Depression predicts cognitive and functional decline one month after coronary artery bypass graft surgery (Neuropsychiatric Outcomes After Heart Surgery study)

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.