Neuropsychological function five years after cardiac surgery and the effect of psychological distress

Abstract

Research has shown conflicting results with regard to the influence of depression and anxiety on neuropsychological performance following coronary artery bypass graft (CABG) surgery. Notably, the independent effects of depression and anxiety have not been examined among CABG candidates in the longer term where it is has been suggested that these patients show marked cognitive deterioration. A neuropsychological test battery and measures of psychological distress were completed by 86 CABG patients and 50 nonsurgical control participants at baseline and 6 months, whereas 75 patients and 36 controls, respectively, completed a 5-year follow-up. In CABG patients, cognitive and affective depressive symptoms were independently associated with lower and worse performance on the Boston Naming Test, Purdue Peg Board, and Digit Symbol Coding 6 months after surgery, whereas at 5-year follow-up an effect for Digit Symbol persisted, and an association was also observed for the Trail Making Test (TMT). On average, CABG patients performed worse on TMT and Digit Symbol at 6 months, whereas at 5-year follow-up their performance was worse on short-term delayed verbal recall. The results among the CABG patients did not show a consistent pattern of association between psychological distress and those neuropsychological domains that were on average significantly lower than a nonsurgical control group. The results here also support the use of nonbiased statistical methodology to document dysfunction among heterogeneous cognitive domains after CABG surgery.