Cerebral changes and cognitive impairment after an ischemic heart disease: a multimodal MRI study

Abstract

Three to 6 months after an acute coronary syndrome (ACS), cognitive impairment is observed in more than 30 % of the patients, mainly in executive functioning. The aim of this study was to investigate, using multimodal MRI, cerebral anatomo-functional substratum of executive dysfunction. Thirty-three patients were recruited 4 ± 1 months after a first ACS. Executive functions were evaluated with the Trail-Making-Test-B (TMTB) at baseline (ie 4 ± 1 months after ACS) and 6 months later (ie 10 ± 1 months after ACS). Using both time-points, we identified 3 groups of patients according to normative data based on age, gender and education level: 15 'cognitively normal' patients without impairment at each follow-up, 10 'transient impaired' patients with an impairment only at baseline and 8 'impairing' patients with an impairment only at follow-up. We explored, in the whole-brain, the structural integrity using Voxel-Based Morphometry and Tract-Based Spatial Statistics and the resting-state functional connectivity using Network-Based Statistics. No structural difference was observed between impaired and cognitively normal patients. At the functional level, compared to the 'cognitively normal' group, the 'transient impaired' patients presented an increased functional connectivity in a network centered on middle-orbito-frontal regions, whereas the 'impairing' patients presented only a non-significant decrease of functional connectivity. Executive dysfunction in ACS patients is associated to functional but no structural characteristics, particularly to an increased functional connectivity in cognitive networks in transient impaired patients. Further studies with larger sample size are needed to confirm these results and to determine if these patients could be at higher risk for developing permanent cognitive disorders.

Neurocognitive impairment after acute coronary syndrome: Prevalence and characterization in a hospital-based cardiac rehabilitation program sample

“…23 These alterations are related to an increased functional connectivity in prefrontal regions. 12 Memory, especially verbal memory, 20 is another domain frequently implied in coronary disease. A recent animal study showed that after myocardial ischemia, reperfusion leads to reactive gliosis in hippocampal subregions CA1, CA3 and dentate gyrus, thus suggesting an inflammatory basis for the memory deficits.…”

“…11 The executive dysfunction in these patients is associated with an increased functional connectivity in middle-orbito-frontal regions. 12 …”

Prevalence and patterns of cognitive impairment in acute coronary syndrome patients: A systematic review

“…9 It is theorised that vascular changes, similar to those noted in the heart during ACS, cause silent infarcts in the brain leading to CI. 10,11 Changes in connectivity intensity, presence of white matter and grey matter atrophy have also been noted in the middle orbito-frontal region following ACS. 11 These changes may lead to CI as the middle orbito-frontal regions are the key areas of the brain that perform cognitive tasks.…”

“…10,11 Changes in connectivity intensity, presence of white matter and grey matter atrophy have also been noted in the middle orbito-frontal region following ACS. 11 These changes may lead to CI as the middle orbito-frontal regions are the key areas of the brain that perform cognitive tasks. 11 Additionally, other factors arising from the ACS diagnosis and hospitalisation, such as depression and anxiety, are likely to contribute further to CI in the early recovery stages.…”

“…11 These changes may lead to CI as the middle orbito-frontal regions are the key areas of the brain that perform cognitive tasks. 11 Additionally, other factors arising from the ACS diagnosis and hospitalisation, such as depression and anxiety, are likely to contribute further to CI in the early recovery stages. 11…”