Neuropsychological functioning 3-5 years after coronary artery bypass grafting: does the pump make a difference?

Neurocognitive sequelae after coronary artery bypass grafting (CABG) are frequently reported. The present study investigated the possible difference between on- and off-pump CABG patients in a long-term perspective.

We administered seven standardized neuropsychological tests 1 day before, 6 days after, 6 months after and 3-5 years after CABG. We measured intra-operative high intensity transient signals (HITS) as a reflection of embolic load by transcranial Doppler ultrasonography.

Of the 74 patients originally recruited, 54 of the patients (73%) (mean age 59 years+/-7.5 years) completed the neuropsychological battery. Cognitive decline was defined as 20% decline on two or more tests. Three to 5 years after the operation, 30% of the patients showed neurocognitive problems in domains of non-verbal immediate memory and attention, speed for visual search, visual attention and mental flexibility. Neither difference in frequency of cognitive dysfunction nor a difference in evolution over the 5 year time period between on- and off-pump patients was observed. No significant predictors for cognitive decline were found.

Three to 5 years after the CABG surgery no difference in neurocognitive deficits is found between on- and off-pump CABG patients, indicating that the extracorporeal circulation (ECC) may not be the main cause of late neuropsychological decline.