A simple blood test may allow earlier diagnosis of acute kidney injury (AKI) in children who undergo cardiac surgery with cardiopulmonary bypass. AKI occurs in at least 30 percent of these surgeries, which are most common major surgical procedures performed in hospitals around the world.
The test, which measures a biomarker called serum cystatin C, may enable diagnosis of acute kidney injury (AKI) as early as 12 hours after heart surgery with cardiopulmonary bypass, according to a new study conducted by Catherine Krawczeski, MD, a pediatric cardiologist at the Cincinnati Children’s Hospital Medical Center Heart Institute and Associare Professor of Pediatrics at the University of Cincinnati College of Medicine. In addition, cystatin C levels were shown to predict the severity and duration of AKI, which occurs frequently in adults and children after cardiopulmonary bypass.
Krawczeski presented her study on Tuesday, Nov. 16, at the annual meeting of the American Heart Association in Orlando.
"Cystatin C can predict AKI with reasonable certainty within 12 hours of cardiopulmonary bypass,” says Krawczeski. "It is highly accurate, commercially available and gives results several days before the problem otherwise would be detected. This could allow early intervention and improve patient outcomes.”
More than a million children and adults in the United States undergo cardiac surgery with bypass each year. Infants and children with congenital heart disease may be especially vulnerable to developing AKI, according to Krawczeski.
AKI affects up to 5 percent of hospitalized patients. In the critical care setting alone, about 6 percent of AKI requires dialysis. Of those, 60 percent die. Timing of treatment may be crucial to assure the best possible outcome.
"Early forms of AKI may be reversible, but treatment must be initiated within a ‘window of opportunity’,” says Krawczeski. "Experimental studies have identified interventions that may be used to prevent or treat AKI if instituted early in the disease process. The use of biomarkers such as cystatin C can help guide future therapeutic trials to test agents that may prevent or lessen the degree of injury.”
Krawczeski and her colleagues at Cincinnati Children’s studied 374 patients under the age of 18 who underwent cardiopulmonary bypass at Cincinnati Children’s between January 2004 and June 2007. Cystatin C as measured 12 hours after surgery not only predicted duration and severity of AKI but also length of hospital stay and mortality.
The study was supported by a grant from the National Institutes of Health. Collaborators on the study included Prasad Devarajan, MD, director of Nephrology at Cincinnati Children’s and Professor of Pediatrics & Developmental Biology at The University of Cincinnati College of Medicine.