Abstract 58: Implementation Of An Electronic Health Records-based Safe Contrast Limit For Preventing Contrast-associated Acute Kidney Injury After Percutaneous Coronary Intervention

Background: Contrast-associated acute kidney injury (CA-AKI) after percutaneous coronary intervention (PCI) is associated with cardiovascular complications and mortality. We previously published a multivariable model for calculating safe contrast volume limits derived from National Cardiovascular Data Registry (NCDR) data. We assessed the performance of this safe contrast limit when implemented in an electronic health records (EHR) system. Methods: We created an advisory alert in our Epic EHR system, which displayed the safe contrast limit to catheterization lab staff and operators prior to PCI along with CA-AKI risk reduction strategies. The alert required no clinician data entry and used risk factors automatically pulled from the EHR: age, sex, body mass index, creatinine clearance, hemoglobin, and use of intra-aortic balloon pump pre-procedure. We included procedures from 11/1/2020 to 10/1/2021 that had pre- and post-procedure creatinine data; the intervention went live 2/10/2021. We used NCDR-defined CA-AKI events to assess the performance of the safe contrast limit in predicting CA-AKI. We used interrupted time series analysis to determine if the intervention reduced contrast use and CA-AKI. Results: There were 201 PCIs; 10.4% (21 out of 201) had CA-AKI. The contrast limit predicted CA-AKI well using real-time EHR data (sensitivity 76.2%, specificity 50.0%, negative predictive value 94.7%). Among 178 patients with modifiable CA-AKI risk (defined as safe contrast limit ≤ 500mL), the intervention was associated with an immediate significant decrease in contrast use (-44.34mL (95% CI -81.71, -6.97)) and a decrease with time (-0.77mL/day (-1.31, -0.22)). For 23 patients at low CA-AKI risk (contrast limit > 500mL), there was a non-significant increase in contrast use (28.55 (-92.79, 149.88) and with time (1.15 (-0.73, 3.03)). There was no significant decrease in CA-AKI (OR 0.21 (0.03, 1.37)). Conclusion: An EHR-based safe contrast limit using automatically derived patient data performed well in predicting CA-AKI. The intervention significantly decreased contrast use for patients with modifiable CA-AKI risk and non-significantly increased contrast in patients with low risk. Longer follow-up will help clarify effects on CA-AKI rates.