Annemieke M. A. Keizer

The incidence of cognitive decline after (not) undergoing coronary artery bypass grafting: the impact of a controlled definition

Background:  After coronary artery bypass grafting (CABG), 20–30% of patients are reported to suffer from cognitive decline. Studies reporting these high incidences, however, have not included an appropriate control group.

Association between early and three month cognitive outcome after off-pump and on-pump coronary bypass surgery

Objective: To describe the association between cognitive outcome in the first postoperative week and that at three months after both off-pump and on-pump coronary bypass surgery, and to make a direct comparison of early cognitive outcome after off-pump versus on-pump surgery. Design: Randomised trial with an additional prediction study within the two randomised groups. Setting: Three centres for heart surgery in the Netherlands. Patients: 281 patients, mean age 61 years. Interventions: Participants were randomly assigned to off-pump or on-pump coronary bypass surgery. Main outcome measures: Cognitive outcome, assessed by psychologists who administered neuropsychological tests one day before and four days and three months after surgery. A logistic regression model was used to study the predictive association between early cognitive outcome, together with eight clinical variables, and cognitive outcome after three months. Results: Cognitive outcome in the first week after surgery was determined for 219 patients and was a predictor of cognitive decline after three months. This association was stronger in on-pump patients (odds ratio (OR) 5.24, p < 0.01) than in off-pump patients (OR 1.80, p  =  0.23). Early decline was present in 54 patients (49%) after off-pump surgery and 61 patients (57%) after on-pump surgery (OR 0.73, p  =  0.25). Conclusions: In patients undergoing first time coronary bypass surgery, early cognitive decline predicts cognitive outcome after three months. Early cognitive decline is not significantly influenced by the use of cardiopulmonary bypass.

Cognitive self-assessment one year after on-pump and off-pump coronary artery bypass grafting

BACKGROUND Coronary artery bypass grafting (CABG) is associated with significant cerebral morbidity. This is usually manifested as cognitive decline and may be caused by cardiopulmonary bypass. The primary objective of this study was to explore whether patients report more cognitive failures 1 year after CABG than preoperatively. Secondary objectives were to evaluate whether there is a difference in reported cognitive failures between patients undergoing on-pump and off-pump CABG and whether a difference between CABG patients and healthy control subjects exists. Finally the relation between objective and subjective cognitive functioning was quantified. METHODS In this prospective study, the Cognitive Failures Questionnaire (CFQ) was assigned preoperatively and 1 year postoperatively to 81 patients who were randomly assigned to undergo off-pump (n = 45) or on-pump (n = 36) CABG. A control sample of 112 age-matched healthy subjects was included who were administered the CFQ once. RESULTS No difference was found in the total CFQ score (p = 0.222) and CFQ worry score (p = 0.207) between 1 year after CABG and before CABG. There was no difference between on-pump and off-pump CABG (total score, p = 0.458; worry score, p = 0.563). A significant difference was found in CFQ total score between CABG patients and control subjects (p < 0.001), with control subjects reporting more cognitive failures than CABG patients. Finally, patients who showed cognitive decline in the Octopus trial did not have a higher CFQ total score (p = 0.671) and CFQ worry score (p = 0.772) than patients without cognitive decline 1 year after CABG. CONCLUSIONS The present findings suggest that CABG does not result in a substantial proportion of patients with subjectively experienced cognitive decline 1 year after the procedure, irrespective of the type of surgical technique (on-pump versus off-pump).

Beating heart versus conventional cardiopulmonary bypass: the octopus experience: a randomized comparison of 281 patients undergoing coronary artery bypass surgery with or without cardiopulmonary bypass.

In the Octopus Study, 281 coronary artery bypass surgery patients were randomized to surgery with or without cardiopulmonary bypass. The primary objective was to compare cognitive outcome between off-pump and on-pump coronary artery bypass surgery. Before and after surgery, psychologists administered a battery of 10 neuropsychological tests to the patients. Cognitive decline was defined as a decrease in an individual’s performance of at least 20% from baseline, in at least 20% of the main variables. According to this definition, cognitive decline was present in 21% in the off-pump group and 29% in the on-pump group, 3 months after the procedure (P = .15). At 12 months, cognitive decline was present in 31% in the off-pump group and 34% in the on-pump group (P = .69). These results indicated that patients undergoing coronary artery bypass surgery without cardiopulmonary bypass had improved cognitive outcomes 3 months after the procedure, but the effects were limited and became negligible at 12 months. The same definition of cognitive decline was also applied to 112 volunteers not undergoing surgery. The definition labeled 28% of the control subjects as suffering from cognitive decline, 3 months after their first assessment. This suggests that the natural fluctuations in performance during repeated neuropsychological testing should be included in the statistical analysis of cognitive decline. Using an alternative definition of cognitive decline that takes these natural fluctuations in performance into account, the proportions of coronary artery bypass surgery patients displaying cognitive decline were substantially lower. This indicates that the incidence of cognitive decline after coronary artery bypass surgery has been overestimated.

Cognitieve achteruitgang na coronaire-bypasschirurgie

In Nederland ondergaan jaarlijks meer dan tienduizend patiënten een coronaire-bypassoperatie. Deze ingreep neemt doorgaans effectief de pijn op de borst weg, die is ontstaan door vernauwingen in de kransslagaders van het hart. De operatie kan echter leiden tot cognitieve achteruitgang. Algemeen wordt aangenomen dat de hart-longmachine, die het mogelijk maakt om het hart tijdens de operatie volledig stil te leggen, hiervoor verantwoordelijk is. In Utrecht werd de Octopus Studie uitgevoerd, waarin is onderzocht of het inderdaad de hart-longmachine is die tot cerebrale complicaties leidt. Daarnaast is een controlestudie uitgevoerd onder vrijwilligers om te onderzoeken of het probleem van cognitieve achteruitgang na bypasschirurgie zo groot is als doorgaans wordt verondersteld.