Objective and subjective neuropsychological impairment and the relationship to depression, in randomized CPB and off-pump patients, following heart surgery.

摘要

The mechanisms of postoperative neuropsychological (NP) impairment following heart surgery are poorly understood but have been linked to factors associated with Cardiopulmonary Bypass (CPB), a technique used to support the circulation while the heart is arrested for Coronary Artery Bypass Grafting (CABG). Alternatively, CABG can be performed without CPB, with the heart beating (off-pump technique). There is some evidence that post CABG patients that report NP disturbances are actually suffering from mood disorders such as depression instead of cognitive dysfunction. To date, no studies have evaluated the impact of the type of surgery (off-pump; on-pump) on NP decline (objective testing and subjective reporting) as it relates to depression. Moreover, if the CPB component of CABG is linked to NP decline, there should be a stronger relationship between subjective cognitive reporting and objective cognitive performance in the CPB group versus off-pump patients. Consequently, the impact of depression could be stronger in those off-pump patients that subjectively report a cognitive decline. A total of 74 patients were randomized into the CPB or off-pump group. Sixty-two patients completed both baseline and post-surgical testing trials (4 months after surgery). Eight neuropsychological tests, a depression scale, and a subjective test of neuropsychological outcome were administered to patients. Some improvements were recorded for RAVLT in both groups (B.H.: p=0.0031; CPB: p 0.0001). Improvements in Similarities scores were significantly higher in the beating heart group only (B.H.: p=0.0012). Grooved pegboard scores decreased significantly in the CPB group (p=0.0473) with no change in the off-pump group. Overall, there was no relationship between surgery type and NP impairment (p=0.9999). Post-operative depressed patients tended to subjectively report greater NP deterioration than non-depressed patients (p=0.0416). Amongst patients who reported the highest degree of NP impairment, there were no differences in NP impairment with respect to treatment type (p=1.000) and depression was similar in both treatment groups (p=0.7207). These results suggest that CPB may not be the major cause of NP impairment after CABG surgery. This research also suggests that a patient's mood may be an important variable that impacts the self-appraisal of the individuals' health status.