Contrast-Associated AKI (CA-AKI) is a form of Acute Renal Failure that is caused by exposure to contrast media during image-guided cardiology and radiology procedures. The lack of effective treatment to prevent CA-AKI remains problematic for patients with renal-insufficiency.

Millions of cardiovascular and peripheral diagnostic and interventional procedures are performed worldwide each year. These less invasive, image-guided medical procedures require the use of an iodine-based radio-contrast media, or dye, to facilitate the capture and display of x-ray images. These contrast agents are known to be toxic to the kidney, whose main function is to filter and remove wastes and fluids from the body. Patients who undergo this type of procedure and who present themselves with a certain level of pre-existing impaired renal (kidney) function are especially susceptible to the toxic effects of these contrast agents and to developing CA-AKI.

In patients at risk, the concentration of contrast agents in the collecting duct may be increased. Along with this continuous concentration process, tubular fluid containing contrast agents will become increasingly viscous and can lead to tubular obstruction. This increases tubular pressure and intrarenal tissue pressure. As a result, renal perfusion pressure for the renal medulla (17mmHg) may no longer be high enough to assure sufficient perfusion to critical kidney areas; thus aggravating hypoxic injury.2

According to Marenzi, et al,3 hospitalized patients who received contrast media and who acquired CA-AKI had significantly higher mortality rate (31% vs. .6%) than patients who did not acquire CA-AKI. These consequences usually lead to higher health care costs.

A meta-analysis4 of 10 studies related to the use of RenalGuard in high-risk patients showed that RenalGuard was associated with significant risk reduction in CA-AKI compared to the control group. Use of RenalGuard was associated with decreased mortality, dialysis and major adverse cardiac events (MACCE) compared to the control.

CA-AKI is associated with increased:5

Major adverse in-hospital cardiac events

In-hospital mortality rates

Long-term mortality


Risk of acceleration toward end-stage renal disease (dialysis)

Longer and more frequent hospital stays

1McCullough et al, Contrast-Induced Nephropathy: Clinical Insights and Practical Guidance
A Report from the CIN Consensus Working Panel, Supplement to the American Journal of Cardiology, Vol. 98 (6A), September 18, 2006

2Bartorelli, Antonio L., Marenzi, Giancarlo; Contrast-Induced Nephropathy: In Interventional Cardiovascular Medicine, 2005; pp. 3-11

3Marenzi, G, Lauri, G, et al. Contrast-induced nephropathy in patients undergoing primary angioplasty for acute myocardial infarction. JACC 2004;44:780-5

4Prasad, A, et al. Use of the RenalGuard system to prevent contrast‐induced AKI: A meta‐analysis. Journal of Interventional Cardiology, 4 Sept. 2017; 10.1111/joic.12417.

5Merten et al., Prevention of Contrast-Induced Nephropathy With Sodium Bicarbonate – A Randomized Controlled Trial; JAMA, May 19, 2004; 291; 2328-2334