Contrast-induced nephropathy (CIN) related to the use of contrast agents can lead to an increase in morbidity, mortality, and increased costs. CIN can be a serious consequence post coronary angiography, but can be significantly reduced or prevented by adequate peri-procedural administration of intravenous sodium chloride.
The Chester County Hospital has 3 procedural rooms, which include electrophysiology, peripheral vascular, and coronary procedures. Our annual volumes average greater than 1200 diagnostic procedures, over 300 percutaneous coronary intervention (PCI) procedures, and an average of 50 primary PCI procedures. Our pre-cath assessment tool captures both CIN risk and bleeding risk. The cath lab registry coordinator monitors CIN as an outcome metric as part of the NCDR (National Cath Database Registry). His analysis of the data post implementation of our pre-cath screening tool revealed significant improvement in our acute kidney injury (AKI) outcome metric.
A collaborative approach to help decrease CIN in patients undergoing cardiac catheterization may result in reduction of AKI. Our invasive cardiology advanced practice providers, with support from our physician director, led an initiative spearheading the implementation of a screening tool to decrease CIN on all patients undergoing coronary angiography. A multidisciplinary core group was utilized to develop the screening tool, consisting of an interventional cardiologist, a cardiology advanced practice provider, and the National Cardiovascular Data Registry (NCDR) registry coordinator. This original team is part of a broader team across the four Penn Medicine entities, which is where the idea of the pre-cath assessment tool was initiated. The core group at Chester County Hospital tailored the initiative to our unique entity, in which the advanced practice providers are utilizing the screening tool. The tool also incorporates key elements of a risk-adjusted algorithm as defined by the American College of Cardiology’s NCDR CathPCI Registry, which include prior myocardial infarction (MI), prior percutaneous coronary intervention (PCI), diabetes, and hypertension. These co-morbidities are used to help predict expected risk of CIN. The NCDR’s risk-adjusted acute kidney injury (AKI) was utilized for benchmarking. AKI is defined as an absolute increase of >0.3mg/dl during the hospital admission. The patient population consisted of both inpatients and outpatients undergoing PCI, excluding ST-elevation MI patients.
The pre-cath screening tool (Figure 1) was incorporated into the advanced practice providers’ workflow. Prior to initiation of the screening tool, the advanced practice provider seeing the patient was cognizant of CIN risk, evaluated creatinine and glomerular filtration rate (GFR), and initiated the appropriate IV hydration for our patients. The screening tool makes all providers more accountable when patients are seen prior to their cardiac cath. It mandates that the advanced practice provider answers appropriate questions to assess the patient’s CIN risk. Our data registry coordinator proposed the idea of having the CVNPs fill out the form to Jennifer McCullough, Lead Cardiovascular Nurse Practitioner. There is always some hesitancy when there is one more form to fill out; however, our team of cardiovascular advanced practice providers see every patient and are the most appropriate team members to evaluate patient CIN risk. The screening tool was initially paper, but recently has been incorporated into the electronic medical record, offering a quicker and more efficient process. It takes approximately 4 to 5 extra minutes to fill out the tool. Three prompts are provided. The first prompt asks if a patient is on ACE (angiotensin-converting enzyme inhibitors), ARBs (angiotensin-receptor blockers), or diuretics. The second asks if the patient has received contrast in the last 48 hours. The third prompt asks if the patient will require additional hydration. Patients identified as high risk by the pre-cath screening tool receive additional hydration. The hourly hydration rate is adjusted relative to GFR and ejection fraction as described in the protocol (Figure 2). The advanced practice provider informs the interventionalist of high-risk patients in advance of their procedure, allowing the interventionalist to adjust contrast dosing during the procedure accordingly. It is important that the physician evaluates contrast dose, because there is a direct correlation between amount of contrast and potential CIN. The less contrast given, the less chance of CIN. The technologists and nurses are aware of contrast dosing throughout the case and let the physician know when they are approaching maximum dose. The physician may limit further exposure to contrast by limiting left ventriculograms. In addition, the cath lab at Chester County Hospital now primarily uses radial access, which has been associated with reduced AKI compared to femoral artery access.
The advanced practice provider’s evaluation of patients in conjunction with use of the pre-cath screening tool is key to identifying at-risk patients. Along with use of the hydration protocol, this initiative has successfully decreased Chester County Hospital’s overall rate of risk-adjusted AKI (Figure 3). Prior to implementation, our risk-adjusted AKI was 4.15% for 2016 Q3. After implementing our screening tool, the risk-adjusted AKI rate decreased to 2.81% for 2017 Q1. With this new process, we made improvements towards the 90th percentile of 2.56% for 2017 Q1. The screening tool helps raise awareness of individual patient risk, and guides all providers to implement practices that decrease risk of risk-adjusted AKI. Each component is essential to the success of the screening tool. The advanced practice provider provides key care coordination.
Potential cost savings include the prevention of acute kidney injury, which is associated with chronic renal disease and increases in mortality, morbidity, length of stay, and readmissions. Plans for the future include an evaluation of a different contrast agent on higher risk patients to include oncology patients, those with chronic kidney disease (CKD) stage G3 (eGFR 30-59 ml/min/1.73m2), and diabetics. We will maintain current practice utilizing our screening tool to decrease AKI, which currently reflects the 90th percentile per NCDR data element. The team routinely reviews the most recent literature and makes adjustments accordingly.
- NCDR® CathPCI Registry® Outcomes Reports 2016Q3, Q4; 2017Q1, Q2, and Q3 Contrast Induced Nephropathy Prevention in Patients Undergoing PCI protocol-2016.
- Weisbord SD, Gallagher M, Jneid H, et al; PRESERVE Trial Group. Outcomes after angiography with sodium bicarbonate and acetylcysteine. N Engl J Med. 2018 Feb 15; 378(7): 603-614. doi: 10.1056/NEJMoa1710933.
- Ando G, Cortese B, Russo F, et al; MATRIX Investigators. Acute kidney injury after radial or femoral access for invasive acute coronary syndrome management: AKI-MATRIX. J Am Coll Cardiol. 2017 May 11. pii: S0735-1097(17)36897-3. doi: 10.1016/j.jacc.2017.02.070.
Disclosures: The authors report no conflicts of interest regarding the content herein.
The authors can be contacted via Jennifer McCullough, CRNP, Lead Cardiovascular Nurse Practitioner, at Jennifer.McCullough2@uphs.upenn.edu.