Assessing contrast-induced nephropathy risk in older adults undergoing coronary angiography and intervention: The CV/GFR ratio versus Mehran score

Background: Contrast-induced nephropathy is a prevalent cause of hospital-acquired renal insufficiency and increases adverse events in older patients undergoing angiography and percutaneous coronary intervention. The Mehran risk score has been widely used in Vietnam to assess contrast-induced nephropathy risk in patients before coronary angiography and percutaneous coronary intervention. Recently, there has been a shift toward the adoption of simpler risk prediction models, such as the contrast volume-to-glomerular filtration rate ratio. This study aimed to (1) determine the incidence of contrast-induced nephropathy in older patients undergoing coronary angiography and/or percutaneous coronary intervention, and (2) compare the validity of the contrast volume-to-glomerular filtration rate ratio and the Mehran score in predicting contrast-induced nephropathy.

Method: This is a prospective cohort study conducted at a hospital in Vietnam from September 2019 to May 2020. Consecutive patients aged ⩾60 years who underwent coronary angiography and/or percutaneous coronary intervention were recruited. The contrast volume-to-glomerular filtration rate ratio and the Mehran score were evaluated for their predictive utility regarding contrast-induced nephropathy risk. The receiver operator characteristic was employed to calculate the area under the curve for both the contrast volume-to-glomerular filtration rate ratio and the Mehran score in predicting contrast-induced nephropathy.

Results: The study included 170 participants with a mean age of 70 years and 33.1% were female. Contrast-induced nephropathy was diagnosed in 9.4% of the participants. Participants with contrast-induced nephropathy exhibited a higher prevalence of chronic kidney disease, anemia, and heart failure. There was no significant difference between the area under the curves of the contrast volume-to-glomerular filtration rate ratio (0.79, 95% CI: 0.65-0.92), and the Mehran score (0.65, 95% CI: 0.51-0.82) in predicting contrast-induced nephropathy.

Conclusion: Our findings indicate that contrast-induced nephropathy was prevalent among older patients following percutaneous coronary intervention. The contrast volume-to-glomerular filtration rate ratio demonstrated a good prognostic value for predicting contrast-induced nephropathy comparable to that of the Mehran score. Further research is needed to identify optimal cutoff values for the contrast volume-to-glomerular filtration rate ratio in older patients.