Abstract 1531: Altered Brain Fiber Tracts in Heart Failure
Introduction: Heart failure (HF) patients show neuronal brain injury which contributes to cognitive, affective, and autonomic symptoms. However, earlier studies did not consistently report injury within cognitive sites (e.g., frontal cortex) or limbic structures linked to affective and autonomic function. The inconsistent signs of injury in these neuronal structures may result from compromised communication between cognitive and limbic regions from damaged axons.
Methods: We studied axon integrity between these regions using tract-based spatial statistics (TBSS; allows study of white matter tracts) in 17 HF (age 54 ± 8 years; 12 males; LVEF 0.28 ± 0.07) and 51 control subjects (age 50 ± 7 years, 29 males). We collected diffusion tensor imaging data using a 3T MRI scanner, from which we calculated fractional anisotropy (FA), an index of axonal integrity. Whole-brain FA “maps” for each subject were processed using TBSS, giving estimated axonal tracts co-localized across subjects. FA values throughout the tracts were compared between groups using 2-sample t-tests, controlling for multiple comparisons by permutation testing (form of randomization test).
Results: Fiber tracts in HF showed reduced FA values across multiple brain regions (Figure⇓), including the anterior corona radiata (projecting to and from frontal cortex) and the superior and inferior cingulum bundle (communicating to and from the cingulate, hippocampus and other limbic regions), and cerebellum (dampens blood pressure changes).
Discussion: Cognitive and affective symptoms in HF patients may arise from a combination of damaged structural areas and poor communication between brain regions.