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.