Biomarkers for Detection of Brain Ischemia

Brain injury occurs in one-quarter to one-half of congenital heart defect infants during the perioperative period. A blood test using a biomarker to diagnose brain injury would be important. Postoperative cerebral ischemia may be decreased by inotropic support, ventilation, medical management aimed at increasing oxygen delivery to the brain. Currently there are no FDA approved blood tests to assess brain ischemia in infants undergoing cardiac surgery. Specific Aim 1: We will prospectively study 10 neonates (\< 30 days of age) undergoing cardiac surgery utilizing cardiopulmonary bypass for arterial switch operation or Norwood operation to determine the specificity and sensitivity of a blood test for brain injury. This aim will be accomplished by analyzing blood samples for S-100 and NSE drawn prior to surgery, once each day following cardiac surgery as long as the patient remains in the intensive care unit (maximum 5 days)and at the time of postoperative brain magnetic resonance imaging. The S-100B and NSE values will then be correlated with brain magnetic resonance imaging studies before cardiac surgery and at following cardiac surgery. Hypothesis: We expect the concentration of S-100B and NSE will be significantly higher in the blood of neonates with congenital heart disease who have documented brain injury on brain magnetic resonance imaging (MRI). Furthermore, we predict that the blood levels of S-100B and NSE may correlate to clinical outcome (time to extubation, hospital discharge, neurodevelopmental outcome at 6 months of age). Specific Aim 2: We will prospectively study these neonates at 6 months following cardiac surgery to determine a correlation between neurodevelopment and concentration of S-100B and NSE. To achieve this specific aim, a blood sample for S-100B and NSE and neurodevelopmental testing will be done at 6 months following cardiac surgery. Hypothesis: We expect neonates with elevated S-100B and NSE and abnormal brain magnetic resonance imaging documented in specific aim 1 to have a significant decline in neurodevelopment at 6 months after cardiac surgery. Long-term: The long-term goal of this research is to diagnose brain ischemia in infants using a biomarker blood test.