POSEIDON: Sliding-Scale Hydration Successfully Prevents Contrast-Induced Nephropathy

MIAMI BEACH, FLA.—A treatment strategy of sliding-scale hydration successfully prevents contrast-induced nephropathy in patients undergoing cardiac catheterization, according to results of a randomized trial presented in a late breaking session at TCT 2012.

For the single-blind POSEIDON (Prevention of Contrast Renal Injury with Different Hydration Strategies) trial, Somjot S. Brar, MD, MPH, of Kaiser Permanente, Los Angeles, and colleagues randomized 396 patients undergoing coronary angiography or PCI with stable renal insufficiency and one additional risk factor to left ventricular end diastolic pressure (LVEDP)-guided hydration (n = 196) or standard hydration (n = 200). Patients were treated between November 2010 and July 2012.

A better option

Sliding-scale hydration resulted in a 59% relative and 10% absolute reduction in contrast-induced nephropathy (primary endpoint defined as a >25% or >0.5 mg/dL increase in serum creatinine; see Figure) primarily driven by fewer instances of increased serum creatinine more than 25% in the LVEDP-guided group (6.7% vs. 15.7%; P=.008). Increases in serium creatinine >0.5 mg/dL were also lower in the sliding-scale hydration group, but the difference was not significant (3.4% vs. 7%; P=.13).

Median hydration volume was greater in the study arm compared with the standard hydration group (1,711 mL vs. 807 mL; P<.001).

In multiple subgroup analyses, the treatment effect was consistently in favor of LVEDP-guided hydration.

There was no difference in major adverse events (composite of death, MI, and dialysis) between the study and control treatment groups (1.0% vs. 4.0%; P=.11), but contrast nephropathy was associated with an increased risk of this endpoint (P<.001). Hydration was terminated in a total of six patients (1.5%, three in each group) because of either shortness of breath or diuretic treatment.

“This is an easily implemented protocol that can be readily adapted in both the inpatient and outpatient settings,” Brar said. “These findings reaffirm that contrast nephropathy, as defined, is associated with a significant increase in [major adverse events] including mortality and death after cardiac catheterization.”

Discussant William W. O’Neill, MD, of the University of Miami, congratulated the researchers and said that the findings highlight the importance of adequately hydrating patients preprocedure. “It’s really the most potent method of preventing renal failure,” he said, adding that the patients should be followed out to 1 year in order to see even more dramatic differences in outcomes.

Co-moderator David R. Holmes Jr, MD, of the Mayo Clinic, Rochester, Minn., concluded the discussion by saying the trial shows that “it is a great time to implement these [type of treatments] because they are cost-effective and they work.”

Study details

Both groups received 0.9% saline at 3 mL/kg for at least 1 hour prior to their procedure. LVEDP was measured in all patients at the start of the procedure and prior to contrast administration. In the study arm, the fluid rate was adjusted according to the patients’ pressure as follows:

• 5 mL/kg/hr for pressure < 13 mm Hg
• 3 mL/kg/hr for 13 mm Hg to 18 mm Hg
• 1.5 mL/kg/hr for > 18 mm Hg

The standard hydration group was hydrated at 1.5 mL/kg/hr. The fluid rate was set at the start of the procedure prior to contrast exposure, and continued during the procedure and for 4 hours postprocedure.