AKI in the Cath Lab

The Problem, The Impact, and The Solution.

The Problem.

Approximately 30% of patients presenting for coronary angiography procedures are at risk of having an AKI event.1 Dye used to visualize the coronaries may be toxic and can damage kidney function in high risk patients.

Contrast Induced Nephropathy (CIN), also known as Contrast Induced-Acute Kidney Injury (AKI) is a frequent complication associated with the administration of contrast agents during diagnostic cardiac catheterization and percutaneous coronary intervention (PCI).

Patients with normal kidney function can generally tolerate dye usage because their kidneys can ‘flush’ the toxic dye through their system quickly. However for patients with compromised kidney function, it is well documented, that they are less able to tolerate dye usage due to slower flushing through their kidneys.

As a result, the dye spends more time in the kidneys, with a greater chance of causing additional damage including:

  • Irreversible damage to the kidneys
  • Longer hospitalization
  • Increased risk of heart disease
  • Long-term dialysis
  • Higher risk of death

Additional factors compounding the risk for an AKI event include:

  • Older age
  • Diabetes
  • Congestive heart failure

Patients with compromised kidneys are categorized based on their Serum Creatinine (SCr) levels (blood test) or estimated glomerular filtration rate (eGFR). Patients at high risk for an AKI event secondary to a heart angiography procedure have either a SCr above 1.5 mg/Dl or an eGFR below 60 ml/min.

Serum Creatinine

The Impact.

The amount of dye used during angiographic imaging procedures increases the patient’s risk for dye-related kidney damage.2

Patients who experience an AKI event as a result of their procedure can have poor clinical outcomes including higher morbidity and mortality.3

If patients experiencing AKI events survive their hospital stay, their risk of mortality remains high within the first year following a heart procedure, and continues to increase within 5 years of the procedure.4

Poor clinical outcomes

AKI can be a significant economic burden to hospitals. The average additional length of stay in the hospital is 4 days and patients needing dialysis can require much longer hospitalizations. These added days in the hospital are estimated to cost $10,000-$12,000, most often with no additional payer reimbursement.

Patients with AKI are also at a higher risk of being readmitted to the hospital within 30 days of their discharge. The Medicare Readmission Reduction Program Penalty implemented in 2012 penalizes hospitals due to patient readmissions within 30 days. Patients with AKI frequently present with Heart Failure and Acute Myocardial Infarction symptoms at the time of re-admission.5

Patient readmissions within 30 days

The Solution.

“Clinical guidelines are generally created to help clinicians do the best for their patients.  In part to create best practices to provide efficient and efficacious care for them (patients).”

David Lee
Associate Professor of Medicine and Director of Cardiac Cath Lab
Stanford University, CA

Current practice is to focus on tracking the procedural incidence of AKI and to follow clinical guidelines to reduce the risk of AKI in high risk patients.

The National Cardiovascular Data Registry (NCDR®) is the ACC’s suite of cardiovascular data registries helping hospitals measure and improve the quality of care they provide.

The CathPCI Registry® assesses the characteristics, treatments and outcomes of cardiac disease patients who receive diagnostic catheterization and/or percutaneous coronary intervention (PCI) procedures. Data is captured that measures adherence to American College of Cardiology/American Heart Association (ACC/AHA) clinical practice guideline recommendations, procedure performance standards and appropriate use criteria for coronary revascularization.

The CathPCI Registry currently tracks contrast volume and kidney health (SCr levels) measures and reports on individual hospital risk adjusted AKI rates.6

The professional medical societies (i.e. ACC, SCAI, etc) have issued evidence-based guidelines for coronary angiography in patients at-risk for kidney injury.

The ACC/AHA/SCAI guidelines recommend:

  • Screening for patients at risk of acquiring AKI
  • Appropriately hydrating pre-, intra-, and post- cardiac procedure
  • Minimizing contrast volume in patients with Chronic Kidney Disease (eGFR < 60 ml/min) including monitoring for contrast dosage in real-time and establishing contrast thresholds.

Acute Kidney Injury (AKI) is a frequent complication associated with administration of contrast agents during diagnostic cardiac catheterization and percutaneous coronary interventions (PCIs) and leads to increased morbidity and mortality.7

A Kidney Care Protocol starts with effectively screening each patient for risk to identify the most vulnerable patients with poor kidney function.

Patients with moderate to severe kidney function should receive pre-, intra-, and post- procedure care to reduce their risk of having an AKI event.

Patients with compromised kidneys are categorized by their Serum Creatinine (SCr) levels (blood test) of estimate glomerular filtration rate (eGFR).  Patients at high risk for an AKI event secondary to a heart angiography procedure have either a SCr above 1.5 mg/Dl or an eGFR below 60 ml/min.

Serum Creatinine

Clinical Society Guidelines recommend that the only strategies consistently shown to reduce the risk of AKI in high-risk patients are hydration and reducing the Dye dosage administered to patients.8


Hydration protocols to prevent the risk of AKI in high risk patients have been evaluated in various clinical publications. A single standard protocol has yet to be defined.

Clinical guidance includes:

  • Clinical guidelines recommend Intravenous hydration as preferable to oral hydration and that hydration four hours before and after exposure to dye is preferable to a bolus administration.9

Clinical studies have also outlined hydration protocols including:

  • The POSEIDON trial’s use of Left Ventricle End Diastolic Pressure (LVEDP) guided hydration.

Contrast Reduction:

The volume of dye and risk of AKI has been well documented. Clinical studies have shown that minimization of dye is an important step to preventing AKI in patients undergoing heart imaging procedures (angiography).

DyeVert Plus guidelines

Modeling based off of Gurm, et al. study predicts that a reduction of dye by 30-45% in patients with CKD decreases the risk of AKI by 13-18%.10

Reducing contrast in patients with chronic kidney disease decreases AKI risk

Establishing Dye threshold volumes and real-time monitoring of Dye administration to patients at risk for AKI are well defined in clinical publications.11

Contrast threshold volumes

1,3Tsai T., et al., Contemporary Incidence, Predictors, and Outcomes of Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Interventions. JACC, Vol. 7, Jan. 2014

2Gurm, et al., Renal function-based contrast dosing to define safe limits of radiographic contrast media in patient undergoing PCI. JACC 2011;58:907-14

4Rihal, et al., Incidence and Prognostic Importance of Acute Renal Failure after PCI. Circulation. 2002 May 14;105(19):2259-64.

5Koulouridis I, et al., Hospital-Acquired Acute Kidney Injury and Hospital Readmission: A Cohort Study. Am J Kidney Dis. 2015;65(2):275-282.


7Lambert P, et al. Reducing AKI Due to Contrast Material: How Nurses Can Improve Patient Safety. Critical Care Nurse. 2017;37(1):13-26

8,9Levine GN, et al., ACCF/AHA/SCAI – Guideline for Percutaneous Coronary Intervention. A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions. Circulation. 2011; 124:e574-e651.

10Gurm, et al, Impact of Contrast Dose Reduction on the Incidence of AKI Among Patients Undergoing PCI: A Modeling Study. JIC 2016 Col. 28, Epub Jan. 15

11Naidu, et al., SCAI expert consensus Statement: 2016 Best Practices in the Cardiac Catheterization Laboratory. Cath and Cardiovasc intervention. April, 2016

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