New study challenges current thinking on risk factors for contrast induced nephrotoxicity

Contrary to current belief, a new study finds that patients with a history of diabetes are not one of the most at risk for contrast induced nephrotoxicity. Instead, the study found that patients with a history of renal disease, hypertension and/or heart disease are more likely to suffer from renal insufficiency, putting them at greater risk for contrast induced nephrotoxicity.

The study, done at Northwestern Memorial Hospital-Northwestern University in Chicago, included 2,404 patients. All patients underwent an estimated glomerular filtration rate (eGFR) test immediately before undergoing a CT examination. "Since all patients underwent the eGFR test, we had an unusual opportunity to see if the traditional risk factors truly predict reduced renal function, said Vahid Yaghmai, MD, one of the authors of the study.

The study found that "patients with history of renal disease, hypertension and heart disease had significantly higher odds of having abnormal eGFR," said Dr. Yaghmai. That was not the case for patients with diabetes, he said.

Many facilities ask patients to fill out a survey to help determine if the patients are at risk for contrast induced nephropathy, said Dr. Yaghmai. Based on the survey results, patients most at risk undergo a test to measure their renal function. "Measuring eGFR right before the CT scan can help us more accurately determine at-risk patients. Our results suggest that history of diabetes is not independent predictors of having reduced renal function," noted Dr. Yaghmai.

The study will be presented May 1, during the 2012 ARRS Annual Meeting in Vancouver, Canada.