Abstract 18081: Impaired Cerebral Autoregulation is Associated With Brain Abnormalities in Neonatal Congenital Heart Disease: Initial Experience
Introduction: Congenital heart disease (CHD) is associated with abnormalities of brain maturation as well as brain injury, which may be related to impaired cerebral autoregulation (CA). Using serial magnetic resonance imaging (MRI), we sought to test the hypothesis that pre-operative (op) hemodynamics including impaired CA may drive: (1) brain dysmaturation and (2) post-op brain injury.
Methods: Full-term neonates with complex CHD prospectively underwent pre and post-op brain 3T MRI to assess cortical/subcortical abnormalities & injury, and short echo single voxel spectroscopy of parietal white matter (WM) to assess metabolic brain maturation. Pre-op hemodynamic monitoring included continuous mean arterial pressure (MAP), oxygen saturation (SaO2), and INVOS cerebral near infrared spectroscopy (CrSO2). Data were divided into 20 minute epochs for analysis, with significant low frequency coherence between MAP and CrSO2 waveforms defining impaired CA. Pressure passivity index (PPI) was calculated as percentage of epochs with abnormal CA per subject. Cerebral fractional tissue oxygen extraction FTOE = (SaO2 - CrSO2)/ SaO2, was calculated, as was time with significant low frequency coherence between MAP and FTOE (FTOE-PPI). Multivariate mixed-effect modeling was used with corrections for age, pre/post-op status, and number of epochs.
Results: We evaluated 22 neonates with both brain MRI (32 scans) and hemodynamics (62 ± 34 epochs per subject). Mean PPI = 14 ± 13%, range 0-52%; mean FTOE-PPI =13 ± 8%, range 0-29%. PPI correlated with concurrent brain dysmaturation including structural abnormalities of the hippocampus (p=0.02) and lower glutamate/glutamine (p=0.02), but not cortical maturation. FTOE-PPI correlated with lower concurrent glutamate/glutamine (p=0.02) and post-op WM injury (p=0.003). Higher pre-op MAP predicted post-op brain hemorrhage (p=0.016). Pre-op SaO2, CrSO2, and FTOE showed no association with MRI findings.
Conclusions: Impaired pre-op CA in CHD neonates is associated with concurrent brain dysmaturation, including hippocampal abnormalities and alterations in glutaminergic WM cellular substrate. In addition, our data suggest that susceptibility to post-op brain injury may be related to pre-op hemodynamics.
- Congenital heart disease
- Cerebrovascular circulation
- Pediatric cardiac intensive care
- Magnetic resonance neuroimaging
- Magnetic resonance spectroscopy
Author Disclosures: J.K. Votava-Smith: None. N. Tran: None. J. Abbott: None. S. Soleymani: None. H.A. Lai: None. S. Del Castillo: None. V. Lee: None. C.W. Lo: None. S. Bluml: None. L.B. Paquette: None. A. Panigrahy: None.
- © 2016 by American Heart Association, Inc.