Sex Differences in Delirium after Coronary Artery Bypass Graft Surgery and Perioperative Neuropsychiatric Conditions: A Secondary Analysis of a Cohort Study

BACKGROUND

Biological sex influences the risk of depression and cognitive impairment, but its role in relation to postoperative delirium is unclear. This analysis investigates sex differences in delirium risk after coronary artery bypass graft (CABG) surgery and sex-related differences in relation to affective and cognitive symptoms.

METHODS

This is a secondary analysis of the Neuropsychiatric Outcomes After Heart Surgery (NOAHS) study, a single-site, observational study of a CABG surgery cohort (n = 149). Preoperative characteristics are stratified by sex, and baseline variables that differ by sex are evaluated to understand whether sex modifies their relationships with delirium. We also evaluate sex differences in one-month depression and cognition.

RESULTS

Female sex is associated with several delirium risk factors, including higher risk of preoperative depression and middle cerebral artery (MCA) stenosis. MCA stenosis was statistically associated with delirium only among women (OR 15.6, 95% CI 1.5, 164.4); mild cognitive impairment (MCI) was associated with delirium only in men (OR 4.6, 95% CI 1.2, 17.9). Other sex-based differences failed to reach statistical significance. Depression remained commoner among women 1 month post-CABG.

CONCLUSIONS

Women in this CABG cohort were more likely to have depression at baseline and 1 month postoperatively, as well as MCA stenosis and postoperative delirium. Sex might modify the relationship between post-CABG delirium and its risk factors including MCA stenosis and MCI. Cerebrovascular disease deserves study as a potential explanation linking female sex and a range of poor outcomes among women with coronary heart disease.

Functional, cognitive, and cerebrovascular aspects of depression before coronary artery bypass graft surgery: Testing the vascular depression hypothesis

OBJECTIVE

Depression in patients undergoing coronary artery graft bypass (CABG) surgery is associated with morbidity and mortality, making its early identification and clinical management crucial. Vasculopathy and older age, hallmarks of patients requiring CABG, are also features of vascular depression. In this study, we assess for features of vascular depression in patients undergoing CABG surgery.

METHODS

This is a cross-sectional analysis of a single-site prospective observational cohort study of patients undergoing CABG surgery. Subjects were assessed preoperatively using the Depression Interview and Structured Hamilton (DISH), depression scales, transcranial Doppler, neuropsychological testing, and clinical dementia rating (CDR).

RESULTS

Of 161 subjects (mean age 66.2 ± 9.3, female 25%) who completed DISH, 18 had major or minor depression, 17 of whom had a past history of major or minor depression (mean age of onset 35.8 years-old). Pre-CABG depression was associated with greater functional impairment on CDR Sum of Boxes (OR = 3.7, 95% CI: 1.4, 9.7) and worse performance on letter fluency test (OR = 0.90, 95% CI: 0.81, 0.99) and trail-making tests (A: OR = 1.06, 95% CI: 1.01, 1.12; B: OR 1.02, 95% CI: 1.01, 1.04). Pre-CABG depression was not associated with middle cerebral artery (MCA) stenosis.

CONCLUSIONS

Pre-CABG depression is associated with cognitive and functional impairment similar to vascular depression, but we did not find evidence of an association with older age of onset and MCA stenosis. Further studies on white matter disease in this population are needed to examine the vascular depression hypothesis for pre-CABG depression.

Brain Small-Worldness Properties and Perceived Fatigue in Mild Cognitive Impairment

BACKGROUND

Perceived fatigue is among the most common complaints in older adults and is substantially influenced by diminished resources or impaired structure of widespread cortical and subcortical regions. Alzheimer's disease and its preclinical stage - mild cognitive impairment (MCI) - is considered a brain network disease. It is unknown, however, whether those with MCI will therefore perceive worse fatigue, and whether an impaired global brain network will worsen their experience of fatigue.

METHODS

In this pilot case-control study of age-, sex-, and education-matched MCI and their cognitively healthy counterparts (HC), perceived fatigue was measured using Multidimensional Fatigue Inventory, and diffusion tensor imaging (DTI) tractography data was analyzed using graph theory methods to explore small-worldness properties: segregation and integration.

RESULTS

Perceived fatigue was more severe in MCI than HC. Despite a trend for greater network alterations in MCI, there were no significant group differences in integration or segregation. Greater perceived fatigue was related to higher segregation across groups; more perceived fatigue was related to higher segregation and lower integration in MCI but not HC.

CONCLUSIONS

Findings of the present study support the notion that altered whole-brain small-worldness properties in brain aging or neurodegeneration may underpin perceived fatigue.

Sequence of 1000 nucleotides at the 3' end of tobacco mosaic virus RNA

The sequence of 1000 nucleotides at the 3' end of tobacco mosaic virus RNA has been determined. The sequence contains the entire coat protein cistron as well as regions to its left and right. Sequence characterization was by conventional methods for use with uniformly 32P labeled RNA complemented by newer methods for in vitro 5' and 3' 32P end-labeling of RNA and its subsequent rapid analysis. The noncoding region separating the coat protein cistron from the 3' terminus is 204 residues long and may be folded into a clover-leaf-type secondary structure. The distribution of termination codons to the left of the coat protein cistron suggests that the end of the adjacent cistron is separated from the beginning of the coat protein cistron by only two nucleotides. The subgenomic viral coat protein mRNA was isolated from infected tissue and shown to be capped. The nontranslated sequence separating the cap from the AUG initiation codon is 9 residues long and thus overlaps a portion of the adjacent cistron on the genome RNA.