Study sheds light on contrast-induced nephropathy in high-risk patients

August 8, 2008

Researchers have established the safety of nonionic contrast media in adult and pediatric patients, but questions remained regarding the use of low- and iso-osmolar agents, particularly in patients at high risk of developing contrast-induced nephropathy. Now results from a prospective multicenter study done in China and the U.S. suggest that risk is equally low with either type of agent.

Researchers have established the safety of nonionic contrast media in adult and pediatric patients, but questions remained regarding the use of low- and iso-osmolar agents, particularly in patients at high risk of developing contrast-induced nephropathy. Now results from a prospective multicenter study done in China and the U.S. suggest that risk is equally low with either type of agent.

For some time, the use of nonionic low-osmolar contrast media has been deemed as generally safe in patients at high risk for CIN. The clinical literature, however, lacked weighty data comparing low- and iso-osmolar agents in patients with preexisting renal dysfunction and diabetes, two of the strongest independent predictors of the condition.

Until the publication of the Patients with REnal impairment and DIabetes undergoing Computed Tomography (PREDICT) study, no definitive indication existed to determine if one agent provides additional benefits compared with the other, according to lead investigator Dr. Matthew J. Kuhn, a clinical professor of radiology, neurology, and neurosurgery at Southern Illinois University School of Medicine.

"The PREDICT study reinforces the results of earlier published studies, the IMPACT Study and the CARE Study, that also failed to find a difference between iodixanol and iopamidol when administered to at-risk patients," Kuhn said.

From January 2006 to April 2007, Kuhn and colleagues enrolled 248 patients with moderate to severe chronic kidney disease and diabetes mellitus at 23 sites in the U.S. and China. Patients were referred for multislice CT scans of the brain, head and neck, thorax, abdomen, or pelvis or to MSCT angiography. They were randomly assigned to an IV bolus of iopamidol 370 (Isovue, manufactured by Bracco Diagnostics) or iodixanol 320 (Visipaque, manufactured by GE Healthcare).

The investigators found that the incidence of CIN in these high-risk patients was low and not statistically significantly different after administration of either agent. They published results in the July issue of the American Journal of Roentgenology (2008;191:151-157).

Patients in the study had comparable demographics and baseline renal function. Seven patients (5.6%) receiving iopamidol 370 and six patients (4.9%) receiving iodixanol 320 experienced increases of 25% or more in serum creatinine levels (p = 1.0). The mean serum creatinine change from the baseline level was 0.04 mg/dL in both groups (covariance, p = 0.80).

In patients with a baseline serum creatinine value equal to or greater than 2 mg/dL, baseline estimated glomerular filtration rate equal to or less than 40 mL/min/1.73 m2, or those receiving more than 140 mL of contrast media, the incidence of CIN was low and comparable between the two study groups (p = 1.0).

"During the last five years, there has been a great deal of discussion about CIN and the safety profile of various contrast media," said Dr. Alberto Spinazzi, senior vice president of medical and regulatory affairs at Bracco. "It has been our goal to support research that could provide valid and reliable clinical evidence to the healthcare community on this very serious topic."

Bracco funded a clinical grant for the study.

For more information from the Diagnostic Imaging archives:

Contrast-induced nephropathy fears ease

Oral fluids may dilute contrast reaction risk in patients with kidney disorders

Cheap drug protects against CT contrast-induced nephropathy

Nonionic contrast media prove safe in pediatric patients