• Renal Disease
• Interventional Techniques & Devices
• Cardiology Clinical Trials

Procedures using intravascular iodinated contrast media are being widely applied for both diagnostic and therapeutic purposes but represent one of the main causes of contrast-induced nephropathy (CIN) and hospital-acquired renal failure. In selected subsets of patients with major risk factors (eg, advanced chronic kidney disease, diabetes, or impending percutaneous coronary interventions [PCIs]), CIN risk can run as high as 50% [Marenzi G et al. Intern Emerg Med 2012]. Somjot S. Brar, MD, MPH, Kaiser Permanente, Los Angeles, California, USA, presented findings on the Prevention of Contrast Renal Injury with Different Hydration Strategies [POSEIDON; NCT01218828] trial.

Several studies have shown that CIN is associated with increased morbidity and mortality, extended length of hospital stay, and increased costs [Gallagher S, Knight C. BMJ 2011]. CIN has no effective treatment [Marenzi G. et al. Intern Emerg Med 2012]. The hallmark of therapy is prevention, yet preventive strategies remain limited, said Dr. Brar.

The Phase 3, randomized POSEIDON trial compared standard intravenous (IV) hydration (0.9% saline) with left ventricular end diastolic pressure (LVEDP)-based hydration therapy. Questions surrounding standard IV hydration therapy include its rate and duration, and whether it can be optimized to the patient's needs. The trial's hypothesis was that LVEDP-guided hydration would reduce the incidence of CIN. LVEDP is an intravascular, hemodynamic parameter routinely measured in the cardiac catheterization laboratory, representing a patient's preload or volume status.

The single-blinded POSEIDON trial was carried out between November 2010 and July 2012 in patients undergoing angiography or PCI (inpatient and outpatient) at a high-volume tertiary care center. Inclusion criteria included estimated glomerular filtration rate <60 mL/min/1.73 m² (by Modification of Diet in Renal Disease equation) and at least one of the following: diabetes mellitus, age >75 years, hypertension (>140/90 mm Hg or treatment), or history of congestive heart failure. The primary endpoint was a 25% or 0.5 mg/dL increase in serum creatinine on two measurements between Days 1 and 4.

In the trial, 396 patients were randomized (1:1) to either LVEDP-guided hydration (n=196) or standard hydration (n=200). Prior to the procedure, all subjects received 0.9% saline IV at a rate of 3 mL/kg for 1 hour. Standard hydration patients then received 1.5 mL/kg/hr for 4 hours post-procedure. Those with LVEDP hydration received 5, 3, or 1.5 mL/kg/hr for 4 hours based on LVEDP of <13 mm Hg, 13 to 18 mm Hg, or >18 mm Hg, respectively.

The LVEDP-guided approach significantly reduced the primary endpoint by 59% compared with conventional hydration (RR, 0.41; 95% CI, 0.22 to 0.79; p=0.005). Treating 11 patients with an LVEDP-guided hydration approach would prevent 1 case of contrast nephropathy (Figure 1).

• Download figure
• Open in new tab
• Download powerpoint

Figure 1.

POSEIDON Primary Endpoint.

LVEDP=left ventricular end diastolic pressure; NNT=number needed to treat.Reproduced with permission from S Brar, MD.

Dr. Brar pointed out that this was the first trial to test the hypothesis of an LVEDP-guided hydration strategy for prevention of CIN. In subgroup analyses, the treatment effect was also consistently in favor of LVEDP-guided hydration (Figure 2).

• Download figure
• Open in new tab
• Download powerpoint

Figure 2.

Outcomes of Subgroup Analyses.

LVEDP=left ventricular end diastolic pressure.Reproduced with permission from S. Brar, MD.

• © 2012 MD Conference Express®