MIAMI—A personally tailored hydration regimen can significantly reduce the incidence of kidney injury in patients at risk of contrast-induced nephropathy undergoing coronary angiography, researchers reported Oct. 25 at the Transcatheter Cardiovascular Therapeutics (TCT) conference. Contrast dye is injected into a patient for visualization during cardiac catheterization, and exposure to contrast damages the kidneys of some patients.
“Contrast nephropathy is a common and serious complication of contrast exposure that results in increased morbidity, mainly MI and the need for dialysis, mortality, and cost in terms of increased length of hospital stay,” said Somjot Brar, MD, of Kaiser Permanente in Los Angeles, during a presentation of findings from the Prevention of Contrast Renal Injury with Different Hydration Strategies (POSEIDON) study.
For the trial, researchers designed a sliding scale hydration protocol based on the individual patient’s left ventricular end-diastolic pressure measurements (LEVDP). This measurement is routinely taken in patients undergoing cardiac catheterization.
The researchers studied 398 coronary angiography patients with stable renal insufficiency and one other risk factor for contrast-induced kidney injury. The primary endpoint was a 25 percent increase in serum creatinine levels. The secondary endpoints were death, MI and dialysis.
Patients were divided into two groups; one received the standard hydration protocol and the other group received a protocol based on the patient’s LEVDP measured before the administration of contrast. The groups were balanced as to age, gender, diabetes and other relevant factors.
All patients received .09 saline fluid at a rate of 3mL/kg for at least one hour prior to cardiac catheterization. The patients in the control group received fluid at that rate throughout the procedure and four hours post-procedure. Patients in the LEVDP guided group received fluids on a sliding scale throughout the procedure and four hours post-procedure: 5mL/kg/hr if LEVDP was less than 13mmHg; 3mL/kg/hr if LEVDP was between 13mmHg and 18mmHg; and 1.5mL/kg if LEVDP was greater than 18mmHg.
The results showed significant differences in the rate of kidney damage between the two groups, with the primary endpoint reached in 6.7 percent of the patients in the LEVDP guided group and in 16.3 percent of the patients in the control group. There was a 59 percent reduction in risk among the group who received the LEVDP-guided hydration protocol.
“These results are applicable to patients at risk of contrast nephropathy undergoing coronary angiography or PCI, which we estimate to be about one out of every six patients [undergoing these procedures],” Brar said. He also pointed out that he and his colleagues reviewed the literature and found that only about 45 percent of patients undergoing coronary angiography received normal saline hydration during the procedure, despite the fact that hydration is recommended in position papers and guidelines.
This is believed to be the first randomized study to test whether a pressure-guided hydration protocol could prevent contrast nephropathy. Noting that kidney damage is a frequent complication of contrast administration, discussants on the panel were enthusiastic about the results.
Panelist Alice Jacobs, MD, of Boston University Medical Center, said, “Contrast nephropathy is certainly a real problem; it’s something that we struggle with, especially with patients at risk of having this problem. These results are lovely; it’s inexpensive, it’s fast, it’s easy to do, and it seems to work.” Ajay J. Kirtane, MD, of New York Presbyterian Hospital added, “This is something that is practically free …and I think it’s a great advance.”