New Study on Cardiac Catheterization Offers Insight into Reducing Risk of Complications

PASADENA, Calif. – When physicians conduct heart-related procedures on patients, they commonly include a process called cardiac catheterization, which allows physicians to learn about the condition of the heart. In some instances, dye is used to help physicians visualize a patient’s blood vessels. Among the potential complications associated with using dye in these procedures is the risk of kidney damage in some patients. 

In a new research study led by Kaiser Permanente physician Somjot Brar, MD, MPH, of the Kaiser Permanente Los Angeles Medical Center, he and a team researchers found that tailoring the use of saline solution for patients undergoing coronary angiography or stenting procedures that use dye in the process resulted in a 59 percent reduction in kidney damage and a 68 percent lower rate of post-operation dialysis, heart attack, or death versus the risk associated with standard therapy. The study was recently published in The Lancet. 

We spoke to Dr. Brar about the study and its implications for clinical care. 

Why is this study interesting for the average person? 

The findings of the POSEIDON trial would be interesting and relevant for many patients with kidney disease undergoing cardiac catheterization. This is the first randomized controlled trial to show that a personalized hydration strategy reduces the rates of contrast exposurerelated acute kidney injury and major adverse clinical events in patients undergoing cardiac catheterization and at the risk for acute kidney injury from contrast. 

These findings are pertinent to patients with chronic kidney disease who undergo coronary angiography or stenting. Specifically, the findings are relevant to patients with estimated glomerular filtration rates (a measure of kidney function) of less than 60; these patients are at heightened risk for acute kidney injury from contrast exposure. 

With the aging of the population and increase in the prevalence of diseases that place patients at risk for developing acute kidney injury from contrast exposure, such as diabetes and hypertension, the number of patients impacted by these findings is large and will continue to increase.

Could you give us some background on your study? 

It is well-known that contrast (the dye used to visualize blood vessels) used during cardiac procedures can cause acute kidney injury in some patients. Intravenous fluid administration is regarded as the most effective strategy for the prevention of this complication related to contrast exposure. Nevertheless, it remains unknown how much or how long fluids should be administered to minimize the risk of kidney injury from the contrast exposure. 

What did you find in this study? 

In the POSEIDON trial, we found that a personalized fluid administration strategy, guided by an intracardiac pressure measurement, resulted in a 59 percent reduction in the rate of acute kidney injury from contrast exposure in patients undergoing cardiac catheterization (coronary angiography or stenting). Preservation of renal (kidney) function also had significant benefit on clinical outcomes. The combined rate of need for dialysis, heart attack, or all-cause mortality was 68 percent lower with the personalized fluid administration strategy when compared with standard therapy. 

What’s the take-away message for clinicians? 

The POSEIDON trial protocol provides a framework for targeted intravascular volume expansion. This removes much of the uncertainty around how much and how long fluids should be administered before, during, and after contrast exposure for cardiac catheterization. The protocol was designed to integrate into existing patterns of care. There are little to no costs related to implementation of the protocol.

In all patients, fluid administration should begin one hour before the procedure. The physician should measure the left ventricular end diastolic pressure at the start of the procedure and prior to contrast administration. Thereafter, the fluid rate should be set according to the POSEIDON protocol and continued for the duration of the procedure and for 4 hours post-procedure. 

These findings are not applicable to patients who are not candidates for treatment with intravenous fluids. For example, this may include patients with acute decompensated heart failure or severe valvular heart disease. Further research is needed to identify preventive therapies for these populations.