ABSTRACT
BACKGROUND: Prior research on cognitive and functional outcomes after coronary artery bypass graft (CABG) surgery has largely explored these two domains in isolation. In this study, we assess baseline depression and cognition as risk factors for decline in the Clinical Dementia Rating Sum-of-Boxes (CDR-SB) 1 month post-CABG surgery, which a combined measure of cognition and function. DESIGN: The Neuropsychiatric Outcomes After Heart Surgery study is a prospective observational cohort study. SETTING: A tertiary care, academic center. PARTICIPANTS: Of a total study sample of 148 patients undergoing CABG surgery, 124 (83.8%) completed 1-month follow-up assessment. Mean age was 66.3, 32 (25.8%) female and 112 (90.3%) White. MEASUREMENTS: Cognition, function, and depression were assessed on semi-structured clinical interviews. Cognitive and functional status were defined using CDR-SB; mild or major depression was defined by the Hamilton Depression Rating Scale. Additionally, neuropsychological battery was performed at baseline. RESULTS: CDR-SB decline occurred in 18 (14.5%) subjects. Older age, depression, baseline CDR-SB, and postoperative delirium were associated with 1-month decline on univariate analysis. Older age (OR 1.1 [1.0-1.2]) and depression (OR 6.2 [1.1-35.0]) remained significant on multivariate regression. In separate models, baseline performance on visual Wechsler memory scale (delayed), Hopkins verbal learning test (immediate and delayed), controlled oral word fluency test, and Trails B predicted CDR-SB decline. CONCLUSION: Roughly one in seven patients experienced CDR-SB decline 1 month after CABG surgery. Also, preoperative depression deserves recognition for being a predictor of CDR-SB decline one month post-CABG.
Subject(s)
Cardiac Surgical Procedures , Depression , Aged , Cognition , Coronary Artery Bypass , Female , Humans , Neuropsychological Tests , Prospective StudiesABSTRACT
OBJECTIVE: Although depression is a known risk factor for delirium after coronary artery bypass graft (CABG) surgery, it is unclear whether this risk is independent of delirium risk attributable to cognitive impairment or cerebrovascular disease. This study examines depression, mild cognitive impairment (MCI), and cerebrovascular disease as post-CABG delirium risk factors. METHODS: This prospective observational cohort study was performed in a tertiary-care academic hospital. Subjects were without dementia and undergoing CABG surgery. Preoperative cognitive assessment included Clinical Dementia Rating and neuropsychological battery; depression was assessed using Depression Interview and Structured Hamilton. Baseline intracranial stenosis was evaluated by transcranial Doppler of bilateral middle cerebral arteries (MCAs). Study psychiatrists assessed delirium on postoperative days 2-5 using the Confusion Assessment Method. RESULTS: Our analytic sample comprised 131 subjects (average age: 65.8 ± 9.2years, 27% women). MCI prevalence was 24%, preoperative depression 10%, lifetime depression 35%, and MCA stenosis (≥50%) 28%. Sixteen percent developed delirium. Multivariate analysis revealed that age, MCI (odds ratio [OR]: 5.1; 95% confidence interval [CI]: 1.3-20.1), and preoperative depression (OR: 9.9; 95% CI: 1.3-77.9)-but not lifetime depression-predicted delirium. MCA stenosis and severity predicted delirium in univariate but not multivariate analysis. Right MCA stenosis severity predicted delirium severity, but left-sided stenosis severity did not. CONCLUSION: We established that the risk of delirium attributable to depression extends beyond the potential moderating influence of cognitive impairment and cerebrovascular disease alone. Even mild depression and cognitive impairment before CABG deserve recognition for their effect on post-CABG cognitive health.
