Maximum Allowable Contrast Dose and Risk of Acute Kidney Injury After Coronary Procedures

Recent studies have questioned whether iodinated contrast is causally related to acute kidney injury (AKI).

We pursed a contemporary analysis to determine the impact of contrast dose on AKI following coronary procedures in an era of lower contrast doses and less nephrotoxic agents.

This national cohort study examined patients who had percutaneous coronary intervention (PCI) or diagnostic angiography from October 2010 to May 2023. We used logistic regression to test associations between (1) baseline (pre-procedural) AKI risk and contrast dose, and (2) contrast dose and post-procedure AKI. Contrast exposure was quantified as a proportion of the maximal allowable contrast dose (MACD; 2.5 mL × body weight (kg)/serum creatinine).

Median contrast volume decreased during our study period for PCI (200 to 150 mL, p < 0.01) and angiography (95 to 60 mL, p < 0.01). In the combined cohort of 175,963 procedures, the mean patient age was 68.5 years; 97.5% were male. Decile plots revealed that patients at higher baseline risk of AKI received lower contrast volumes. When the contrast dose exceeded MACD, there was a stepwise association between contrast dose and adjusted odds of AKI. The highest odds of AKI were observed for patients with eGFR < 30 who received > 200% of the MACD (OR, 2.89; 95% CI, 2.21 to 3.79).

In this large national cohort of patients undergoing coronary procedures, there was a reduction in contrast dose over time and evidence that physicians are reducing contrast volume for high-risk patients. The MACD remains a reasonable target to reduce AKI.