Vietnam. In recent years, new simpler risk prediction models have been proposed, in which the contrast volume-to-glomerular filtration rate ratio (CV/GFR ratio) is promising. This study aimed to (1) examine the incidence of CIN in older patients undergoing coronary angiography and/or PCI, (2) compare the validity of the CV/GFR ratio and the Mehran score in predicting CIN, and (3) to identify optimal cut-off points of these scales through which can help identify older patients at high risk of developing CIN. Method. This is a prospective cohort study conducted at a tertiary hospital in Vietnam from September 2019 to May 2020. Consecutive patients aged ≥ 60 who underwent coronary angiography and/or PCI were recruited. CIN was defined as a 25% increase in serum creatinine from baseline or 0.5mg/dL absolute increase in serum creatinine within 48 hours post IV contrast administration. The CV/GFR ratio and the Mehran score were applied to predict CIN risk. Receiver Operator Characteristic (ROC) was applied to evaluate the area under the curve (AUC) of the CV/GFR ratio and Mehran score in predicting CIN, and the sensitivity and specificity for common cut-off points that were suggested in previous studies. Results There were 170 participants, with a mean age of 70 years and 33.1% were women. The incidence of CIN was 9.4%. Participants with CIN had higher prevalence of chronic kidney disease, heart failure and anaemia at admission. The AUC of the CV/GFR ratio against CIN was 0.79 (95%CI 0.65–0.92), and the Mehran score against CIN was 0.65 (95%CI 0.51–0.82). Conclusion Our study found that CIN was common in older patients after PCI. The CV/GFR ratio showed a good prognostic value for predicting CIN in the study participants as the Mehran score. Further research is needed to identify the optimal cut-off values for the CV/GFR ratio in older patients in Vietnam.